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Despite effective evidenced-based therapies, acute coronary syndrome (ACS) and its complications remains one of the leading causes of mortality, morbidity and healthcare expenditure worldwide. ACS has a significant impact on families and communities with approximately 12,000 patients admitted to New Zealand hospitals every year.[[1]] Of those who survive, a third suffer a second cardiovascular event in the first year with approximately 50% of all major coronary events occurring in those with a previous diagnosis of cardiovascular disease.[[2]]

The mortality rates from ischaemic heart disease (IHD) have been declining steadily in New Zealand, due to a systematic focus on the prevention and management of cardiovascular disease.[[3]] These interventions include reductions in cholesterol and smoking prevalence, improvements in blood pressure control and timely revascularisation in the treatment of ACS.[[4]] While quality improvement initiatives have improved many facets of ACS interventional and medical management, less attention has been focussed on the long-term disease process that requires a lifelong and structured approach to care.[[5]]

The early recovery period following ACS is important, with a higher risk of mortality and recurrent events requiring a focus on prevention, including primary care follow-up, cardiac rehabilitation,[[6]] support around lifestyle change and evidence-based pharmacological interventions.[[7]] However, it’s clear that much more can be achieved as guideline targets for secondary prevention interventions, following the transition from in-hospital to outpatient care, remain sub-optimal.[[8]] This may be partly due to increasing patient volumes with complex health needs and a lack of medical resources, including inconsistent funding for primary care involvement.[[9]]

Despite a focus on system improvements over the years, in our own department, timely access to cardiologist outpatient care remains an issue and new models of care have been introduced. These include a number of interventions led by clinical nurse specialists (CNS) and nurse practitioners (NP)[[10–12]] to support patients to better understand and manage their cardiac condition, address service gaps due to high demand or workforce shortages[[13]] and support patient outcomes following discharge.[[14]] These interventions are aligned with evidence-based cardiology best practice and include a focus on patient self-management[[15]] and cardiac rehabilitation/exercise promotion.[[11]] In these models the nurses work closely with the cardiologists.

Local audits[[16–17]] have identified that patients managed in the nurse-led clinics are more likely to be prescribed preventative therapies and individualised lifestyle advice e.g., smoking cessation support, exercise guidance and dietary advice, compared to usual care.[[18]] However, it is important that we demonstrate these interventions deliver outcomes that are as effective as medical-only models of care, before we promote nurse-led models more widely.

The aim of this study is to compare the quality of care and outcomes between patients referred for follow-up after an ACS via a traditional medical model to those with a nurse-led and cardiologist-supported follow-up model. Clinical outcomes studied include time to clinic review, medication dispensation, mortality and cardiac rehospitalisation.

Methods

This study used a retrospective cohort study design based on the ANZACS-QI registry and linked Middlemore Hospital, based in the Counties Manukau District Health Board (CMDHB), electronic health records. The ANZACS-QI registry is a web-based electronic database, which captures a mandatory dataset for all patients admitted with an acute coronary syndrome (ACS), and is used by the Middlemore Hospital Coronary Care Unit. Data collected includes patient demographics, admission ACS risk stratification, cardiovascular risk factors, investigations and management, inpatient outcomes and medications prescribed at discharge. Details regarding this data collection have previously been reported.[[19]] The Middlemore Hospital ACS cohort was identified from ANZACS-QI and encrypted National Health Index (NHI) numbers linked this cohort with corresponding CMDHB hospital coding data to identify patients who were followed by the nurse-led and medical-only services. The cohort was also anonymously linked to national health datasets including hospitalisations, mortality and drug dispensing.

At CMDHB, patients with ACS are admitted to the Cardiology team in Coronary Care Unit, and are cared for by one of seven cardiologists working on a weekly rotation. Follow-up of each patient is then under one of the seven cardiologist’s clinics. Before 2010, all patients at discharge after ACS were followed up by a consultant cardiologist or consultant supervised registrar, designating a medical-only follow-up clinic model. Increasing demand and long waiting times for outpatient review led to funding for a nurse-led post-ACS follow-up clinic model, designated a nurse-led follow-up clinic model. The nurses leading this service were experienced in cardiology, cardiac rehabilitation and long-term condition support; they were mentored by a senior cardiologist.

During the period of this study, 1 January 2010 to 31 December 2018, four of the cardiologist clinics transitioned to the nurse-led clinic model, where the majority of patients were seen by a nurse but with a small proportion of patients still seen by the consultant or the registrar. The decision regarding which patient would see a cardiologist vs the nurse in these clinics was at the discretion of medical staff at hospital discharge. The nurse-led model progressively expanded as additional nurses were trained and credentials were certified using a locally designed mentorship and competency process.

Overall, ACS care after discharge is based on established and agreed guidelines and protocols, and substantial variation in practice between cardiologists is unlikely and this care has been largely unchanged over the study time period. Guidelines recommend, following ACS, the scheduling of a timely follow-up appointment.[[20]] At the follow-up visit, a clinician obtains a history of any interval symptoms of ischemia, heart failure and/or arrhythmias and performs a focused cardiovascular examination. Management and interventions are implemented as required. The nurse-led process provides 30-minute appointments to facilitate an additional structured exploration of self-management, psychological coping, adherence and optimisation of the pharmacotherapy regimen to meet secondary prevention targets, when applicable. Support is offered, where appropriate, on stress management, medications adherence, diet, exercise and smoking cessation. All patients are offered referral to the “Healthy Hearts” cardiac rehabilitation/exercise program.[[16]] The cardiologists work alongside the nurse-led clinics and are available to review and advise. Standard medical follow-up appointments were 20 minutes.

Ethics review

ANZACS-QI is part of the wider Health Research Council (HRC) and National Heart Foundation (NHF) funded Vascular Informatics using Epidemiology and the Web (VIEW) research programme based at the University of Auckland. The VIEW research team oversees the use and governance of any audit or research use of the national routine information datasets. As all ANZACS-QI registry data and national Routine data is anonymised before being sent to the VIEW researchers; individual patient consent is not required by ethics committees. The VIEW study was approved by the Northern Region Ethics Committee Y in 2003 (AKY/03/12/314), with subsequent amendments to include the ANZACS-QI registries, and with annual approvals by the National Multi-Region Ethics Committee since 2007 (MEC07/19/EXP). Approval was also granted by the Middlemore Hospital research department (#442).

Statistical analysis

The main outcomes of interest were rehospitalisation for myocardial infarction, stroke, and heart failure in the year after discharge, mortality in the year after discharge and the proportion of patients dispensed guideline-recommended medication.

The cohort is described in relation to summary data for patients followed in the nurse-led compared to medical-only follow-up models where continuous variables were reported as mean and standard deviation (SD) and/or median and inter-quartile range (IQR), and categorical variables were reported as counts and proportions were expressed as percentages. Comparison between groups was done using Chi-squared test for categorical data, and for the continuous data comparison between groups was done using non-parametric Mann–Whitney U tests, Kruskal–Wallis tests, student’s T-tests or ANOVA tests where appropriate. All patients had at least one year of available follow-up time. Cox proportional hazard regression models were constructed to estimate the hazard ratios and 95% confidence interval for the one-year all-cause mortality, each rehospitalisation outcome and the composite of one-year all-cause mortality and rehospitalisation MI/stroke/HF outcomes to compare outcomes between the two models of care (“medical only” and “nurse led”). The results of univariate and multivariable adjusted models are presented. Variables adjusted for were for age, sex, ethnicity, ACS type, GRACE score, LV function, revascularisation and admission year from 2010 to 2018, after ensuring that the assumption of proportional hazards was met. Survival curves are shown using Kaplan–Meier estimates.

All p-values reported were two tailed and a p-value <0.05 was considered significant. No adjustment is made for multiple statistical testing. Data was analysed using SAS statistical package, version 9.4 (SAS Institute, Cary, NC). The survival curves were plotted using RStudio version 1.2.1335.

Results

Between 2010 to 2018, we identified 5296 New Zealand residents, eligible for outpatient follow-up, who were discharged alive following a first ACS event. Of these 4395 (83%) had a follow-up with a clinician, of whom 1,161 (26%) had their first follow-up via a medical model, and 3234 (74%) used the nurse-led model (Figure 1). The proportion of patients seen in the nurse-led follow-up clinics was stable over the time period.

Baseline characteristics (Table 1)

There were some differences between the two cohorts: compared with the medical cohort the nurse-led cohort were slightly younger (62 years vs 63.5 years, p=0.001), had experienced more ST Elevation myocardial infarctions (17.8% vs 14.4%, p=0.002) with more moderate or severe left ventricular impairment (16.3% vs 11.9%, p=0.001). The nurse-led cohort were more likely to require coronary artery bypass referral (18.2% vs 17.8%, p=0.002). Ethnicity, socio-economic measures, risk factors, risk scores and comorbid conditions were similar.

Time to follow-up (Figure 2)

The recommended time to follow up is six to 12 weeks in our service. Patients followed up under the nurse-led model were seen earlier than the medical model (mean (SD) 83.2 days (50.1) vs 101 days (76.5), p<0.001).

Outcomes (Table 2, Figures 3 & 4)

In the year post-discharge there were no differences between the two cohorts in all-cause mortality, rehospitalisation for MI, stroke, heart failure or a composite endpoint of all-cause mortality and/or rehospitalisation for MI/stroke/HF. Compared with the reference medical only model the multivariable adjusted hazard ratios for the nurse-led model did not differ significantly for either all-cause mortality (HR 0.80, 95% CIs 0.58 to 1.10) or the composite outcomes (HR 0.93, 95% CIs 0.78 to 1.11).

