Implantable Cardioverter Defibrillators in Patients with Continuous Flow Left Ventricular Assist Devices: Utilization Patterns, Shock Therapies and Complications.

Abstract

Background The use of implantable cardioverter defibrillators (ICDs) in patients with continuous flow left ventricular assist devices (LVADs) has not been evaluated in randomized clinical trials and the observational data published so far is controversial. To our knowledge, the burden of ICD related procedures after LVAD has not been previously described. Methods This is a retrospective single center study that included patients who underwent continuous flow LVAD implantation at the Cleveland Clinic between October 2004 and March 2017. Patients were grouped according to the presence or absence of ICD at the time of LVAD insertion. Outcomes after LVAD insertion were assessed including revisions of existing and subsequent implantation of ICDs. Results There were 486 patients in the study cohort; of those, 387 (79.6%) had an ICD prior to LVAD insertion. Patients with ICD prior to LVAD were older and had lower use of inotropes, extracorporeal membrane oxygenation, and mechanical ventilation before LVAD. There were 4 patients with leads cut or removed during LVAD, and 12 that had post-operative lead dysfunction due to dislodgment. There were 80 patients (21% of patients with ICD) who required 96 procedures after LVAD: 74 generator exchanges because of end of life or technical failure, 15 lead revisions, and 7 complete system removals because of infection. Of the 99 patients without ICD, 52 underwent ICD implantation: 38 for primary prevention and 14 for secondary prevention. Of those 4, had additional procedures: 2 generator changes due to end of life, 1 lead revision, and 1 system extraction due to pseudomonas endocarditis. The median follow ICD data follow up was 227 days in the pre-LVAD ICD group and 390 days in the post LVAD ICD group. There were 115(30%) and 13 (25%) patients that experimented ICD shocks in the pre-LVAD and post-LVAD ICD groups respectively. In both groups approximately 80% were categorized as appropriate.The unadjusted 30-day mortality was 5.2% and 10.1% in patients with and without ICD respectively (p=0.097). Conclusion In this cohort, ICD related procedures are common in patients with continuous flow LVADs and occur in about 1/5th of patients. During LVAD implantation displacement or cut of the ICD lead because of tricuspid valve intervention is not infrequent. More than half of patients without an ICD at baseline had an ICD implanted after LVAD. A substantial proportion of patients experience ICD shocks. The impact of shocks in outcomes remains to be determined.