Po-01-134 an international multicenter cohort study on beta-blocker free treatment strategies for catecholaminergic polymorphic ventricular tachycardia

Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare potentially life-threatening genetic heart disease. Non-selective beta-blockers (BBs, namely nadolol and propranolol) are highly effective in reducing CPVT-triggered arrhythmic events. However, some patients suffer from unacceptable BB side effects and might require BB-free treatment strategies that include flecainide, left cardiac sympathetic denervation (LCSD), combination therapy, or potentially even intentional non-therapy (INT) as has been published for long QT syndrome. To review the spectrum of and outcomes associated with BB-free treatment configurations in CPVT from the International CPVT Registry. From the Registry, all patients with RYR2 variant-positive CPVT treated with a BB-free strategy for ≥ 6 months were included. Four BB-free treatment groups were defined: INT, flecainide monotherapy, LCSD monotherapy, and LCSD/flecainide combination therapy. Overall, 100 out of 1017 (10%) patients were on a BB-free treatment strategy (53 females (53%), mean age at BB-free therapy initiation 24 ± 22 years). There were 73 patients (42 males and 31 females) in the INT group. For majority of these patients (n=62; 88%), INT was pursued following low-risk assessment in asymptomatic patients and absent or negligible stress test phenotype (characterized by the absence of bigeminy, couplets, or more complex ventricular ectopy). Twenty-one patients were on flecainide monotherapy with BB intolerance the main reason in 14 of 21 patients (67%). Two patients were treated with LCSD alone because of BB intolerance. Lastly, combination therapy with LCSD and flecainide was used in 4 patients. During a mean follow-up of 6 ± 4 years for all patients, only 2 patients had a self-limiting syncopal episode while on INT after which BB therapy was restarted. Though non-selective BBs remain the cornerstone treatment for CPVT either alone or in combination with flecainide, 10% of patients with CPVT required a BB-free treatment strategy because of unacceptable BB side-effects. After careful risk-assessment, safe and effective BB-free treatment strategies can be configured without an implantable cardioverter defibrillator for such patients.