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CE-521-03 LONG TERM OUTCOMES OF LEFT CARDIAC SYMPATHETIC DENERVATION FOR LONG QT SYNDROME AND CATHECHOLAMINERGIC POLYMORPHIC VENTRICULAR TACHYCARDIA

      Background

      Left cardiac sympathetic denervation (LCSD) is an effective anti-fibrillatory, minimally invasive therapy for patients with cardiac channelopathies such as long QT syndrome (LQTS) and catecholaminergic polymorphic ventricular tachycardia (CPVT). While performed for a few decades, only now are cohorts getting large enough to evaluate long term outcomes.

      Objective

      To examine the frequency of breakthrough cardiac events (BCEs) after LCSD in patients with either LQTS or CPVT.

      Methods

      We performed a retrospective review of all patients with either LQTS or CPVT who underwent LCSD at our institution since 2005. Clinical data was abstracted for each patient, including cardiac event rates before and after LCSD. BCEs were defined as arrhythmogenic syncope, seizure, appropriate ventricular fibrillation (VF)-terminating therapies, and/or sudden cardiac death (SCD).

      Results

      Overall, 301 patients were included [173 female (57%); mean age at LCSD 19 ± 13 years] of which 235 (78%) had LQTS [121 (51%) LQT1, 56 (24%) LQT2, 13 (5%) LQT3 and 23 (10%) ≥ 1 LQTS mutation (LQTM)] and 66 (22%) had CPVT. Overall, 180 (60%) patients were symptomatic prior to LCSD (53% for LQTS; 85% for CPVT). Mean follow-up for the cohort was 6.5 ± 4.1 years with a total follow-up of 1963 patient-years. In total, 50 (17%) patients [42/235 (18%) with LQTS and 8/66 (12%) with CPVT) have experienced ≥ 1 non-lethal BCE post-LCSD. Among the main LQTS genotypes, BCE rates were significantly higher in those with LQT3 (82%) or LQTM (35%) compared to LQT1 (12%) or LQT2 (11%: p<0.001). Additionally, among the 180 previously symptomatic patients, their post-LCSD BCE rate was significantly higher (24%) compared to 5% (p<0.001) for the 121 who were asymptomatic before their LCSD.

      Conclusion

      Long term follow-up continues to demonstrate that LCSD is a safe intervention with high therapeutic efficacy. However, LCSD is not a curative therapeutic option as one out of four previously symptomatic patients have experienced a channelopathy-associated BCE, albeit no deaths, following their LCSD with nearly 2000 patient-years of observation.