Investigation of Catheter-Based Renal Denervation in Patients With Uncontrolled Hypertension in the Absence of Antihypertensive Medications - SPYRAL HTN-OFF MED Pilot

Contribution To Literature:

The SPYRAL HTN-OFF MED Pilot trial showed that renal denervation was superior at improving blood pressure.


The goal of the trial was to evaluate renal sympathetic denervation compared with sham among patients with uncontrolled hypertension (HTN) not on blood pressure medications.

Study Design

  • Randomized
  • Parallel
  • Sham

Patients with uncontrolled HTN not on blood pressure medications were randomized to renal denervation (n = 38) versus sham (n = 42).

  • Total number of enrollees: 80
  • Duration of follow-up: 3 months
  • Mean patient age: 56 years
  • Percentage female: 32%
  • Percentage with diabetes: 3%

Inclusion criteria:

  • Elevated HTN defined as office systolic blood pressure (SBP) ≥150 and <180 mm Hg, or ambulatory SBP ≥140 and <170 mm Hg, or office diastolic blood pressure ≥90 mm Hg

Exclusion criteria:

  • Ineligible renal artery anatomy
  • Estimated glomerular filtration rate <45 ml/min/1.73 m2
  • Type 1 diabetes or uncontrolled type 2 diabetes
  • Secondary cause of HTN

Other salient features/characteristics:

  • At baseline, office SBP was 162 mm Hg in the denervation group vs. 161 mm Hg in the sham group, and ambulatory SBP was 153 mm Hg in the denervation group vs. 152 mm Hg in the sham group.
  • Total number of ablations: 44 in the denervation group

Principal Findings:

The primary outcome, change in ambulatory SBP from baseline to 3 months, was -5.5 mm Hg in the denervation group vs. -0.5 mm Hg in the sham group (p-value between groups = 0.04).

Secondary outcomes:

  • Change in office SBP from baseline to 3 months: -10.0 mm Hg in the denervation group vs. -2.3 mm Hg in the sham group (p-value between groups = 0.02).
  • No major adverse events were observed in either group.


Among patients with uncontrolled HTN not on blood pressure medications, this proof-of-concept trial revealed the efficacy of renal sympathetic denervation. There were no adverse events from this strategy. A notable difference of this trial compared with SYMPLICITY HTN-3 was that more ablation attempts were performed in the main renal artery and branch vessels. A larger pivotal trial is warranted.


Townsend RR, Mahfoud F, Kandzari DE, et al. Catheter-based renal denervation in patients with uncontrolled hypertension in the absence of antihypertensive medications (SPYRAL HTN-OFF MED): a randomized, sham-controlled, proof-of-concept trial. Lancet 2017;390:2160-70.

Presented by Dr. Michael Boehm at the European Society of Cardiology Congress, Barcelona, Spain, August 28, 2017.

Keywords: Antihypertensive Agents, Blood Pressure, Blood Pressure Determination, Blood Pressure Monitoring, Ambulatory, Catheter Ablation, Catheters, Denervation, ESC2017, ESC Congress, Hypertension, Primary Prevention, Sympathectomy, Vascular Diseases

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