Easing high blood pressure without medication?

The Symplicity trial tests a minimally invasive procedure known as renal denervation. The experimental procedure uses heat that is generated by radio frequency to disrupt nerve communication to and from the kidneys. This can reduce overactivity in the sympathetic nervous system, a frequent cause of chronic high blood pressure.

"The sympathetic nervous system controls blood pressure and can cause hypertension initiated by life and stress," says David L. Brown, M.D., principal investigator at THE HEART HOSPITAL Baylor Plano. "This investigational device is being tested to determine if it will disrupt the sympathetic nervous system, which may significantly lower blood pressure, stop multiple antihypertensive medications, and have an effect on other conditions affected by the sympathetic nervous system."

Blood pressure is measured in millimeters of mercury (mmHg). Less than 120/80 is considered healthy. To enroll in the Symplicity trial, patients must have a blood pressure level in which the top (systolic) number is above 160. They must also be taking the maximum dose of three to five different blood pressure medications simultaneously but not achieving the desired lower blood pressure levels.

"In previous studies of this device in limited numbers of people, this simple procedure reduced patients' blood pressure by an average of about 30 mmHg, a reduction that persisted throughout subsequent assessments," says Sonia Prashar, M.S.,CCRC, research coordinator at THE HEART HOSPITAL Baylor Plano. Baylor Jack and Jane Hamilton Heart and Vascular Hospital also is participating in the study.

Two Groups Comprise the Study

Participants will be randomly assigned into two groups: One group will have the renal denervation procedure and the other group will not. (No one but the surgical team will know who is in each group.) Patients will be given home blood pressure monitors and followed up with frequently. After six months, participants who did not have the procedure may be given the option of having it done, if they still qualify.

If the study confirms that renal denervation can result in a large, persistent decrease in blood pressure, it could be excellent news for people who have high blood pressure that isn't being successfully controlled with medication.

"Improving blood pressure has a profound effect on longevity and reducing the risk of stroke," says James W. Choi, M.D., primary investigator for the Symplicity trial at Baylor Heart and Vascular Hospital. "Catheterbased renal denervation is an exciting, investigational treatment for patients with resistant hypertension who otherwise might not be able to be helped."