Aspirin is a well-established therapy for the secondary prevention of cardiovascular events. However, its role in the primary prevention of cardiovascular disease is unclear, especially in older persons, who have an increased risk.

To evaluate this issue, these researchers enrolled 19,114 community dwelling healthy men and women in Australia and the US. Half were assigned to receive aspirin and the other half placebo. At a median follow-up of 4.7 years the rate of cardiovascular disease was 10.7 events per 1,000 person years in the aspirin group and 11.3 events in the placebo cohort. The rate of major haemorrhage was significantly worse in the aspirin group (hazard ratio 1.38).

It was concluded that the use of low-dose aspirin as a primary prevention strategy in older adults resulted in a significantly higher risk of major haemorrhage and did not result in a significantly lower risk of cardiovascular disease than placebo. An editorial reviewer noted these results and opined that beyond diet maintenance, exercise and smoking cessation, the best strategy for the use of aspirin in the primary prevention of cardiovascular disease may simply be to prescribe a statin instead.

N Engl J Med 2018; 379:1509–18 & 2018; 379:1572–74

Intramuscular versus intravenous oxytocin to prevent postpartum haemorrhage at vaginal delivery

Postpartum haemorrhage (PPH) is one of the leading causes of maternal mortality worldwide, accounting for nearly a quarter of maternal deaths. This report is of a study to determine whether intravenous oxytocin is more effective than intramuscular oxytocin at preventing postpartum haemorrhage at vaginal delivery.

One thousand and thirty-five pregnant women were included in the study. Half received intramuscular oxytocin and the other half received intravenous oxytocin at vaginal delivery. The incidence of PPH was not significantly lower in the intravenous group. However, the incidence of severe PPH and the need for blood transfusion was significantly lower in the patients receiving the intravenous treatment.

Intravenous oxytocin for the third stage of labour results in less frequent severe PPH, blood transfusion and admission to a high dependency unit than intramuscular oxytocin, and without excess side effects.

BMJ 2018; 362:k3546

Association of dairy intake with cardiovascular disease and mortality in 21 countries fom five continents

Dietary guidelines recommend minimising consumption of whole-fat dairy products, as they are a source of saturated fats and presumed to adversely affect blood lipids and increase cardiovascular disease and mortality. The authors of this paper note that evidence for this contention is sparse.

They enrolled 136,384 individuals aged between 35–70 years from 21 countries in five continents. Dietary intakes of dairy products (milk, yoghurt and cheese) were recorded using validated questionnaires. They further grouped these foods into whole-fat and low-fat dairy. The primary outcome was the composite of mortality or major cardiovascular events (non-fatal myocardial infarction, stroke or heart failure).

The results of this study were that dairy consumption was associated with lower risk of mortality and major cardiovascular disease events in a diverse multinational cohort.

Lancet 2018; 392:2288–97

‍