Lower heart rate in patients with acute heart failure : the role of left ventricular ejection fraction

Background: The clinical impact of heart rate (HR) in heart failure with preserved ejection fraction (HFpEF) is a matter of debate. Among those with HFpEF, chronotropic incompetence (CI) has emerged as a pathophysiological mechanism linked to the severity of the disease. In this study, we sought to evaluate whether admission heart rate in acute heart failure differs along left ventricular ejection fraction (LVEF). Methods: We included retrospectively 3,712 consecutive patients admitted for acute heart failure (AHF) in the Cardiology department of a third level center. HR values were assessed at presentation. LVEF was assessed by transthoracic echocardiogram during the index admission and stratified into four categories: reduced ejection fraction ((Formula presented.) 40%), mildly reduced ejection fraction (41-49%), preserved ejection fraction (50-64%) and supranormal ejection fraction ((Formula presented.) 65%). The association between HR and LVEF was assessed by multivariate linear and multinomial regression analyses. Results: The mean age of the sample was 73,9 ± 11.3 years, 1,734 (47,4%) were women, and 1,214 (33,2%), 570 (15,6%), 1,229 (33,6%) and 648 (17,7%) patients showed LVEF (Formula presented.) 40%, 41-49%, 50-64%, and ≥65% respectively. The median HR at admission was 95 (IQR 78-120) beats per minute and 1,653 were on atrial fibrillation (45.2%). There was an inverse relationship between HR at admission and LVEF. Lower HR was significantly associated with a higher LVEF in the whole sample (p < 0,001). This inverse relationship was found in sinus rhythm but not in patients with atrial fibrillation. Conclusion: HR at admission for AHF is a predictor of LVEF but only in patients with sinus rhythm.