Incidence, predictors and clinical impact of electrical storm in patients with left ventricular assist devices: new insights from the ASSIST-ICD study

Abstract Background Ventricular arrhythmias (VAs) can occur after continuous-flow left ventricular assist devices(LVAD) implantation, as a single arrhythmic event, or as an electrical storm (ES) with multiple repetitive VAs episodes. Objectives We aimed at analyzing the incidence, predictors and clinical impact of ES in LVAD recipients. Methods Patients analyzed were those included in the multicenter ASSIST-ICD observational study. ES was consensually defined as occurrence of ≥3 separate episodes of sustained VAs within a 24-hour interval. Results Among 652 LVAD patients, 61 (9.4%) presented an ES during a follow-up period of 9.1 (2.5-22.1) months. First ES occurred after 17 (4.0-56.2) days after LVAD implantation, most of them during the first month after the device implantation (62.9%). The incidence then tended to decrease the first years of follow-up and re-increased after the third year post-LVAD implantation. A history of VAs prior to LVAD implantation and heart failure duration > 84 months were independent predictors of ES. The occurrence of ES was associated with an increased early mortality since 20 patients (32.8%) died within the first two weeks after ES. Twenty-two patients (36.1%) presented at least one recurrence of ES, occurring 43.0 (8.0-69.0) days after the initial ES. Patients experiencing ES had a significantly lower 1-year survival compared those free from ES (Log-rank p=0.039). Conclusion There is a significant incidence of ES in LVAD patients. The short-term mortality after ES is high, and one-third of the patients will die within 15 days. Whether radiofrequency ablation of arrhythmias improves outcomes would require further studies.