Abstract 100: The Wearable Cardioverter Defibrillator Is Cost-Effective in Protecting High-Risk Patients After Acute Myocardial Infarction
Introduction Patients after an acute myocardial infarction (AMI) are at high risk of sudden cardiac death (SCD). According to guidelines, they do not qualify for an implantable cardioverter defibrillator (ICD) until at least 40 days and at least 90 days post bypass surgery or percutaneous coronary intervention (PCI). The wearable cardioverter defibrillator (WCD) has been proven effective in protecting this group against SCD during their waiting period. However, no studies have evaluated the cost-effectiveness of WCD in AMI patients.
Hypothesis We sought to assess our hypothesis that WCD is cost-effective in bridging AMI patients.
Methods All WCD patients with a first diagnosis of AMI, either with or without a bypass surgery or PCI, were retrospectively included in this analysis. Event rate, shock outcome, compliance, and end of use reasons were extracted from the manufacturer database (ZOLL). Published articles and historical data were used to approximate cost, incidence of ventricular arrhythmia and mortality. 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. Data from non-WCD patients who utilized regular emergency medical service (EMS) was used as the baseline. We then 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 for single or paired variables. All monetary cost was converted to 2010 dollars at a 3% discount rate.
Results A total of 6,703 AMI patients wore the device for an average of 47.2±41.2 days. Upon our analysis, 6,046 patients had finished the WCD therapy course, among which 30.7% got an ICD. Assuming a cardiac arrest survival rate of 20% with EMS, the calculated WCD ICER was $161,906 per life saved and $42,808 per life-year gained (ICLYG). The ICER increased in a community with an expected SCA survival rate below the assumed 20% with EMS. For example, if a community's cardiac arrest survival rate was 10%, WCD ICLYG would be $31,887. The ICER is intimately linked to individual's risk of SCD and patients' compliance.
Conclusions WCD is cost-effective in protecting post-AMI patients against sudden death.
- © 2011 by American Heart Association, Inc.