CLINICAL QUESTION: Does therapy with a beta-blocker reduce mortality and myocardial infarction (MI) in patients with a recent myocardial infarction with preserved ejection fraction?
BACKGROUND: The effects of beta-blockers in patients with MI with reduced ejection fraction are well documented. However, the relevance of routine long-term beta-blocker therapy in patients with preserved left ventricular ejection fraction has become uncertain. Early coronary revascularization, statins, antiplatelet therapy, and renin-angiotensin system inhibitors have substantially lowered post-MI mortality and may have attenuated the incremental benefit of beta-blockers in this population. Despite this uncertainty, current guidelines continue to recommend beta-blockers for most patients after MI. The data on patients with preserved ejection fraction are lacking.
STUDY DESIGN: Multicenter parallel-group, open-label trial (REDUCE-AMI)
SETTING: 45 centers across Sweden, Estonia, and New Zealand
SYNOPSIS: 5,020 patients with recent (less than seven days) MI were enrolled up to 2023, all with preserved ejection fraction (greater than 50%), and were randomized to receive either beta-blocker treatment (metoprolol or bisoprolol) or no beta-blocker treatment. Median follow-up was 3.5 years (median age 65), and the prevalence of comorbidities was similar. The majority had one-vessel disease and were treated with percutaneous coronary intervention. The composite primary endpoint was death from any cause or new MI. This endpoint occurred in 7.9% of the patients in the beta-blocker group compared to 8.3% in the control group (HR, 0.96; 95% CI, 0.79 to 1.16, P=0.64). There were also no significant differences in secondary outcomes, including hospitalization for heart failure or cardiovascular death. Safety outcomes, such as bradycardia or asthma exacerbations, were similar between groups.
BOTTOM LINE: Beta-blocker treatment after an acute myocardial infarction in patients with a preserved left ventricular ejection fraction did not lead to a lower cumulative incidence of death from any cause or new myocardial infarction.
CITATION: Yndigegn T, et al. Beta-blockers after myocardial infarction and preserved ejection fraction. N Engl J Med. 2024;390(15):1372-1381. doi: 10.1056/NEJMoa2401479.
Dr. Gauto is a hospitalist in the department of clinical medicine at Hospital Aleman and an instructor of internal medicine at the University of Salvador, both in Buenos Aires, Argentina.