Investigation of Catheter-Based Renal Denervation in Patients With Uncontrolled Hypertension in the Presence of Antihypertensive Medications - SPYRAL HTN-ON MED

Contribution To Literature:

The SPYRAL HTN-ON MED trial showed that renal denervation was superior to sham control at improving blood pressure.

Description:

The goal of the trial was to evaluate renal denervation compared with sham control among patients with uncontrolled blood pressure on antihypertensive drug therapy.


Study Design

  • Randomized
  • Parallel
  • Masked (patients, caregivers, and those assessing blood pressure)

Patients with uncontrolled blood pressure on antihypertensive drug therapy were randomized to renal denervation (n = 38) versus sham control (n = 42).

Renal denervation was performed in a spiral fashion in four quadrants: the renal artery and branch vessels 3-8 mm in diameter with the Symplicity Spyral or the Symplicity G3 denervation catheter.

In the sham group, patients underwent a renal angiogram and stayed on the table for ≥20 minutes.

  • Total number of enrollees: 80
  • Duration of follow-up: 6 months
  • Mean patient age: 54 years
  • Percentage female: 13%
  • Percentage with diabetes: 13%

Inclusion criteria:

  • Ambulatory patients 18-80 years of age with systolic blood pressure 150-180 mm Hg and diastolic blood pressure ≥90 mm Hg, and 24-hour ambulatory systolic blood pressure between 140 and 170 mm Hg
  • On 1-3 antihypertensive drugs with stable doses for ≥6 weeks

Principal Findings:

The first co-primary outcome, change in 24-hour systolic blood pressure from baseline to 6 months, was -9.0 mm Hg in the renal denervation group compared with -1.6 mm Hg in the sham group (p = 0.0051 between groups).

The second co-primary outcome, change in 24-hour diastolic blood pressure from baseline to 6 months, was -6.0 mm Hg in the renal denervation group compared with -1.9 mm Hg in the sham group (p = 0.029 between groups).

Secondary outcomes:

  • Change in office systolic blood pressure from baseline to 6 months: -9.4 mm Hg in the renal denervation group compared with -2.6 mm Hg in the sham group (p = 0.021 between groups)
  • Change in office diastolic blood pressure from baseline to 6 months: -5.2 mm Hg in the renal denervation group compared with -1.7 mm Hg in the sham group (p = 0.048 between groups)
  • There were no procedural or intermediate-term adverse safety events associated with renal denervation.

Interpretation:

Among patients with uncontrolled hypertension on blood pressure medication, this proof-of-concept trial revealed the efficacy of renal sympathetic denervation. Compared with sham, renal denervation was associated with an approximate 7 mm Hg reduction in 24-hour systolic blood pressure at 6 months. 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.

This study parallels the findings of the SPYRAL HTN-OFF MED trial, which treated patients not on antihypertensive medications. Future research will need to identify patients most likely to benefit from this technology, while long-term efficacy and safety also needs to be examined.

References:

Kandzari DE, Böhm M, Mahfoud F, et al., on behalf of the SPYRAL HTN-ON MED trial investigators. Effects of renal denervation on blood pressure in the presence of antihypertensive drugs: 6-month efficacy and safety results from the SPYRAL HTN-ON MED proof-of-concept randomised trial. Lancet 2018;391:2346-55.

Editorial Comment: Blankestijn PJ, Bots ML. Renal denervation in uncontrolled hypertension: the story continues to unfold. Lancet 2018;391:2300-2.

Clinical Topics: Arrhythmias and Clinical EP, Diabetes and Cardiometabolic Disease, Invasive Cardiovascular Angiography and Intervention, Prevention, SCD/Ventricular Arrhythmias, Atrial Fibrillation/Supraventricular Arrhythmias, Interventions and Imaging, Angiography, Nuclear Imaging, Hypertension

Keywords: Angiography, Antihypertensive Agents, Blood Pressure, Blood Pressure Determination, Blood Pressure Monitoring, Ambulatory, Catheter Ablation, Denervation, Hypertension, Metabolic Syndrome X, Primary Prevention, Renal Artery


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