Long-term mortality after catheter ablation of focally-triggered polymorphic ventricular tachycardia or ventricular fibrillation: single centre experience

Abstract Background Focally-triggered polymorphic ventricular tachycardia (pVT) or ventricular fibrillation (VF) are malignant arrhythmias initiated by ectopic beats, often originating from the Purkinje system or outflow tracts. Catheter ablation (CA) of triggering ectopy and associated substrate is an effective therapeutic option, but data on long-term outcomes are limited. Purpose To evaluate long-term mortality after CA of focally-triggered pVT/VF and compare outcomes between idiopathic and structural heart disease (SHD)-related cases. Methods We retrospectively analysed patients who underwent their first CA for focally-triggered pVT/VF between 2006 and 2023. The procedure targeted triggering ectopy and, when indicated, included substrate modification. Two subgroups of patients were compared: Group 1 (idiopathic pVT/VF) and Group 2 (SHD-related pVT/VF). Results Seventy patients (58 ± 14 years; 74% male) were included. Group 1 patients were younger (41 ± 15 vs 62 ± 10 years, P 0.001), had higher LVEF (58 ± 7 vs 29 ± 10%, P 0.001), fewer comorbidities, and more women (50% vs 20%, P = 0.04). Ablation in Group 1 was less extensive (radiofrequency time of 12 ± 8 vs 22 ± 13 min, P 0.01) and more often involved the right ventricle (50% vs 2%, P 0.001). During median follow-up of 4.4 (IQR 1.2-8.9) years, mortality was 21% vs 66% (log-rank P = 0.016) for Groups 1 and 2, respectively. Reablation for all types of VT recurrences was performed in 24 (34%) patients (43% vs 32%, P = 0.5), with a trend toward a shorter time to reablation in Group 1 (235 ± 315 vs 418 ± 735 days, P = 0.6). Major complications occurred in 6 (8.6%) patients, including three cases of acute hemodynamic decompensation (one requiring ECMO support), one hemopericardium managed by pericardiocentesis, and two groin hematomas treated conservatively; all events occurred in Group 2. Conclusion In this large single-centre cohort, CA of focally triggered pVT/VF was effective and safe, particularly in idiopathic cases. Long-term mortality remains high in SHD patients, reflecting comorbidities and advanced heart failure.