Angiotensin-converting enzyme inhibitors (ACEi) and angiotensin receptor blockers (ARB) are effective in the long-term treatment of myocardial infarction with reduced left ventricular ejection fraction (LVEF). However, it is unknown whether there is a benefit in myocardial infarction with preserved LVEF (≥50%). We used Swedish healthcare registries to emulate a target trial of ACEi/ARBs vs. no ACEi/ARBs for the prevention of a composite outcome (death, myocardial infarction, or heart failure) and its individual components among individuals under 75 years with myocardial infarction and LVEF ≥ 50% between September 2010 and June 2021. We estimated observational analogues of the intention-to-treat effect and the per-protocol effect with confounding adjustment via inverse probability weighting. The 10 697 individuals in the ACEi/ARB group were on average older (median 61 vs. 60 years) and more likely to be male (80.2% vs. 75.3% male) than the 4730 individuals in the no ACEi/ARB group. The estimated 5-year risk of the composite outcome was 7.8% (95% confidence interval 7.1%, 8.5%) in the ACEi/ARB group and 8.1% (7.0%, 9.3%) in the no ACEi/ARB group; risk difference -0.3% (-1.6%, 1.0%). After adjustment for adherence, the risk of the composite outcome was 6.5% (5.9%, 7.2%) in the ACEi/ARB group and 6.7% (5.6%, 8.1%) in the no ACEi/ARB group; risk difference -0.2% (-1.7%, 1.0%). The estimated risk of a composite of death, myocardial infarction or heart failure was similar in recipients and non-recipients of ACEi/ARB. Our estimates suggest ACEi/ARB treatment in myocardial infarction with preserved LVEF does not confer a benefit.
Humphreys et al. (Sun,) studied this question.