Stereotactic arrhythmia radioablation for refractory ventricular tachycardia—The initial Australian experience

Abstract

Background

Stereotactic arrhythmia radioablation (STAR) is a novel, noninvasive technique for the management of refractory ventricular tachycardia (VT).

Objective

This retrospective study aimed to assess the feasibility, efficacy, and safety of STAR in an Australian cohort.

Methods

From February 2020 to August 2023, 12 patients with drug-refractory VT for whom catheter ablation had failed or who were unsuitable for it were treated with STAR in 2 Australian centers. A combination of electrocardiograms, multimodality imaging, and noninvasive or invasive mapping data was used to target the presumed VT substrate. All treatments (25 Gy in 1 fraction) were delivered without anesthesia. Efficacy end points were defined as the number of VT episodes, antitachycardia pacing sequences, VT storms, and shocks 6 months before and after treatment (6-week blanking period). Mortality and adverse event data were collected during 12-month follow-up.

Results

In the 9 patients who survived the blanking period, a significant reduction (64.5%; P = .011) in VT burden and VT storm (71.7%; P = .027) was observed during a 6-month follow-up. However, 66.7% (6/9) of these patients experienced VT recurrence; 3 of 6 patients with recurrence with electrocardiograms available for review had the same VT morphology as before STAR. During a 12-month follow-up, 5 patients died and 3 adverse events were recorded (undersensing of defibrillator lead, increased rate of reflux, and radiation pneumonitis).

Conclusion

This paper summarizes the initial Australian experience treating refractory VT with STAR. It demonstrates that STAR can significantly decrease the VT and VT storm burden during a 6-month follow-up with an acceptable acute adverse effect profile, albeit with a high VT recurrence rate.