Incidence and predictors of early and late sudden cardiac death in hospitalized Japanese patients with new-onset systolic heart failure

Abstract

Background: Patients with heart failure (HF) and low left ventricular ejection fraction (LVEF) are at high risk of sudden cardiac death (SCD). Optimal HF treatment can improve LVEF and reduce the risk of SCD. The aim of this study was to evaluate the incidence and predictors of SCD in Japanese patients with new-onset systolic HF and to investigate factors that affect LVEF improvement. Methods: We retrospectively studied 174 consecutive hospitalized patients with new-onset HF and LVEF ≤35% (median age, 66 years; men, 71%). The primary outcome was a composite of SCD, sustained ventricular arrhythmias, and appropriate implantable cardioverter-defibrillator therapy. Results: The cumulative rates of meeting of the primary outcome at 3, 12, and 36 months after discharge were 3.9%, 8.1%, and 10.5%, respectively. Atrial fibrillation was a significant predictor of the primary outcome within 12 months after discharge (odds ratio, 5.87; 95% confidence interval [CI], 1.60–21.57). Among 104 patients who completed follow-up echocardiography within 12 months after discharge, changes in LVEF were inversely associated with SCD (odds ratio/1% increase, 0.78; 95% CI, 0.65–0.93). A QRS duration <130 ms and a B-type natriuretic peptide level <170 pg/mL were predictors of LVEF improvement to >35% (odds ratio, 3.69; 95% CI, 1.15–11.77; odds ratio, 3.19; 95% CI, 1.33–7.69, respectively). Conclusions: Our results showed a high incidence of meeting of the primary outcome within 12 months after discharge in hospitalized patients with new-onset systolic HF. An improved LVEF may reduce the risk of late SCD.