Artificial Heart Valve Carries Very Low Risk of Stroke, Study Says
A landmark artificial heart valve trial that included patients from Houston Methodist DeBakey Heart & Vascular Center and Texas Heart Institute showed positive results for those diagnosed with aortic stenosis, a condition in which the aortic valve stiffens and fails to open properly.
The clinical trial evaluated the CoreValve System, an artificial heart valve and nonsurgical delivery system made by Medtronic. To implant the CoreValve, doctors make a small incision in the groin area, then use a catheter to thread the artificial valve upward through the arteries until it reaches its destination – the heart. The valve fixes in place in the patient’s failing aortic valve and takes over the failing valve’s function to ensure that oxygen-rich blood flows into the aorta and circulates throughout the body.
The DeBakey Heart & Vascular Center and Texas Heart Institute are among the 40 sites in the country to enroll patients in the trial’s “extreme risk study,” which focused on patients with severe aortic stenosis who were too ill to have their aortic valves replaced through traditional open-heart surgery. Houston Methodist was the leading site for patient enrollment with 34 patients enrolled – more than any other site. At all 40 sites, a total of 471 patients were enrolled.
One year after receiving a CoreValve implant, nearly three-quarters of the patients were alive without a major stroke, which is highly significant given their complex medical conditions.
The rate of stroke was only 2.4 percent soon after the procedure, and it remained low over time with a one-year rate of 4.1 percent – some of the lowest stroke rates ever reported.
Stroke is one of the complications most concerning to physicians and patients because it increases mortality and affects quality of life.
|Michael Reardon, M.D.|
“We are very happy with the positive results and with the role we played in taking care of these patients,” said Michael Reardon, M.D., a Houston Methodist DeBakey Heart & Vascular Center cardiothoracic surgeon. Reardon was chair of the national patient selection committee and also a member of the national steering committee that looked at the trial design and execution.
About 300,000 people worldwide suffer from severe narrowing of their aortic valves, which prohibits blood from efficiently pumping from their heart to the body. One-third of these patients are too ill or frail to undergo open-heart surgery. Without treatment, these patients have a 50 percent chance of death within one year. The CoreValve offers a nonsurgical option to those who are poor candidates for surgery.
The goal of aortic valve replacement for these high-risk patients is not only to improve their survival but also to enhance their lives, Reardon said.
The CoreValve System has been implanted in more than 45,000 patients in more than 60 countries. The CoreValve System is currently limited to investigational use in the United States.
Results from this study were released at Transcatheter Cardiovascular Therapeutics, the world’s largest educational meeting specializing in interventional cardiovascular medicine. This year’s meeting was held Oct. 27 through Nov. 1 in San Francisco.