Abstract 14747: Renal Denervation via Catheter-Based Delivery of Radiofrequency Energy Significantly Reduces Blood Pressure in Subjects With Severe Treatment-Resistant Hypertension: Long-Term Results From the Symplicity HTN Clinical Trials
Background: Renal denervation (RDN) with the Symplicity™ catheter involves the ablation of nerves surrounding the renal artery using low power radiofrequency energy. The procedure results in reduced sympathetic nerve activity and consequent blood pressure (BP) reductions in subjects with resistant hypertension (rHTN). The Symplicity HTN-1 study and the randomized Symplicity HTN-2 trial demonstrated significantly lower BP at 6 months following RDN with no immediate safety concerns.
Objectives: We conducted a pooled analysis of the prospective Symplicity HTN 1 and HTN 2 studies to investigate the durability of response and assess long-term safety of this new therapy.
Methods: Included subjects had rHTN (i.e., systolic BP (SBP) ≥160 mm Hg despite ≥3 antihypertensive medications, including a diuretic), and eGFR ≥45 mL/min/1.73 m2. Office-based BP was measured at 1, 3 and 6 months and annually to 3 yrs after RDN and compared with baseline BP. Subjects generally continued their antihypertensive medications but changes were allowed as deemed medically necessary.
Results: The mean age of the 239 subjects was 57 yrs, mean BMI was 32 kg/m2, mean baseline BP and eGFR were 178±18/98±15 mm Hg and 82.7±19.9 mL/min/1.73 m2. Reduction in BP was -24±23/-10±13 mm Hg at 6 months, -26±24/-12±13 mm Hg at 1 yr and -30±24/-13±14 mm Hg at 2 yrs (p<0.01 for all). At 2 yrs the proportion of subjects with SBP <140 mm Hg and SBP < 160 mm Hg was 37% and 77%, respectively. eGFR was stable (80.8±18.6 mL/min/1.73 m2) through 1 yr post-RDN. Procedural complications included 2 renal artery dissections, and 4 access site complications all treated without further consequence. Intraprocedural bradycardia requiring atropine occurred in 10.7% of subjects. Renal artery stenosis (n=2) and death (n=5) were unrelated to RDN treatment. Twelve hypertensive events and 5 hypotensive events required hospitalization; 3 episodes of acute renal failure unrelated to RDN all resolved completely.
Conclusions: Results from the Symplicity HTN-1 and Symplicity HTN-2 studies demonstrate safe and sustained BP reduction through 2 yrs. Adverse events were mostly those commonly reported with percutaneous procedures or in subjects with severe rHTN. Results through 3 yrs will be available for presentation at the meeting.
- © 2013 by American Heart Association, Inc.