[II-AEPCYIA-1] Atenolol should not be the ß-blocker of choice for symptomatic children with catecholaminergic polymorphic ventricular tachycardia
Introduction
Children with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for malignant ventricular arrhythmias during exercise and emotions, which may lead to arrhythmic events such as sudden cardiac death (SCD). Symptomatic patients are at particular risk for the reoccurrence of arrhythmic events. Beta-blockers are the cornerstone of therapy in patients with CPVT. However, studies comparing the efficacy of different types of betablockers are scarce. We aimed to determine the efficacy of different types of beta-blockers in reducing the risk for recurrent arrhythmic events in a large cohort of symptomatic children with CPVT.
Methods
Data were derived from the International CPVT Registry, a large retrospective observational cohort study. We included symptomatic children aged <19 years who were carrier of a RYR2 variant and who were prescribed a beta-blocker. The primary endpoint was the occurrence of an arrhythmic event (AE), defined as SCD, aborted cardiac arrest, appropriate ICD discharge or syncope. Time-dependent Cox-regression analyses were used to compare the occurrence of AEs between different beta-blockers corrected for possible confounders with nadolol as reference group.
Results
We included 267 children treated with a beta-blocker. One hundred five (39.3%) children were first treated with nadolol, 64 (24.0%) with propranolol, 43 (16.1%) with atenolol, 26 (9.7%) with metoprolol and 21 (7.9%) bisoprolol. Age at initiation of beta-blocker differed between the groups, with the youngest mean age in propranolol and highest in bisoprolol and metoprolol (10±4 years in propranolol, 13±4 years in bisoprolol and nadolol, overall-p=0.023). Sex, the proportion of probands and the proportion of patients treated with flecainide, left cardiac sympathetic denervation and an ICD were equally distributed among all groups. In total 86 (32.2%) children had an AE. The AE-rate was significantly higher in patients treated with atenolol compared to nadolol (hazard ratio (HR) 2.15, 95% confidence interval (CI) 1.05-4.40, p=0.036, Table). There were no significant differences in the AE-rate in patients treated with bisoprolol (HR 2.08, 95% CI 0.92-4.71), metoprolol (HR 1.79, 95% CI 0.82-3.92), and propranolol (HR 1.55, 95% CI 0.84-2.86) compared with nadolol.
Conclusions
Atenolol is associated with a higher risk for a subsequent arrhythmic event in symptomatic children with CPVT compared to nadolol.
Children with catecholaminergic polymorphic ventricular tachycardia (CPVT) are at risk for malignant ventricular arrhythmias during exercise and emotions, which may lead to arrhythmic events such as sudden cardiac death (SCD). Symptomatic patients are at particular risk for the reoccurrence of arrhythmic events. Beta-blockers are the cornerstone of therapy in patients with CPVT. However, studies comparing the efficacy of different types of betablockers are scarce. We aimed to determine the efficacy of different types of beta-blockers in reducing the risk for recurrent arrhythmic events in a large cohort of symptomatic children with CPVT.
Methods
Data were derived from the International CPVT Registry, a large retrospective observational cohort study. We included symptomatic children aged <19 years who were carrier of a RYR2 variant and who were prescribed a beta-blocker. The primary endpoint was the occurrence of an arrhythmic event (AE), defined as SCD, aborted cardiac arrest, appropriate ICD discharge or syncope. Time-dependent Cox-regression analyses were used to compare the occurrence of AEs between different beta-blockers corrected for possible confounders with nadolol as reference group.
Results
We included 267 children treated with a beta-blocker. One hundred five (39.3%) children were first treated with nadolol, 64 (24.0%) with propranolol, 43 (16.1%) with atenolol, 26 (9.7%) with metoprolol and 21 (7.9%) bisoprolol. Age at initiation of beta-blocker differed between the groups, with the youngest mean age in propranolol and highest in bisoprolol and metoprolol (10±4 years in propranolol, 13±4 years in bisoprolol and nadolol, overall-p=0.023). Sex, the proportion of probands and the proportion of patients treated with flecainide, left cardiac sympathetic denervation and an ICD were equally distributed among all groups. In total 86 (32.2%) children had an AE. The AE-rate was significantly higher in patients treated with atenolol compared to nadolol (hazard ratio (HR) 2.15, 95% confidence interval (CI) 1.05-4.40, p=0.036, Table). There were no significant differences in the AE-rate in patients treated with bisoprolol (HR 2.08, 95% CI 0.92-4.71), metoprolol (HR 1.79, 95% CI 0.82-3.92), and propranolol (HR 1.55, 95% CI 0.84-2.86) compared with nadolol.
Conclusions
Atenolol is associated with a higher risk for a subsequent arrhythmic event in symptomatic children with CPVT compared to nadolol.