Renal Denervation Effective at Reducing Blood Pressure Without Medication

MARCH 29, 2020
Patrick Campbell
Results of the SPYRAL-HTN OFF MED pivotal trial suggest renal denervation can result in statistically significant reductions in average blood pressure without causing an increase in major adverse effects.

Designed to test whether renal denervation could reduce blood pressure without the use of antihypertensive medication in patients with untreated hypertension—indicating reductions of 3.9 mmHg for 24-hour systolic blood pressure (SBP) and 6.5 mmHg for office SBP compared to those who underwent a sham procedure.

“These results show that renal denervation offers an effective alternative approach to traditional medications that require patient adherence for reducing blood pressure,” said study presenter Michael Böhm, MD, of Saarland University Medical Center in Hamburg, Germany, in a statement. “Furthermore, the findings show that RDN lowers blood pressure not just during the day but also throughout the night and early-morning periods when risk is highest for (adverse) clinical events and the effect of some medications on blood pressure is reduced.”

Presented at the American College of Cardiology’s Annual Scientific Session Together with World Congress of Cardiology (ACC.20/WCC), the pivotal trial, which will be included in the application for FDA approval from Medtronic Inc. for their renal denervation device, examined the effect of renal denervation in a population of 331 patients.

The international, prospective, single-blinded, randomized, sham-controlled study was performed at 46 sites recruited patients from 9 different countries. Patients included in the study had a mean age of 53 years, 67% were men, 5% had type 2 diabetes, and the average systolic blood pressure over 24 hours was between 140-170 mmHg. Inclusion criteria included the absence of antihypertensive medication for at least 3 weeks prior to their blood pressure measurement at study entry.

Additional inclusion criteria were an office SBP of 150 mmHg or greater but less than 180 mmHg, an office diastolic blood pressure 90 mmHg or greater, and a mean 24-SBP of 140 mmHg or greater but less than 170 mmHg as measured through ambulatory blood pressure monitoring.

In total, 166 patients were randomized to renal denervation and 165 underwent a sham procedure. The primary efficacy endpoint of the trial was change in average 24-hour SBP and the secondary efficacy endpoint was change in average SBP measured in the doctor’s office at 3 months. Investigators also assessed safety events including death, stroke, changes in renal function, or any injury to arteries surrounding the kidney.

Analysis for the primary and secondary efficacy endpoints revealed the difference between groups was -3.9 mmHg for 24-hour SBP and -6.5 mmHg for office SBP—investigators noted a 99.9% probability that renal denervation was superior to the sham procedure. Additionally, there were incidences of death, stroke, or changes in renal function during the 3-month follow-up period. 

“This study establishes RDN as an additional option beyond exercise or lifestyle modification for patients with high blood pressure who are unwilling to take or cannot tolerate medication,” said Böhm, in the aforementioned release.

This study, “Catheter-based Renal Denervation In The Absence Of Antihypertensive Medications: Primary Results From The SPYRAL HTN-OFF MED Pivotal Trial,” was presented at ACC.20/WCC.

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