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

Contribution To Literature:

Highlighted text has been updated as of November 7, 2022.

The SPYRAL HTN-ON MED trial failed to show that renal denervation was superior to sham control at improving ambulatory blood pressure, though office blood pressure was modestly improved and medication burden was reduced.

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 = 206) vs. sham control (n = 131). Pilot cohort (n = 80 patients) and expansion cohort (n = 257 patients).

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: 337
  • Duration of follow-up: 6 months
  • Mean patient age: 55 years
  • Percentage female: 19%
  • Percentage with diabetes: 11%

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:

Pilot cohort:

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.

Long-term outcomes (3 years):

  • Change in 24-hour systolic blood pressure: -18.7 mm Hg in the renal denervation group vs. -8.6 mm Hg in the sham group (p = 0.004)
  • Change in office systolic blood pressure: -20.9 mm Hg in the renal denervation group vs. -12.5 mm Hg in the sham group (p = 0.07)
  • Change in nighttime systolic blood pressure: -19.3 mm Hg in the renal denervation group vs. -6.6 mm Hg in the sham group (p = 0.002)

Total cohort:

  • Major adverse events at 1 month: 1% in the renal denervation group (p < 0.001 vs. historical performance goal)
  • Mean number of antihypertensive medications at 6 months: 1.9 in the renal denervation group vs. 2.1 in the sham group (p = 0.01)
  • Medication burden (based on number, class, and dosage) at 6 months: 2.9 in the renal denervation group vs. 3.5 in the sham group (p = 0.04)
  • 24-hour ambulatory systolic blood pressure: -6.5 mm Hg in the renal denervation group vs. -4.5 mm Hg in the sham group (p = 0.12)
  • Office systolic blood pressure: -9.9 mm Hg in the renal denervation group vs. -5.1 mm Hg in the sham group (p = 0.001)

Interpretation:

Pilot cohort:

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 and a 10 mm Hg reduction at 36 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.

Total cohort:

When the entire cohort was considered (pilot + expansion cohorts), there was no longer a significant reduction in ambulatory systolic blood pressure for renal denervation vs. sham at 6 months. Major adverse events were low with renal denervation. There was a reduction in number of medications and medication burden for renal denervation vs. sham. Although there was no reduction in ambulatory systolic blood pressure, there was a reduction in office systolic blood pressure for renal denervation vs. sham.

References:

Presented by Dr. David E. Kandzari at the American Heart Association Scientific Sessions, Chicago, IL, November 7, 2022.

Mahfoud F, Kandzari DE, Kario K, et al. Long-term efficacy and safety of renal denervation in the presence of antihypertensive drugs (SPYRAL HTN-ON MED): a randomized, sham-controlled trial. Lancet 2022;399:1401-10.

Presented by Dr. Felix Mahfoud at the American College of Cardiology Annual Scientific Session (ACC 2022), Washington, DC, April 4, 2022.

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: ACC22, ACC Annual Scientific Session, Angiography, Antihypertensive Agents, Blood Pressure, Blood Pressure Determination, Blood Pressure Monitoring, Ambulatory, Catheter Ablation, Denervation, Hypertension, Metabolic Syndrome, Primary Prevention, Renal Artery, AHA22, AHA Annual Scientific Sessions


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