OBJECTIVE: Until recently, primary prevention of sudden cardiac death depended on anti-arrhythmic drugs. The SCD-HeFT Trial confirmed the efficacy of ICD, as all-cause mortality was decreased 23% versus placebo. Estimating lives saved and economic impact of primary prevention of sudden cardiac death with an ICD versus amiodarone in France was the object of this study. METHODS: A discrete event simulation was developed to estimate effects over three years. Identical patients received either device or amiodarone. Post-implantation complications (lead and device-related) or toxicity from amiodarone could arise. Model parameters and risk functions were developed based on SCD-HeFT data, assuming life-threatening arrhythmia rates and other death are not differential. Probability of death given arrhythmia was 90% with amiodarone, 47% with ICD. To avoid ageism inherent in QALYs, the economic value society places on a life (5,697,127€) was derived from a meta-analysis and used in cost-benefit analyses. While estimates of the value of life vary from country to country, this value reflects a recent average for European countries. Costs are reported in 2004 € and discounted at 3%. In total, 100 replications of 1000 identical twin pairs were run. Sensitivity analyses were performed for key input parameters. RESULTS: ICD use in 1000 patients was predicted to prevent 62 premature deaths over three years. Total additional costs accrued were 20,121€ per patient. The cost/benefit ratio was 0.06 which means for every 1€ gained, 0.06€ has to be invested. In 55% of the replications ICD dominates Amiodarone. Investment in ICD is worthwhile whenever society values a life at more than 325,000€. CONCLUSION: ICDs increase immediate costs but their use is consistent with the value of life estimated in Western societies.