Cost Effectiveness of the Implantable Cardioverter‐Defibrillator: Better in Higher‐Risk Patients and Extended Duration

Abstract

Recent clinical trials have demonstrated the efficacy of implantable cardioverter-defibrillators (ICDs) for preventing arrhythmic death in patients at high risk for this outcome.1 However, the high cost of the ICD and estimates of over 50,000 new candidates for the device each year2 continue to concern clinicians and payors, which has stimulated interest in refining the criteria for patient selection for this form of therapy. The cost effectiveness of ICDs is addressed in a recent analysis of results from the Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II by Zwanziger et al.3 continue to concern clinicians and payors, which has stimulated interest in refining the criteria for patient selection for this form of therapy. The cost effectiveness of ICDs is addressed in a recent analysis of results from the Multicenter Automatic Defibrillator Implantation Trial (MADIT)-II by Zwanziger et al.3 in a detailed study based on clinical outcome and economic data to elucidate this issue. MADIT-II was a randomized trial of ICD compared with conventional medical therapy in patients with a prior myocardial infarction and left ventricular ejection fraction ≤30%.4 No electrophysiologic testing was required. The cost-effectiveness analysis included 1095 US patients with complete data relating to clinical costs. The study group included 664 patients who received an ICD and 431 patients in the medical treatment arm, a distribution that was based on the 3:2 randomization process in the clinical trial. The results demonstrated an all-cause mortality of 21% (n=90) in the medically treated patients and 15% (n=97) in the ICD arm, yielding an estimated hazard ratio (HR) of 0.677. Extensive information was collected for analysis of cost effectiveness, including number of office visits, diagnostic tests and procedures, hospitalizations, emergency department visits, medications, and other health care services. The cost effectiveness of ICD therapy during a 3.5-year interval was $235,000 per year of life saved. However, three alternate projections extrapolated to 12 years of follow-up revealed incremental cost-effectiveness ratios ranging from $78,600 to $114,000. The authors concluded that the estimated cost per year of life saved by ICD therapy in the MADIT-II study was high at 3.5 years, but it was considerably lower based on projections for longer intervals. For a perspective, the authors note that the current National Cholesterol Education Program Adult Treatment Panel III report (NCEP ATP III) guidelines for management of elevated cholesterol are associated with incremental cost-effectiveness ratios of $100,000 per quality-adjusted life year.5 Cost effectiveness in MADIT-II patients was clearly better in the higher-risk patients. The latter group was characterized by age older than 65 years, New York Heart Association (NYHA) class II or higher, electrocardiographic QRS duration ≥120 milliseconds, and blood urea nitrogen >25 mg/mL. Analysis of cost effectiveness is complex and involves multiple factors. As Zwanziger et al.3 note, a major element in the high initial cost of ICD therapy is implantation of the device. Additionally, as would be anticipated, their findings suggest that the incremental cost-effectiveness ratio increases in the higher-risk patients. The significance of this issue is reflected in the estimate by the authors that application of ICD therapy to all patients with MADIT-II criteria in this country would cost more than $5 billion annually. Studies such as this and methods to improve identification of patients most likely to benefit from ICD therapy will further enhance the application of these remarkable devices. In this regard, the utility of T-wave alternans testing for assessment of susceptibility to ventricular arrhythmias in candidates for ICD therapy is awaited with keen anticipation.6