Therapeutic approach for patients with catecholaminergic polymorphic ventricular tachycardia: state of the art and future developments

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is an inherited arrhythmia syndrome characterized by bidirectional or polymorphic ventricular arrhythmias under conditions of increased sympathetic activity in young patients with structurally normal hearts. Patients with CPVT are at high risk of developing life-threatening ventricular arrhythmias when untreated. A wide variety of arrhythmic event rates on conventional therapy, with beta-blockers as the cornerstone, has been reported. Here, we systematically review all available studies describing the efficacy of beta-blocker therapy for prevention of arrhythmic events in CPVT. Because of heterogeneity between the studies, a random-effects meta-analysis model was used to assess the efficacy of beta-blocker therapy in preventing any arrhythmic event [syncope, aborted cardiac arrest (ACA), and sudden cardiac death (SCD)], near-fatal arrhythmic events (ACA and SCD), and fatal arrhythmic events. Eleven studies including 403 patients, of whom 354 (88%) had a beta-blocker prescribed, were identified. Mean follow-up ranged from 20 months to 8 years. Estimated 8-year arrhythmic, near-fatal, and fatal event rates were 37.2% [95% confidence interval (CI): 16.6-57.7], 15.3% (95% CI: 7.4-23.3), and 6.4% (95% CI: 3.2-9.6), respectively. In addition, we review the recent developments in alternate chronic treatment options for CPVT patients, including calcium channel blockers, flecainide, left cardiac sympathetic denervation, and implantable cardioverter defibrillators. A new treatment strategy is proposed, including a stepwise addition of the alternate treatment options to beta-blockers in patients who do not respond sufficiently to this first-line therapy. Finally, future developments in chronic treatment options and acute treatment options of ventricular arrhythmias are discussed.