Predictors of recurrence of sudden cardiac arrest in patients treated with an implantable cardioverter defibrillator

Abstract

Introduction. Randomised clinical trials have demonstrated the indispensable role of implantable cardioverter defibrillators in reducing mortality among patients at high risk of sudden cardiac death. This study aimed to assess the incidence and predictors of cardiac arrest recurrence in such patients. Material and Methods. This retrospective study included 240 patients who underwent defibrillator implantation for secondary prevention at the Institute for Cardiovascular Diseases of Vojvodina between 2008 and 2020. The cumulative incidence of recurrence was determined using Kaplan-Meier curves, while Cox regression was used to identify predictors of sudden cardiac arrest recurrence. Results. The median follow-up was 4.46 years, and recurrence of sudden cardiac arrest occurred in 60% (n=144) of patients. Sustained ventricular tachycardia as the indication for implantation was shown to be an independent predictor of recurrence. These patients also had a significantly higher number of hospitalisations during follow-up. Patients diagnosed with channelopathy or arrhythmogenic right ventricular dysplasia had a significantly higher number of hospitalisations than those diagnosed with ischaemic or non-ischaemic cardiomyopathy. Conclusion. The incidence of sudden cardiac arrest recurrence following defibrillator implantation is high across all patient groups, regardless of aetiology. Sustained ventricular tachycardia as the indication for device implantation predicts a higher incidence of cardiac arrest recurrence.