Ventricular arrhythmias and sudden cardiac death in heart failure with mildly reduced or preserved ejection fraction: knowledge gaps

This editorial refers to ‘Investigator-reported ventricular arrhythmias and mortality in heart failure with mildly reduced or preserved ejection fraction’, by J. P. Curtain et al., https://doi.org/10.1093/eurheartj/ehac801. Sudden cardiac death (SCD) is the main mode of death and is responsible for a greater burden of premature death than any individual cancer.1,2 Among patients with heart disease, while the focus has long been on very high risk patients with systolic heart failure, data have shown that SCD was also the leading cause of death in heart failure patients with preserved ejection fraction.3–5 However, specific data regarding the incidence of ventricular arrhythmias (VAs) in this population remain sparse. In this issue of the European Heart Journal, Curtain and colleagues address this knowledge gap by reporting important observations from combined data of four trials conducted in heart failure patients with ejection fraction >40%.6 To summarize the main findings, among a total of 13 609 enrolled patients, VAs (including non-sustained) were reported in 146 (1.1%) patients, giving an incidence rate of 0.3 per 100 person-years. The incidence rate of the composite secondary outcome of VAs or resuscitated cardiac arrest (n = 34) was 0.4 per 100 person-years. N-terminal probrain natriuretic peptide (NT-proBNP), history of atrial arrhythmia, male sex, and hypertension were all associated with an increased risk of VAs. Of note, the incidence of VAs was twice as high in patients with mildly reduced ejection fraction (41–49%) compared with patients with preserved ejection fraction (≥50%). The authors also observed that overall mortality, cardiovascular death, and death from heart failure were higher in patients with reported VAs, whereas no association was identified with SCD.