Short-term and long-term effects of noninvasive cardiac radioablation for ventricular tachycardia: A single-center case series

Won Ick Chang; Ha Hye Jo; Myung-Jin Cha; Ji Hyun Chang; Chang Heon Choi; Hak Jae Kim; Seil Oh; Clifford G Robinson; Phillip S Cuculich

doi:10.1016/j.hroo.2022.11.006

Short-term and long-term effects of noninvasive cardiac radioablation for ventricular tachycardia: A single-center case series

Heart Rhythm O2. 2022 Dec 5;4(2):119-126. doi: 10.1016/j.hroo.2022.11.006. eCollection 2023 Feb.

Authors

Won Ick Chang¹, Ha Hye Jo², Myung-Jin Cha², Ji Hyun Chang¹, Chang Heon Choi¹, Hak Jae Kim¹, Seil Oh³, Clifford G Robinson⁴, Phillip S Cuculich⁵

Affiliations

¹ Department of Radiation Oncology, Seoul National University Hospital, Seoul, Korea.
² Division of Cardiology, Department of Internal Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Korea.
³ Division of Cardiology, Department of Internal Medicine, Seoul National University Hospital, Seoul, Korea.
⁴ Department of Radiation Oncology, Washington University in St Louis, St Louis, Missouri.
⁵ Cardiovascular Division, Department of Internal Medicine, Washington University in St Louis, St Louis, Missouri.

Abstract

Background: Noninvasive cardiac radioablation is reported to be effective and safe for the treatment of ventricular tachycardia (VT).

Objective: This study aimed to analyze the acute and long-term effects of VT radioablation.

Methods: Patients with intractable VT or premature ventricular contraction (PVC)-induced cardiomyopathy were included in this study and treated using a single-fraction 25-Gy dose of cardiac radioablation. To quantitatively analyze the acute response after treatment, continuous electrocardiography monitoring was performed from 24 hours before to 48 hours after irradiation and at the 1-month follow-up. Long-term clinical safety and efficacy were assessed 1-year follow-up.

Results: From 2019 to 2020, 6 patients were treated with radioablation for ischemic VT (n = 3), nonischemic VT (n = 2), or PVC-induced cardiomyopathy (n = 1). In the short-term assessment, the total burden of ventricular beats decreased by 49% within 24 hours after radioablation and further decreased by 70% at 1 month. The VT component decreased earlier and more dramatically than the PVC component (decreased by 91% and 57% at 1 month, respectively). In the long-term assessment, 5 patients showed complete (n = 3) or partial (n = 2) remission of ventricular arrhythmias. One patient showed recurrence at 10 months, which was successfully suppressed with medical treatment. The posttreatment PVC coupling interval was prolonged (+38 ms at 1 month). Ischemic VT burden decreased more markedly than nonischemic VT burden after radioablation.

Conclusion: In this small case series of 6 patients, without a comparison group, cardiac radioablation appeared to decrease the intractable VT burden. A therapeutic effect was apparent within 1-2 days after treatment but was variable by etiology of cardiomyopathy.

Keywords: Cardiac radioablation; Early antiarrhythmic effect; Electrophysiologic change; Safety; Ventricular tachycardia.