Beta-Blockers after myocardial infarction: returning from injured reserve

This editorial refers to ‘Beta-blockers for secondary prevention following myocardial infarction in patients without reduced ejection fraction or heart failure: an updated meta-analysis’, by K.-Y. Chi et al., https://doi.org/10.1093/eurjpc/zwae298. Significant improvements have been made in the management of myocardial infarction (MI) over the past decades, and reasonable questions have arisen on the current benefit of beta-blockers (BB) when early reperfusion preserves left ventricular (LV) function and when modern antiplatelet and lipid-lowering therapies are used. If MI with reduced ejection fraction (EF) is a well-validated indication for BB,1 uncomplicated MI with preserved LV function has become a debated indication for BB.2,3 The open-label, underpowered REDUCE-MI trial which had high cross-over rates could not demonstrate with the superiority of BB introduction during the acute phase of MI in low-risk patients with EF > 50%, as evaluated on death or MI. Thus, neither a benefit nor the absence of a benefit with beta-blocker could be claimed in this MI population.4,5 More recently, the adequately powered ABYSS trial6 randomly assigned 3698 patients to either interruption or continuation of BB on average 2.9 years after an uncomplicated MI with preserved LV function (EF > 40%). A safety signal was observed with BB interruption associated with a significant increase of the primary end-point [hazard ratio (HR) 1.16, 95% CI (1.01–1.33)], consistent across the secondary outcomes, driven by more rehospitalizations for angina or heart failure and, non-inferiority could not be demonstrated vs. BB continuation. Hard end-points and quality of life were not impacted by BB interruption, the latter being the expected benefit for the strategy of interruption.