Medication dispensed (Table 3)

The dispensing of important secondary prevention pharmacotherapies was high at discharge, with no important differences between patients at discharge followed up in the medical or the nurse-led model of care. Dispensing of ACE inhibitors (ACEi)/angiotensin receptor blockers (ARB) by one-year was slightly higher in the nurse-led follow-up (68.3% vs 63.9%) but this difference had been present early post-discharge, before any follow-up visits.

Dispensing of HF pharmacotherapy post-ACS with LVEF <40% at one year following discharge (Table 4)

Beta blockers and ACE I/ARB, at the doses used in clinical trials, are consistently recommended by all guidelines for patients with a reduced left ventricular ejection fraction (LVEF <40%).[[21]] We identified 594 patients who met these criteria and identified no significant differences in the rates of dispensing of these important medications between the cohorts.

View Figures and Tables.

Discussion

This is the first study to compare hard clinical outcomes between a traditional medical model and a nurse-led model of care post-ACS. Patients managed under the nurse-led model had one-year clinical outcomes and medical management, which were as good as those managed under a traditional medical model. They also had timelier access to outpatient review.

The nurse-led model of care is not novel and examples have been reported overseas, but implementation has been slow to develop in New Zealand. A frequent impediment to developing new nurse clinics is that the growing body of nurse-led literature is often classed as low-level evidence[[22]] with a highly selected patient cohort[[23]] and a heterogenous evidence base.[[24,25]] Despite this, many studies describe successful implementation[[26,27]] and report a positive impact on risk factors,[[28,27]] patient satisfaction,[[29]] access to care,[[14,30]] timely and more frequent monitoring of high‐risk post‐MI patients[[31]] with mixed results on cost-effectiveness.[[29,32]]

The evidence supporting nurse-led models post-ACS in the context of care co-ordination, rehabilitation programmes and IHD secondary prevention is also increasing. Some of these models involve nurses triaging whether a cardiologist medical review appointment is necessary[[33,34]] and most report nurse-led clinical follow-ups are feasible[[13]] and useful in freeing up clinical resources. To date, we have no evidence that nurse-led ACS clinics improve clinical outcomes, such as survival. However, a small UK audit of a nurse follow-up clinic in patients with ACS reported a reduction in six-month readmission rate (from 28.5% to 14.2%). The clinic provided early follow-up to patients classified as a higher risk based on TIMI scores: the nurses reviewed diagnosis, management plan and any symptoms in a 30-minute appointment. Cardiac rehabilitation was offered to all patients, and all patients were discussed with a consultant cardiologist.[[34]]

Guidelines[[35]] now recommend follow-up at 2–6 weeks depending on risk status of the patient, however, this has been difficult to achieve due to high patient demand. Our service recommends seeing a primary care clinician in one week and then cardiology clinic review in six to 12 weeks. The cardiac rehabilitation team contact the patient within two weeks and offer further support as required. Patients with impaired heart function are seen earlier with an aim of 2–6 weeks.

Reducing delay in seeking care for the initial presentation of ACS has been a successful quality improvement focus across the globe[[36]] and in New Zealand.[[37]] Delays to outpatient review has been less of a focus but delays are associated with worse outcomes compared to earlier follow-up[[38]] with reports of increased hospitalisation and worse short-term and long-term medication adherence.[[39]] The recovery period following ACS is stressful and impacts on patient’s work, family situation and both physical and psychological health.[[40]] A significant number of patients continue to experience emotional symptoms that may impair their daily functioning.[[41]] It is important to provide early access to answer questions, correct misconceptions and identify and address significant issues affecting recovery. While cardiac rehabilitation has an important role in providing support, many patients choose or are unable to partake in these programmes. The nurse-led clinic model meant we were able to bring patients in for review earlier and address barriers to recovery and encourage engagement with their primary care team.

There appears to be a lot of variation in different healthcare systems about the ongoing relationship and responsibilities of outpatient and primary care. Goddard[[42]] describes a protocol for a four-week post-ACS practice nurse appointment in primary care. This appointment is timed to ensure recommended treatments and medication changes are implemented appropriately, as well as advice on lifestyle changes and assessment of psychosocial health. In New Zealand, lifelong secondary prevention following ACS is usually managed in primary care, although structured care is inconsistently delivered and has not been a focus of primary care targets in recent years. It is important that health systems support patients following ACS not just in the acute and early recovery period but for life. In New Zealand, who provides this ongoing care is usually the general practitioner; however, little is known about the level of management provided.[[9]] Nurse practitioner or practice nurse involvement has not been well described in post-ACS care. However, for many patients, successful, lifelong secondary prevention requires a structured and holistic approach, that nurses have shown they can provide.[[43]]

Non-adherence following ACS is associated with increased risks of mortality and hospital readmissions. Medication dispensing is a useful way to measure adherence, and we identified a decline in important secondary prevention medication usage at one year. A New Zealand study investigated high dose statin use and reported that 21% of the cohort were not on a statin at one year.[[1]] More work is required to understand the best approach to supporting long-term medication usage and will require more collaboration between the patient and whānau, the cardiology team, primary care and community pharmacists.

Limitations

There are several limitations in this paper. This was a retrospective observational study, so patients were not formally randomised to follow-up under medical vs nurse-led models. Nevertheless, patients were effectively randomised because ACS admissions are not planned, and the only determinant of which model of follow-up they received was the week in which they were admitted to hospital – patients admitted in a week when a consultant with medical only follow-up was on-call were managed under the medical model and those admitted in a week where a consultant had a nurse-led follow up model were managed under the nurse-led model. There were only a small number of differences identified between the two groups and some of these may have been due to the multiple statistical comparisons performed (Type I error). However, the observed group difference in age, distribution of ACS type and of LV ejection fraction were potentially clinically significant and may have been a source of bias. Multivariable regression modelling was therefore performed as an additional check that any differences between the cohorts did not impact on the study conclusions. The study is limited by the number of patients who presented with ACS during the study period and it is possible that with a larger study population differences in outcomes between the cohorts might be apparent. The development and growth of the nurse-led process was non-linear and started as a purely educational adjunct to standard cardiology care and grew as the nurses gained clinic experience to take on a more hybrid nurse/medical focus. The main goals of the clinic remain engrained in nursing philosophy and offer an experience that is different to standard medical practice. However, it is difficult to adjust for improving clinical experience and diagnostic skills, nurse prescribing and eventually nurse practitioner preparedness, which will all have had impacts on outcomes. There were also a number of other processes that we could not account fully for, including access and contact with cardiac rehabilitation, involvement of the heart failure up-titration clinics and the likelihood of patients having multiple admissions and crossing over from the nurse-led process to the medical-only process and vice versa. Data collection in cardiac rehabilitation and the community HF clinics have improved over the last few years and we now have robust data bases, but for the majority of this study we could not account for additional nurse input.

There is very little information on patient experience, however, qualitative research with patients is planned and will provide further insight into accessibility and acceptability of the different models, particularly for our diverse local populations.

Conclusion

This is a large New Zealand cohort study that reports on the safety of the addition of a nurse-led model of care to usual cardiologist-only care and is associated with earlier access to follow-up. The nurse-led model is as effective at maintaining secondary prevention pharmacotherapy as the gold standard medical model with no difference in clinical outcomes.

Further studies examining cost effectiveness and patient experience have the potential to support the implementation of this model across New Zealand.

View Appendices.

Summary

Abstract

Aim

At Middlemore Hospital, acute coronary syndrome (ACS) patients are admitted under the care of one of seven cardiologists working on a weekly rotation. Between 2010 and 2018 patients under the care of three of the cardiologists were followed up in a “medical only” post-ACS follow-up clinic model where the cardiologist or registrar saw all patients. Those admitted under the other four cardiologists were seen in a “nurse-led, cardiologist-supported” follow-up model where the majority of patients were seen by a nurse specialist. The study aim was to compare quality of care and outcomes between patients managed under these two follow-up clinic models.

Method

The ANZACS-QI registry was used to identify all ACS admissions, 2010 to 2018. The ANZACS-QI records for 5296 patients, discharged alive, were anonymously linked with hospital clinic follow-up and national administrative datasets. Time to follow-up, medication dispensation and titration and one-year clinical outcomes were compared for the two follow-up models.

Results

Characteristics of patients managed under each model were similar. 4395 patients attended follow up, 74% in the nurse-led model. At one year there were no differences between the medical- and nurse-led cohorts in all-cause mortality (4.6% vs 3.9, p=0.29), rehospitalisations for myocardial infarction (MI) (9.2% vs 8.3%, p=0.31), stroke (1.2% vs 1.4% p=0.71), heart failure (5.7% vs 6.9%, p=0.15) or a combined endpoint of all-cause mortality and/or rehospitalisation for MI/stroke/HF (15.2% vs 14.8%, p=0.71). Patients were seen earlier post-discharge in the nurse-led model, (mean 83 vs 101 days). Medication dispensation one year post-discharge was similar for both models of care.

Conclusion

The nurse-led model is associated with earlier access to follow-up, was equally as effective at maintaining secondary prevention pharmacotherapy and associated with similar survival and readmission with non-fatal ACS/stroke/heart failure.

Author Information

Andrew McLachlan: Nurse Practitioner | Mātanga Tapuhi: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand. Professor Andrew Kerr, MD: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand; School of Population Health, The University of Auckland; Department of Medicine, The University of Auckland. Mildred Lee, MSc: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand; School of Population Health, The University of Auckland.

Acknowledgements

Courtney Harper: Information Specialist – provided library support and literature review. Mildred Lee received salary support from the Middlemore Cardiac Trust. The cardiologists at CMDHB who have so willingly provided their expertise to grow the nurse-led model.

Correspondence

Andrew McLachlan: Nurse Practitioner | Mātanga Tapuhi: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand.

Correspondence Email

Andrew.McLachlan@cmdhb.org.nz.

Competing Interests

Nil.

