Although the results of the first controlled trial on renal denervation, SYMPLICITY HTN-3, to treat resistant hypertension (HTN) were not as anticipated, the study did show that a systematic approach dramatically lowered blood pressure in select participants with HTN. Given this finding, Duke is now undertaking 2 new trials on renal denervation designed with added standardization and controls.
Researchers overseeing the new trials, REDUCE-HTN and SPYRAL-HTN, hope to show the effects of renal denervation—which uses radiofrequency energy to treat high blood pressure that isn’t controlled by medication—and identify study patients with hypertension who responded to treatment.
“I believe these trials will show that some patients will respond when doing this in the most controlled way possible,” says Manesh Patel, MD, director of interventional cardiology, co-director of Duke Heart Center, and a principal investigator of the trial.
In the initial trial, all study participants, including those treated and those who received sham treatment, had a significant reduction in blood pressure (mean reduction, 11 mm Hg). “The patients receiving denervation had a reduction of 14 mm Hg, which was not significant compared with 11 mm Hg in the control group,” Patel reports. “This taught us that, with good care and a systematic approach, we could reduce blood pressure in many patients.”
In the current trial, Duke researchers are trying to determine whether renal denervation has a more significant effect in very standardized-control patients.
“For patients on 2 medications or fewer, we are stopping medication for 4 months and seeing if the treatment works better compared with placebo,” Patel explains. “If a patient’s blood pressure increases, we can use medication again. For patients on 3 standard medications (ie, diuretic, calcium channel blocker, angiotensin receptor blocker/angiotensin-converting enzyme inhibitor), we will use sham treatment instead of renal denervation.”
To be eligible to participate in the trials, patients must have a systolic blood pressure value above 150 mm Hg but below 180 mm Hg and take no more than 3 medications or take no medication at all.
“For patients with hypertension problems, this study is one of a few in the United States where they can get access to this type of technology and treatment,” Patel says.