Stereotactic Body Radiation for Refractory Ventricular Tachycardia in Patients with Left Ventricular Assist Devices

Purpose Stereotactic body radiation therapy (SBRT) combined with electrocardiographic mapping has emerged as a potential noninvasive ablation technique for the treatment of refractory ventricular tachycardia (VT). The role of SBRT in patients with a left ventricular assist device (LVAD) is unknown. Methods Retrospective chart review was performed on all heart failure (HF) patients who underwent SBRT from January 1, 2018 to September 1, 2019. In this case series, we describe two patients who underwent SBRT after LVAD implantation. Results Of eleven heart failure patients who underwent SBRT, two had LVADs. The first was a 51 year old male with nonischemic cardiomyopathy and ventricular tachycardia refractory to medical therapy and stellate ganglion block. Given his intractable VT and cardiogenic shock, he underwent HeartMate 3 LVAD implantation as bridge-to-transplant (BTT). After LVAD implantation, he continued to have refractory VT despite subsequent VT ablations. CT cardiac mapping identified a 4 mm arrhythmic scar along the lateral wall of the right ventricle, and SBRT was performed with a single fraction of 25 Gy. Two weeks after SBRT, he experienced recurrent VT and eventually underwent orthotopic heart transplantation (OHT) four months after VT recurrence. The second patient was a 66 year old male with a history of nonischemic cardiomyopathy status post HeartWare LVAD as BTT who presented with recurrent VT three years following LVAD implantation. He was referred for SBRT after failure of antiarrhythmic drug (AAD) therapy and VT ablation. 4D-CT simulation defined a myocardial scar in the left ventricular outflow tract, and SBRT was performed with a single fraction of 25 Gy. His ventricular arrhythmias returned after four months, and additional AAD were utilized to suppress the arrhythmias until he underwent OHT two months later. The frequency of hospitalizations for VT did decrease following SBRT (Pt 1: 6 pre-SBRT vs. 3 post-SBRT, Pt 2: 4 pre-SBRT vs. 2 post-SBRT), but did not reach statistical significance (p= 0.12). Conclusion LVAD patients are prone to ventricular arrhythmias, and noninvasive SBRT may serve as an alternative therapy if AAD and traditional VT ablation have been unsuccessful, potentially keeping ventricular arrhythmias quiescent while awaiting heart transplantation. Further research is needed in this patient population.