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Despite effective evidenced-based therapies, acute coronary syndrome (ACS) and its complications remains one of the leading causes of mortality, morbidity and healthcare expenditure worldwide. ACS has a significant impact on families and communities with approximately 12,000 patients admitted to New Zealand hospitals every year.[[1]] Of those who survive, a third suffer a second cardiovascular event in the first year with approximately 50% of all major coronary events occurring in those with a previous diagnosis of cardiovascular disease.[[2]]

The mortality rates from ischaemic heart disease (IHD) have been declining steadily in New Zealand, due to a systematic focus on the prevention and management of cardiovascular disease.[[3]] These interventions include reductions in cholesterol and smoking prevalence, improvements in blood pressure control and timely revascularisation in the treatment of ACS.[[4]] While quality improvement initiatives have improved many facets of ACS interventional and medical management, less attention has been focussed on the long-term disease process that requires a lifelong and structured approach to care.[[5]]

The early recovery period following ACS is important, with a higher risk of mortality and recurrent events requiring a focus on prevention, including primary care follow-up, cardiac rehabilitation,[[6]] support around lifestyle change and evidence-based pharmacological interventions.[[7]] However, it’s clear that much more can be achieved as guideline targets for secondary prevention interventions, following the transition from in-hospital to outpatient care, remain sub-optimal.[[8]] This may be partly due to increasing patient volumes with complex health needs and a lack of medical resources, including inconsistent funding for primary care involvement.[[9]]

Despite a focus on system improvements over the years, in our own department, timely access to cardiologist outpatient care remains an issue and new models of care have been introduced. These include a number of interventions led by clinical nurse specialists (CNS) and nurse practitioners (NP)[[10–12]] to support patients to better understand and manage their cardiac condition, address service gaps due to high demand or workforce shortages[[13]] and support patient outcomes following discharge.[[14]] These interventions are aligned with evidence-based cardiology best practice and include a focus on patient self-management[[15]] and cardiac rehabilitation/exercise promotion.[[11]] In these models the nurses work closely with the cardiologists.

Local audits[[16–17]] have identified that patients managed in the nurse-led clinics are more likely to be prescribed preventative therapies and individualised lifestyle advice e.g., smoking cessation support, exercise guidance and dietary advice, compared to usual care.[[18]] However, it is important that we demonstrate these interventions deliver outcomes that are as effective as medical-only models of care, before we promote nurse-led models more widely.

The aim of this study is to compare the quality of care and outcomes between patients referred for follow-up after an ACS via a traditional medical model to those with a nurse-led and cardiologist-supported follow-up model. Clinical outcomes studied include time to clinic review, medication dispensation, mortality and cardiac rehospitalisation.

Methods

This study used a retrospective cohort study design based on the ANZACS-QI registry and linked Middlemore Hospital, based in the Counties Manukau District Health Board (CMDHB), electronic health records. The ANZACS-QI registry is a web-based electronic database, which captures a mandatory dataset for all patients admitted with an acute coronary syndrome (ACS), and is used by the Middlemore Hospital Coronary Care Unit. Data collected includes patient demographics, admission ACS risk stratification, cardiovascular risk factors, investigations and management, inpatient outcomes and medications prescribed at discharge. Details regarding this data collection have previously been reported.[[19]] The Middlemore Hospital ACS cohort was identified from ANZACS-QI and encrypted National Health Index (NHI) numbers linked this cohort with corresponding CMDHB hospital coding data to identify patients who were followed by the nurse-led and medical-only services. The cohort was also anonymously linked to national health datasets including hospitalisations, mortality and drug dispensing.

At CMDHB, patients with ACS are admitted to the Cardiology team in Coronary Care Unit, and are cared for by one of seven cardiologists working on a weekly rotation. Follow-up of each patient is then under one of the seven cardiologist’s clinics. Before 2010, all patients at discharge after ACS were followed up by a consultant cardiologist or consultant supervised registrar, designating a medical-only follow-up clinic model. Increasing demand and long waiting times for outpatient review led to funding for a nurse-led post-ACS follow-up clinic model, designated a nurse-led follow-up clinic model. The nurses leading this service were experienced in cardiology, cardiac rehabilitation and long-term condition support; they were mentored by a senior cardiologist.

During the period of this study, 1 January 2010 to 31 December 2018, four of the cardiologist clinics transitioned to the nurse-led clinic model, where the majority of patients were seen by a nurse but with a small proportion of patients still seen by the consultant or the registrar. The decision regarding which patient would see a cardiologist vs the nurse in these clinics was at the discretion of medical staff at hospital discharge. The nurse-led model progressively expanded as additional nurses were trained and credentials were certified using a locally designed mentorship and competency process.

Overall, ACS care after discharge is based on established and agreed guidelines and protocols, and substantial variation in practice between cardiologists is unlikely and this care has been largely unchanged over the study time period. Guidelines recommend, following ACS, the scheduling of a timely follow-up appointment.[[20]] At the follow-up visit, a clinician obtains a history of any interval symptoms of ischemia, heart failure and/or arrhythmias and performs a focused cardiovascular examination. Management and interventions are implemented as required. The nurse-led process provides 30-minute appointments to facilitate an additional structured exploration of self-management, psychological coping, adherence and optimisation of the pharmacotherapy regimen to meet secondary prevention targets, when applicable. Support is offered, where appropriate, on stress management, medications adherence, diet, exercise and smoking cessation. All patients are offered referral to the “Healthy Hearts” cardiac rehabilitation/exercise program.[[16]] The cardiologists work alongside the nurse-led clinics and are available to review and advise. Standard medical follow-up appointments were 20 minutes.

Ethics review

ANZACS-QI is part of the wider Health Research Council (HRC) and National Heart Foundation (NHF) funded Vascular Informatics using Epidemiology and the Web (VIEW) research programme based at the University of Auckland. The VIEW research team oversees the use and governance of any audit or research use of the national routine information datasets. As all ANZACS-QI registry data and national Routine data is anonymised before being sent to the VIEW researchers; individual patient consent is not required by ethics committees. The VIEW study was approved by the Northern Region Ethics Committee Y in 2003 (AKY/03/12/314), with subsequent amendments to include the ANZACS-QI registries, and with annual approvals by the National Multi-Region Ethics Committee since 2007 (MEC07/19/EXP). Approval was also granted by the Middlemore Hospital research department (#442).

Statistical analysis

The main outcomes of interest were rehospitalisation for myocardial infarction, stroke, and heart failure in the year after discharge, mortality in the year after discharge and the proportion of patients dispensed guideline-recommended medication.

The cohort is described in relation to summary data for patients followed in the nurse-led compared to medical-only follow-up models where continuous variables were reported as mean and standard deviation (SD) and/or median and inter-quartile range (IQR), and categorical variables were reported as counts and proportions were expressed as percentages. Comparison between groups was done using Chi-squared test for categorical data, and for the continuous data comparison between groups was done using non-parametric Mann–Whitney U tests, Kruskal–Wallis tests, student’s T-tests or ANOVA tests where appropriate. All patients had at least one year of available follow-up time. Cox proportional hazard regression models were constructed to estimate the hazard ratios and 95% confidence interval for the one-year all-cause mortality, each rehospitalisation outcome and the composite of one-year all-cause mortality and rehospitalisation MI/stroke/HF outcomes to compare outcomes between the two models of care (“medical only” and “nurse led”). The results of univariate and multivariable adjusted models are presented. Variables adjusted for were for age, sex, ethnicity, ACS type, GRACE score, LV function, revascularisation and admission year from 2010 to 2018, after ensuring that the assumption of proportional hazards was met. Survival curves are shown using Kaplan–Meier estimates.

All p-values reported were two tailed and a p-value <0.05 was considered significant. No adjustment is made for multiple statistical testing. Data was analysed using SAS statistical package, version 9.4 (SAS Institute, Cary, NC). The survival curves were plotted using RStudio version 1.2.1335.

Results

Between 2010 to 2018, we identified 5296 New Zealand residents, eligible for outpatient follow-up, who were discharged alive following a first ACS event. Of these 4395 (83%) had a follow-up with a clinician, of whom 1,161 (26%) had their first follow-up via a medical model, and 3234 (74%) used the nurse-led model (Figure 1). The proportion of patients seen in the nurse-led follow-up clinics was stable over the time period.

Baseline characteristics (Table 1)

There were some differences between the two cohorts: compared with the medical cohort the nurse-led cohort were slightly younger (62 years vs 63.5 years, p=0.001), had experienced more ST Elevation myocardial infarctions (17.8% vs 14.4%, p=0.002) with more moderate or severe left ventricular impairment (16.3% vs 11.9%, p=0.001). The nurse-led cohort were more likely to require coronary artery bypass referral (18.2% vs 17.8%, p=0.002). Ethnicity, socio-economic measures, risk factors, risk scores and comorbid conditions were similar.

Time to follow-up (Figure 2)

The recommended time to follow up is six to 12 weeks in our service. Patients followed up under the nurse-led model were seen earlier than the medical model (mean (SD) 83.2 days (50.1) vs 101 days (76.5), p<0.001).

Outcomes (Table 2, Figures 3 & 4)

In the year post-discharge there were no differences between the two cohorts in all-cause mortality, rehospitalisation for MI, stroke, heart failure or a composite endpoint of all-cause mortality and/or rehospitalisation for MI/stroke/HF. Compared with the reference medical only model the multivariable adjusted hazard ratios for the nurse-led model did not differ significantly for either all-cause mortality (HR 0.80, 95% CIs 0.58 to 1.10) or the composite outcomes (HR 0.93, 95% CIs 0.78 to 1.11).

