Pooled, 6-month Renal Safety And Blood Pressure Reductions Using The Symplicity Spyral Radiofrequency Renal Denervation Catheter

Background: Renal denervation (RDN) targets the sympathetic nervous system to lower blood pressure (BP). Impact on long-term renal function after RDN is less well known. We report 6-month renal safety and BP reductions after RDN from the largest database, using the latest generation, multi-electrode, radiofrequency (RF) Symplicity Spyral™ catheter. Methods: A broad spectrum of patients with hypertension were enrolled in the SPYRAL HTN Global Clinical Program (4 major studies; SPYRAL First-In-Man, SPYRAL HTN-OFF MED, -ON MED and Global SYMPLICITY Registry [GSR]). GSR is an all-comer registry for patients with uncontrolled hypertension, including chronic kidney disease (CKD), whereas patients enrolled in the SPYRAL HTN-OFF and -ON MED trials required to have OSBP ≥150 and <180 mmHg and ODBP ≥90 mmHg. OFF MED patients were required to have a drug washout period prior to treatment and did not take drugs for the first 3 months. ON MED patients were on a stable 1-3 antihypertensive drug regimen for 6 months. All were treated with RF RDN using the Spyral catheter. We pooled reductions in office and 24-h ambulatory BP, safety outcomes include changes in the estimated glomerular filtration rate (eGFR) and renal artery stenosis incidence (>70%, confirmed by angiography). Results: As of December 2022, 1,284 patients have received RF RDN with the Spyral catheter. Patients at baseline were 58±12yrs old, 37.6% female, 29.1% had type 2 diabetes, eGFR was 77.7±23.9mL/min/1.73m2, 20.7% had CKD stage 3 or higher, OSBP was 166±21mmHg and ASBP was 153±16mmHg. 6 months after RDN, OSBP changed by -14.8±22.1 (n=940; p<0.001) and ASBP changed by -8.9±16.0 (n=678; p<0.001). Significant diastolic BP reductions were also observed. eGFR changed by -2.0mL/min/1.73m2. There was no incidence of renal artery stenosis (>70%). Conclusion: In this large, pooled population of patients receiving RF RDN using the Spyral catheter, there were significant and consistent BP reductions through 6 months. There was no incidence of renal artery stenosis, and eGFR change was consistent with the natural progression of the aging hypertensive population. These data highlight the safety and efficacy of RF RDN as an adjunctive therapy to antihypertensive drugs to treat high BP.