The duration of beta‐blocker therapy and outcomes in patients without heart failure or left ventricular systolic dysfunction after acute myocardial infarction: A multicenter prospective cohort study

The duration of beta-blocker therapy in patients without heart failure (HF) or left ventricular systolic dysfunction after acute myocardial infarction (AMI) is unclear.Continuous beta-blocker therapy is associated with an improved prognosis.This is a prospective, multicenter, cohort study. One thousand four hundred and eighty-three patients eventually met the inclusion criteria. The study groups included the continuous beta-blocker therapy group (lasted ≥6 months) and the discontinuous beta-blocker therapy group (consisting of the no-beta-blocker therapy group and the beta-blocker therapy <6 months group). The inverse probability treatment weighting was used to control confounding factors. The study tried to learn the role of continuous beta-blocker therapy on outcomes. The median duration of follow-up was 13.0 months. The primary outcomes were cardiac death and major adverse cardiovascular events (MACE). The secondary outcomes were all-cause death, stroke, unstable angina, rehospitalization for HF, and recurrent myocardial infarction (MI).Compared with discontinuous beta-blocker therapy, continuous beta-blocker therapy was associated with a reduced risk of unstable angina, recurrent MI, and MACE (hazard ratio [HR]: 0.51; 95% CI: 0.32-0.82; p = 0.006); but this association was not available for cardiac death (HR: 0.57; 95% CI: 0.24-1.36; p = 0.206). When compared to the subgroups of no-beta-blocker therapy and beta-blocker therapy <6 months, respectively, continuous beta-blocker therapy was still observed to be associated with a reduced risk of unstable angina, recurrent MI, and MACE.Continuous beta-blocker therapy was associated with a reduced risk of unstable angina or recurrent MI or MACE in patients without HF or left ventricular systolic dysfunction after AMI.