Comparison of the effects of losartan and captopril on mortality in patients after acute myocardial infarction: the OPTIMAAL trial design. Optimal Therapy in Myocardial Infarction with the Angiotensin II Antagonist Losartan.

Patients with acute myocardial infarction and evidence of heart failure or left ventricular dysfunction during the acute phase have an excessive mortality risk. Therapy with angiotensin-converting enzyme inhibitors attenuates the detrimental effects of angiotensin II and has been shown to substantially reduce morbidity and mortality in this population. Selective, angiotensin type 1 receptor antagonism with losartan, which inhibits the effects of angiotensin II regardless of its source at the receptor level, may provide more complete blockade of the renin-angiotensin system. The Optimal Therapy in Myocardial Infarction with the Angiotensin II Antagonist Losartan (OPTIMAAL) study is a multicenter, double-blind, randomized, parallel, captopril-controlled trial. The primary hypothesis is that, compared with captopril, losartan will decrease the risk for all-cause mortality by 20% in high-risk patients after acute myocardial infarction. The study population will consist of 5,000 patients, > or = 50 years of age, with heart failure during the acute phase or with a new Q-wave anterior infarction or reinfarction. Patients will be randomized to treatment with either losartan or captopril. All patients will be followed until 937 deaths occur (event-driven). The primary end point is total mortality (all-cause mortality). The secondary and tertiary end points are sudden death (and/or resuscitated cardiac death) and fatal/nonfatal reinfarction. Based on the assumed event rate, treatment effect and a 95% power to detect a 20% reduction in all-cause mortality at the 4.3% significance level (2-sided, adjusted for 2 interim analyses), the trial will enroll at least 5,004 patients and continue until a total number of 937 events has been reached (intention-to-treat analysis).