A Randomized Sham-Controlled Trial of Renal Sympathetic Denervation in Mild Resistant Hypertension - Symplicity Flex


The SYMPLICITY-HTN 3 trial failed to demonstrate a reduction in blood pressure from renal sympathetic denervation compared with sham among individuals with severe refractory hypertension (n = 535 patients). The goal of the current trial was to evaluate renal sympathetic denervation compared with sham among participants with mild resistant hypertension.


Renal sympathetic denervation will improve blood pressure.

Study Design

  • Randomized
  • Blinded
  • Parallel

Patient Populations:

  • Participants with mild resistant hypertension
  • Mean daytime ambulatory systolic blood pressure 135-149 mm Hg and/or mean diastolic blood pressure 90-94 mm Hg
  • ≥3 antihypertensive medications and stable dosage within the last 4 weeks
  • ≥18 years to ≤75 years

    Number of enrollees: 71
    Duration of follow-up: 6 months
    Mean patient age: 65 years
    Percentage female: 23%


  • Unsuitable anatomy for renal sympathetic denervation
  • Estimated glomerular filtration rate <45 ml/min/1.73 m2

Primary Endpoints:

  • Change in 24-hour systolic blood pressure at 6 months

Drug/Procedures Used:

Participants with mild resistant hypertension were randomized to renal sympathetic denervation with the Symplicity Flex catheter (n = 35) versus sham procedure (n = 36).

Renal sympathetic denervation consisted of 4-6 circumferential ablation runs of 2 minutes. Sham procedure consisted of renal angiography and acoustic signals to mimic the denervation procedure, and saline infusion to mimic analgesic medications.

Principal Findings:

Overall, 71 patients were randomized. The mean age was 65 years, 23% were women, mean body mass index was 32 kg/m2, and 54% had diabetes. The mean number of antihypertensive medications was 4.4.

The mean change in 24-hour blood pressure (intention to treat) was -7.0 mm Hg in the renal denervation group versus -3.5 mm Hg in the sham group (p = 0.15). The mean change in 24-hour blood pressure (treatment received) was -8.3 mm Hg in the renal denervation group versus -3.5 mm Hg in the sham group (p = 0.042).


Among patients with mild resistant hypertension on a mean of 4.4 antihypertensive medications, renal denervation failed to reduce the mean ambulatory blood pressure at 6 months. However, analysis according to actual treatment received suggested a benefit from renal denervation. The current study is limited by small sample size and no urine analysis to assess medication adherence.


Presented by Dr. Steffen Desch at the Transcatheter Cardiovascular Therapeutics meeting (TCT 2014), Washington, DC, September 16, 2014.

Clinical Topics: Prevention, Hypertension

Keywords: Medication Adherence, Denervation, Body Mass Index, Sympathectomy, Intention to Treat Analysis, Blood Pressure Determination, Hypertension, Diabetes Mellitus

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