Medication dispensed (Table 3)

The dispensing of important secondary prevention pharmacotherapies was high at discharge, with no important differences between patients at discharge followed up in the medical or the nurse-led model of care. Dispensing of ACE inhibitors (ACEi)/angiotensin receptor blockers (ARB) by one-year was slightly higher in the nurse-led follow-up (68.3% vs 63.9%) but this difference had been present early post-discharge, before any follow-up visits.

Dispensing of HF pharmacotherapy post-ACS with LVEF <40% at one year following discharge (Table 4)

Beta blockers and ACE I/ARB, at the doses used in clinical trials, are consistently recommended by all guidelines for patients with a reduced left ventricular ejection fraction (LVEF <40%).[[21]] We identified 594 patients who met these criteria and identified no significant differences in the rates of dispensing of these important medications between the cohorts.

View Figures and Tables.

Discussion

This is the first study to compare hard clinical outcomes between a traditional medical model and a nurse-led model of care post-ACS. Patients managed under the nurse-led model had one-year clinical outcomes and medical management, which were as good as those managed under a traditional medical model. They also had timelier access to outpatient review.

The nurse-led model of care is not novel and examples have been reported overseas, but implementation has been slow to develop in New Zealand. A frequent impediment to developing new nurse clinics is that the growing body of nurse-led literature is often classed as low-level evidence[[22]] with a highly selected patient cohort[[23]] and a heterogenous evidence base.[[24,25]] Despite this, many studies describe successful implementation[[26,27]] and report a positive impact on risk factors,[[28,27]] patient satisfaction,[[29]] access to care,[[14,30]] timely and more frequent monitoring of high‐risk post‐MI patients[[31]] with mixed results on cost-effectiveness.[[29,32]]

The evidence supporting nurse-led models post-ACS in the context of care co-ordination, rehabilitation programmes and IHD secondary prevention is also increasing. Some of these models involve nurses triaging whether a cardiologist medical review appointment is necessary[[33,34]] and most report nurse-led clinical follow-ups are feasible[[13]] and useful in freeing up clinical resources. To date, we have no evidence that nurse-led ACS clinics improve clinical outcomes, such as survival. However, a small UK audit of a nurse follow-up clinic in patients with ACS reported a reduction in six-month readmission rate (from 28.5% to 14.2%). The clinic provided early follow-up to patients classified as a higher risk based on TIMI scores: the nurses reviewed diagnosis, management plan and any symptoms in a 30-minute appointment. Cardiac rehabilitation was offered to all patients, and all patients were discussed with a consultant cardiologist.[[34]]

Guidelines[[35]] now recommend follow-up at 2–6 weeks depending on risk status of the patient, however, this has been difficult to achieve due to high patient demand. Our service recommends seeing a primary care clinician in one week and then cardiology clinic review in six to 12 weeks. The cardiac rehabilitation team contact the patient within two weeks and offer further support as required. Patients with impaired heart function are seen earlier with an aim of 2–6 weeks.

Reducing delay in seeking care for the initial presentation of ACS has been a successful quality improvement focus across the globe[[36]] and in New Zealand.[[37]] Delays to outpatient review has been less of a focus but delays are associated with worse outcomes compared to earlier follow-up[[38]] with reports of increased hospitalisation and worse short-term and long-term medication adherence.[[39]] The recovery period following ACS is stressful and impacts on patient’s work, family situation and both physical and psychological health.[[40]] A significant number of patients continue to experience emotional symptoms that may impair their daily functioning.[[41]] It is important to provide early access to answer questions, correct misconceptions and identify and address significant issues affecting recovery. While cardiac rehabilitation has an important role in providing support, many patients choose or are unable to partake in these programmes. The nurse-led clinic model meant we were able to bring patients in for review earlier and address barriers to recovery and encourage engagement with their primary care team.

There appears to be a lot of variation in different healthcare systems about the ongoing relationship and responsibilities of outpatient and primary care. Goddard[[42]] describes a protocol for a four-week post-ACS practice nurse appointment in primary care. This appointment is timed to ensure recommended treatments and medication changes are implemented appropriately, as well as advice on lifestyle changes and assessment of psychosocial health. In New Zealand, lifelong secondary prevention following ACS is usually managed in primary care, although structured care is inconsistently delivered and has not been a focus of primary care targets in recent years. It is important that health systems support patients following ACS not just in the acute and early recovery period but for life. In New Zealand, who provides this ongoing care is usually the general practitioner; however, little is known about the level of management provided.[[9]] Nurse practitioner or practice nurse involvement has not been well described in post-ACS care. However, for many patients, successful, lifelong secondary prevention requires a structured and holistic approach, that nurses have shown they can provide.[[43]]

Non-adherence following ACS is associated with increased risks of mortality and hospital readmissions. Medication dispensing is a useful way to measure adherence, and we identified a decline in important secondary prevention medication usage at one year. A New Zealand study investigated high dose statin use and reported that 21% of the cohort were not on a statin at one year.[[1]] More work is required to understand the best approach to supporting long-term medication usage and will require more collaboration between the patient and whānau, the cardiology team, primary care and community pharmacists.

Limitations

There are several limitations in this paper. This was a retrospective observational study, so patients were not formally randomised to follow-up under medical vs nurse-led models. Nevertheless, patients were effectively randomised because ACS admissions are not planned, and the only determinant of which model of follow-up they received was the week in which they were admitted to hospital – patients admitted in a week when a consultant with medical only follow-up was on-call were managed under the medical model and those admitted in a week where a consultant had a nurse-led follow up model were managed under the nurse-led model. There were only a small number of differences identified between the two groups and some of these may have been due to the multiple statistical comparisons performed (Type I error). However, the observed group difference in age, distribution of ACS type and of LV ejection fraction were potentially clinically significant and may have been a source of bias. Multivariable regression modelling was therefore performed as an additional check that any differences between the cohorts did not impact on the study conclusions. The study is limited by the number of patients who presented with ACS during the study period and it is possible that with a larger study population differences in outcomes between the cohorts might be apparent. The development and growth of the nurse-led process was non-linear and started as a purely educational adjunct to standard cardiology care and grew as the nurses gained clinic experience to take on a more hybrid nurse/medical focus. The main goals of the clinic remain engrained in nursing philosophy and offer an experience that is different to standard medical practice. However, it is difficult to adjust for improving clinical experience and diagnostic skills, nurse prescribing and eventually nurse practitioner preparedness, which will all have had impacts on outcomes. There were also a number of other processes that we could not account fully for, including access and contact with cardiac rehabilitation, involvement of the heart failure up-titration clinics and the likelihood of patients having multiple admissions and crossing over from the nurse-led process to the medical-only process and vice versa. Data collection in cardiac rehabilitation and the community HF clinics have improved over the last few years and we now have robust data bases, but for the majority of this study we could not account for additional nurse input.

There is very little information on patient experience, however, qualitative research with patients is planned and will provide further insight into accessibility and acceptability of the different models, particularly for our diverse local populations.

Conclusion

This is a large New Zealand cohort study that reports on the safety of the addition of a nurse-led model of care to usual cardiologist-only care and is associated with earlier access to follow-up. The nurse-led model is as effective at maintaining secondary prevention pharmacotherapy as the gold standard medical model with no difference in clinical outcomes.

Further studies examining cost effectiveness and patient experience have the potential to support the implementation of this model across New Zealand.

View Appendices.

Summary

Abstract

Aim

At Middlemore Hospital, acute coronary syndrome (ACS) patients are admitted under the care of one of seven cardiologists working on a weekly rotation. Between 2010 and 2018 patients under the care of three of the cardiologists were followed up in a “medical only” post-ACS follow-up clinic model where the cardiologist or registrar saw all patients. Those admitted under the other four cardiologists were seen in a “nurse-led, cardiologist-supported” follow-up model where the majority of patients were seen by a nurse specialist. The study aim was to compare quality of care and outcomes between patients managed under these two follow-up clinic models.

Method

The ANZACS-QI registry was used to identify all ACS admissions, 2010 to 2018. The ANZACS-QI records for 5296 patients, discharged alive, were anonymously linked with hospital clinic follow-up and national administrative datasets. Time to follow-up, medication dispensation and titration and one-year clinical outcomes were compared for the two follow-up models.

Results

Characteristics of patients managed under each model were similar. 4395 patients attended follow up, 74% in the nurse-led model. At one year there were no differences between the medical- and nurse-led cohorts in all-cause mortality (4.6% vs 3.9, p=0.29), rehospitalisations for myocardial infarction (MI) (9.2% vs 8.3%, p=0.31), stroke (1.2% vs 1.4% p=0.71), heart failure (5.7% vs 6.9%, p=0.15) or a combined endpoint of all-cause mortality and/or rehospitalisation for MI/stroke/HF (15.2% vs 14.8%, p=0.71). Patients were seen earlier post-discharge in the nurse-led model, (mean 83 vs 101 days). Medication dispensation one year post-discharge was similar for both models of care.

Conclusion

The nurse-led model is associated with earlier access to follow-up, was equally as effective at maintaining secondary prevention pharmacotherapy and associated with similar survival and readmission with non-fatal ACS/stroke/heart failure.

Author Information

Andrew McLachlan: Nurse Practitioner | Mātanga Tapuhi: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand. Professor Andrew Kerr, MD: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand; School of Population Health, The University of Auckland; Department of Medicine, The University of Auckland. Mildred Lee, MSc: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand; School of Population Health, The University of Auckland.

Acknowledgements

Courtney Harper: Information Specialist – provided library support and literature review. Mildred Lee received salary support from the Middlemore Cardiac Trust. The cardiologists at CMDHB who have so willingly provided their expertise to grow the nurse-led model.

Correspondence

Andrew McLachlan: Nurse Practitioner | Mātanga Tapuhi: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand.

Correspondence Email

Andrew.McLachlan@cmdhb.org.nz.

Competing Interests

Nil.

