Benefits of the Implantable Cardioverter-Defibrillator

The state-of-the-art review by Tung and colleagues provides a thoughtful perspective on balancing the benefits and risks of implantable cardioverter-defibrillator (ICD) therapy addressing the concerns of many caring physicians. In this response: 1) the clinical benefits of ICD therapy are reviewed using the evidence base resulting from controlled clinical trials; 2) untoward effects of ICDs on quality of life are acknowledged, and it is argued that they do not negate the results of studies in which the aggregate show benefit; and 3) cost-effectiveness of ICD therapy is considered. Although clinical trials evaluating ICD therapy have limitations, there are few interventions in which multiple trial settings have consistently over a >10-year period produced a 20% to 30% reduction in total mortality. Research to better identify patients expected to benefit from ICD therapy is ongoing, but at present we have the results of clinical trials that show improved survival in a broad selection of patients with left ventricular dysfunction and either demonstrated or anticipated risk for arrhythmic death. Evidence-based medicine; the rigorous process of guideline writing, review, and approval; and the ethical consideration of offering proven life-prolonging therapies to all patients provide a compelling rationale for clinicians to carefully consider guidelines in their clinical decision making. Updates in the new Device-Based Therapy Guidelines for the implantation of ICDs and pacemakers advance these goals.