Discontinuation of Beta-Blocker Therapy after Myocardial Infarction

BACKGROUND: The role of long-term beta-blocker therapy after a myocardial infarction in patients without left ventricular systolic dysfunction or heart failure is unclear in the era of contemporary coronary-artery reperfusion and secondary prevention interventions. METHODS: We conducted an open-label, randomized, noninferiority trial at 25 centers in South Korea. Patients whose condition remained stable after a myocardial infarction, who had a left ventricular ejection fraction of at least 40% and no heart failure, and who had received beta-blocker therapy for at least 1 year after the myocardial infarction were randomly assigned in a 1:1 ratio to discontinue or to continue beta-blocker therapy. The primary end point was a composite of death from any cause, recurrent myocardial infarction, or hospitalization for heart failure. The prespecified noninferiority margin was an upper limit of the 95% confidence interval for the hazard ratio of 1.4. RESULTS: A total of 2540 patients underwent randomization; 1246 were assigned to beta-blocker discontinuation and 1294 to beta-blocker continuation. The mean age of the patients was 63.2 years, and 12.8% were women. At a median follow-up of 3.1 years (interquartile range, 2.5 to 3.5), a primary end-point event had occurred in 58 patients (4-year Kaplan-Meier estimate, 7.2%) in the discontinuation group and in 74 patients (4-year Kaplan-Meier estimate, 9.0%) in the continuation group (hazard ratio, 0.80; 95% confidence interval, 0.57 to 1.13; P = 0.001 for noninferiority). The incidence of serious adverse events was similar in the two groups. CONCLUSIONS: Among patients who received beta-blocker therapy beyond the first year after a myocardial infarction, discontinuation of beta-blocker therapy was noninferior to continuation with respect to a composite of death from any cause, recurrent myocardial infarction, or hospitalization for heart failure. (Funded by Patient-Centered Clinical Research Coordinating Center in the Ministry of Health and Welfare, South Korea; SMART-DECISION ClinicalTrials.gov number, NCT04769362.).