Comparative efficacy of stereotactic body radiotherapy versus radiofrequency catheter ablation in refractory ventricular tachyarrhythmia: results from the vt-art consortium
O Anzalone, F Percio, F Cellini, G Pelargonio, T Sanna, G Pinnacchio, F Perna, G Bencardino, F Burzotta, M A Gambacorta, M L NarducciAbstract
Background
Refractory ventricular tachycardia (VT) in patients with structural heart disease (SHD) remains a major therapeutic challenge, often unresponsive to antiarrhythmic drugs and radiofrequency catheter ablation (RFCA). Stereotactic body radiotherapy (SBRT) has recently emerged as a non-invasive treatment option for patients unsuitable for or unresponsive to conventional ablation.
Purpose
To assess the clinical efficacy and safety of SBRT compared with RFCA in patients with refractory monomorphic VT and SHD.
Methods
The multicentric VT-ART observational study included 64 patients with recurrent VT and SHD: 15 treated with SBRT (25 Gy in a single fraction) and 49 matched controls treated with RFCA. Patients were matched by type of cardiomyopathy, VT characteristics, mapping modality, and clinical profile. The primary composite endpoint included cardiovascular (CV) death, sustained VT recurrence, or rehospitalization. Median follow-up was 11 months.
Results
At baseline, SBRT patients had a greater arrhythmic burden (11.5 ± 14 vs 3.3 ± 2.7 VT/VF episodes in 2 months; p < 0.001) and more advanced NYHA/INTERMACS class. During follow-up, the composite endpoint occurred in 60% of SBRT and 39% of RFCA patients (p = 0.09). Sustained VT recurrence was higher after SBRT (40% vs 18%, p = 0.049), but both groups showed a significant reduction in arrhythmic burden post-treatment (−85% with SBRT, −80% with RFCA; p < 0.001). CV mortality was greater in the SBRT group (40% vs 10%, p = 0.05), while rehospitalization rates were similar (20% vs 31%, p = 0.50). No cardiological or pulmonary complications were observed after SBRT, whereas 10% of RFCA patients developed procedure-related adverse events. Multivariate analysis identified only left ventricular ejection fraction (p = 0.013) as an independent predictor of outcomes.
Conclusions
In patients with advanced SHD and refractory VT, SBRT achieved comparable overall efficacy to RFCA in reducing arrhythmic burden and rehospitalizations, despite a higher-risk clinical profile. The absence of acute complications supports SBRT as a feasible and potentially safer alternative in patients ineligible for catheter ablation. Larger prospective studies are warranted to further define its role in this complex population.