Clinical outcomes and procedural characteristics of ventricular tachycardia ablation in patients with or without electrical storm

Abstract

Funding Acknowledgements Type of funding sources: None. Introduction Electrical storm (ES) is a life-threatening clinical condition characterized by the recurrence of three or more episodes of ventricular tachycardia (VT) and/or ventricular fibrillation within 24 hours, leading to ICD therapy. Catheter ablation of VT in patients with ES is a high-risk procedure but has been shown to reduce VT recurrence and the number of appropriate ICD therapies in patients with structural heart disease. Purpose Our study aimed to compare the characteristics and outcomes of VT ablation in patients with or without ES. Methods Our single-center study included a cohort of 39 consecutive patients (31 men, mean age=60.9±18.4 years) who underwent VT ablation between January 2020 and January 2022, 21 of them (53.8%) due to ES and 18 patients (46.2%) had an elective procedure. Clinical and procedural characteristics, VT recurrence, and mortality rates were compared between the two groups. Results Patients with ES were older than patients without ES (67.8 vs 54.2 years, p=0.004), they were mainly presented with ischaemic cardiomyopathy (85.7% vs 27.8%, p<0.0001), had a higher prevalence of congestive heart failure (90.5% vs 44.4%, p=0.001) and a more severe left ventricular dysfunction (LVEF: 30.8% vs 46.9%, p=0.002). During the procedure, in the ES group, all of the patients had left-sided ablation (transaortic: 80.9%, transseptal: 19.1%), while in patients without ES, 72.2% of the procedures were left-sided (p=0.04). In 8/39 patients (20.5%) endo-epicardial access was needed. The number of RF ablation points was significantly higher in the ES group (64.1 vs 36.1 points, p=0.01). Complications were detected only in the ES group: intraprocedural death occurred in one case due to an ES and consequently cardiogenic shock, and one patient had a dissection of the right femoral artery. There was no significant difference regarding procedure time, fluoroscopy time, and radiation exposure. The in-hospital 30-day mortality was 8/21 (28.6%) in patients with ES, while no patients died in the non-ES group. During longer clinical follow-up, there was no significant difference in the recurrence of VT episodes and mortality. Conclusion Patients presented with ES are a more vulnerable population with many comorbidities. Catheter ablation of VT in patients with ES is a more complex procedure with a higher complication rate and these patients have a higher risk of in-hospital mortality. Further studies are needed to determine the optimal timing of VT ablation in this patient population.