Long-term results of stereotactic arrhythmia radioablation for refractory ventricular Arrhythmias—A Taiwanese population study

Background: Stereotactic arrhythmia radioablation (STAR) has proven to be effective in refractory ventricular tachyarrhythmia (VT). We report the long-term results in first Asian series of STAR for refractory VT in a group of Taiwanese. Methods: This study prospectively enrolled patients with treatment-failure VT. 3D electroanatomic maps, delayed enhancement magnetic resonance imaging and dual energy computed tomography were used to identify scar substrates. The main target volume was treated with a single radiation dose of 25 Gy delivered by Varian/Edge TrueBeam System. Efficacy was assessed by VT events recorded by implantable cardioverter defibrillator. Results: From February 2019 to Feburary 2023, 11 patients were enrolled and followed up for at least 1 year. Ten male and one female patient received the treatment. During the median follow-up of 53 months, VT episodes decreased by 88% in post-treatment first 6 months. Late VT recurrence was observed in most of patients. Five patients received repeated catheter ablation for recurrent VTs. One-year survival rate was 83%. Among surviving patients, 1 received heart transplant and 2 had HeartMate III implantation. Conclusion: In patients with medication and catheter ablation refractory VT, STAR is associated with a marked acute reduction in the burden of VT. The acute response of VT burden reduction helps to bridge patients to the next treatment step of heart failure, including medical optimization or surgical management, and enhance clinical outcomes.