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Despite effective evidenced-based therapies, acute coronary syndrome (ACS) and its complications remains one of the leading causes of mortality, morbidity and healthcare expenditure worldwide. ACS has a significant impact on families and communities with approximately 12,000 patients admitted to New Zealand hospitals every year.[[1]] Of those who survive, a third suffer a second cardiovascular event in the first year with approximately 50% of all major coronary events occurring in those with a previous diagnosis of cardiovascular disease.[[2]]

The mortality rates from ischaemic heart disease (IHD) have been declining steadily in New Zealand, due to a systematic focus on the prevention and management of cardiovascular disease.[[3]] These interventions include reductions in cholesterol and smoking prevalence, improvements in blood pressure control and timely revascularisation in the treatment of ACS.[[4]] While quality improvement initiatives have improved many facets of ACS interventional and medical management, less attention has been focussed on the long-term disease process that requires a lifelong and structured approach to care.[[5]]

The early recovery period following ACS is important, with a higher risk of mortality and recurrent events requiring a focus on prevention, including primary care follow-up, cardiac rehabilitation,[[6]] support around lifestyle change and evidence-based pharmacological interventions.[[7]] However, it’s clear that much more can be achieved as guideline targets for secondary prevention interventions, following the transition from in-hospital to outpatient care, remain sub-optimal.[[8]] This may be partly due to increasing patient volumes with complex health needs and a lack of medical resources, including inconsistent funding for primary care involvement.[[9]]

Despite a focus on system improvements over the years, in our own department, timely access to cardiologist outpatient care remains an issue and new models of care have been introduced. These include a number of interventions led by clinical nurse specialists (CNS) and nurse practitioners (NP)[[10–12]] to support patients to better understand and manage their cardiac condition, address service gaps due to high demand or workforce shortages[[13]] and support patient outcomes following discharge.[[14]] These interventions are aligned with evidence-based cardiology best practice and include a focus on patient self-management[[15]] and cardiac rehabilitation/exercise promotion.[[11]] In these models the nurses work closely with the cardiologists.

Local audits[[16–17]] have identified that patients managed in the nurse-led clinics are more likely to be prescribed preventative therapies and individualised lifestyle advice e.g., smoking cessation support, exercise guidance and dietary advice, compared to usual care.[[18]] However, it is important that we demonstrate these interventions deliver outcomes that are as effective as medical-only models of care, before we promote nurse-led models more widely.

The aim of this study is to compare the quality of care and outcomes between patients referred for follow-up after an ACS via a traditional medical model to those with a nurse-led and cardiologist-supported follow-up model. Clinical outcomes studied include time to clinic review, medication dispensation, mortality and cardiac rehospitalisation.

Methods

This study used a retrospective cohort study design based on the ANZACS-QI registry and linked Middlemore Hospital, based in the Counties Manukau District Health Board (CMDHB), electronic health records. The ANZACS-QI registry is a web-based electronic database, which captures a mandatory dataset for all patients admitted with an acute coronary syndrome (ACS), and is used by the Middlemore Hospital Coronary Care Unit. Data collected includes patient demographics, admission ACS risk stratification, cardiovascular risk factors, investigations and management, inpatient outcomes and medications prescribed at discharge. Details regarding this data collection have previously been reported.[[19]] The Middlemore Hospital ACS cohort was identified from ANZACS-QI and encrypted National Health Index (NHI) numbers linked this cohort with corresponding CMDHB hospital coding data to identify patients who were followed by the nurse-led and medical-only services. The cohort was also anonymously linked to national health datasets including hospitalisations, mortality and drug dispensing.

At CMDHB, patients with ACS are admitted to the Cardiology team in Coronary Care Unit, and are cared for by one of seven cardiologists working on a weekly rotation. Follow-up of each patient is then under one of the seven cardiologist’s clinics. Before 2010, all patients at discharge after ACS were followed up by a consultant cardiologist or consultant supervised registrar, designating a medical-only follow-up clinic model. Increasing demand and long waiting times for outpatient review led to funding for a nurse-led post-ACS follow-up clinic model, designated a nurse-led follow-up clinic model. The nurses leading this service were experienced in cardiology, cardiac rehabilitation and long-term condition support; they were mentored by a senior cardiologist.

During the period of this study, 1 January 2010 to 31 December 2018, four of the cardiologist clinics transitioned to the nurse-led clinic model, where the majority of patients were seen by a nurse but with a small proportion of patients still seen by the consultant or the registrar. The decision regarding which patient would see a cardiologist vs the nurse in these clinics was at the discretion of medical staff at hospital discharge. The nurse-led model progressively expanded as additional nurses were trained and credentials were certified using a locally designed mentorship and competency process.

Overall, ACS care after discharge is based on established and agreed guidelines and protocols, and substantial variation in practice between cardiologists is unlikely and this care has been largely unchanged over the study time period. Guidelines recommend, following ACS, the scheduling of a timely follow-up appointment.[[20]] At the follow-up visit, a clinician obtains a history of any interval symptoms of ischemia, heart failure and/or arrhythmias and performs a focused cardiovascular examination. Management and interventions are implemented as required. The nurse-led process provides 30-minute appointments to facilitate an additional structured exploration of self-management, psychological coping, adherence and optimisation of the pharmacotherapy regimen to meet secondary prevention targets, when applicable. Support is offered, where appropriate, on stress management, medications adherence, diet, exercise and smoking cessation. All patients are offered referral to the “Healthy Hearts” cardiac rehabilitation/exercise program.[[16]] The cardiologists work alongside the nurse-led clinics and are available to review and advise. Standard medical follow-up appointments were 20 minutes.

Ethics review

ANZACS-QI is part of the wider Health Research Council (HRC) and National Heart Foundation (NHF) funded Vascular Informatics using Epidemiology and the Web (VIEW) research programme based at the University of Auckland. The VIEW research team oversees the use and governance of any audit or research use of the national routine information datasets. As all ANZACS-QI registry data and national Routine data is anonymised before being sent to the VIEW researchers; individual patient consent is not required by ethics committees. The VIEW study was approved by the Northern Region Ethics Committee Y in 2003 (AKY/03/12/314), with subsequent amendments to include the ANZACS-QI registries, and with annual approvals by the National Multi-Region Ethics Committee since 2007 (MEC07/19/EXP). Approval was also granted by the Middlemore Hospital research department (#442).

Statistical analysis

The main outcomes of interest were rehospitalisation for myocardial infarction, stroke, and heart failure in the year after discharge, mortality in the year after discharge and the proportion of patients dispensed guideline-recommended medication.

The cohort is described in relation to summary data for patients followed in the nurse-led compared to medical-only follow-up models where continuous variables were reported as mean and standard deviation (SD) and/or median and inter-quartile range (IQR), and categorical variables were reported as counts and proportions were expressed as percentages. Comparison between groups was done using Chi-squared test for categorical data, and for the continuous data comparison between groups was done using non-parametric Mann–Whitney U tests, Kruskal–Wallis tests, student’s T-tests or ANOVA tests where appropriate. All patients had at least one year of available follow-up time. Cox proportional hazard regression models were constructed to estimate the hazard ratios and 95% confidence interval for the one-year all-cause mortality, each rehospitalisation outcome and the composite of one-year all-cause mortality and rehospitalisation MI/stroke/HF outcomes to compare outcomes between the two models of care (“medical only” and “nurse led”). The results of univariate and multivariable adjusted models are presented. Variables adjusted for were for age, sex, ethnicity, ACS type, GRACE score, LV function, revascularisation and admission year from 2010 to 2018, after ensuring that the assumption of proportional hazards was met. Survival curves are shown using Kaplan–Meier estimates.

All p-values reported were two tailed and a p-value <0.05 was considered significant. No adjustment is made for multiple statistical testing. Data was analysed using SAS statistical package, version 9.4 (SAS Institute, Cary, NC). The survival curves were plotted using RStudio version 1.2.1335.

Results

Between 2010 to 2018, we identified 5296 New Zealand residents, eligible for outpatient follow-up, who were discharged alive following a first ACS event. Of these 4395 (83%) had a follow-up with a clinician, of whom 1,161 (26%) had their first follow-up via a medical model, and 3234 (74%) used the nurse-led model (Figure 1). The proportion of patients seen in the nurse-led follow-up clinics was stable over the time period.

Baseline characteristics (Table 1)

There were some differences between the two cohorts: compared with the medical cohort the nurse-led cohort were slightly younger (62 years vs 63.5 years, p=0.001), had experienced more ST Elevation myocardial infarctions (17.8% vs 14.4%, p=0.002) with more moderate or severe left ventricular impairment (16.3% vs 11.9%, p=0.001). The nurse-led cohort were more likely to require coronary artery bypass referral (18.2% vs 17.8%, p=0.002). Ethnicity, socio-economic measures, risk factors, risk scores and comorbid conditions were similar.

Time to follow-up (Figure 2)

The recommended time to follow up is six to 12 weeks in our service. Patients followed up under the nurse-led model were seen earlier than the medical model (mean (SD) 83.2 days (50.1) vs 101 days (76.5), p<0.001).

Outcomes (Table 2, Figures 3 & 4)

In the year post-discharge there were no differences between the two cohorts in all-cause mortality, rehospitalisation for MI, stroke, heart failure or a composite endpoint of all-cause mortality and/or rehospitalisation for MI/stroke/HF. Compared with the reference medical only model the multivariable adjusted hazard ratios for the nurse-led model did not differ significantly for either all-cause mortality (HR 0.80, 95% CIs 0.58 to 1.10) or the composite outcomes (HR 0.93, 95% CIs 0.78 to 1.11).

