Clinical experience of stereotactic body radiation for refractory ventricular tachycardia in advanced heart failure patients

Abstract

Stereotactic body radiation therapy (SBRT) has been shown to be effective in treating patients with refractory ventricular tachycardia. The purpose of this study was to describe outcomes for SBRT in advanced heart failure patients admitted for repeated implantable cardioverter-defibrillator (ICD) therapies who were refractory to standard treatments. SBRT simulation, planning, and treatments were performed using standard techniques with collaboration from a radiation oncologist, electrophysiologist, and cardiac imaging specialist. Patients were treated with single-fraction 25 Gy while awake. Efficacy was assessed by total durations in seconds of ventricular tachycardia, frequency of antitachycardia pacing (ATP), and quantity of shocks before and after treatment as recorded by an ICD. A total of 10 patients (mean age 61 years; 3 female) were included. Etiologies of heart failure were ischemic in 40% (4/10) and nonischemic in 60% (6/10). Among 8 patients with available ICD data, the total reduction in seconds of detected VT was 69% (pretreatment 1065 seconds/month vs posttreatment 332 seconds/month). The total reduction in ATP sequences was 48% (17.3 pretreatment and 8.9 posttreatment). Reduction in total ICD shocks after SBRT was 68% (2.9 shocks/month pretreatment and 0.9 shocks/month posttreatment). When excluding a single nonresponder, there was a significant reduction in VT seconds (94%; P = .04) and a trend toward ICD shock reduction (90%; P= .07) post-SBRT. Noninvasive treatment with SBRT was feasible and modestly effective at reducing VT burden in the critically ill. This suggests that SBRT treatment may be a useful palliation for electrical storm.