May 17, 2013 — Can high blood pressure be safely reduced and controlled by “disconnecting” nerves in the kidneys? That is a question that a new clinical study called Symplicity HTN-3 at University Hospitals (UH) Case Medical Center hopes to answer.
The study will enroll people who have resistant hypertension, meaning that blood pressure remains extremely high despite taking three or more medications. UH is a clinical site for the five-year national study funded by Medtronic and is one of 90 sites in the nation that will enroll more than 500 people with high blood pressure resistant to medical therapy into the study.
At UH, the trial is coordinated by the UH Harrington Heart and Vascular Institute and the Clinical Hypertension Program. It will involve a novel multi-disciplinary approach to hypertension treatment using cardiac and kidney specialists.
Sahil A. Parikh, M.D., an interventional cardiologist in the UH Harrington Heart and Vascular Institute, assistant professor of medicine at Case Western Reserve University School of Medicine and co-principal investigator of the study, said, “This may be a transformative trial if this experimental treatment is found to help patients who have not been able to control their blood pressure and are therefore at extremely high risk for heart attack, stroke, and kidney failure.”
In the Symplicity HTN-3 clinical study, research subjects will be randomly assigned to one of two groups: One-third will continue the best available medical treatment and two-thirds will combine the best available medical treatment with a procedure where participants will have the nerves in their renal arteries disrupted with radio frequency energy that generates heat. The process is called renal denervation.
An earlier study (Symplicity HTN-2), performed in Europe and Australia, found that patients who underwent renal denervation experienced a nearly 30mmHg of systolic blood pressure reduction compared to treatment with medications alone. (Systolic blood pressure refers to the peak pressure in the arteries and is the top number in a blood pressure reading, which is measured in millimeters of mercury, written as mmHg.) Symplicity HTN-3 will be a much larger trial conducted entirely in the United States.
The denervation of the kidney arteries will be performed in the cardiac catheterization lab by Parikh and colleagues, including Marco Costa, M.D., director, Interventional Cardiovascular Center, UH Harrington Heart and Vascular Institute, and Vikram Kashyap, M.D., co-director, UH Harrington Heart and Vascular Institute and Chief, Division of Vascular Surgery and Endovascular Therapy. Both Costa and Kashyap are professors of medicine at Case Western Reserve University School of Medicine.
“The procedure itself takes about 45 minutes,” said Parikh. “We use low level radio frequency energy to heat the tissue in the renal artery just enough to eliminate the nerves without hurting the arterial wall. Patients generally experience minimal discomfort during the procedure. So far, long-term side effects have been minimal in the patients treated in Europe and Australia.”
Co-principal investigator of the study at UH is Jackson T. Wright, Jr., M.D., Ph.D., director of the Clinical Hypertension Program and director of the WT Dahms, M.D., Clinical Research Unit at UH. “This study will provide the most challenging test of this procedure in the most resistant hypertensive patients who are uncontrolled despite the best therapy available,” said Wright, who is also professor of medicine at Case Western Reserve University and a leading expert in hypertension research.
Hypertension is one of the leading contributors to death from cardiovascular causes in the world. Nearly 1 billion patients worldwide have hypertension requiring therapy.
The study is currently enrolling patients 18 to 80 years old.
For more information: www.uhhospitals.org