The BETAMI-DANBLOCK (Beta-Blockers after Myocardial Infarction in Patients without Heart Failure) trial results demonstrated that, in patients with recent type 1 or type 2 myocardial infarction (MI) and left ventricular ejection fraction (LVEF) ≥40%, beta-blocker therapy was associated with reduced mortality and major adverse cardiovascular events (MACE) compared with no beta-blockers.¹ This finding is in contrast to the results of other recent randomized controlled trials, the CAPITAL-RCT (Carvedilol Post-Intervention Long-Term Administration in Large-Scale Randomized Controlled Trial) and REDUCE-AMI (Randomized Evaluation of Decreased Usage of Beta-Blockers After Acute Myocardial Infarction), that failed to demonstrate a positive effect of beta blockade post MI in patients with LVEF >40%.^2,3

The BETAMI (BEtablocker Treatment After Acute Myocardial Infarction in Patients Without Reduced Left Ventricular Systolic Function) and DANBLOCK (Danish Trial of Beta Blocker Treatment After Myocardial Infarction Without Reduced Ejection Fraction) were prospective, randomized, open-label, blinded endpoint evaluation trials with similar designs. The trials encompassed 5,574 patients (2,783 in the beta-blocker group and 2,791 in the no–beta-blocker group) from 44 clinical sites in Denmark and Norway. The primary endpoint of composite of death from any cause or MACE occurred in 394 patients (14.2%) in the beta-blocker group and in 454 patients (16.3%) in the no–beta-blocker group (hazard ratio [HR], 0.85; 95% confidence interval [CI], 0.75-0.98; p = 0.03), amounting to a point estimate for number needed to treat (NNT) of 48. Death from any cause occurred in 4.2% of patients in the beta-blocker group and in 4.4% in the no–beta-blocker group (HR, 0.94; 95% CI, 0.73-1.21). The primary endpoint was mainly driven by a reduction in MI, which occurred in 5% of patients in the beta-blocker group and in 6.7% in the no–beta-blocker group (HR, 0.73; 95% CI, 0.59-0.92), amounting to an NNT of 59. Subgroup analysis suggests that the patients who may derive the most benefit from beta-blocker use include women, those <70 years of age, those with ST-segment elevation MI, and those without pre-existing hypertension, although it was not powered for such analyses.

The trial limitations included an open-label design, combining separate trials with a harmonized primary endpoint due to slow enrollment of the individual trials, low proportion of female participants, and metoprolol succinate 50 mg being predominantly used, which limits generalizability to other beta-blockers and doses.

References

1. Munkhaugen J, Kristensen AMD, Halvorsen S, et al. Beta-blockers after myocardial infarction in patients without heart failure. N Engl J Med. 2025;393(19):1901-1911. doi:10.1056/NEJMoa2505985
2. Watanabe H, Ozasa N, Morimoto T, et al. Long-term use of carvedilol in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention. PLoS One. 2018;13(8):e0199347. Published 2018 Aug 28. doi:10.1371/journal.pone.0199347
3. Yndigegn T, Lindahl B, Mars K, et al. Beta-blockers after myocardial infarction and preserved ejection fraction. N Engl J Med. 2024;390(15):1372-1381. doi:10.1056/NEJMoa2401479