Less-invasive catheter-based aortic valve replacement as safe and effective as open surgery

NewYork-Presbyterian Hospital/Columbia University Medical CenterApr 5 2011

Less-invasive catheter-based aortic valve replacement has a similar one-year survival as open valve-replacement surgery for patients at high risk for surgery.

Results from The PARTNER (Placement of AoRTic traNscathetER valves) Trial -- the world's first randomized clinical trial of a transcatheter aortic heart valve -- were presented today by co-principal investigator Dr. Craig Smith of NewYork-Presbyterian Hospital/Columbia University Medical Center at the American College of Cardiology's 60th Annual Scientific Session & Expo in New Orleans, La.

"These results show that a balloon-expandable transcatheter valve replacement in patients at high risk for surgery is as safe and effective as open surgery, which is the 'gold standard' for most patients," says Dr. Smith, chairman of the Department of Surgery at NewYork-Presbyterian Hospital/Columbia University Medical Center and the Johnson & Johnson Distinguished Professor and the Valentine Mott Professor of Surgery at Columbia University College of Physicians and Surgeons. The study was conducted at 26 centers in the United States, Germany and Canada.

Aortic valve replacement treats severe aortic stenosis, a narrowing of the valve that restricts blood flow from the heart and is associated with a high risk for death if left untreated. Annually, some 200,000 people in the U.S. need a new heart valve.

"Many patients with aortic stenosis are at high risk for complications and death following open surgery due to advanced age, poor left ventricular function, and other co-morbidities. For these patients, a less-invasive treatment may be desirable," says Dr. Martin Leon, the study's co-principal investigator, associate director of the Cardiovascular Interventional Therapy (CIVT) Program at NewYork-Presbyterian Hospital/Columbia University Medical Center, and professor of medicine at Columbia University College of Physicians and Surgeons.

The transcatheter valve procedures take about 90 minutes, compared with four to six hours for open heart surgery. In open heart surgery, the surgeon cuts through the breastbone, stops the heart, removes the valve and replaces it. Recovery for transcatheter procedures can be as short as a few days, compared with two or three months for open heart surgery.

A total of 699 patients with severe aortic stenosis who were high risk for surgery were randomly assigned to receive the less-invasive transcatheter aortic valve replacement (TAVR) or traditional aortic valve replacement (AVR).

Patients in the TAVR group were implanted with the Edwards SAPIEN heart valve, made of bovine pericardial tissue leaflets hand-sewn onto a metal frame, via one of two catheter-based methods -- either navigated to the heart from the femoral artery in the patient's leg, or through a small incision between the ribs and into the left ventricle. (The approach was chosen based on whether the patient's femoral artery could accommodate the size of the device.) The replacement valve was then positioned inside the patient's existing valve, using a balloon to deploy the frame, which holds the replacement valve in place. These procedures are performed on a beating heart, without the need for cardiopulmonary bypass and its associated risks. Patients in the AVR group received a valve replacement device through open heart surgery.

The study showed that in the first 30 days after the procedure, death from any cause happened in 3.4 percent of patients in the TAVR group, compared with 6.5 percent in the AVR group. But after a year, the risk for death was roughly the same at 24.2 percent vs. 26.8 percent, respectively.

Additionally, there were several differences in cardiovascular outcomes following the procedures. Major strokes were more common in the TAVR group than the AVR group at 30 days (3.8 percent vs. 2.1 percent) and after a year (5.1 percent vs. 2.4 percent). Major vascular complications were more frequent after TAVR (11.0 percent vs. 3.2 percent), whereas major bleeding (9.3 percent vs. 19.5 percent) and new-onset atrial fibrillation (8.6 percent vs. 16.0 percent) were more frequent after AVR. Symptom improvement favored TAVR at 30 days, but was similar after one year. Para-valvular regurgitation was more frequent after TAVR than AVR.

Dr. Smith notes that stroke and vascular complications remain a concern for TAVR, although their incidence has decreased since the previous cohort was reported in September 2010. "Clinical experience and device development is helping us mitigate these risks," he says.

Patients meeting the criteria for the trial -- aortic stenosis and high risk for surgery -- make up less than 5 percent of those receiving AVR. Going forward, these data support future trials that would expand the patient population to include intermediate risk patients.

In September 2010, The PARTNER Trial reported that in patients who were not candidates for AVR, TAVR was associated with a dramatic (20 percent) improvement in one-year survival and reduced symptoms, compared with standard medical intervention, including a combination of watchful waiting, medications and balloon aortic valvuloplasty.

In addition to NewYork-Presbyterian/Columbia, The PARTNER Trial was conducted at NewYork-Presbyterian Hospital/Weill Cornell Medical Center's Ronald O. Perelman Heart Institute, led by Dr. Karl H. Krieger, vice chairman of cardiovascular surgery and the Philip Geier Professor of Cardiothoracic Surgery at Weill Cornell Medical College, and Dr. Shing-Chiu Wong, director of cardiac catheterization laboratories and professor of medicine at Weill Cornell Medical College.

Other centers in The PARTNER Trial include Scripps Memorial Hospital/Scripps Green Hospital, La Lolla, Calif.; Cedars-Sinai Medical Center, Los Angeles, Calif.; Stanford University Medical Center, Stanford, Calif.; Washington Hospital Center, Washington, D.C.; University of Miami, Miami, Fla.; Emory University School of Medicine, Atlanta, Ga.; Northwestern University, Chicago, Ill.; NorthShore University HealthSystem, Evanston, Ill.; Ochsner Clinic, New Orleans, La.; Boston Mass General, Boston, Mass.; Brigham and Women's, Boston, Mass.; Mayo Clinic, Rochester, Minn.; St. Luke's Hospital of Kansas City, Kansas City, Mo.; Barnes-Jewish/Washington University, St. Louis, Mo.; Cleveland Clinic Foundation, Cleveland, Ohio; University of Pennsylvania, Philadelphia, Pa.; Medical City Dallas, Dallas, Texas; Intermountain Medical Center, Murray, Utah; University of Virginia, Charlottesville, Va.; University of Washington, Seattle, Wash.; Vancouver St. Paul's, Vancouver, Canada; Toronto General Hospital; Toronto, Canada; Laval Hospital, Quebec, Canada; and Heart Center Leipzig, Leipzig, Germany.

Both aortic valve replacement devices used in the study are manufactured by Edwards Lifesciences of Irvine, Calif., which also funded the study.