Implantable cardioverter defibrillators: from evidence of trials to clinical practice

A series of landmark randomized trials has validated the role of implantable cardioverter defibrillators (ICDs) not only in the setting of secondary prevention of sudden cardiac death (SCD) but also in the challenging subset of primary prevention of SCD, i.e. for high-risk patients without previous malignant ventricular tachyarrhythmias. Despite definite indications provided by consensus guidelines, the use of ICDs in clinical practice still encounters a series of barriers mainly related to the characteristics of such treatment (a 'rescue' treatment) and its up-front cost, resulting in substantial under-referral and rationing. Cost is Likely to remain a major determinant of full acceptance, and implementation of ICD therapy and the problem of how broadened evidence-based indications for implantation can be translated into routine clinical practice require an analysis of available economic resources and identification of priorities for health care. Economic analysis (cost-effectiveness, cost-utility and cost-benefit estimates) provides the most appropriate tool for weighing ICD costs against likely eventual outcome benefits. A series of data indicate that the use of ICDs in appropriately selected high-risk SCD patients is associated with cost-effectiveness ratios similar to, or better than, other accepted treatments, such as renal dialysis. Improvement in risk stratification for SCD and assessment of the cost-effectiveness profile of ICD treatment in specific subgroups of patients appears to be a crucial step in any attempt to maximize health outcomes in a context of Limited economic resources.