Strength of clinical indication and therapeutic impact of the implantable cardioverter defibrillator in patients with hypertrophic cardiomyopathy

Abstract

Listen

Translate article

BackgroundThe implantable cardioverter defibrillator(ICD) has revolutionized the management of patients with hypertrophic cardiomyopathy (HCM) at risk of sudden cardiac death (SCD). However, the identification of ideal candidates remains challenging. We aimed to describe the long-term impact of the ICD for primary prevention in patients with HCM based on stringent (high SCD risk) vs lenient indications (need for pacing/personal choice). MethodsData from two Italian HCM Cardiomyopathy Units were retrospectively analyzed. Only patients >1 follow-up visits were divided into two groups according to ICD candidacy:stringent (high SCD risk) and lenient (need for pacing, patients' choice, physician advice despite lack of high SCD risk).Major cardiac events (composite of appropriate shock/intervention and SCD) was the primary endpoint. A safety endpoint was defined as a composite of inappropriate shocks and device-related complications. ResultsOf 2009 patients, 252(12.5%) received an ICD, including 27(1.3%) in secondary prevention and 225(11.2%) in primary prevention (age at implantation 49 ± 16 years; men 65.3%). Among those in primary prevention, 167(74.2%) had stringent, while 58(25.8%) had lenient indications.At 5 ± 4 years, only stringent ICD patients experienced major cardiac events (2.84%/year, 5-year cumulative incidence: 8.1%, 95%CI [3.5–14.1%]).ICD-related complications were similar across stringent and lenient subgroups. However, patients implanted >60 years had a significantly higher risk of adverse events. ConclusionOne third of ICD recipients with HCM in primary prevention received a lenient implantation and had no appropriate intervention. ICD implantation due to systematic upgrade in patients requiring pacing and increased risk perception may offer little advantage and increase complication rates.