As of May 2011, performance of MitraClip, a minimally invasive procedure to correct mitral regurgitation, has been voluntarily suspended due to a problem with its catheter delivery system.
Since 2008, about 3000 patients with severe mitral valve regurgitation (leaky mitral valve) have been treated with MitraClip rather than open surgery. In this minimally invasive procedure a small clip is delivered via catheter to the heart, where it is carefully placed over the center of the mitral valve. This non-surgical option has been an important alternative for patients who may be unable to withstand open surgery. MitraClip has been advanced and investigated at NewYork-Presbyterian/Columbia since the first EVEREST trial in 2004, and is currently available throughout the U.S. as part of the EVEREST II trial. Read more »
*This blog post was originally published at Columbia University Department of Surgery Blog*
I am saddened that Elizabeth Taylor died recently of heart failure. In his appreciation of her, film critic Roger Ebert said in the Chicago Sun-Times, “Of few deaths can it be said that they end an era, but hers does.”
She is a star that many of us felt we knew. She was a great actress and a woman of great beauty who was a hard working champion of people with AIDS and always seemed to be a determined person who knew herself. Yet she always had a vulnerable side. So many marriages, so many illnesses, so many, many surgeries, over 40, I’ve read. And then her heart problem developed. Which leads me to talk a little about that problem, mitral valve leakage.
The heart’s mitral valve
The heart has four chambers and four valves that open to let blood through to the next chamber of the heart and on out to the body and back. The valves, acting as gates, then immediately close to prevent the blood from running back where it just came from. The mitral valve looks like a mouth with leaflets that look like lips that open and close. When I saw it in action on an echocardiogram, a test that uses sound waves to show moving pictures of the heart, I thought it looked like a very sensuous mouth. Each of the valves looks different. But because it looks like a mouth, the mitral valve stands out. Blood has just left the lungs carrying oxygen and arrives at the left atrium of the heart. The mitral valve’s mouth opens to let the blood pour through into the left ventricle. As the left ventricle contracts, the mitral valve closes and the aortic valve opens to allow blood to leave the heart and get out to the body.
A mitral valve can start to leak. This can range anywhere from a condition that is minor and does not need treatment to a serious problem that leads to a weakened heart and heart failure. In Elizabeth Taylor’s case, it led to heart failure and her symptoms must have included difficulty breathing and fatigue.
I asked Edward K. Kasper, M.D., director of clinical cardiology at Johns Hopkins Hospital, to talk a little about what can go wrong with a mitral valve. I should mention for disclosure that Ed is my cardiologist and co-authored with me the book Living Well with Heart Failure, the Misnamed, Misunderstood Condition:
A leaky mitral valve – mitral regurgitation, is common and has many causes. Most people tolerate a leaky valve well, but some need surgery to correct the leak. Repair is preferred to replacement. The MitraClip (which was used for Elizabeth Taylor) is a new technique to try and fix mitral regurgitation in the cath lab rather than in the operating room. There are no long-term comparison studies of this technique compared to standard OR repair – that I know of. Repair is currently the gold standard for those who have severe mitral regurgitation and symptoms of heart failure. Outcomes are better including improvement in symptoms and survival in patients with repair rather than replacement.
What takes a person from a leaking mitral valve to heart failure?
The leakage back into the left atrium increases the pressure in the left atrium. This increased pressure in the left atrium is passed back to the lungs, causing fluid to leak into the lungs, leading to heart failure. With time, the demands of severe mitral regurgitation on the left ventricle will lead to a weakened left ventricle, a dilated cardiomyopathy (disease of the heart muscle). We try to prevent this by operating before it gets to that point.
Mitral regurgitation can also be a consequence of a dilated cardiomyopathy – the orifice of the mitral valve enlarges as the left ventricle enlarges. The leaflets of the mitral valve do not enlarge. Therefore, they no longer close correctly, leading to mitral regurgitation.
It’s easy to see why anyone would want to opt for the Evalve MitraClip over open heart surgery. The MitraClip is little different from a common test known as an angiogram in which a catheter is passed through the femoral vein in the groin up to the heart. In this repair procedure, however, the catheter guides a clip to the mitral valve where the metal clip covered with polyester fabric is positioned over the leakage and brought down below the open flaps and back up, fastening the valve’s open leaflets together. The manufacturer, Abbott, shows in a video here how blood still is able to pass through on either side of the fastening.
Elizabeth Taylor got her MitraClip repair a year and a half ago, so it must have worked for awhile. Then about six weeks ago she was hospitalized with heart failure at Cedars-Sinai Medical Center in Los Angeles where she died with her family at her bedside. For more on mitral regurgitation, see this NIH site.
Heart failure has many other causes. High blood pressure can damage the lining of blood vessels leading to deposits of cholesterol. Coronary artery disease causes heart attacks. A heart attack kills part of the heart muscle, forcing the rest of the heart to work harder and in doing so, get large and weak. Only about half the people who develop heart failure have a weak heart. In another cause of heart failure, the left ventricle becomes stiff and the heart does not fill properly. And in some heart failure, the heart itself is normal but connecting blood vessels are not or a valve may be too narrow. In all of these cases, a person is said to have heart failure because the heart and vascular system are not able to provide the body with the blood and oxygen it needs.
*This blog post was originally published at HeartSense*