Abstract 12010: Efficacy and Safety of Dofetilide and Sotalol in Patients With Hypertrophic Cardiomyopathy

Abstract

Introduction: Patients with hypertrophic cardiomyopathy (HCM) often have atrial fibrillation (AF) and ventricular arrhythmias (VA) requiring rhythm control. In the 2014 AF Guidelines, class III anti-arrhythmic drugs are not recommended in patients with left ventricular hypertrophy, but in the 2020 HCM Guidelines, sotalol (STL) and dofetilide (DOF) are deemed “reasonable” for rhythm control, both based on limited data. Methods: We conducted an observational study (2001-2021) of patients with HCM who were treated with DOF or STL for AF and/or VA. Baseline characteristics and drug-related adverse events were analyzed from the electronic medical record, and rates of discontinuation and arrhythmia recurrence at 1 year and by time of chart review were compared using Kaplan Meier curves and log rank test. Results: There were 21 DOF and 52 STL HCM patients with AF, and 18 STL patients with VA. At 1 year, AF patients on DOF or STL had no significant difference in rates of AF recurrence (42.9% vs 44.2%, p=0.664) or drug discontinuation (38.1% vs 29.4%, p=0.582). Recurrence and discontinuation rates of VA on STL were comparable (Figure). Over a median follow up of 1603 days (IQR 994, 4131), there was a trend toward greater efficacy for STL with respect to less AF recurrence (p=0.085) and less frequent discontinuation (p=0.153; Figure). On univariate analysis, only NYHA class predicted AF recurrence. Reasons for discontinuation were most often for inefficacy or mild side-effects. One patient with prior alcohol septal ablation who was on STL for AF developed complete heart block followed by non-sustained torsades de pointes in the setting of a severe influenza infection and later underwent defibrillator implantation. There were no other cases of pro-arrhythmia or sudden death related to DOF. Conclusions: DOF and STL are modestly effective for the treatment of AF and VA in HCM patients, with a low rate of serious adverse events.