Temporal trends in sudden cardiac death after acute decompensation in HFrEF patients: a 13-year Japanese multicentre registry study

Abstract Background The implementation of guideline-based medical therapy (GBMT) for heart failure with reduced ejection fraction (HFrEF) has significantly contributed to reducing mortality risks. Yet, detailed analyses on temporal trends of sudden cardiac death (SCD) among these patients, especially post-discharge following acute decompensation, remain scarce. Purpose This study aimed to explore changes in the incidence of SCD over the last 13 years in patients with HFrEF discharged after acute decompensation treatment, and to identify clinical factors associated with SCD risk. Methods We analyzed 2,604 consecutive HFrEF (left ventricular ejection fraction [LVEF] ≤40%) patients enrolled in a Japanese multicentre acute heart failure (HF) registry from 2009 to 2021. SCD was defined as an unexpected and otherwise unexplained death in a previously stable patient or death due to documented or presumed cardiac arrhythmia without a clear non-cardiovascular cause. The determination of death cause (SCD, pump failure death, or other) was made by a central adjudicating committee. The Fine and Gray method was employed to analyze factors associated with SCD. The variables submitted to the model included age (≥70 years), gender, LVEF (<30%), ischaemic aetiology and prescription of GBMT (use of renin-angiotensin system inhibitors, β-blockers and mineralocorticoid receptor antagonist) at discharge. Results The mean age of studied patients was 70.9±14.2 years, and 70.0% were male. During the 1-year follow-up period, 262 deaths (10.1%) occurred, including 51 SCDs (2.0%). Older age was associated with an increased risk of SCD (adjusted hazard ratio [HR] 2.81, 95% confidence interval [CI] 1.40-5.64, P=0.004). Further, patients with an ischaemic aetiology had a higher risk of SCD (HR 1.84, 95% CI 1.06-3.22, P=0.032). During the study period, mean age remained constant (71.0 years to 70.7 years, P for trend =0.884). The proportion of ischaemic aetiology also remained constant (from 37.2% to 38.2%, P for trend =0.972). Overall, there were significant decreases in the incidence of all cause death and SCD (from 13.7% to 8.4%, P for trend =0.002; and from 3.5% to 1.0%, P for trend <0.001; Figure A). Notably, there was an increase in the prescription rate of three classes of GBMT at discharge (from 30.9% to 45.6%, P for trend <0.001; Figure B), and the rate of implantable cardioverter-defibrillator (ICD) use in eligible patients (New York Heart Association functional class II-III with LVEF ≤35%) remained constant (from 9.6% to 11.6%, P for trend =0.157; Figure B). Conclusions With the increasing use of GBMT, the incidence of SCD decreased in real-world patients with HFrEF registered in a Japanese acute HF registry over the past decade.