Long-term outcomes of ventricular tachycardia ablation in patients presenting with electrical storm

Abstract Background Catheter ablation (CA) is an established therapy for drug-resistant ventricular tachycardia (VT). Although previous reports suggest higher recurrence and mortality rates in patients presenting with electrical storm (ES), data on mid- and long-term outcomes remain scarce. We aimed to evaluate the clinical characteristics and long-term outcomes of patients presenting with ES undergoing VT ablation. Methods Single-centre registry of consecutive patients undergoing scar-related VT ablation from 2010 to 2024. ES was defined as ≥3 episodes of sustained VT or ventricular fibrillation in 24h. Clinical and procedural characteristics were assessed and compared between groups. The outcomes of interest were VT-free survival and all-cause mortality. Safety outcome was a composite of tamponade, hemodynamic decompensation, acute heart failure, stroke, and procedure-related mortality. Results A total of 298 patients (aged 65±13years, 91% male, mean left ventricular ejection fraction [LVEF] 34±11%, 67% with ischemic cardiomyopathy, 20% redo procedures) were included. Among those, 32% (n=96) had ES at presentation. Compared to those without ES, patients with ES had worse functional status (NYHA III-IV: 38.5% vs. 17.8%, P<0.001), although there were no differences regarding age, sex, aetiology, and LVEF. Procedure and fluoroscopy duration were similar (165 vs. 154 min, P=0.20; and 15 vs. 13 min, P=0.20; respectively), and acute non-inducibility of VT was achieved in 81.4% (P=0.772). Major complications rate was higher in the ES group (5.2% vs. 1.0%, P=0.025). During a median follow-up of 3.4 (IQR 1.4-7.2) years, 127 patients (42.6%) suffered a VT relapse and 104 (34.9%) died. Compared to non-ES group, patients presenting with ES had higher rates of VT recurrence (53.3%/year vs. 23.6%/ year, log rank P=0.014) and death (16.4%/ year vs. 9.7%/ year, log rank P=0.007). – Figure 1. ES remained independently associated with VT recurrence, even after adjusting for six clinical confounders (aHR 1.50 [95% CI 1.02-2.19], P=0.039). Non-ischaemic aetiology (aHR 1.79 [95% CI 1.21-2.66], P=0.004), atrial fibrillation (aHR 1.71 [95% CI 1.17-2.52], P=0.006) and chronic kidney disease (aHR 1.59 [95% CI 1.08-2.35], P=0.019) were the other predictors of relapse. Conclusions Patients presenting with ES undergoing VT ablation had higher rates of VT recurrence, mortality, and major complications compared to those without ES, even achieving similar acute procedural success. ES was an independent predictor of poorer long-term outcomes, highlighting the need for targeted strategies to improve prognosis in this high-risk population