Management of unstable angina and myocardial infarction

Sir—John Eikelboom and colleagues (June 3, p 1936) conclude from their meta-analysis that low-molecular-weight heparins offer no clinical benefits over unfractionated heparin in acute coronary syndromes. However, this conclusion runs contrary to the findings of two major randomised controlled trials included in the meta-analysis, Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q-wave Coronary Events Study Group (ESSENCE) and Thrombolysis in Myocardial Infarction 11B Trial (TIMI 11B), which showed a significant reduction in acute cardiac events with enoxaparin compared with unfractionated heparin. The choice of endpoints—death and myocardial infarction—was intended to keep differences in outcome definitions from different studies to a minimum. But recurrent angina and need for revascularisation are important in assessing the long-term effect of therapy. Comparison of triple and double endpoints from ESSENCE at 48 h to 43 days also invalidates Eikelboom and colleagues’ contention that the anxiolytic agents with fewer side-effects than conventional benzodiazepine anxiolytics. Flaws in the methods of drug trials have led to a regrettable stop in the development in BRPAs.