Study to examine SYMPLICITY renal denervation system for treatment-resistant hypertension

The University of Michigan Cardiovascular Center will participate in a national clinical trial to treat the most challenging form of high blood pressure.

"There are many good options for treating high blood pressure," says University of Michigan interventional cardiologist and co-principal investigator Hitinder Gurm, M.D. "There are lifestyle changes people can make, and medications that can help. But for a group of patients their blood pressure remains high even after doing all the right things."

The SYMPLICITY HTN-3 Trial is considered a landmark study to examine the investigational SYMPLICITY renal denervation system for treatment-resistant hypertension.

Treatment-resistant hypertension is blood pressure that remains high - greater than 140/90 mmHG -- despite treatment with antihypertensive drugs. The chronic condition poses a serious health threat to millions of Americans.

Uncontrolled hypertension is dangerous because it raises the risk for stroke and heart attack, as well as heart failure and kidney disease.

"There are nearly six million Americans who are unable to get their blood pressure under control despite treatment with three, four, five or six blood pressure medications," says U-M cardiologist and co-principal investigator Robert Brook, M.D. "This investigational treatment may represent a new and innovative approach to help patients reach their target blood pressure levels."

U-M interventional radiologists and cardiologists will collaborate on the study. The U-M study team will also include interventional vascular radiologist David M. Williams, M.D., and cardiologists Daniel Stephen Menees, M.D., and James Brian Bryd, M.D.

People considering participation in the trial should be diagnosed with hypertension and unable to control their blood pressure even when taking three or more blood pressure medications.

Blood pressure is typically recorded as two numbers and systolic is the top number. It measures the pressure in the arteries when the heart beats.
The bottom number, called diastolic, measures the pressure in the arteries between heartbeats when the heart muscle is resting.

SYMPLICITY HTN-3 is a randomized, controlled trial designed to evaluate the safety and effectiveness of renal denervation in patients with treatment-resistant hypertension with systolic blood pressure greater than 160 mmHg.

The renal denervation therapy being investigated is a minimally invasive, catheter-based procedure. It uses a tiny device that is threaded into the arteries to deactivate the nerves to the kidneys.

The nerves are part of the sympathetic nervous system, which is one of the ways the body controls blood pressure. When overactive, these nerves can raise blood pressure and contribute to heart, kidney and blood vessel damage.

The study will enroll approximately 530 treatment-resistant hypertension patients.

People enrolled in the SYMPLICITY trial who receive the investigational treatment will be compared with a control group that does not, with all patients continuing to take their blood pressure medications. Patients will be randomly assigned to a treatment group or control group.

"This study has a unique design since patients in the control group may have the option to receive renal denervation treatment six months following randomization, which may help extend the potential benefit of renal denervation to all participants if the trial demonstrates the procedure is effective," Wlliams says.

The SYMPLICITY HTN-3 renal denervation system has been successfully used since 2007 to treat more than 4,000 patients worldwide. It has been commercially available in Europe and Australia since April 2010.

The SYMPLICITY system is not approved by the U.S. Food and Drug Administration for commercial distribution in the United States and is only available through clinical trial.