Background: Benefit of β-blockers (BB) and angiotensin-converting-enzyme inhibitors (ACEI) on mortality following acute myocardial infarction (MI) is well demonstrated. This study assessed the impact of BB and ACEI doses administered following ST-elevation MI on mortality and outcome up to 1 year. METHODS AND RESULTS: The French prospective observational cohort "RIMA" included 1,461 MI patients. Dosing of BB and ACEI given at 24 h and at time of discharge was assessed as follows: no treatment; <50% of target dose; or ≥50% of target dose. For in-hospital mortality, after MI, the use of BB in the first 24 h, but not ACEI, was associated with significantly lower event rate on multivariate analysis (OR, 5.78; 95% CI: 2.62-12.76, P<0.001). In contrast at 1 year, use of higher doses of ACEI, but not BB, was associated with significantly lower CV mortality, readmission for heart failure and the composite of CV mortality and readmission for heart failure (HR, 2.65; 95% CI: 1.32-5.31, P=0.006 for absence of ACEI at discharge).
Conclusions: Prescription of BB in the first 24 h was independently associated with a lower in-hospital mortality following MI. There appeared to be a significant dose effect on outcome with regard to <50% vs. ≥50% of target dose, which requires confirmation in further large-scale clinical studies.