Heart rate prediction of outcome in heart failure following myocardial infarction depend on heart rhythm status an analysis from the high-risk myocardial infarction database initiative

Abstract Background Heart rate has been reported to be associated with adverse outcome in heart failure (HF) and myocardial infarction (MI), but conflicting evidence exists regarding its impact in patients with associated atrial fibrillation (AF). Objectives We investigated the differential impact of heart rate on clinical outcomes according to the presence or absence of AF in patients with reduced systolic function and/or HF after MI. Methods We studied the association of heart rate with outcome using Cox-models in a merged dataset ( n =28,771) of four randomized trials (CAPRICORN, EPHESUS, OPTIMAAL, and VALIANT). Results At baseline, 3736 (13%) patients had AF. We identified a significant interaction between AF and heart rate, and a decreasing effect of heart rate with time, heart rate being less associated with outcome after 1year of follow-up (both p for interaction p p =0.0007), CV-mortality (1.12 [1.03 to 1.22], p =0.006), and HF-hospitalisation (1.16 [1.07 to 1.26], p =0.0006, p for interaction with AF Conclusions In patients with reduced systolic function and/or HF post-MI, higher heart rate predicts increased major cardiovascular events during the first year following MI in patients without AF. This association is markedly attenuated in subjects with AF.