247 - Stereotactic Arrhythmia Radiotherapy (STAR) vs. Repeat Catheter Ablation for High-Risk Refractory Ventricular Tachycardia: 3-Year Safety and Efficacy Outcomes

03:10pm - 03:20pm PT

Room 310-312

Presenter(s)

Shannon Jiang, MD - Washington University/B-JH/SLCH Consortium, St. Louis, MO

S. J. Jiang¹, P. Samson¹, P. Cuculich², C. Contreras³, K. M. S. Moore², M. Faddis², T. W. Smith², M. Gleva², D. H. Cooper², and C. G. Robinson¹; ¹Washington University School of Medicine in St. Louis, Department of Radiation Oncology, St. Louis, MO, ²Washington University School of Medicine in St. Louis, Department of Internal Medicine, Division of Cardiology, St. Louis, MO, ³Washington University in St. Louis, St. Louis, MO

Purpose/Objective(s): Stereotactic Arrhythmia Radiotherapy (STAR) is a noninvasive treatment alternative to catheter ablation (CA) for management of highly refractory ventricular tachycardia (VT). No studies have directly compared the safety and efficacy profile of STAR to CA. We hypothesize that STAR offers comparable VT control with potential for improved early safety outcomes given its noninvasive approach. This study reports on 3-year outcomes for patients treated with STAR vs CA for high-risk refractory VT at a high-volume center.

Materials/Methods: We evaluated patients with refractory VT who had failed prior CA (or were medically unfit for CA) and treated with either STAR or repeat CA between 2015 and 2018 at a single institution. Patients were followed for serious adverse events (SAE) (deemed possibly, probably, or definitely treatment related); overall survival (OS); and freedom from death, shock, or storm (FFDSS, with 6-week blanking period). Survival analyses were performed by Kaplan-Meier method and comparisons by log-rank test.

Results: A total of 43 patients were included: 22 treated with STAR (18 failed prior CA, 4 CA contraindicated) and 21 treated with repeat CA (all failed prior CA). STAR and CA cohorts had similar baseline demographics: 91% male, median NYHA class III, and median LVEF 25%. However, STAR patients tended to be older (median 64.5 vs 59 years, STAR vs CA), have “High Risk” I-VT score (64% vs 52%, STAR vs CA), and higher PAINESD score (median 18.5 vs 17, STAR vs CA). Median follow up was 3 years. Ninety-one percent of patients treated with STAR (N=20) and 76% treated with CA (N=16) survived the 6-week blanking period. STAR patients had superior median time of FFDSS (6.9 vs 2.9 months, STAR vs CA, p=0.88). 1-year FFDSS was 32% vs 27% (STAR vs CA), 2-year FFDSS was 27% for both, and 3-year FFDSS was 18% vs 21% (STAR vs CA). More CA patients (N=8, 38%) developed 1-year treatment-related (probably, definitely) SAEs compared to STAR (N=3, 14%). Median time to any SAE was shorter for patients treated with CA (0.2 months) compared to STAR (10.0 months), and most early CA deaths occurred immediately following an SAE. For patients treated with STAR, no treatment related SAEs occurred beyond 3 years post treatment. Of the 12 STAR patients who died within 3 years, most (N=9, 75%) died from causes unrelated to VT and none from treatment related SAE. Median OS was higher for STAR, (28.2 vs 12.2 months, p=0.91). One-year OS was 73% vs 58% (STAR vs CA), 2-year OS was 55% vs 45% (STAR vs CA), and 3-year OS was 45% for both.

Conclusion: At 3-year follow-up, patients treated with STAR (vs repeat CA) had similar VT control, less treatment related SAEs, longer time to SAE, and higher median and 1 to 2-year OS. The improved safety profile and clinically equivalent outcomes between STAR vs CA have significant implications for future practice. (IRB 202102076-1001)