Do beta-blockers still offer protection after MI in patients with preserved ejection fraction in the era of modern reperfusion and revascularization?

A study published in the European Heart Journal evaluated the long-term efficacy of beta-blockers in patients with (MI) and preserved left ventricular ejection fraction (LVEF). The pragmatic, open-label trial enrolled 8,438 patients with type 1 or 2 MI who underwent invasive evaluation and had an LVEF greater than 40%. Patients with prior heart failure (HF) or contraindications to beta-blockers were excluded.

Participants were randomized at hospital discharge to receive beta-blockers or no beta-blocker therapy. During a median follow-up of 3.7 years the primary composite endpoint—death from any cause, reinfarction, or hospitalization for HF—occurred in 316 patients in the beta-blocker group and 307 patients in the control group. 

This difference was not statistically significant (hazard ratio 1.04; 95% CI, 0.89–1.22). 
Secondary outcomes, including all-cause mortality, reinfarction, and hospitalization for HF, were also comparable between groups.

Bisoprolol and metoprolol were the most commonly prescribed beta-blockers. Subgroup analyses suggested possible signals of harm in women and ST-segment elevation myocardial infarction (STEMI) patients, though these findings were not conclusive.

The REBOOT trial findings are consistent with REDUCE-AMI and CAPITAL-RCT, both of which showed no benefit of beta-blockers in post-MI patients with preserved EF. Despite current guideline recommendations, these findings suggest beta-blockers should not be prescribed as routine therapy after uncomplicated MI when LVEF is preserved