Abstract Body (Do not enter title and authors here): Objectives:
This meta-analysis sought to explore the long-term arrhythmic outcomes of cardiac sympathetic denervation (CS) by measuring event rates of recurrent ventricular arrhythmias (VA) and implantable cardiac defibrillator shocks (ICD) post CSD.

Background:
The role of sympathetic nervous system in the beginning and continuation of ventricular arrhythmias (VAs) is well known. CS has been associated with improved arrhythmic outcomes in patients with refractory ventricular arrhythmias. However, whether CSD lowers shock event rates after the procedure is still uncertain and therefore, we performed a systematic review and meta-analysis to evaluate this.

Methods & Materials:
A comprehensive literature search was performed at Medline and Embase until March 2023. Our primary outcome was event rate of ICD shocks at 30 days, 90 days, and 1 year following CS. All analysis was conducted using Comprehensive Meta-Analysis software.

Results:
The initial search found 1,324 articles. After all articles were examined, a total of 29 studies fit our criteria. ICD shocks 1 year post CSD had a pooled event rate of 66.5% with a 95% confidence interval (CI) of 57.7% to 74.3% and the I-squared (I2) statistics. ICD shocks at 6 months had an event rate at 61.7% with a 95% confidence interval of 53.3% to 69.4% with I2 at 46. VA in one year post CSD had a pooled event rate of 62.5 with a 95% with a CI of 53.3% to 69.1% and I2 at 22%. At 6 months the event rate was 64.2 with a 95% CI of 56.3% to 71.4% with I2 at 33% Mortality from cardiac arrhythmia and classified 0-30 days (short term), 21-364 days (medium term), and >365 days (long term). The pooled event rate for short term morality was 6.8% with a 95% CI of 4.2%-11.0% with I2 at 0%, medium term was 5.2% with a 95% CI of 2.9% to 8.9% with I2 at 0%, and long term was 5.0% with a 95% CI of 2.7% to 9.2% and I2 at 0%.

Conclusion:
CSD may be an alternative form of therapy that reduces shock event rates and recurrent VA in patients that are refractory to ablation and medical therapy. However larger prospective studies are needed to further evaluate the usefulness and safety of CSD.