Neuromodulation in electrical storm: safety and efficacy of renal denervation

Abstract Background Catheter ablation (CA) has shown efficacy in managing ventricular arrhythmias (VA) associated with structural heart disease. However, some patients continue to experience refractory VA despite pharmacological therapy and multiple CA attempts. In such cases, additional interventions, including autonomic neuromodulation, have been investigated. Renal denervation (RDN), a technique originally developed to treat resistant arterial hypertension, works by inhibiting the afferent renal sympathetic pathways, thereby reducing systemic sympathetic overactivity. Given this mechanism, RDN has been studied as a therapeutic option for arrhythmias, including atrial fibrillation and VA, with promising outcomes. Objective This study aims to evaluate both the effectiveness and safety profile of renal denervation as a therapeutic strategy for managing refractory ventricular arrhythmia storms in patients classified as high-risk. Methods A retrospective analysis was conducted on renal denervation procedures performed to manage electrical storms at a tertiary center from February 2020 to October 2024. Baseline patient characteristics, procedural details, and acute complications were recorded. Recurrence of ventricular arrhythmia post-RDN was evaluated at one month and six months to assess the intervention's impact on arrhythmia control. Results A total of 11 patients underwent renal denervation (RDN) for the treatment of refractory ventricular arrhythmias (VA). The cohort had a mean age of 63 ± 10 years, with 9 males. The primary diagnosis in most patients was ischemic cardiomyopathy (n=7), characterized by a mean left ventricular ejection fraction (LVEF) of 25 ± 8%, with no history of resistant arterial hypertension. All patients had implantable cardioverter-defibrillators (ICDs), and two of these devices included concomitant cardiac resynchronization therapy. Nine patients had previously undergone endocardial VA ablation. Among the two patients without prior ablation, one was contraindicated due to a large left ventricular thrombus, while the other underwent an electrophysiological study without inducible ventricular tachycardia. In the four weeks preceding RDN, patients experienced an average of 18 ± 20 sustained VA episodes, meeting the criteria for an electrical storm (≥3 episodes within 24 hours). During RDN, a mean of 15 ± 9 radiofrequency applications were delivered to the right renal artery and 12 ± 9 to the left renal artery. No acute procedural complications were observed. One month post-RDN, VA episodes were reduced to a mean of 0 ± 1, with only two patients experiencing recurrent VA. At the six-month follow-up, VA recurrence remained low (mean 1 ± 2 episodes), and at one year, there was an increase in mean episodes (29 ± 50), with only one patient experiencing new episodes. Conclusion In our pilot study, RDN appeared to be a safe and effective treatment for the management of VA.