Dr. Randy Martin: Aortic stenosis means hardening or narrowing of the aortic valve – the valve that sits between the pumping chamber of the left side of the heart and the large blood vessel, called the aorta, that takes blood to the body. When this valve is narrowed, it significantly limits the flow of blood to the body and the brain. When it’s severely narrowed, it can lead to sudden cardiac death or even dying within a very short period of time. Typically, those with severe aortic stenosis have undergone open heart surgery to replace the valve. However, a revolutionary technique may soon provide another option for correcting aortic stenosis and may become an alternative to surgical techniques.
“At least 10 percent of the population over 65 has some degree of aortic stenosis,” says Vivek Rajagopal, M.D., interventional cardiologist at Piedmont Hospital. He says that in the traditional setting, aortic valves are replaced by cardiac surgeons. Open-heart surgery involves opening up the chest, stopping the heart and lungs while a heart-lung machine takes over, and replacing the old valve with a new one. In contrast, the new procedure only requires a small incision in the groin.
Many have described this new technique as revolutionary; Dr. Rajagopal agrees. “Revolutionary is not an exaggeration here. This technique is far less invasive, and it’s quite exciting.”
The procedure is not done in a traditional operating room. It’s either done in the Cardiac Catheterization Lab or what is called a Hybrid Lab. The replacement heart valve is implanted via a catheter – a thin, flexible tube that is inserted into the aorta through a small incision in the groin. The catheter containing the collapsed vale is then carefully guided up to the patient’s aortic valve and then through a quick and very unique process the new valve is deployed and replaces the diseased valve.
There are two new valves, both being currently used in Europe and Canada. However, in the United States, both are undergoing U.S. Food and Drug Administration protocol to assure their safety and usefulness.
A recent study randomly assigned 700 high-risk, elderly participants to either receive a valve using this new technique or to get a valve with traditional open-heart surgery. All participants needed valve replacement but were considered high risk for surgery. Of those who received the minimally invasive technique, about 3.4 percent died. And of those who had open-heart surgery, about 6.5 percent died.
“Those statistics seems like the less-invasive technique is only a little bit better for these high-risk patients, but I want to emphasize that that this is early-stage technology. These interventional cardiologists have just started to perform this procedure, whereas cardiac surgeons have been performing these types of surgeries for years.” Dr. Rajagopal believes this technique will rapidly become a primary therapy for aortic stenosis – not only for high-risk patients, but intermediate-risk patients as well.
Dr. Martin: This process of replacing the narrowed aortic valve in a non-surgical manner is called TAVI – Transcatheter Aortic Valve Implantation. And while it looks very exciting, it does have to undergo rigorous investigation to insure that the valve is as durable as the current valves that are surgically implanted and that the procedure is done safely, so that the patient’s best interests are always upheld.