Minimally invasive procedure to treat high blood pressure

A radically different approach to treating high blood pressure – using a minimally invasive procedure – is being evaluated as part of a Pivotal Phase III 90-site national trial that includes The Carl H. and Edyth Lindner Center for Research and Education at The Christ Hospital.

Resistant hypertension affects more than 12 percent of patients who take anti-hypertensive medications to manage the condition. Despite being on three or more medications, these patients have blood pressure that remains high enough to put them at risk for heart attack or stroke. For every 20 point increase in systolic pressure, the risk of cardiovascular episodes doubles, according to The Christ Hospital cardiology researchers.

"Some patients who have resistant hypertension may already be survivors of heart attacks or have undergone surgery, making their blood pressure management that much more critical," said Eugene Chung, M.D., a lead investigator of the study at The Christ Hospital and medical director of outcomes for the hospital's Heart and Vascular Center.

In earlier studies, patients who underwent this minimally invasive procedure were able to reduce their pressure by about 30 or so points. The positive earlier trial results warranted further study.

The investigational SYMPLICITY™ Renal Denervation System® includes inserting a catheter at the groin and advancing it to the renal arteries where radiofrequency (RF) energy is delivered that disrupts sympathetic nerves around the renal arteries. This prevents neurotransmitters released by these nerves from triggering a hormone response that increases heart rate, constricts blood vessels and raises blood pressure. It is similar to an ablation procedure technique typically used for atrial fibrillation treatment. The application to the sympathetic nerves is novel in the U.S. In earlier SYMPLICITY Phase I and II studies conducted in Europe and Australia, results indicated that the procedure reduced blood pressure significantly.

"Preliminary results suggest that patients need only one such treatment to achieve optimal results, and these results can last for years, significantly decreasing the odds for these higher-risk patients of experiencing a serious heart attack or stroke," said Dean Kereiakes, M.D., also a lead investigator on the study at The Christ Hospital and medical director of The Christ Hospital Heart and Vascular Center, as well as The Carl and Edyth Lindner Center for Research and Education.

The SYMPLICITY Phase III trial is a prospective, single-blind, randomized, controlled trial that will enroll approximately 530 patients in up to 90 research sites nationwide. Those enrolled will be assigned randomly to either treatment or control groups at a 2:1 ratio. Patients' blood pressure will be monitored for six months. Researchers will track and report any major adverse events, including death, end-stage renal disease, or organ damage. After six months, patients in the control group will be allowed to receive the RF procedure if deemed clinically necessary.

In the United States alone, it is estimated that one in every three adults, or about 65 million, have high blood pressure, and many more are at risk of developing it.