Impact of Improved Left Ventricular Systolic Function on the Recurrence of Ventricular Arrhythmia in Heart Failure Patients With an Implantable Cardioverter-Defibrillator.

Introduction: Data are lacking on the relationship between improved left ventricular ejection fraction (LVEF) and the incidence of ventricular arrhythmia in patients with an implantable cardioverter-defibrillator (ICD) for secondary prevention. The aim of this study was to evaluate the incidence and predictors of improvement in left ventricular (LV) function and determine the impact of improved LVEF on the occurrence of appropriate ICD therapy in patients with reduced LVEF and ICD for secondary prevention.

Methods: In this study, 93 patients who received ICDs for secondary prevention, had an LVEF of < 45%, and underwent echocardiographic follow-up assessment after receiving an ICD were enrolled.

Results: The mean patient age was 56.9 ± 13.1 years, the median time of repeat LVEF assessment was 19.7 (10.4-29.7) months, and the mean LVEF was 30.6 ± 8.5%. Of the patients, 58 (62.4%) had nonischemic cardiomyopathy. LV function improved after ICD implantation in 24 (25.8%) of 93 patients. Multivariable logistic regression revealed a short duration from the time of diagnosis of heart failure to ICD implantation and the presence of ventricular fibrillation as significant predictors of improved LV function. The incidence of appropriate ICD therapy was lower in the patients with than in those without LV function improvement. The composite endpoint of all-cause mortality or heart transplant was lower in the patients with than in those without LV function improvement.

Conclusion: Overall survival was better and the recurrence of ventricular arrhythmia was lower in the patients with improved LV function.