Catheter-based renal denervation for treatment of patients with treatment-resistant hypertension: 36 month results from the SYMPLICITY HTN-2 randomized clinical trial

Abstract

Aim: The aim of this study was to determine long-term results of renal artery denervation for treatment of treatment-resistant hypertension in the SYMPLICITY HTN-2 study.

Methods: SYMPLICITY HTN-2 randomized 106 subjects with treatment-resistant hypertension to renal denervation or medical therapy alone. At 6 months, 37 control subjects crossed over to renal denervation. Office blood pressure measurements, antihypertensive medication use, and safety events were followed every 6 months through 3 years.

Results: Follow-up was available at 36 months in 40 of 52 subjects in the initial renal denervation group and at 30 months in 30 of 37 subjects who crossed over and received renal denervation at 6 months. Baseline blood pressure was 184 ± 19/99 ± 16 mmHg in all treated subjects. At 30-month post-procedure, systolic blood pressure decreased 34 mmHg (95% CI: -40, -27, P < 0.01) and diastolic blood pressure decreased 13 mmHg (95% CI: -16, -10, P < 0.01). The systolic and diastolic blood pressure reduction at 36 months for the initial renal denervation group was -33 mmHg (95% CI: -40, -25, P < 0.01) and -14 mmHg (95% CI: -17, -10, P < 0.01), respectively. Procedural complications included one haematoma, and one renal artery dissection before energy delivery that was treated successfully. Later complications included two cases of acute renal failure, which fully resolved, 15 hypertensive events requiring hospitalization, and three deaths.

Conclusion: Renal denervation resulted in sustained lowering of blood pressure at 3 years in a selected population of subjects with severe, treatment-resistant hypertension without serious safety concerns.

Clinical trial registration: NCT00888433.

Keywords: Renal denervation; Resistant hypertension; Symplicity.

Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

Figures

Figure 1

Study flow.

Figure 2

(A) Office systolic blood pressure (all P < 0.01 by 6 months after renal denervation and after crossover) and heart rate (P < 0.01 at 6, 12, 18 months, P = 0.06 at 24 months, P = 0.16 at 30 months, and P = 0.04 at 36 months and for difference in the mean heart rate in the pooled population from baseline to follow-up). RDN, renal denervation. Solid bar: original renal denervation treatment group. Hashed bar: crossover to renal denervation treatment from control group. (B) Post-procedure change in office blood pressure. Systolic blood pressure, SBP; diastolic blood pressure, DBP. P < 0.01 at all-time periods for blood pressure difference from baseline. White bar: SBP. Black bar: DBP.

Figure 3

Systolic blood pressure response rate. Systolic blood pressure, SBP, white bar: ≥10 mm reduction in SBP, black bar: ≥20 mm reduction in SBP, CI, confidence interval.

Figure A1

Study randomization, 24-h ambulatory blood pressure measurement, ABPM; month, mo; week, wk; systolic blood pressure, SBP; classes of antihypertensive medications, meds; magnetic resonance angiography, MRA; computed tomography angiography, CTA; duplex ultrasonography, duplex.