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 β-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 β-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 β-blocker therapy compared to no β-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 β-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 β-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 β-blockers following MI in patients without reduced LVEF. EudraCT number 2018-000590-75.