Survival, ventricular arrhythmia, and implantable cardioverter‐defibrillator usefulness in toxic cardiomyopathy due to substance abuse

Abstract

AbstractBackgroundToxic dilated cardiomyopathy (T‐DCM) due to substance abuse is now recognized as a potential cause of severe left ventricular dysfunction. The burden of ventricular arrhythmias (VA) and the role of a prophylactic implantable cardioverter‐defibrillator (ICD) are not well documented in this population. We aim to assess the usefulness of ICD implantation in a T‐DCM cohort.MethodsPatients younger than 65 years with a left ventricular ejection fraction (LVEF) < 35% followed at a tertiary center heart failure (HF) clinic between January 2003 and August 2019 were screened for inclusion. The diagnosis of T‐DCM was confirmed after excluding other etiologies, and substance abuse was established according to the DSM‐5 criteria. The composite primary endpoints were arrhythmic syncope, sudden cardiac death (SCD), or death of unknown cause. The secondary endpoints were the occurrence of sustained VA and/or appropriate therapies in ICD carriers.ResultsThirty‐eight patients were identified, and an ICD was implanted in 19 (50%) of these patients, only one for secondary prevention. The primary outcome was similar between the two groups (ICD vs. non‐ICD; p = 1.00). After a mean follow‐up of 33 ± 36 months, only two VA episodes were reported in the ICD group. Three patients received inappropriate ICD therapies. One ICD implantation was complicated with cardiac tamponade. Twenty‐three patients (61%) had an LVEF ≥35% at 12 months.ConclusionVA are infrequent in the T‐DCM population. The prophylactic ICD benefit was not observed in our cohort. The ideal timing for potential prophylactic ICD implantation in this population needs further studies.