由 Lynn Shapiro
, Writer | January 07, 2009
An innovative approach for implanting a new aortic heart valve without open-heart surgery is being offered to patients at New York-Presbyterian Hospital / Columbia University Medical Center.
Known as the PARTNER (placement of aortic transcatheter valves) trial, this Phase 3 multicenter study is being led by national co-principal investigators Dr. Martin Leon and Dr. Craig Smith, and is focused on the treatment of patients who are at high risk or not candidates for open-heart valve replacement surgery.
The transcatheter heart valve--dubbed the SAPIEN--is being developed by medical device company Edwards Lifesciences. What's new about the procedure is that the valve is implanted through a catheter and involves a new method of fixation. The experimental procedure is similar to the placement of a stent in catheterization of a blocked coronary artery.
The valves in the PARTNER trial are made of bovine pericardial tissue (from the pericardial sac) and this tissue is formed into leaflets. The bovine valve is hand-sewn onto a metal frame and is implanted 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. It is then positioned inside the patient's existing valve, using a balloon to deploy the frame, which holds the artificial valve in place. Either procedure is performed on a beating heart, without the need for open heart surgery, cardiopulmonary bypass and its associated risks.
While many industry watchers are enthusiastic about the promise of this approach, financial analysts who spoke with DOTmed News remain cautious about long-term safety. However, the company notes that bovine pericardial tissue valves were introduced to the market by Edwards Lifesciences in 1981. The company has more than 20 years' follow-up on the effectiveness and durability of the pericardial tissue valves.
"This breakthrough technology could save the lives of thousands of patients with heart valve disease who have no other therapeutic options," says Dr. Leon, associate director of the Cardiovascular Interventional Therapy (CIVT) Program at New York-Presbyterian Hospital and Columbia University Medical Center, and professor of medicine at Columbia University College of Physicians and Surgeons.
Annually, some 200,000 people in the U.S. need a new heart valve, but nearly half of them do not receive a new valve for a variety of reasons.
"This study may show that transcatheter valve replacement is a safe and effective alternative to open surgery, which remains the 'gold standard' for most patients," says Dr. Smith, interim surgeon-in-chief and chief of cardiothoracic surgery at New York-Presbyterian Hospital/Columbia University Medical Center, and the Calvin F. Barber Professor of Surgery 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.
For videos demonstrating the implantation procedures, go to this link and click on the medical illustrations of the catheter:
Read DOTmed's previous coverage of this innovation at: