Primary prevention ICD generator at end of life: to replace or not to replace?

Abstract

Implantable cardioverter-defibrillators (ICDs) are the cornerstone of therapy for primary prevention of sudden cardiac death in patients with severely depressed left ventricular ejection fraction (EF) ≤35%, irrespective of the aetiology.1–3 Current device guidelines and appropriate use criteria lay profound emphasis on the baseline left ventricular EF and New York Heart Association functional class in selecting appropriate candidates for primary prevention ICD implantation.4 5 However, these society guidelines do not provide guidance regarding a decision about replacing ICD generators, especially in patients who have not had any appropriate ICD therapies during the lifespan of the device and/or in whom the left ventricular EF improves to >35% at the time of reimplantation. Prior studies have shown that among primary prevention ICD recipients, about 75% do not experience any appropriate ICD therapies during the lifetime of their first ICD generator6 7 and about 25%–40% have improvements in their left ventricular EF >35% after ICD implantation.7–12 Furthermore, patients requiring generator replacements are older and have significantly greater comorbidities compared with the initial recipients.6 13 14 A significant proportion of ICD-related procedures in the USA, approximately 40%, involve ICD generator replacement based on the National Cardiovascular Data Registry data.6 Device replacements are associated with substantial healthcare costs and greater risk of major complications compared with initial implant.15 16 This raises a critical question as to whether the risk of sudden cardiac death warrants ICD generator replacement in patients who have not had any prior appropriate ICD therapies. Does improvement in left ventricular EF >35% lower the risk of sudden cardiac death negating the potential benefits of ICD? In this issue of the Journal , Looi et al 17 report their single-centre outcomes in patients with heart failure after primary prevention ICD generator replacement. …