Oral anticoagulants are effective long term after acute myocardial infarction

Three long-term studies on oral anticoagulation, the Sixty Plus trial, the WARIS study, and the ASPECT trial all meet the methodological requirements for modern stand alone clinical trials: large number of patients, double-blinded, placebo-controlled design, and intention to treat analysis. All demonstrate significant reduction in recurrent myocardial infarction, and all show reduction in the risk of total stroke. The WARIS study, however, is the only study demonstrating efficacy in terms of statistically significant reduction of all-cause mortality. These findings are confirmed by a recent meta-analysis. The overall benefit of oral anticoagulation after myocardial infarction suggests avoidance of 4-26 events per 100 patients treated for 2-3 years. Given the results from the trials applying the most adequate control of anticoagulation, avoidance of 10-14 events per 100 patients treated seems to be a realistic benefit. Provided there is sound management of the anticoagulant therapy, especially employment of suitable control methods, the incidence of bleeding may be kept at a low level.