Long-Term Follow-Up Supports Renal Denervation in Resistant Hypertension

Once likened to science fiction, the prospect of renal denervation as an option for treatment-resistant hypertension in real-world settings seems closer to reality than ever after new data was presented at the 34th Transcatheter Cardiovascular Therapeutics (TCT) conference, the annual scientific symposium of the Cardiovascular Research Foundation.

With a pair of late breaking trials related to renal denervation, including final follow-up data from SYMPLICITY HTN-3, the meeting served as a showcase of the potential renal denervation could have in populations with treatment-resistant hypertension.

"In this long-term follow-up from the SYMPLICITY HTN-3 trial, we observed significant reductions in the blood pressures of patients who underwent treatment with renal denervation, with no long-term complications emerging from this minimally invasive procedure," said coprincipal investigator Deepak L. Bhatt, MD, MPH, executive director of Interventional Cardiovascular Programs at Brigham and Women's Hospital and Professor of Medicine at Harvard Medical School, in a statement from Medtronic.

A single-blind, multicenter, sham-controlled, randomized clinical trial, SYMPLICTY HTN-3 was conducted across 88 sites in the US with the intent of assessing whether use of the Simplicity system for catheter-based renal artery denervation could serve as a treatment for treatment-resistant hypertension in adult patients. The trial enrolled 535 and randomized them in a 2:1 ratio to renal artery denervation or a sham procedure.

The primary outcome of interest for the trial was change in office systolic blood pressure (SBP) from baseline to 6 months. In the TCT 2022 presentation, Bhatt presented data related to the 36-month results from the trial. Of the 535 who underwent randomization, 36-month follow-up was available for 219 patients in the original renal artery denervation group, 63 patients in the crossover group, and 33 patients in the noncrossover group.

Upon analysis, results indicated the change in office SBP was -26.4 mmHg (SD, 25.9) in the renal artery denervation group and -5.7 mmHg (SD, 24.4) in the sham control group (adjusted treatment difference, -22.1 mmHg [95% CI, -27.2 to -17.0]; P <.001). Further analysis demonstrated the change in 24-hour ambulatory SBP at 36 months was -15.6 mmHg (SD, 20.8) in the denervation group and -0.3 mmHg (SD, 15.1) in the sham control group (adjusted treatment difference, -16.5 mmHg [95% CI -20.5 to -12·5]; P ≤.0001).

Results also indicated the denervation group spent a significantly greater amount of time in therapeutic blood pressure range than those in the sham control group (18% [SD, 25.0] vs 9% [SD, 18.8]; P<.0001). Investigators pointed out the rate of the composite safety endpoint up to 48 months was 15%, 14%, and 14% for the denervation, crossover, and noncrossover groups, respectively.

"These findings provide important insights into the evolution of patients' blood pressure control, with and without renal denervation, in a scenario more akin to the real-world setting— under everyday physician management without the frequent follow-up visits and monitoring that occur in research settings,” Bhatt added, in the aforementioned statement. “The results illustrate that for certain patients with high blood pressure, despite attempts to adhere to multiple medications and modify their lifestyles, their blood pressure remains poorly controlled, putting them at risk for cardiovascular complications such as stroke."

With an interest in learning more about the results of SYMPLICITY HTN-3 and the prospect of renal denervation outside of clinical trial settings, Practical Cardiology reached out to Bhatt and that conversation is the subject of the following TCT 2022 House Call.

This study, “Long-term outcomes after catheter-based renal artery denervation for resistant hypertension: final follow-up of the randomised SYMPLICITY HTN-3 Trial,“ was presented at TCT 2022 and simultaneously published in The Lancet.