Evaluation of Trials of Antithrombotic Agents in Acute Myocardial Infarction

Forty randomized control trials dealing with antithrombotic therapy in the treatment and secondary prevention of myocardial infarction were evaluated for quality of trial design, implementation and analysis. To reduce bias, methods sections were differentially xeroxed before evaluation. Two quality scores were obtained: 1) one reflects the authors’ description of patients and treatments; blinding of randomization and of patients, physicians and observers; measurements of efficacy of randomization, blinding, and compliance; and prior estimate of appropriate sample sizes. 2) The other reflects appropriateness and adequacy of statistical analysis. Hiqher quality scores were obtained by large multi-centered trials (P=.03); those with credit given to a biostatistician (P=.02); and those done recently (P=.04). Decrease in control CFR was found across time (P=.03). Results obtained for anticoagulant treatment showed 8 of the 11 trials with reduction in CFR, 2 with no difference and one with an increase in CFR. 5 of the 10 trials of fibrinolyses were positive. 5 of 9 secondary anticoagulant trials were positive. Two large trials with a trend in favor of aspirin plus a positive sulfinpyrazone (P<.02) trial suggest that antiplatelet agents may be prophylactic. No association between above results and the quality score of the trials was found. This study indicates that anticoagulants but not fibrinolysins reduce acute mortality, and antiplatelet agents are potentially useful in prophylaxis.