A prospective, international, multicentre registry (STOPSTORM: Standardized Treatment and Outcome Platform for Stereotactic Therapy Of Re-entrant tachycardia by a Multidisciplinary team) published in the European Heart Journal evaluated outcomes of stereotactic arrhythmia radioablation (STAR) in patients with refractory ventricular tachycardia (VT). The analysis represents a planned interim evaluation of registry data collected across 28 centers in Europe. 

A total of 193 patients were included (mean age 68±9 years; 88% male), with 53% having non-ischemic cardiomyopathy. Inclusion criteria comprised patients undergoing STAR for refractory VT, while specific exclusion criteria were not detailed in the abstract. The primary efficacy endpoint was the change in sustained VT episode burden comparing the 6 months before versus 6 months after STAR. 

The primary safety endpoint was the occurrence of serious adverse events (SAEs) considered possibly or probably related to treatment. Overall survival was assessed using time-to-event analysis.

With a median follow-up of 19 months, 107 patients had evaluable data for the primary efficacy endpoint. In this subgroup, the median VT episode burden decreased by 80% following STAR. Among patients who survived at least 6 months post-procedure, 72% were free from implantable cardioverter-defibrillator (ICD) shocks. 

Across the full cohort, 12 SAEs were classified as possibly or probably treatment-related, including pericardial effusion, coronary events, and early post-treatment ventricular arrhythmias.

The estimated overall survival probability at 12 months was 77%.
STAR was associated with a marked reduction in VT burden and ICD shocks. Treatment-related SAEs were infrequent within the observed follow-up period.