Medication dispensed (Table 3)

The dispensing of important secondary prevention pharmacotherapies was high at discharge, with no important differences between patients at discharge followed up in the medical or the nurse-led model of care. Dispensing of ACE inhibitors (ACEi)/angiotensin receptor blockers (ARB) by one-year was slightly higher in the nurse-led follow-up (68.3% vs 63.9%) but this difference had been present early post-discharge, before any follow-up visits.

Dispensing of HF pharmacotherapy post-ACS with LVEF <40% at one year following discharge (Table 4)

Beta blockers and ACE I/ARB, at the doses used in clinical trials, are consistently recommended by all guidelines for patients with a reduced left ventricular ejection fraction (LVEF <40%).[[21]] We identified 594 patients who met these criteria and identified no significant differences in the rates of dispensing of these important medications between the cohorts.

View Figures and Tables.

Discussion

This is the first study to compare hard clinical outcomes between a traditional medical model and a nurse-led model of care post-ACS. Patients managed under the nurse-led model had one-year clinical outcomes and medical management, which were as good as those managed under a traditional medical model. They also had timelier access to outpatient review.

The nurse-led model of care is not novel and examples have been reported overseas, but implementation has been slow to develop in New Zealand. A frequent impediment to developing new nurse clinics is that the growing body of nurse-led literature is often classed as low-level evidence[[22]] with a highly selected patient cohort[[23]] and a heterogenous evidence base.[[24,25]] Despite this, many studies describe successful implementation[[26,27]] and report a positive impact on risk factors,[[28,27]] patient satisfaction,[[29]] access to care,[[14,30]] timely and more frequent monitoring of high‐risk post‐MI patients[[31]] with mixed results on cost-effectiveness.[[29,32]]

The evidence supporting nurse-led models post-ACS in the context of care co-ordination, rehabilitation programmes and IHD secondary prevention is also increasing. Some of these models involve nurses triaging whether a cardiologist medical review appointment is necessary[[33,34]] and most report nurse-led clinical follow-ups are feasible[[13]] and useful in freeing up clinical resources. To date, we have no evidence that nurse-led ACS clinics improve clinical outcomes, such as survival. However, a small UK audit of a nurse follow-up clinic in patients with ACS reported a reduction in six-month readmission rate (from 28.5% to 14.2%). The clinic provided early follow-up to patients classified as a higher risk based on TIMI scores: the nurses reviewed diagnosis, management plan and any symptoms in a 30-minute appointment. Cardiac rehabilitation was offered to all patients, and all patients were discussed with a consultant cardiologist.[[34]]

Guidelines[[35]] now recommend follow-up at 2–6 weeks depending on risk status of the patient, however, this has been difficult to achieve due to high patient demand. Our service recommends seeing a primary care clinician in one week and then cardiology clinic review in six to 12 weeks. The cardiac rehabilitation team contact the patient within two weeks and offer further support as required. Patients with impaired heart function are seen earlier with an aim of 2–6 weeks.

Reducing delay in seeking care for the initial presentation of ACS has been a successful quality improvement focus across the globe[[36]] and in New Zealand.[[37]] Delays to outpatient review has been less of a focus but delays are associated with worse outcomes compared to earlier follow-up[[38]] with reports of increased hospitalisation and worse short-term and long-term medication adherence.[[39]] The recovery period following ACS is stressful and impacts on patient’s work, family situation and both physical and psychological health.[[40]] A significant number of patients continue to experience emotional symptoms that may impair their daily functioning.[[41]] It is important to provide early access to answer questions, correct misconceptions and identify and address significant issues affecting recovery. While cardiac rehabilitation has an important role in providing support, many patients choose or are unable to partake in these programmes. The nurse-led clinic model meant we were able to bring patients in for review earlier and address barriers to recovery and encourage engagement with their primary care team.

There appears to be a lot of variation in different healthcare systems about the ongoing relationship and responsibilities of outpatient and primary care. Goddard[[42]] describes a protocol for a four-week post-ACS practice nurse appointment in primary care. This appointment is timed to ensure recommended treatments and medication changes are implemented appropriately, as well as advice on lifestyle changes and assessment of psychosocial health. In New Zealand, lifelong secondary prevention following ACS is usually managed in primary care, although structured care is inconsistently delivered and has not been a focus of primary care targets in recent years. It is important that health systems support patients following ACS not just in the acute and early recovery period but for life. In New Zealand, who provides this ongoing care is usually the general practitioner; however, little is known about the level of management provided.[[9]] Nurse practitioner or practice nurse involvement has not been well described in post-ACS care. However, for many patients, successful, lifelong secondary prevention requires a structured and holistic approach, that nurses have shown they can provide.[[43]]

Non-adherence following ACS is associated with increased risks of mortality and hospital readmissions. Medication dispensing is a useful way to measure adherence, and we identified a decline in important secondary prevention medication usage at one year. A New Zealand study investigated high dose statin use and reported that 21% of the cohort were not on a statin at one year.[[1]] More work is required to understand the best approach to supporting long-term medication usage and will require more collaboration between the patient and whānau, the cardiology team, primary care and community pharmacists.

Limitations

There are several limitations in this paper. This was a retrospective observational study, so patients were not formally randomised to follow-up under medical vs nurse-led models. Nevertheless, patients were effectively randomised because ACS admissions are not planned, and the only determinant of which model of follow-up they received was the week in which they were admitted to hospital – patients admitted in a week when a consultant with medical only follow-up was on-call were managed under the medical model and those admitted in a week where a consultant had a nurse-led follow up model were managed under the nurse-led model. There were only a small number of differences identified between the two groups and some of these may have been due to the multiple statistical comparisons performed (Type I error). However, the observed group difference in age, distribution of ACS type and of LV ejection fraction were potentially clinically significant and may have been a source of bias. Multivariable regression modelling was therefore performed as an additional check that any differences between the cohorts did not impact on the study conclusions. The study is limited by the number of patients who presented with ACS during the study period and it is possible that with a larger study population differences in outcomes between the cohorts might be apparent. The development and growth of the nurse-led process was non-linear and started as a purely educational adjunct to standard cardiology care and grew as the nurses gained clinic experience to take on a more hybrid nurse/medical focus. The main goals of the clinic remain engrained in nursing philosophy and offer an experience that is different to standard medical practice. However, it is difficult to adjust for improving clinical experience and diagnostic skills, nurse prescribing and eventually nurse practitioner preparedness, which will all have had impacts on outcomes. There were also a number of other processes that we could not account fully for, including access and contact with cardiac rehabilitation, involvement of the heart failure up-titration clinics and the likelihood of patients having multiple admissions and crossing over from the nurse-led process to the medical-only process and vice versa. Data collection in cardiac rehabilitation and the community HF clinics have improved over the last few years and we now have robust data bases, but for the majority of this study we could not account for additional nurse input.

There is very little information on patient experience, however, qualitative research with patients is planned and will provide further insight into accessibility and acceptability of the different models, particularly for our diverse local populations.

Conclusion

This is a large New Zealand cohort study that reports on the safety of the addition of a nurse-led model of care to usual cardiologist-only care and is associated with earlier access to follow-up. The nurse-led model is as effective at maintaining secondary prevention pharmacotherapy as the gold standard medical model with no difference in clinical outcomes.

Further studies examining cost effectiveness and patient experience have the potential to support the implementation of this model across New Zealand.

View Appendices.

Summary

Abstract

Aim

At Middlemore Hospital, acute coronary syndrome (ACS) patients are admitted under the care of one of seven cardiologists working on a weekly rotation. Between 2010 and 2018 patients under the care of three of the cardiologists were followed up in a “medical only” post-ACS follow-up clinic model where the cardiologist or registrar saw all patients. Those admitted under the other four cardiologists were seen in a “nurse-led, cardiologist-supported” follow-up model where the majority of patients were seen by a nurse specialist. The study aim was to compare quality of care and outcomes between patients managed under these two follow-up clinic models.

Method

The ANZACS-QI registry was used to identify all ACS admissions, 2010 to 2018. The ANZACS-QI records for 5296 patients, discharged alive, were anonymously linked with hospital clinic follow-up and national administrative datasets. Time to follow-up, medication dispensation and titration and one-year clinical outcomes were compared for the two follow-up models.

Results

Characteristics of patients managed under each model were similar. 4395 patients attended follow up, 74% in the nurse-led model. At one year there were no differences between the medical- and nurse-led cohorts in all-cause mortality (4.6% vs 3.9, p=0.29), rehospitalisations for myocardial infarction (MI) (9.2% vs 8.3%, p=0.31), stroke (1.2% vs 1.4% p=0.71), heart failure (5.7% vs 6.9%, p=0.15) or a combined endpoint of all-cause mortality and/or rehospitalisation for MI/stroke/HF (15.2% vs 14.8%, p=0.71). Patients were seen earlier post-discharge in the nurse-led model, (mean 83 vs 101 days). Medication dispensation one year post-discharge was similar for both models of care.

Conclusion

The nurse-led model is associated with earlier access to follow-up, was equally as effective at maintaining secondary prevention pharmacotherapy and associated with similar survival and readmission with non-fatal ACS/stroke/heart failure.

Author Information

Andrew McLachlan: Nurse Practitioner | Mātanga Tapuhi: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand. Professor Andrew Kerr, MD: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand; School of Population Health, The University of Auckland; Department of Medicine, The University of Auckland. Mildred Lee, MSc: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand; School of Population Health, The University of Auckland.

Acknowledgements

Courtney Harper: Information Specialist – provided library support and literature review. Mildred Lee received salary support from the Middlemore Cardiac Trust. The cardiologists at CMDHB who have so willingly provided their expertise to grow the nurse-led model.

Correspondence

Andrew McLachlan: Nurse Practitioner | Mātanga Tapuhi: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand.

Correspondence Email

Andrew.McLachlan@cmdhb.org.nz.

Competing Interests

Nil.

