Risk of ventricular arrhythmias and relapse of systolic dysfunction in patients with heart failure with improved left ventricular ejection fraction: results of long-term follow-up

Aim. To assess the long-term risk of life-threatening ventricular arrhythmias and recurrent systolic dysfunction in patients with chronic heart failure (CHF) and improved left ventricular ejection fraction (LVEF) following implantation of implantable cardioverter-defibrillators (ICD) or cardiac resynchronization therapy defibrillators (CRT-D) for primary prevention of sudden cardiac death (SCD), and to identify factors associated with these outcomes.

Methods. The study represents a continuation of the analysis of a previously described single-center retrospective cohort of patients with CHF and improved LVEF who had undergone ICD or CRT-D implantation for primary prevention of SCD. The study included 87 patients: 34 with ICDs and 53 with CRT-D. In contrast to the previously published work, which focused on survival, inappropriate electrical therapy, and complications related to implanted devices, the primary endpoint of the present study was the development of sustained ventricular arrhythmia terminated by ICD/CRT-D therapy (arrhythmic composite endpoint - ACE), while the secondary endpoint was relapse to an LVEF ≤35%.

Results. Duration follow-up after study inclusion was 5.2±2.8 years, and the total duration after device implantation was 8.3 ± 3.6 years. ACE was observed in 7.1% (n=6) of patients, and in 4.8% of those with persistently improved LVEF. Recurrent reduction in LVEF to ≤35% occurred in 24.4% (n=20) of patients and was associated with higher all-cause mortality (35.0% vs. 5.0%), presence of atrial fibrillation, more pronounced baseline left ventricular remodeling.

Conclusion. While a significantly reduced risk of life-threatening arrhythmias is observed upon improvement in LVEF, a certain risk of recurrent progression of systolic dysfunction persists. Despite the retrospective design and limited sample size, these results underscore the need for an individualized management approach for this patient category and provide a basis for planning further prospective studies in this field.

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