Radiosurgery for ventricular tachycardia (RAVENTA): interim analysis of a multicenter multiplatform feasibility trial

Abstract

Background: Single-session cardiac stereotactic radiation therapy (SBRT) has demonstrated promising results for patients with refractory ventricular tachycardia (VT). However, the full safety profile of this novel treatment remains unknown and very limited data from prospective clinical multicenter trials are available.

Methods: The prospective multicenter multiplatform RAVENTA (radiosurgery for ventricular tachycardia) study assesses high-precision image-guided cardiac SBRT with 25 Gy delivered to the VT substrate determined by high-definition endocardial and/or epicardial electrophysiological mapping in patients with refractory VT ineligible for catheter ablation and an implanted cardioverter defibrillator (ICD). Primary endpoint is the feasibility of full-dose application and procedural safety (defined as an incidence of serious [grade ≥ 3] treatment-related complications ≤ 5% within 30 days after therapy). Secondary endpoints comprise VT burden, ICD interventions, treatment-related toxicity, and quality of life. We present the results of a protocol-defined interim analysis.

Results: Between 10/2019 and 12/2021, a total of five patients were included at three university medical centers. In all cases, the treatment was carried out without complications. There were no serious potentially treatment-related adverse events and no deterioration of left ventricular ejection fraction upon echocardiography. Three patients had a decrease in VT episodes during follow-up. One patient underwent subsequent catheter ablation for a new VT with different morphology. One patient with local VT recurrence died 6 weeks after treatment in cardiogenic shock.

Conclusion: The interim analysis of the RAVENTA trial demonstrates early initial feasibility of this new treatment without serious complications within 30 days after treatment in five patients. Recruitment will continue as planned and the study has been expanded to further university medical centers.

Trial registration number: NCT03867747 (clinicaltrials.gov). Registered March 8, 2019. Study start: October 1, 2019.

Keywords: Cardiac arrhythmia; Implantable cardioverter defibrillator; Stereotactic arrythmia radioablation; Stereotactic body radiotherapy; Structural heart disease.

Fig. 1

Left ventricular ejection fraction (LV-EF) during the study. Asterisk Patient 4 died after the 6‑week follow-up visit with recurrent ventricular tachycardia

Fig. 2

Ventricular tachycardia (VT) episodes per patient during the study. Asterisk Patient 4 died after the 6‑week follow-up visit with recurrent ventricular tachycardia

Fig. 3

Number of implantable cardioverter defibrillator (ICD) shocks per patient during the study. Asterisk Patient 4 died after the 6‑week follow-up visit with recurrent ventricular tachycardia