If you suffer from high blood pressure but despite dieting, exercise, and medication still have not been able to lower your blood pressure level to accepted norms, there may be a new procedure that can help.

With over 30 percent of adults in the U.S. alone suffering from hypertension (typically gauged at a normal level of 120/80) the urgency of getting high blood pressure under control has never been more urgent. Indeed, the “risk of cardiovascular death doubles with every 20 point increase in systolic (the higher number) blood pressure,” according to Dr. Stephen Worthley of the Royal Adelaide Hospital in Australia. While lifestyle changes, exercise and diet – along with appropriate medication – have been and continue to be the mainstream methods of getting hypertension under control, there is a new method that is gaining credibility in the research and medical communities.

An estimated 68 million Americans alone, or one in three, have high blood pressure, considered a risk factor for heart disease, the world's number one killer [1]. The cost of hypertension is significant, not only to people individually, but to the national economy. In 2010, high blood pressure was projected to cost the United States $93.5 billion in health care services, medications, and missed days of work. And sometimes, the disease is not even evident to people who have it. About one in five (20.4 percent) U.S. adults with high blood pressure don't know that they have it.

Renal Denervation illustratedCredit: National Institutes of Health

Renal Denervation or RD

Of the many things people can do to lower their blood pressure, one - Renal Denervation or RD - may not be a familiar term, but it could soon be. RD (also known as endovascular catheter technology), involves threading a catheter through the renal arteries from the femoral artery in the groin. The catheter delivers radiofrequency energy to create tiny lesions along the renal sympathetic nerves that help regulate blood pressure. The lesions disrupt the nerve supply to decrease systolic blood pressure, the top number in a blood pressure reading. It’s often the renal nerves that contribute to the type of hypertension that is resistant to treatment.

The method is becoming so popular that a number of companies have begun selling the device that is used in the procedure. For example, St Jude Medical Inc. has received European approval to begin selling their RD device called the EnligHTN Renal Denervation System and expects to launch the device for use in the United States in the near future. Many more medical technology companies are investing heavily in developing similar devices. In fact the device is expected to become so popular that some financial analysts who specialize in the medical technology field believe the worldwide market for such devices could grow to $2.8 billion by 2020.

Studies Have Proven RD Benefits

Several recent studies support the international optimism over RD’s future.

In one study [2], conducted in 2011, scientists acknowledged that hypertension prevention and treatment methods often don’t work well for some people. The researchers observed that current treatment methods fail in a considerable number of patients for various reasons including drug-intolerance, the patients don’t stick to their hypertension control regimen, and more. In reviewing the RD method, the researchers were able to state that “the available evidence from the limited number of uncontrolled hypertensive patients in whom Renal Denervation has been performed are auspicious and indicate that the procedure has a favorable safety profile and is associated with a substantial and presumably sustained BP reduction.”

In an early 2009 clinical trial of the method 45 patients underwent the procedure. The volunteers were in their late 50s and had an average blood pressure of 177/101 (even though they were already taking hypertension medication). The RD procedure took about 38 minutes and there were no long-term adverse effects from the procedure. The researchers were able to report a “highly significant reduction in both systolic and diastolic blood pressures” in the patients following the RD procedure. Even better, the reduced hypertension levels stayed low.

While the study group was small, and the volunteers’ conditions were more serious than most, the researchers noted that additional studies could find that other patients may benefit from the RD procedure and several clinical trials have been conducted and more are planned.

Study Looked At Hypertension In All AgesThe EnligHTN device for RDCredit: St. Jude Medical, Inc.

In another study [3], researchers utilized 106 participants (each of whom had a systolic blood pressure level of 160 or more despite taking three or more medications for the condition), 52 underwent the RD procedure and 54 were controls that did not undergo the procedure. The ages of the volunteers ranged from 18 to 85. Data at six months demonstrated a blood pressure reduction in 84 percent of those undergoing the procedure, but only 35 percent of the control group. And a follow up of the volunteers over a year’s time showed they were able to maintain the reduction in blood pressure.

While the buzz about RD continues to be positive, there are some cautions being expressed. Primarily these concerns involve whether or not the treatment will last and whether the nerves that are affected in the procedure might re-grow over time and if they do to what degree. There is also discussion about what other effects the procedure might have even though few or little negative effects have been noted so far.

So, the sum of the findings among researchers is that catheter-based RD can safely be used to substantially reduce blood pressure in treatment-resistant hypertensive patients. There are also studies planned that would determine if the RD procedure is viable in people with only mild hypertension.

For those with hypertension the RD method may not yet be readily available, but it soon may be.



[1] According to the U.S. Centers for Disease Control and Prevention

[2] Renal Denervation and Hypertension. American Journal of Hypertension 2011; 24 6, 635–642. doi:10.1038/ajh.2011.35

 [3] Renal Sympathetic Denervation in Patients With Treatment-Resistant Hypertension (The Symplicity HTN-2 Trial): A Randomised Controlled Trial. Lancet. 2010 Dec 4; 376(9756): 1903-9. Epub 2010 Nov. 17.