Association of Beta-Blocker Therapy With Cardiovascular Outcomes in Patients With Stable Ischemic Heart Disease

Abstract

BackgroundPrevious studies have failed to show a cardioprotective benefit of beta-blockers in patients with stable coronary artery disease (CAD). ObjectivesThis study sought to determine the association between beta-blockers and cardiovascular events in patients with stable CAD using a new user design. MethodsAll patients aged >66 years undergoing elective coronary angiography in Ontario, Canada, from 2009 to 2019 with diagnosed obstructive CAD were included. Exclusion criteria included heart failure or a recent myocardial infarction, as well as having a beta-blocker prescription claim in the previous year. Beta-blocker use was defined as having at least 1 beta-blocker prescription claim in the 90 days preceding or after the index coronary angiography. The main outcome was a composite of all-cause mortality and hospitalization for heart failure or myocardial infarction. Inverse probability of treatment weighting using the propensity score was used to account for confounding. ResultsThis study included 28,039 patients (mean age: 73.0 ± 5.6 years; 66.2% male), and 12,695 of those (45.3%) were newly prescribed beta-blockers. The 5-year risks of the primary outcome were 14.3% in the beta-blocker group and 16.1% in the no beta-blocker group (absolute risk reduction: −1.8%; 95% CI: −2.8 to −0.8; HR: 0.92; 95% CI: 0.86-0.98; P = 0.006). This result was driven by reductions in myocardial infarction hospitalization (cause-specific HR: 0.87; 95% CI: 0.77-0.99; P = 0.031), whereas no differences were observed in all-cause death or heart failure hospitalization. ConclusionsIn patients with angiographically documented stable CAD without heart failure or a recent myocardial infarction, beta-blockers were associated with a small but significant reduction in cardiovascular events at 5 years.