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Despite effective evidenced-based therapies, acute coronary syndrome (ACS) and its complications remains one of the leading causes of mortality, morbidity and healthcare expenditure worldwide. ACS has a significant impact on families and communities with approximately 12,000 patients admitted to New Zealand hospitals every year.[[1]] Of those who survive, a third suffer a second cardiovascular event in the first year with approximately 50% of all major coronary events occurring in those with a previous diagnosis of cardiovascular disease.[[2]]

The mortality rates from ischaemic heart disease (IHD) have been declining steadily in New Zealand, due to a systematic focus on the prevention and management of cardiovascular disease.[[3]] These interventions include reductions in cholesterol and smoking prevalence, improvements in blood pressure control and timely revascularisation in the treatment of ACS.[[4]] While quality improvement initiatives have improved many facets of ACS interventional and medical management, less attention has been focussed on the long-term disease process that requires a lifelong and structured approach to care.[[5]]

The early recovery period following ACS is important, with a higher risk of mortality and recurrent events requiring a focus on prevention, including primary care follow-up, cardiac rehabilitation,[[6]] support around lifestyle change and evidence-based pharmacological interventions.[[7]] However, it’s clear that much more can be achieved as guideline targets for secondary prevention interventions, following the transition from in-hospital to outpatient care, remain sub-optimal.[[8]] This may be partly due to increasing patient volumes with complex health needs and a lack of medical resources, including inconsistent funding for primary care involvement.[[9]]

Despite a focus on system improvements over the years, in our own department, timely access to cardiologist outpatient care remains an issue and new models of care have been introduced. These include a number of interventions led by clinical nurse specialists (CNS) and nurse practitioners (NP)[[10–12]] to support patients to better understand and manage their cardiac condition, address service gaps due to high demand or workforce shortages[[13]] and support patient outcomes following discharge.[[14]] These interventions are aligned with evidence-based cardiology best practice and include a focus on patient self-management[[15]] and cardiac rehabilitation/exercise promotion.[[11]] In these models the nurses work closely with the cardiologists.

Local audits[[16–17]] have identified that patients managed in the nurse-led clinics are more likely to be prescribed preventative therapies and individualised lifestyle advice e.g., smoking cessation support, exercise guidance and dietary advice, compared to usual care.[[18]] However, it is important that we demonstrate these interventions deliver outcomes that are as effective as medical-only models of care, before we promote nurse-led models more widely.

The aim of this study is to compare the quality of care and outcomes between patients referred for follow-up after an ACS via a traditional medical model to those with a nurse-led and cardiologist-supported follow-up model. Clinical outcomes studied include time to clinic review, medication dispensation, mortality and cardiac rehospitalisation.

Methods

This study used a retrospective cohort study design based on the ANZACS-QI registry and linked Middlemore Hospital, based in the Counties Manukau District Health Board (CMDHB), electronic health records. The ANZACS-QI registry is a web-based electronic database, which captures a mandatory dataset for all patients admitted with an acute coronary syndrome (ACS), and is used by the Middlemore Hospital Coronary Care Unit. Data collected includes patient demographics, admission ACS risk stratification, cardiovascular risk factors, investigations and management, inpatient outcomes and medications prescribed at discharge. Details regarding this data collection have previously been reported.[[19]] The Middlemore Hospital ACS cohort was identified from ANZACS-QI and encrypted National Health Index (NHI) numbers linked this cohort with corresponding CMDHB hospital coding data to identify patients who were followed by the nurse-led and medical-only services. The cohort was also anonymously linked to national health datasets including hospitalisations, mortality and drug dispensing.

At CMDHB, patients with ACS are admitted to the Cardiology team in Coronary Care Unit, and are cared for by one of seven cardiologists working on a weekly rotation. Follow-up of each patient is then under one of the seven cardiologist’s clinics. Before 2010, all patients at discharge after ACS were followed up by a consultant cardiologist or consultant supervised registrar, designating a medical-only follow-up clinic model. Increasing demand and long waiting times for outpatient review led to funding for a nurse-led post-ACS follow-up clinic model, designated a nurse-led follow-up clinic model. The nurses leading this service were experienced in cardiology, cardiac rehabilitation and long-term condition support; they were mentored by a senior cardiologist.

During the period of this study, 1 January 2010 to 31 December 2018, four of the cardiologist clinics transitioned to the nurse-led clinic model, where the majority of patients were seen by a nurse but with a small proportion of patients still seen by the consultant or the registrar. The decision regarding which patient would see a cardiologist vs the nurse in these clinics was at the discretion of medical staff at hospital discharge. The nurse-led model progressively expanded as additional nurses were trained and credentials were certified using a locally designed mentorship and competency process.

Overall, ACS care after discharge is based on established and agreed guidelines and protocols, and substantial variation in practice between cardiologists is unlikely and this care has been largely unchanged over the study time period. Guidelines recommend, following ACS, the scheduling of a timely follow-up appointment.[[20]] At the follow-up visit, a clinician obtains a history of any interval symptoms of ischemia, heart failure and/or arrhythmias and performs a focused cardiovascular examination. Management and interventions are implemented as required. The nurse-led process provides 30-minute appointments to facilitate an additional structured exploration of self-management, psychological coping, adherence and optimisation of the pharmacotherapy regimen to meet secondary prevention targets, when applicable. Support is offered, where appropriate, on stress management, medications adherence, diet, exercise and smoking cessation. All patients are offered referral to the “Healthy Hearts” cardiac rehabilitation/exercise program.[[16]] The cardiologists work alongside the nurse-led clinics and are available to review and advise. Standard medical follow-up appointments were 20 minutes.

Ethics review

ANZACS-QI is part of the wider Health Research Council (HRC) and National Heart Foundation (NHF) funded Vascular Informatics using Epidemiology and the Web (VIEW) research programme based at the University of Auckland. The VIEW research team oversees the use and governance of any audit or research use of the national routine information datasets. As all ANZACS-QI registry data and national Routine data is anonymised before being sent to the VIEW researchers; individual patient consent is not required by ethics committees. The VIEW study was approved by the Northern Region Ethics Committee Y in 2003 (AKY/03/12/314), with subsequent amendments to include the ANZACS-QI registries, and with annual approvals by the National Multi-Region Ethics Committee since 2007 (MEC07/19/EXP). Approval was also granted by the Middlemore Hospital research department (#442).

Statistical analysis

The main outcomes of interest were rehospitalisation for myocardial infarction, stroke, and heart failure in the year after discharge, mortality in the year after discharge and the proportion of patients dispensed guideline-recommended medication.

The cohort is described in relation to summary data for patients followed in the nurse-led compared to medical-only follow-up models where continuous variables were reported as mean and standard deviation (SD) and/or median and inter-quartile range (IQR), and categorical variables were reported as counts and proportions were expressed as percentages. Comparison between groups was done using Chi-squared test for categorical data, and for the continuous data comparison between groups was done using non-parametric Mann–Whitney U tests, Kruskal–Wallis tests, student’s T-tests or ANOVA tests where appropriate. All patients had at least one year of available follow-up time. Cox proportional hazard regression models were constructed to estimate the hazard ratios and 95% confidence interval for the one-year all-cause mortality, each rehospitalisation outcome and the composite of one-year all-cause mortality and rehospitalisation MI/stroke/HF outcomes to compare outcomes between the two models of care (“medical only” and “nurse led”). The results of univariate and multivariable adjusted models are presented. Variables adjusted for were for age, sex, ethnicity, ACS type, GRACE score, LV function, revascularisation and admission year from 2010 to 2018, after ensuring that the assumption of proportional hazards was met. Survival curves are shown using Kaplan–Meier estimates.

All p-values reported were two tailed and a p-value <0.05 was considered significant. No adjustment is made for multiple statistical testing. Data was analysed using SAS statistical package, version 9.4 (SAS Institute, Cary, NC). The survival curves were plotted using RStudio version 1.2.1335.

Results

Between 2010 to 2018, we identified 5296 New Zealand residents, eligible for outpatient follow-up, who were discharged alive following a first ACS event. Of these 4395 (83%) had a follow-up with a clinician, of whom 1,161 (26%) had their first follow-up via a medical model, and 3234 (74%) used the nurse-led model (Figure 1). The proportion of patients seen in the nurse-led follow-up clinics was stable over the time period.

Baseline characteristics (Table 1)

There were some differences between the two cohorts: compared with the medical cohort the nurse-led cohort were slightly younger (62 years vs 63.5 years, p=0.001), had experienced more ST Elevation myocardial infarctions (17.8% vs 14.4%, p=0.002) with more moderate or severe left ventricular impairment (16.3% vs 11.9%, p=0.001). The nurse-led cohort were more likely to require coronary artery bypass referral (18.2% vs 17.8%, p=0.002). Ethnicity, socio-economic measures, risk factors, risk scores and comorbid conditions were similar.

Time to follow-up (Figure 2)

The recommended time to follow up is six to 12 weeks in our service. Patients followed up under the nurse-led model were seen earlier than the medical model (mean (SD) 83.2 days (50.1) vs 101 days (76.5), p<0.001).

Outcomes (Table 2, Figures 3 & 4)

In the year post-discharge there were no differences between the two cohorts in all-cause mortality, rehospitalisation for MI, stroke, heart failure or a composite endpoint of all-cause mortality and/or rehospitalisation for MI/stroke/HF. Compared with the reference medical only model the multivariable adjusted hazard ratios for the nurse-led model did not differ significantly for either all-cause mortality (HR 0.80, 95% CIs 0.58 to 1.10) or the composite outcomes (HR 0.93, 95% CIs 0.78 to 1.11).

