BEtablocker Treatment After acute Myocardial Infarction in revascularized patients without reduced left ventricular ejection fraction (BETAMI): Rationale and design of a prospective, randomized, open, blinded end point study

Background Current guidelines on the use of beta-blockers in post-acute myocardial infarction (MI) patients without reduced left ventricular ejection fraction (LVEF) are based on studies before the implementation of modern reperfusion and secondary prevention therapies. It remains unknown whether beta-blockers will reduce mortality and recurrent MI in contemporary revascularized post-MI patients without reduced LVEF. Design BETAMI is a prospective, randomized, open, blinded end point multicenter study in 10,000 MI patients designed to test the superiority of oral beta-blocker therapy compared to no beta-blocker therapy. Patients with LVEF >= 40% following treatment with percutaneous coronary intervention or thrombolysis and/or no clinical signs of heart failure are eligible to participate. The primary end point is a composite of all-cause mortality or recurrent MI obtained from national registries over a mean follow-up period of 3 years. Safety end points include rates of nonfatal MI, all-cause mortality, ventricular arrhythmias, and hospitalizations for heart failure obtained from hospital medical records 30 days after randomization, and from national registries after 6 and 18 months. Key secondary end points include recurrent MI, heart failure, cardiovascular and all-cause mortality, and clinical outcomes linked to beta-blocker therapy including drug adherence, adverse effects, cardiovascular risk factors, psychosocial factors, and health economy. Statistical analyses will be conducted according to the intention-to-treat principle. A prespecified per-protocol analysis (patients truly on beta-blockers or not) will also be conducted. Conclusions The results from the BETAMI trial may have the potential of changing current clinical practice for treatment with beta-blockers following MI in patients without reduced LVEF.