BackgroundHypertrophic cardiomyopathy is a heterogeneous disease in which an implantable cardioverter defibrillator (ICD) effectively prevents sudden cardiac death in at-risk individuals. Nevertheless, the cost-effectiveness of ICDs in this specific patient group has not been evaluated. MethodsA Markov cohort model was constructed to simulate the course of identified adult persons with hypertrophic cardiomyopathy with and without an ICD over the course of 12 years based on Swedish disease-specific unit costs. The age distribution was based on empirical data from the nationwide cohort of HCM patients with ICDs (mean age at the time of implant was 51.8 years). The outcomes were costs per saved life and cost per gained quality adjusted life year (QALY). ResultsOf 1000 simulated patients, 402 lives were saved after 12 years with an ICD at a cost of 646,000 Swedish krona (SEK), which corresponds to 57,118 Euro per saved life from the health care sector viewpoint. The cost per gained QALY (the incremental cost effectiveness ratio (ICER)) was 171,000 SEK (15,119 Euro). From a societal viewpoint, including effects on productivity losses, the use of an ICD was absolutely dominant (both cheaper and better, and thus an ICER is of no interest). Both the one-way sensitivity analyses and the probabilistic sensitivity analyses supported the findings in the base option. ConclusionFor identified patients with hypertrophic cardiomyopathy deemed at high risk of sudden cardiac death, the use of an ICD is extremely cost effective, both in terms of the cost for saved lives and gained QALY.