Renal denervation patient registry finds low rate of adverse events

Patients with uncontrolled high blood pressure treated with renal denervation had low rates of adverse events and significant lowering of blood pressure at six months, according to a registry-based study presented at the American College of Cardiology's 63rd Annual Scientific Session.

The Global SYMPLICITY Registry is the first and largest dataset of with treated with renal denervation. The open-label, multicenter study was established to examine the safety and effectiveness of the procedure. Outcomes presented were for the first 1,000 consecutively enrolled patients at six months. There were five attributed to the procedure, including four vascular access site complications (0.34 percent) and one renal artery dissection that was treated. There were also nine hospitalizations for hypertensive emergency (1.0 percent), eight for atrial fibrillation (0.9 percent), eight strokes (0.9 percent), six hospitalizations for new onset heart failure (0.7 percent), five heart attacks (0.6 percent), four deaths (0.4 percent) and two cases of new onset end stage kidney disease (0.2 percent) that were considered unrelated to the procedure.

In addition, office systolic showed a significant drop at six months of 11.9 mmHg for all patients and of 19.8 mmHg for patients with baseline office pressures greater than or equal to 160. Ambulatory systolic blood pressure – measured by a portable machine that patients wore for 24 hours – dropped significantly for all patients at six months, with a drop of 7.9 mmHg for all patients with of 140 or higher – and the largest reductions, 9.2 mmHg, for the subset of patients with ambulatory of 160 or higher.

"This study shows that renal denervation may be an alternative treatment for uncontrolled hypertension," said Michael Böhm, M.D., Ph.D., University of Saarland in Homburg, Germany, and lead investigator of the study. "Our study provides a significant contribution to the discussion about renal denervation when considering the procedure for high risk patients who are suffering from uncontrolled hypertension and have exhausted all other options."

Hypertension increases the risk for heart attack and stroke for more than 77 million Americans and up to one billion adults worldwide. During the Symplicity renal denervation procedure, a catheter is threaded through arteries to deliver radiofrequency energy that inactivates kidney nerves, interrupting electrical signals to and from the kidney, an organ that performs a major role in regulating blood pressure. Although renal denervation is in clinical use for uncontrolled hypertension in more than 80 countries, it is still an experimental approach in the United States.

Enrollment in the registry began in February 2012 and includes patients from 111 international sites. The registry is currently following 2,000 patients with an enrollment goal of 5,000.

Of the 1,000 patients included in this analysis, 60 percent were male and the average age was 61; 49 percent had cardiac disease, 41 percent diabetes, 30 percent chronic kidney disease and 17 percent sleep apnea. At baseline, patients were taking an average of 4.4 blood pressure medications and had an office blood pressure of 164/89. The study collected information on patients' procedures, office and ambulatory blood pressure readings, kidney function, vascular complications and other safety events.

In January 2014, Medtronic announced that it was halting its U.S. pivotal trial on renal denervation because the study had failed to reach its primary efficacy endpoint, though it did meet its primary safety endpoint. Results from this trial will also be presented at ACC.14.

Limitations of the Global Registry study include its open label design and lack of comparison group. Böhm recommends additional research to demonstrate the efficacy of and to identify the patient populations who might benefit most from the procedure.

Related Stories

Renal denervation shows no benefit in resistant hypertension

date Mar 31, 2014

Renal denervation fell short of primary and secondary efficacy goals in patients with severe resistant hypertension but did meet the primary safety endpoints, according to keenly awaited data from SYMPLICITY HTN-3 presented ...

Novel therapy fails for lowering blood pressure

date Mar 29, 2014

An experimental therapy that was once hailed as a possible cure for people whose high blood pressure does not respond to medication, has been shown to be ineffective, a US study said Saturday.

Recommended for you

A-fib recurrence common five years after ablation

date Apr 17, 2015

(HealthDay)—Most patients with atrial fibrillation (AF) and systolic heart failure who undergo ablation have AF recurrence at five years, according to a study published in the April issue of the Journal of ...

Applied physics helps decipher the causes of sudden death

date Apr 17, 2015

Sudden cardiac death accounts for approximately 10% of natural deaths, most of which are due to ventricular fibrillation. Each year, it causes 300,000 deaths in the United States and 20,000 in Spain. Researchers have demonstrated ...

Cognitive problems are common after cardiac arrest

date Apr 17, 2015

Half of all patients who survive a cardiac arrest experience problems with cognitive functions such as memory and attention. This has been shown by a major international study led from Lund University. Surprisingly, however, ...

User comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.