Abstract 20949: Impact of Renal Denervation on Autonomic Nerve Activity

Abstract

Introduction: Recent studies reported potential antiarrhythmic effect of catheter-based renal denervation (RDN). We sought to evaluate impacts of RDN on cardiac autonomic nerve activity in ambulatory canine model. Methods: Telemetry devices (D70-EEE, DSI) were implanted in 17 mongrel dogs to record ambulatory nerve activity simultaneously from left stellate ganglion (SG), superior left ganglionated plexus (SLGP), and left renal nerve. After 1 week of baseline nerve activity recording, RDN was performed at both renal arteries using a specialized catheter (Symplicity TM , Medtronic) (n=10). A control animals underwent autonomic nerve recording operation but with sham procedure (n=3). Bilateral surgical stripping of the renal nerve adventitia was performed in 4 dogs (n=4, surgical RDN). One-minute integrated nerve activities were quantified and compared among groups up to 2 weeks. Results: Renal nerve acvitivity (RNA) decreased after catheter RDN (-6.7±13.4% from baseline), while RNA increased after sham operation by 7.4±9.5% (p=0.103). After surgical RDN, no RNA was observed. In contrast to the increased SG nerve activity (SGNA) after sham operation (+2.2±11.4%), SGNA decreased after catheter RDN (-2.1±10.8%, p=0.073) and surgical RDN (-10.6±13.1%, p=0.061 vs. control). SLGP nerve activity (SLGPNA) also increased by 7.1±3.1% after sham operation, while SLGPNA decreased after catheter-based (-8.1±13.9%, p=0.008), and surgical RDN (-6.3±10.2%, p=0.073 vs. control). Immunohistochemistry showed increment of TH (tyrosine hydroxylase)-negative cells in SG after RDN (% of TH-negative cells: control=1.8%, catheter RDN=5.5% [p=0.058 vs. control], surgical RDN=7.35% [p=0.039, vs. control]). Conclusions: The response of renal nerve and cardiac autonomic nerve activity to catheter based RDN was diverse. Renal denervation decreased SGNA and SLGPNA, with neural remodeling at SG. These results may support anti-arrhythmic effects of RDN.