B-po04-026 non-selective versus β1-selective beta-blockers in the treatment of symptomatic children with catecholaminergic polymorphic ventricular tachycardia

Symptomatic children with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for arrhythmic events (AEs). Beta-blockers (BBs) decrease this risk, but studies comparing non-selective and β1-selective BBs are scarce. To assess the difference in risk for AE between non-selective and β1-selective BBs in a large cohort of symptomatic children with CPVT. Children with CPVT treated with BBs after a syncope or sudden cardiac arrest from two multicenter cohort studies (International CPVT Registry and PACES Pediatric CPVT Registry) were included. A Cox-regression analysis with time-dependent covariates for BB and confounders (flecainide and ICD) was used to compare the risk of an AE, defined as sudden cardiac death, sudden cardiac arrest, appropriate ICD shock, or syncope, between patients using non-selective and β1-selective BBs. We included 329 patients (median age at diagnosis: 12 [7-15] years; 35% female; median follow-up: 6.6 [2.8-12.5] years). A total of 217 (66.0%) patients used a non-selective BB (nadolol or propranolol) as first BB and 112 (34.0%) a β1-selective BB (atenolol, bisoprolol or metoprolol). Baseline characteristics of both groups were similar. Ninety-nine (30.1%) patients experienced an AE during follow-up. AE rates differed significantly between non-selective and β1-selective BBs (Figure, p=0.002). The hazard ratio (HR) of AE was significantly higher for β1-selective compared to non-selective BBs (HR 1.94, 95% CI: 1.24-3.02; p=0.004). In symptomatic children with CPVT, β1-selective BBs were associated with a higher risk for AE compared to non-selective BBs.