Importance of baseline heart rate as a predictor of cardiac functional recovery in newly diagnosed heart failure with reduced ejection fraction

Background Left ventricular ejection fraction (LVEF) has shown to predict outcomes in patients with heart failure (HF). Left ventricular recovery (LVR) has shown to improve prognosis. Hypothesis. Guideline‐directed medical therapy will predict LVR in patients with HF and reduced LVEF. Methods We studied 244 patients with newly diagnosed HF and an LVEF ≤35%. LVR was defined as an increase in LVEF ≥40%. Patients who experienced LVR were compared with those who had persistent left ventricular dysfunction. Results Population characteristics included ischemic etiology, 38.1%; baseline LVEF, 23% ±6%; and mean baseline heart rate (HR), 75 ±13 bpm. Guideline‐directed medical therapy was achieved as follows: angiotensin‐converting enzyme inhibitors, 74.3%; β‐blockers (BB), 95.4%; target dosing of angiotensin‐converting enzyme inhibitors, 33.7%; target dosing of BB, 40.2%. LVR occurred in 154/244 patients (63.1%). By multivariable analysis, baseline HR ≤70 bpm was the only independent predictor of LVR (odds ratio: 3.39, 95% confidence interval: 1.5–7.5, P  = 0.003). Target dosing of BB therapy was predictive of LVR only in the univariate analysis (odds ratio: 1.9, 95% confidence interval: 1.1–3.4, P  = 0.03). Furthermore, the composite endpoint of HF hospitalization or mortality occurred less frequently in those who did vs those who did not achieve target BB doses (5.4% vs 16.7%, respectively; P  = 0.023). Conclusions The novel findings of our analysis reveal that the only predictor of LVR in this study was a low baseline HR. Early modulation of HR in newly diagnosed HF patients may increase the rates of LVR.