Anticipating Food and Drug Administration approval of at least one investigational device for renal denervation (RDN) as a treatment for hypertension (HTN) refractory to medical therapies, the Society for Cardiovascular Angiography and Interventions is asking its members and the public to provide input on a draft position statement to guide use of the procedure.
SCAI is requesting feedback by June 14.
“With the anticipated FDA approval of renal denervation, there will be a need for SCAI to formulate an official position around clinical competence and training standards, best practices, and institutional and operator requirements for RDN,” Herbert D. Aronow, MD, MPH, chair of the statement writing committee, said in an interview.
RDN is an endoscopic procedure that disrupts the sympathetic nerves near the renal arteries. A number of studies, including sham-controlled, randomized trials, have shown that RDN can achieve short-term reductions in blood pressure for patients for whom HTN medications don’t work. Two devices are awaiting FDA premarket approval: the Paradise uRDN system, by ReCor Medical; and the Symplicity Spyral device, by Medtronic.
However, the trajectory of RDN has been uneven, said Dr. Aronow, president of the Society for Vascular Medicine and medical director for heart and vascular services and Benson Ford Chair in cardiology at Henry Ford Health, Detroit.
“Despite supportive early animal and human data, the first sham-controlled randomized trial of RDN was negative on its primary endpoint,” he said. “Modifications to patient inclusion/exclusion criteria, refinements in denervation technology and protocols, and selection of more appropriate study endpoints resulted in a series of positive randomized, sham-controlled trials. These second-generation trials found that RDN, when compared with sham therapy, substantially reduced ambulatory and office blood pressures.”
The draft is available for review at the SCAI website. Comments may be submitted via a link to a questionnaire.
“Through the open comment process, we are hoping to gain broad perspective from stakeholders, including clinicians, hospitals, payers, professional societies, industry and patients,” Dr. Aronow said. “By incorporating this feedback, we hope to enhance the quality of the document before we submit it for publication.”
The bulk of the SCAI draft position statement is devoted to patient selection and procedural and technical considerations. “We believe it will serve as a road map for the successful launch of RDN programs around the United States,” Dr. Aronow said.
Patient selection considerations
The draft statement notes that RDN for all patients with uncontrolled HTN “would not currently be practical.” The average age of patients for whom RDN showed effectiveness in the cited clinical trials was less than 60 years. The effectiveness of RDN for patients in whom arterial stiffness is a primary driver of HTN “is less certain.”
Patients who may benefit most from RDN are those with limited medical treatment options. Initially, RDN was tried on patients who had continued to experience resistant HTN despite taking three or more medications, including a diuretic, the statement noted. But even nonadherent patients may derive some potential benefit from RDN.
The statement also added that RDN isn’t a panacea; about one-third of trial patients didn’t respond to the procedure. The most reliable predictor of response may be higher levels of baseline systolic blood pressure, otherwise known as Wilder’s principle. The statement listed other potential markers of success, including higher nocturnal blood pressure and wider swings in nocturnal blood pressure.