Stereotactic body radioablation therapy as an immediate and early term antiarrhythmic palliative therapeutic choice in patients with refractory ventricular tachycardia

Abstract

Background Stereotactic body radioablation therapy (SBRT) has recently been introduced with the ability to provide ablative energy noninvasively to arrhythmogenic substrate while reducing damage to normal cardiac tissue nearby and minimizing patients’ procedural risk. There is still debate regarding whether SBRT has a predominant effect in the early or late period after the procedure. We sought to assess the time course of SBRT’s efficacy as well as the value of using a blanking period following a SBRT session. Methods Eight patients (mean age 58 ± 14 years) underwent eight SBRT sessions for refractory ventricular tachycardia (VT). SBRT was given using a linear accelerator device with a total dose of 25 Gy to the targeted area. Results During a median follow-up of 8 months, all patients demonstrated VT recurrences; however, implantable cardioverter-defibrillator (ICD) and anti-tachycardia pacing therapies were significantly reduced with SBRT (8.46 to 0.83/per month, p = 0.047; 18.50 to 3.29/per month, p = 0.036, respectively). While analyzing the temporal SBRT outcomes, the 2 weeks to 3 months period demonstrated the most favorable outcomes. After 6 months, one patient was ICD therapy-free and the remaining patients demonstrated VT episodes. Conclusions Our findings showed that the SBRT was associated with a marked reduction in the burden of VT and ICD interventions especially during first 3 months. Although SBRT does not seem to succeed complete termination of VT in long-term period, our findings support the strategy that SBRT can be utilized for immediate antiarrhythmic palliation in critically ill patients with otherwise untreatable refractory VT and electrical storm.

Advanced ventricular arrhythmia ablation: step-by-step problem-solving

“…I look forward to in vivo data from this group, as do Tschabrunn and Frankel, who nicely comment on this study in their editorial [15]. Lastly, Aras and colleagues add to the growing body of literature on VT stereotactic body radiation therapy (SBRT) with their single-center study of 8 patients in whom suppression of VT seemed most prominent in the first 3 months post-SBRT, with questionable long-term efficacy [16].…”

Solving the Reach Problem: A Review of Present and Future Approaches for Addressing Ventricular Arrhythmias Arising from Deep Substrate

“…Solving the Reach Problem: A Review of Present and Future Approaches for Addressing Ventricular Arrhythmias Arising from Deep Substrate Lower VA burden and ICD therapy 63 Improved quality of life in multiple small studies [63][64][65] Non-invasive mapping and Lower procedure time Modification of operator strategy in 43% of cases 45 High correlation of between image identified substrate and critical isthmus/LAVA 46 Imaging processing performed at external site Lead time may be required Advances in ablation catheter technologies include the use of higher impedance irrigation, changes in the energy source used for ablation, and pre-ablation cardiac imaging which has been introduced to improve the efficacy of catheter ablation for VT. 9,10…”

“…In a retrospective study (n=8), the highest arrhythmic benefit in terms of VT burden and ICD interventions was in 2 weeks to 3 months after SBRT, perhaps due to transcription and eventual replacement of gap junctions over time after SBRT. 63 The authors surmised SBRT should be considered as a bailout strategy or bridge therapy until heart transplantation in refractory cases. In a study of 10 patients with repeated ICD therapies and refractory to standard treatment, SBRT demonstrated a reduction in VT duration and a trend for reduction in ICD shocks.…”

Cardiac stereotactic radiation therapy for refractory ventricular arrhythmias in patients with left ventricular assist devices

“…18,[49][50][51] Although some teams subsequently reported less marked improvements, cardiac SBRT has emerged as a promising ablative therapy with a growing number of case series reporting the effectiveness of the technique in reducing the burden or eliminating VAs refractory to conventional therapies. 17,20,[52][53][54][55][56][57][58][59][60][61][62] Regarding quality of life, significant improvement in perceived health change and social functioning has been highlighted after cardiac SBRT for refractory VAs. 18,49,62 Short-term safety profile of cardiac SBRT also appears favorable, although long-term data are needed.…”

“…After the initial case reports in human in 2014 and 2015, the ENCORE‐V and ENCORE‐VT trials demonstrated the short‐term safety and efficacy of the technique for reducing VA recurrences (more than 90% of patients experiencing significant VA burden reduction) 18,49–51 . Although some teams subsequently reported less marked improvements, cardiac SBRT has emerged as a promising ablative therapy with a growing number of case series reporting the effectiveness of the technique in reducing the burden or eliminating VAs refractory to conventional therapies 17,20,52–62 . Regarding quality of life, significant improvement in perceived health change and social functioning has been highlighted after cardiac SBRT for refractory VAs 18,49,62 .…”