Medication dispensed (Table 3)

The dispensing of important secondary prevention pharmacotherapies was high at discharge, with no important differences between patients at discharge followed up in the medical or the nurse-led model of care. Dispensing of ACE inhibitors (ACEi)/angiotensin receptor blockers (ARB) by one-year was slightly higher in the nurse-led follow-up (68.3% vs 63.9%) but this difference had been present early post-discharge, before any follow-up visits.

Dispensing of HF pharmacotherapy post-ACS with LVEF <40% at one year following discharge (Table 4)

Beta blockers and ACE I/ARB, at the doses used in clinical trials, are consistently recommended by all guidelines for patients with a reduced left ventricular ejection fraction (LVEF <40%).[[21]] We identified 594 patients who met these criteria and identified no significant differences in the rates of dispensing of these important medications between the cohorts.

View Figures and Tables.

Discussion

This is the first study to compare hard clinical outcomes between a traditional medical model and a nurse-led model of care post-ACS. Patients managed under the nurse-led model had one-year clinical outcomes and medical management, which were as good as those managed under a traditional medical model. They also had timelier access to outpatient review.

The nurse-led model of care is not novel and examples have been reported overseas, but implementation has been slow to develop in New Zealand. A frequent impediment to developing new nurse clinics is that the growing body of nurse-led literature is often classed as low-level evidence[[22]] with a highly selected patient cohort[[23]] and a heterogenous evidence base.[[24,25]] Despite this, many studies describe successful implementation[[26,27]] and report a positive impact on risk factors,[[28,27]] patient satisfaction,[[29]] access to care,[[14,30]] timely and more frequent monitoring of high‐risk post‐MI patients[[31]] with mixed results on cost-effectiveness.[[29,32]]

The evidence supporting nurse-led models post-ACS in the context of care co-ordination, rehabilitation programmes and IHD secondary prevention is also increasing. Some of these models involve nurses triaging whether a cardiologist medical review appointment is necessary[[33,34]] and most report nurse-led clinical follow-ups are feasible[[13]] and useful in freeing up clinical resources. To date, we have no evidence that nurse-led ACS clinics improve clinical outcomes, such as survival. However, a small UK audit of a nurse follow-up clinic in patients with ACS reported a reduction in six-month readmission rate (from 28.5% to 14.2%). The clinic provided early follow-up to patients classified as a higher risk based on TIMI scores: the nurses reviewed diagnosis, management plan and any symptoms in a 30-minute appointment. Cardiac rehabilitation was offered to all patients, and all patients were discussed with a consultant cardiologist.[[34]]

Guidelines[[35]] now recommend follow-up at 2–6 weeks depending on risk status of the patient, however, this has been difficult to achieve due to high patient demand. Our service recommends seeing a primary care clinician in one week and then cardiology clinic review in six to 12 weeks. The cardiac rehabilitation team contact the patient within two weeks and offer further support as required. Patients with impaired heart function are seen earlier with an aim of 2–6 weeks.

Reducing delay in seeking care for the initial presentation of ACS has been a successful quality improvement focus across the globe[[36]] and in New Zealand.[[37]] Delays to outpatient review has been less of a focus but delays are associated with worse outcomes compared to earlier follow-up[[38]] with reports of increased hospitalisation and worse short-term and long-term medication adherence.[[39]] The recovery period following ACS is stressful and impacts on patient’s work, family situation and both physical and psychological health.[[40]] A significant number of patients continue to experience emotional symptoms that may impair their daily functioning.[[41]] It is important to provide early access to answer questions, correct misconceptions and identify and address significant issues affecting recovery. While cardiac rehabilitation has an important role in providing support, many patients choose or are unable to partake in these programmes. The nurse-led clinic model meant we were able to bring patients in for review earlier and address barriers to recovery and encourage engagement with their primary care team.

There appears to be a lot of variation in different healthcare systems about the ongoing relationship and responsibilities of outpatient and primary care. Goddard[[42]] describes a protocol for a four-week post-ACS practice nurse appointment in primary care. This appointment is timed to ensure recommended treatments and medication changes are implemented appropriately, as well as advice on lifestyle changes and assessment of psychosocial health. In New Zealand, lifelong secondary prevention following ACS is usually managed in primary care, although structured care is inconsistently delivered and has not been a focus of primary care targets in recent years. It is important that health systems support patients following ACS not just in the acute and early recovery period but for life. In New Zealand, who provides this ongoing care is usually the general practitioner; however, little is known about the level of management provided.[[9]] Nurse practitioner or practice nurse involvement has not been well described in post-ACS care. However, for many patients, successful, lifelong secondary prevention requires a structured and holistic approach, that nurses have shown they can provide.[[43]]

Non-adherence following ACS is associated with increased risks of mortality and hospital readmissions. Medication dispensing is a useful way to measure adherence, and we identified a decline in important secondary prevention medication usage at one year. A New Zealand study investigated high dose statin use and reported that 21% of the cohort were not on a statin at one year.[[1]] More work is required to understand the best approach to supporting long-term medication usage and will require more collaboration between the patient and whānau, the cardiology team, primary care and community pharmacists.

Limitations

There are several limitations in this paper. This was a retrospective observational study, so patients were not formally randomised to follow-up under medical vs nurse-led models. Nevertheless, patients were effectively randomised because ACS admissions are not planned, and the only determinant of which model of follow-up they received was the week in which they were admitted to hospital – patients admitted in a week when a consultant with medical only follow-up was on-call were managed under the medical model and those admitted in a week where a consultant had a nurse-led follow up model were managed under the nurse-led model. There were only a small number of differences identified between the two groups and some of these may have been due to the multiple statistical comparisons performed (Type I error). However, the observed group difference in age, distribution of ACS type and of LV ejection fraction were potentially clinically significant and may have been a source of bias. Multivariable regression modelling was therefore performed as an additional check that any differences between the cohorts did not impact on the study conclusions. The study is limited by the number of patients who presented with ACS during the study period and it is possible that with a larger study population differences in outcomes between the cohorts might be apparent. The development and growth of the nurse-led process was non-linear and started as a purely educational adjunct to standard cardiology care and grew as the nurses gained clinic experience to take on a more hybrid nurse/medical focus. The main goals of the clinic remain engrained in nursing philosophy and offer an experience that is different to standard medical practice. However, it is difficult to adjust for improving clinical experience and diagnostic skills, nurse prescribing and eventually nurse practitioner preparedness, which will all have had impacts on outcomes. There were also a number of other processes that we could not account fully for, including access and contact with cardiac rehabilitation, involvement of the heart failure up-titration clinics and the likelihood of patients having multiple admissions and crossing over from the nurse-led process to the medical-only process and vice versa. Data collection in cardiac rehabilitation and the community HF clinics have improved over the last few years and we now have robust data bases, but for the majority of this study we could not account for additional nurse input.

There is very little information on patient experience, however, qualitative research with patients is planned and will provide further insight into accessibility and acceptability of the different models, particularly for our diverse local populations.

Conclusion

This is a large New Zealand cohort study that reports on the safety of the addition of a nurse-led model of care to usual cardiologist-only care and is associated with earlier access to follow-up. The nurse-led model is as effective at maintaining secondary prevention pharmacotherapy as the gold standard medical model with no difference in clinical outcomes.

Further studies examining cost effectiveness and patient experience have the potential to support the implementation of this model across New Zealand.

View Appendices.

Summary

Abstract

Aim

At Middlemore Hospital, acute coronary syndrome (ACS) patients are admitted under the care of one of seven cardiologists working on a weekly rotation. Between 2010 and 2018 patients under the care of three of the cardiologists were followed up in a “medical only” post-ACS follow-up clinic model where the cardiologist or registrar saw all patients. Those admitted under the other four cardiologists were seen in a “nurse-led, cardiologist-supported” follow-up model where the majority of patients were seen by a nurse specialist. The study aim was to compare quality of care and outcomes between patients managed under these two follow-up clinic models.

Method

The ANZACS-QI registry was used to identify all ACS admissions, 2010 to 2018. The ANZACS-QI records for 5296 patients, discharged alive, were anonymously linked with hospital clinic follow-up and national administrative datasets. Time to follow-up, medication dispensation and titration and one-year clinical outcomes were compared for the two follow-up models.

Results

Characteristics of patients managed under each model were similar. 4395 patients attended follow up, 74% in the nurse-led model. At one year there were no differences between the medical- and nurse-led cohorts in all-cause mortality (4.6% vs 3.9, p=0.29), rehospitalisations for myocardial infarction (MI) (9.2% vs 8.3%, p=0.31), stroke (1.2% vs 1.4% p=0.71), heart failure (5.7% vs 6.9%, p=0.15) or a combined endpoint of all-cause mortality and/or rehospitalisation for MI/stroke/HF (15.2% vs 14.8%, p=0.71). Patients were seen earlier post-discharge in the nurse-led model, (mean 83 vs 101 days). Medication dispensation one year post-discharge was similar for both models of care.

Conclusion

The nurse-led model is associated with earlier access to follow-up, was equally as effective at maintaining secondary prevention pharmacotherapy and associated with similar survival and readmission with non-fatal ACS/stroke/heart failure.

Author Information

Andrew McLachlan: Nurse Practitioner | Mātanga Tapuhi: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand. Professor Andrew Kerr, MD: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand; School of Population Health, The University of Auckland; Department of Medicine, The University of Auckland. Mildred Lee, MSc: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand; School of Population Health, The University of Auckland.

Acknowledgements

Courtney Harper: Information Specialist – provided library support and literature review. Mildred Lee received salary support from the Middlemore Cardiac Trust. The cardiologists at CMDHB who have so willingly provided their expertise to grow the nurse-led model.

Correspondence

Andrew McLachlan: Nurse Practitioner | Mātanga Tapuhi: Department of Cardiology, Middlemore Hospital, Auckland, New Zealand.

Correspondence Email

Andrew.McLachlan@cmdhb.org.nz.

Competing Interests

Nil.

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