In patients with chronic heart failure (HF), the most catastrophic outcome is sudden cardiac death (SCD), particularly in a patient who is otherwise doing relatively well. SCD accounts for up… Click to show full abstract
In patients with chronic heart failure (HF), the most catastrophic outcome is sudden cardiac death (SCD), particularly in a patient who is otherwise doing relatively well. SCD accounts for up to 50% of HF deaths. While there are a variety of etiologies, it is most often a ventricular tachycardia progressing to ventricular fibrillation (VT/VF). Numerous large prospective multicenter studies have demonstrated improved patient survival with primary preventive use of an implantable cardioverter defibrillator (ICD) that in guidelines has been assigned a Class IA indication for ‘‘primary prevention of SCD to reduce total mortality in selected patients with nonischemic [dilated cardiomyopathy] or ischemic heart disease at least 40 days post-MI with [a left ventricular rejection fraction] (LVEF) of 35% or less and NYHA class II or III symptoms on [guideline directed medical therapy], who have a reasonable expectation of meaningful survival for more than 1 year.’’ Yet, in spite of such a strong recommendation, it is widely acknowledged that basing primary prevention ICD use on a LVEF threshold, particularly 35%, is not well supported by clinical experience, or when findings of the randomized studies upon which guidelines are based are examined more closely. With current practice,[80% of primary prevention patients do not use their ICD over a duration of as long as 8 years, with the device costing as high as $235,000 per year of life saved, and with a significant potential for serious device complications. It is clear that a better approach to selecting HF patients for primary prevention ICD implantation is needed.
               
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