Cost-benefit analysis of primary prevention of sudden cardiac death with an implantable cardioverter defibrillator versus amiodarone in Canada.

BACKGROUND: Clinical trials have shown that implantable cardioverter defibrillators are effective in primary prevention of sudden cardiac death (SCD) in patients with high risk profiles.

OBJECTIVES: To conduct a cost-benefit assessment of prevention of sudden cardiac death with an implantable cardioverter defibrillator (ICD) vs. amiodarone from the Canadian health-care system perspective.

METHODS: A simulation model that estimates the patient's course following an implantation with an ICD or initiation of amiodarone treatment was created. A thousand pairs of patients with identical characteristics in each treatment group, with similar demographic profiles as observed in the Sudden Cardiac Death in Heart Failure Trial (SCD-HeFT) were simulated. Based on the simulated individual patient characteristics, the model estimated the timing of severe arrhythmic events and deaths due to other causes and implemented the consequences at the time of the events. Patients might die at the time of severe arrhythmia (sudden cardiac death) or survive and become secondary prevention cases and be exposed to a higher risk of severe arrhythmia for the following 6 months. The rates of arrhythmia and death due to other causes were assumed to be the same, whereas the cases of fatality from severe arrhythmia differed between treatments. During the course of the simulation, the clinical (i.e., deaths) and economic outcomes were tallied for both treatment groups. All model parameters were obtained from the literature. The primary data source for clinical inputs was the published results of the SCD-HeFT trial which investigated the impact of ICDs on patients' survival in primary prevention of sudden cardiac deaths compared to amiodarone and conventional therapy. The value of a statistical life (CND$ 5.8 million) was obtained from an analysis previously performed by Health Canada. The direct medical costs and monetary value of lives saved were estimated over 5 years. Sensitivity analyses on key parameters were carried out. The most important study limitation was using two different sources to derive the age dependent clinical risks. This issue was resolved by calibrating the derived risks to account for the population differences.

RESULTS: The model predicted that the overall mortality would be reduced by 19.1% (7.1% absolute reduction) with ICD compared to amiodarone over 5 years. The incremental benefit with ICD was estimated at CND$526,700 and additional cost at CND$28,300, which translated into a 0.05 cost: benefit ratio--around 1: 20 return of investment.

CONCLUSION: In Canada, ICDs are a worthwhile alternative to amiodarone in the primary prevention of sudden cardiac death.