Safety and Efficacy of Cardiac Sympathetic Denervation for Ventricular Arrhythmias: An Updated Review and Meta-Analysis

IntroductionThe role of sympathetic nervous system in the initiation and continuation of ventricular tachyarrhythmias (VTA) is well established. However, whether CSD reduces implantable cardioverter defibrillator (ICD) shocks and recurrent VTA is still uncertain. ObjectiveTo explore long-term arrhythmic outcomes, safety, and efficacy of CSD by measuring event rates of recurrent VTA and ICD shocks after CSD. MethodsA comprehensive literature search was performed at Medline and Embase until March 2023. Our primary outcome was event rate of ICD shocks and VTA. Analyses were conducted using Comprehensive Meta-Analysis software. ResultsInitial search yielded 1,324 scientific studies with a total of 15 studies fitting our inclusion criteria. ICD shocks at 1 year post CSD revealed an event rate of 69.8% (95% CI, 56.4% - 80.4% with 50% heterogeneity) (I2 statistic)). ICD shocks at 6 months had an event rate of 59.1% (95% CI 46.9% - 70.4%, 47 I2). Freedom of VTA 1 year post CSD revealed an event rate of 64.3% (95% CI, 42.3% - 81.5%, 26% I2). Freedom from VTA at 6 months revealed an event rate of of 62.3% (95% CI, 51.2% - 72.2%, 40% I2). Reported mortality due to VTA was subdivided into short-term (0-30 days), intermediate-term (31-364 days) and long-term (32-364 days). The event rate for the short-term tertile was 8.9% (95% CI, 5.0% - 15.4%, 0% I2), medium-term was 5.3% (95% CI, 2.4% - 11.3%, 0% I2) and long-term 5.2% (95% CI, 2.4% - 10.9%, 0% I2). ConclusionCSD seems to be promising as an acceptable treatment strategy for recurrent VTA refractory to traditional pharmacological or ablation therapy.