Beta-blocker therapy was not associated with improved cardiovascular outcomes following myocardial infarction in patients with preserved left ventricular ejection fraction, according to a recent meta-analysis published in JAMA Cardiology. The findings add clarity to an area of ongoing clinical uncertainty as contemporary myocardial infarction management continues to evolve.
Researchers analyzed data from four randomized clinical trials — REDUCE-AMI, CAPITAL-RCT, REBOOT-CNIC, and BETAMI–DANBLOCK — that collectively enrolled nearly 20,000 patients with acute myocardial infarction and preserved left ventricular ejection fraction, defined as 50% or greater. Follow-up ranged from approximately 3.5 to 5 years. Outcomes assessed included all-cause mortality, cardiovascular mortality, recurrent myocardial infarction, heart failure, and unplanned revascularization.
Across the pooled analysis, beta-blocker use was not associated with reductions in all-cause mortality or cardiovascular mortality compared with no beta-blocker therapy. Rates of recurrent myocardial infarction, heart failure, and unplanned revascularization were also similar between treatment groups. These findings were consistent despite differences in trial design, patient populations, and beta-blocker selection.
The results contrast with earlier analyses suggesting benefit from beta-blockers in patients with mildly reduced ejection fraction. According to the researchers, baseline ventricular function appears to be an important determinant of treatment effect. In patients with preserved ejection fraction, the absence of benefit may reflect advances in myocardial infarction care, including early percutaneous coronary intervention and widespread use of evidence-based background therapies such as antiplatelet agents, statins, and renin-angiotensin system inhibitors.
The researchers noted several limitations. The meta-analysis relied on aggregate trial-level data rather than individual patient data, limiting the ability to assess subgroups or time-dependent effects. In addition, the number of eligible trials was modest, and some studies were not specifically designed to evaluate outcomes in patients with an ejection fraction of 50% or greater, raising the possibility of selection bias.
From a clinical standpoint, the findings raise questions about the routine continuation of long-term beta-blocker therapy following myocardial infarction in patients with preserved ejection fraction. Current guidelines recommend early beta-blocker use following myocardial infarction, but the optimal duration of therapy and patient selection remain areas of active investigation. The researchers emphasized the need for future large-scale, targeted studies to better define which patients may still derive benefit and to inform more individualized post–myocardial infarction pharmacologic strategies.
The authors reported no competing interests.
Source: JAMA Cardiology.
