PO-05-083 ICD THERAPY CHARACTERISTICS IN PATIENTS WITH ARRHYTHMOGENIC RIGHT VENTRICULAR CARDIOMYOPATHY, BRUGADA SYNDROME, AND LONG QT SYNDROME

Abstract

Arrhythmogenic right ventricular cardiomyopathy (ARVC), Brugada syndrome (BrS) and Long QT syndrome (LQTS) are inherited arrhythmia disorders that frequently result in sudden death in young populations. ARVC often presents with monomorphic VT amenable to antitachycardia pacing (ATP) therapy, whereas BrS and LQTS are traditionally characterized by polymorphic VT or torsade de pointes requiring shock therapy. To assess the rates of ATP and shock therapies in a cohort of patients with ARVC, BrS and LQTS. Patients with ICD indications for ARVC, BrS and LQTS from the ALTITUDE database (Boston Scientific, Natick, MA) between 2011-2021 were identified. ATP and shock-free survival rates were calculated by Kaplan-Meier (KM) method and hazard ratios were analyzed by the Cox proportional hazards model. A total of 103 ARVC, 218 BrS, and 509 LQTS patients were identified. Mean age (46.6 ± 17.4) did not differ between groups while LQT had more female (69.2%) compared to ARVC (34%) and BrS (30.7%). Mean follow-up was 3.7 years. A total of 47 (45.6%) ARVC patients, 39 (17.9%) BrS, and 136 (26.7%) LQTS patients received any therapies during the follow-up period. Episodes in ARVC patients were significantly less likely to result in a shock (71/402, 18%) compared to BrS (73/157, 47%) and LQTS (333/581, 57%) (p<0.001). Per 100 patient-years (Figure 1a), ARVC patients had arrhythmia episodes requiring only ATP therapy 4.7 times the frequency of episodes requiring shock therapy (89.0 versus 19.1), whereas BrS and LQTS patients had comparable rates of ATP only vs shocks (10.2 versus 8.8 in BrS and 13.5 vs 18.2 in LQTS). From KM curve analysis, three-year rate of an ATP-only event was 43.0% in ARVC, 10.3% in BrS and 18.0% in LQTS. As compared with ARVC, risk of ATP only events in BrS (HR 0.20, 95% CI 0.12-0.33, p<0.001) and LQTS (HR 0.44, 95% CI 0.30-0.65, p<.0.001) were significantly lower. Three-year rate of events requiring shock therapy was 33.4% in ARVC, 14.5% in BrS and 20.0% in LQTS. As compared with ARVC, risk of a shock in BrS (HR 0.33, 95% CI 0.20-0.54, p<0.001) and LQTS (HR 0.62, 95% CI 0.41-0.93, p=0.020) were also significantly lower. ARVC patients had more ventricular arrhythmia episodes. When therapy was triggered, episodes in ARVC were less likely to be treated with a shock compared to BrS and LQTS. This may help guide programming parameters and device type selection in high-risk individuals with inherited arrhythmia syndromes.