Clinical trial establishes value of catheter-based aortic valve replacement

(HealthNewsDigest.com) - ATLANTA--A new way of replacing diseased aortic heart valves in patients too frail or sick to withstand the traditional open-heart surgical approach proved promising in a study published in the New England Journal of Medicine (NEJM).
Since October 2007, Emory University Hospital has been one of approximately 20 hospitals nationwide, and the only site in Georgia, studying the groundbreaking non-surgical treatment option for patients suffering from severe aortic stenosis. The life threatening heart condition affects tens of thousands of Americans each year when the aortic valve tightens or narrows, preventing blood from flowing through normally.
As part of the Phase II clinical trial, Emory Heart & Vascular Center cardiologists and cardiothoracic surgeons performed transcatheter aortic valve implantation (TAVI) comparing this procedure with traditional, open-heart surgery or medication therapy in high-risk patients with aortic stenosis.
The study followed 358 patients who received either catheter-delivered valves or standard non-surgical treatment. The findings showed that patients who had replacement heart valves delivered by catheter were more likely to survive a year than patients who were treated without replacing their original valves. According to the authors, catheter-delivered valves “should be the new standard of care” for patients who are not able to undergo surgery.
During the innovative TAVI procedure, doctors create a small incision in the groin or chest wall and then feed the new valve, mounted on a wire mesh on a catheter. Once the catheter is properly positioned in the opening of the aortic valve, the new valve is rapidly expanded. As it expands it pushes the diseased, native valve aside, allowing blood to flow normally through the implanted valve to the rest of the body.
“These results show great promise for patients with severe aortic stenosis and help us make a giant step forward in our battle against this common disease,” says Peter Block, MD, professor of medicine, Emory School of Medicine and principal investigator of the study at Emory. “They are especially important since the number of people with failing valves is expected to greatly increase as baby boomers continue to age.”
Aortic valve stenosis often occurs with age, most commonly among elderly patients over 70 years of age, but can surface earlier in life in those with rheumatic heart disease or congenital abnormalities of the valve. Patients often develop symptoms of chest pain, shortness of breath, fainting spells and heart failure.
Block and fellow interventional cardiologist Vasilis Babaliaros, MD, assistant professor of medicine at Emory University School of Medicine, led the Emory clinical trial along with their cardiac surgical colleagues Robert Guyton, MD, professor of surgery and chief, Division of Cardiothoracic Surgery, Department of Surgery, Emory University School of Medicine, and Vinod Thourani, MD, associate professor of surgery, Division of Cardiothoracic Surgery, Department of Surgery, Emory University School of Medicine.
Babaliaros spent several years abroad with French cardiologist Alain Cribier, MD, who successfully implanted the first catheter-delivered valve in 2002 in a seriously ill patient with aortic stenosis who had been refused for surgery. Babaliaros worked alongside Cribier to learn the new approach and bring it to the United States and to Emory.
Transcatheter aortic valve implantation is not yet approved by the U.S. Food and Drug Administration (FDA) and therefore is only available in a few centers throughout the country, including Emory, the first center in the Southeast and one of the five largest centers in the country. Approximately 90 patients have received new valves at Emory since the clinical trial started in 2007. It is anticipated that this valve will receive FDA approval in late 2011.