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The Symplicity™ renal denervation catheter uses low power radiofrequency energy to ablate the renal artery nerves and has been shown to lower blood pressure (BP) in patients with treatment-resistant hypertension. Continued follow-up of patients who have undergone renal denervation (RDN) is essential to establish the long-term safety and effectiveness of this procedure.
The open-label Symplicity HTN-1 study enrolled 153 patients with severe resistant hypertension (systolic BP ≥160 mm Hg in the presence of ≥3 antihypertensive drugs, including a diuretic). A subset of patients (n=129) is being followed to 3 years post-RDN (35 consented to laboratory assessments to 3 years). The primary endpoint is change in office-based BP from baseline. Data collection includes office-based BP measurement every 6 months, renal function, electrolytes, and medication usage.
A total of 34 patients have reached the 3 year follow-up time point (9 with labs). Baseline BP was 175/98±12/11 mmHg. Mean SBP change post-RDN was -18.0±16.6 mm Hg at 1 month, -28.4 ± 17.6 mm Hg at 6 months, -27.6 ± 16.3 mm Hg at 2 years and -31.3 ± 14.9 mm Hg at 3 years. Medication usage remained similar to baseline with 35% aldosterone antagonist, 85% beta blocker and 82% calcium channel blocker use at baseline and at 3 years; diuretic use 91% and 88%, angiotensin receptor antagonists 71% and 76%, and ACE inhibitors 50% and 59% at baseline and 3 years, respectively. At 3 years estimated glomerular filtration rates (eGFR) declined by -13.2±12.1 from a baseline of 82.2±16.1 mL/min/m2.
Among patients with full 3 year follow-up, RDN results in significant, sustained lowering of SBP in patients with treatment-resistant hypertension and a baseline SBP > 160 mm Hg. Antihypertensive medication usage was similar at baseline and 3 years.
- 2013 American College of Cardiology Foundation