This paper notes that many Americans believe that gun ownership is necessary to protect their family and themselves. The concept is enshrined in the Second Amendment of the US Constitution. Stephen Lippmann and his co-authors who are based in Louisville, Kentucky review the evidence and reach the conclusion that domestic firearm ownership results in more deaths to the owner and/or family members than to intruders.

They produce frightening evidence to support their view. For example, intimate partner homicide is increased fivefold in gun owner households and the female suicide rate is increased threefold. And approximately 15 children or adolescents die from firearm-related causes every day in the United States.

Chest pain is a common cause for presentation at the emergency department. Its evaluation is often difficult as there may be no abnormal physical findings, a normal ECG and the initial cardiac injury markers may not be raised. Cardiac stress testing is not infallible. In this context the authors of this paper point out that coronary artery calcium (CAC) correlates directly with coronary atherosclerosis and is a marker of plaque burden. And quantification of CAC with cardiac computed tomography (CT) is sensitive, accurate and reproducible.

The study involved 263 men and women presenting with chest pain and low to moderate probability of coronary artery disease. 133 (51%) demonstrated no CAC and only one of these was later shown to have a cardiac cause for their chest pain. On the other hand 30/31 (97%) of those shown to have active coronary artery disease had evidence of CAC on CT. At 5-year follow-up none of the 132 subjects with no CAC had developed coronary artery disease problems.

Clopidogrel is recommended for patients with significant coronary artery disease. Because of the haemorrhagic risks involved proton-pump inhibitors (PPIs) are commonly prescribed with clopidogrel to reduce the risk for serious gastroduodenal bleeding. The biotransformation of clopidogrel to its active metabolite requires the hepatic cytochrome P450 2C19 isoenzyme and this may be adversely affected by the concomitant use of PPIs.

This study aims to throw light on the issue by evaluating outcomes in 20569 patients (including 7593 concurrent users of clopidogrel and PPIs) hospitalised for myocardial infarction, coronary artery revascularisation, or unstable angina pectoris. Gastroduodenal bleeding requiring admission to hospital was 50% lower in those taking PPIs, and there was no clear cut increased risk for serious cardiovascular events in those taking PPIs.

The authors of this meta-analysis state that percutaneous coronary intervention (PCI) has been compared with medical treatment by other reviewers and found to be not superior in terms of death, myocardial infarction and repeated coronary revascularization. Their review focuses on the relief of angina. They pooled data from 14 trials involving 7818 patients and found that PCI was superior and was associated with an overall benefit on angina relief (odds ratio 1.69). However, they note an attenuation of this benefit in the more recent trials. They attribute this to better use of evidence-based medical treatments in the latter trials.

Nateglinide is a short-acting insulin secretagogue and there are theoretical reasons to expect that it might prevent or delay diabetes development in such patients. In this English study over 9000 such patients were randomised to this drug or placebo, together with lifestyle modifications over a 5-year period. Sadly there was no reduction in incidence of diabetes or cardiovascular complications.

The second study, from North Carolina tested the same hypothesis with valsartan, which is a renin-antiogensin system blocker, over a 5-year period. There was a reduction of 14% in the incidence of diabetes but no reduction in the rate of cardiovascular events.

An editorial review points out that both reports were components of a single study—the Nateglinide and Valsartan in Impaired Glucose Tolerance Outcomes Research (NAVIGATOR) Study. Also in each study some of the placebo arm patients were taking the alternative medication. The reviewer recommends that neither drug should be used in such patients.