The use of beta-blockers in managing adverse cardiovascular outcomes in coronary artery disease (CAD) has been supported by evidence from early clinical trials. Studies showed reductions in all-cause and cardiovascular mortality in patients with acute myocardial infarction. However, there is limited randomized trial data on the cardiovascular benefits of beta-blockers in stable CAD, apart from angina relief. The REACH study and other registry studies have failed to demonstrate significant reductions in cardiovascular events, associated with beta-blocker use in stable CAD patients. These studies often included patients with prevalent beta-blocker use and had varying definitions of CAD. Despite the lack of strong evidence, beta-blockers are still widely used in over 70% of stable CAD patients. This reflects the uncertainty and persistence of treatment habits.
In a recent study from Ontario, Canada, the association between recently initiated beta-blocker therapy and long-term cardiovascular events was examined in stable CAD patients. Patients were without heart failure or recent myocardial infarction. Importantly, this study examined the association between beta-blocker use and cardiovascular events in patients with stable coronary artery disease (CAD). It included over 28,000 patients aged >66 years with obstructive CAD who underwent elective coronary angiography in Ontario, Canada. Patients were included between 2009 to 2019. The analysis focused on patients without heart failure or recent myocardial infarction and used inverse probability of treatment weighting to address confounding.
Newly prescribed beta-blockers associated with reduced cardiovascular events
Among the 28,039 patients included the mean age was 73.0 years and 66.2% were male. Furthermore, 12,695 of those patients (45.3%) were prescribed beta-blockers for the first time. Interestingly, results showed that newly prescribed beta-blockers were associated with a small but significant reduction in cardiovascular events at 5 years. The primary outcome at 5 years was 14.3% in the beta-blocker group and 16.1% in the no beta-blocker group. Whereby, absolute risk reduction was 1.8% (95% CI: 2.8-0.8) with a hazard ratio of 0.92 (95% CI: 0.86-0.98; p=0.006). This reduction was primarily driven by a decrease in hospitalizations for myocardial infarction. Meanwhile, no differences were observed in all-cause death or heart failure hospitalization.
The authors conclude that beta-blockers provide a beneficial effect in reducing cardiovascular events in patients with angiographically confirmed stable CAD without heart failure or recent myocardial infarction. Furthermore, randomized trials are needed to further confirm the cardiovascular benefits of beta-blockers in the modern era. Learn more about the study in an animation video.
Original article: Godoy LC et al. J Am Coll Cardiol. 2023 Jun 20;81(24):2299-2311.