Abstract 245: Economic Evaluation of the Wearable Cardioverter-Defibrillator in Patients After ICD Explantation

Abstract

Introduction Device infection and lead failure are severe complications in implantable cardioverter defibrillator (ICD) recipients. The standard of care includes aggressive antibiotic therapy and in many cases ICD system removal, leaving patients unprotected from sudden cardiac death (SCD). Studies have demonstrated that the wearable cardioverter defibrillator (WCD) is effective in bridging patients while infections are resolved and they can have their devices re-implanted. Hypothesis We sought to evaluate whether WCD is cost-effective in ICD explantation patients. Methods We included all WCD patients whose medical orders indicated an ICD removal. Patients' compliance, shock events, outcomes, and end of use reasons were retrieved from the manufacturer database (ZOLL). Direct and indirect costs other than WCD itself, probabilities of ventricular arrhythmia and mortality were estimated from published articles. The WCD survival rate was calculated as number of saves (remain at home or conscious arrival at the ER) out of the total true shock events. Patients who finished a WCD therapy course were most often re-implanted, with some relying on standard medical therapy only. We used non-WCD patients who utilized the regular emergency medical service (EMS) as the baseline; and computed the incremental cost-effectiveness ratio (ICER) as the difference in costs divided by the difference in lives saved and life-year gained, respectively, within 5 years. Sensitivity analyses were performed to assess how the two ICERs responded as the values of variables changed. All monetary cost was converted to 2010 dollars at a 3% discount rate. Results A total of 3,021 patients used a WCD after an ICD explantation. The mean length of use was 45.4±58.3 days, with an average daily use of 20.35±5.8 hours (85% of the day, median=21 hours). Among those who had ended use, 56.1% got re-implanted. We estimated the first-month mortality was 2.5 times higher than the subsequent months. The calculated ICERs for WCD were $105,869 per life saved and $27,493 per life-year gained. Sensitivity analysis revealed that the ratios were not sensitive to the percentage of re-implantation. Conclusions The use of WCD is highly cost-effective in protecting ICD explantation patients against SCD.