The predictions are based on a statistical extrapolation from clinical trial data and were consistent across age groups and event categories, including risk of heart attack and stroke, said researchers presenting today at the SCAI 2013 Scientific Sessions.
Renal denervation has previously been found to reduce drug-resistant hypertension by interrupting sympathetic nerve signals from the kidneys. Now investigators have employed a mathematical model to analyze data from the Symplicity HTN-2 randomized, controlled trial to project the clinical benefits over a 10-year period for patients who are 40, 55 and 70 years old.
“To predict event reductions and understand cardiovascular risk for a range of patient cohorts treated with renal denervation, we looked not only at data from a specific randomized trial, but also at extrapolated data for different age groups and at relatively low hypertension and high hypertension statistics,” said Jan Pietzsch, Ph.D., the study’s lead author and CEO of health economics consultancy firm, Wing Tech Inc., in Menlo Park, Calif., and a consulting associate professor at Stanford University.
Patients in all of the age groups stand to experience clinical benefits from renal denervation, according to the statistical analysis. Among the projected benefits would be significant reductions in risk for heart attack, stroke and kidney failure.
“Pretty much across the board there are clinically meaningful reductions that we project both in terms of absolute and relative reductions of clinical events in all three age groups,” said Dr. Pietzsch.
All of the study’s relative and absolute risk predictions were applicable over a 10-year period. Results revealed predicted reductions of pre-treatment systolic blood pressure from 165 to 135 mmHg in the low range and from 190 to 150 mmHg in the high range, representing the minimum and maximum reported values for each clinical event type. The youngest group, at age 40, showed the largest relative reduction in cardiovascular risk while the oldest cohort, age 70, was projected to experience the most substantial absolute event reduction.
The model projected significant drops in cardiovascular events across each of the three age groups and the two theoretical blood pressures (40/165 mmHg and 70/190 mmHg) at the time of treatment. For example, a more than 40 percent reduced risk of heart attack was projected for patients with systolic blood pressure over 190 mmHg undergoing catheter-based renal denervation at the age of 40, and an 8 percent absolute reduction of risk for all coronary heart disease for those with the same blood pressure undergoing interventional renal denervation at the age of 70.
“Clinical trials will need to be completed to validate these modeled projections,” stressed Dr. Pietzsch.
Renal denervation as a treatment for hypertension has been approved in Europe but is still an investigational procedure in the United States. The Symplicity Renal Denervation System is currently under joint consideration by both the Food and Drug Administration (FDA) and the Centers for Medicare and Medicaid Services (CMS).
The Society for Cardiovascular Angiography and Interventions, 1100 17th Street NW, Suite 330, Washington, DC 20036