The human heart is a highly efficient pump with four chambers – two upper (the atria) and two lower (the ventricles). Each of those chambers is closed off by a one-way valve. As the heart expands and contracts 100,000 times a day, the four valves open and close in sequence to keep the blood flowing the right way.
The four heart valves are:
- the tricuspid valve, which regulates blood flow between the right atrium and right ventricle;
- the pulmonary valve, regulating blood flow from the right ventricle into the pulmonary arteries;
- the mitral valve, which controls the flow of oxygen-rich blood from the left atrium into the left ventricle;
- the aortic valve, which is the final doorway from the left ventricle into the aorta, the body’s main artery.
To work correctly and keep blood flowing smoothly, the valves’ flap-like doors or leaflets must open at the right time in response to a pressure change, then close securely to prevent blood from back flowing. In heart valve disease, the flaps either cannot open sufficiently or close securely.
Women and Heart Valve Disease
Rheumatic fever in childhood used to be the major cause of valve disease in women. Today, rheumatic fever is rare in developed countries, and calcification of the valve or a weakening of the valve tissue with aging are now the most common causes of valve disease. A narrowed mitral valve or a deformed aortic valve also may be a congenital defect (present at birth). Other causes of valve dysfunction include an infection in the lining of the heart's walls and valves and heart disease such as coronary artery disease or heart attack.
Most of the more than 100.000 heart valve repair operations performed in the United States every year are on the mitral and aortic valves, so we will focus on the problems that can occur with those two valves.
Mitral Valve Disease
Mitral Valve Prolapse (MVP)
MVP is the most common forms of valve disease, affecting 6 percent of all women. In this condition one or both of the valve leaflets is enlarged or floppy, preventing the valve from closing evenly. When the valve shuts, the leaflets bulge into the left atrium. You may have heard mitral valve prolapse referred to as click-murmur syndrome from the sound the valve makes when it closes.
Although men and women are affected by MVP in equal numbers, the course of the disease differs by gender. MVP is a fairly common diagnosis in young women, but the incidence decreases among elderly women. For men, the incidence of MVP remains fairly steady across age groups. Men with MVP are more likely than women to require surgical treatment, and the need for surgery increases with age. Overall, 60 percent of people with MVP will not require treatment.
MVP may coexist with coronary artery disease, congestive or hypertrophic cardiomyopathy, atrial septal defect, Marfan syndrome or other connective tissue disorders. But most women with MVP do not have any of these other medical problems, and their MVP is considered idiopathic.
Mitral stenosis is a narrowing or blockage of the mitral valve, which causes blood to back flow into the left atrium instead of flowing down into the left ventricle. Rheumatic fever is the major cause of mitral stenosis. Other causes are infective endocarditis, severe calcification of the valve opening, tumors, systemic lupus erythematosus or cancer.
Three times more women than men have mitral valve stenosis, and women account for 70 percent of all cases. In women, the valve tends to calcify at a later age than in men.
Aortic Valve Disease
Prolapse and stenosis also can occur in the aortic valve. For reasons that are not yet clearly understood, aortic valve prolapse is more common in men than in women.
Aortic Valve Prolapse
Severe, uncontrolled high blood pressure has been associated with aortic valve prolapse. Another cause is a congenital defect in which the valve has only two leaflets instead of the usual three, a condition affecting men more often than women. This deformity also can cause aortic valve stenosis
Calcification is the most common cause of aortic stenosis in elderly patients. This condition affects men and women equally and accounts for the majority of aortic valve disease today. About 25 percent of men and women over age 65 have mild thickening and/or calcification of a tri-leaflet aortic valve but without restriction of valve movement - this is termed aortic sclerosis. Aortic sclerosis is usually not progressive and requires no specific treatment. However, aortic stenosis affects approximately 2 to 3 percent of people over age 75 and frequently requires surgical correction.
Diagnosing Heart Valve Disease
When your doctor suspects valve disease based on a physical examination and your symptoms, he or she will use an electrocardiogram (ECG), echocardiogram and chest X-rays to diagnose the problem. Sophisticated echocardiography technology is the best tool we have today for diagnosing heart valve disease.
Treating Heart Valve Disease
Your physician will determine when your valve disease is serious enough to require treatment. The type of treatment that is recommended for you will depend on several factors, including the type of valve disease, the severity of the damage, your age and medical history.
Heart valve disease is a mechanical problem, and surgery may eventually be needed to repair or replace the damaged valve. Often, the surgeon may not know whether repair is possible until he or she can actually see the valve during the procedure.
In 1996, Cleveland Clinic surgeon Delos M. Cosgrove, M.D., performed the world's first minimally invasive heart valve surgery. Since that time, improvements in the type of incision and surgical techniques have led to a proven, successful minimally invasive approach to valve surgery. Today, nearly 95 percent of valve surgeries performed here are done with minimally invasive techniques.
When possible, most surgeons prefer to repair the native valve, particularly in women of child-bearing age. Although valve repair is a technically difficult procedure, it has a lower risk of infection compared with replacement, does not require long-term use of anti-clotting medicine and has better long-term functional results than a replacement valve. At Cleveland Clinic, 95 percent of operations for mitral valve prolapse are repairs.
When a valve cannot be repaired, it must be replaced. The choices are a mechanical (prosthetic) valve or a tissue (bioprosthetic) valve from an animal source. They both are available in different styles and sizes from various manufacturers. Making the decision of which type of valve can be difficult because both types have advantages and disadvantages. A recent study by the Cleveland Clinic Department of Cardiothoracic Anesthesia comparing outcomes of valve replacement in women and men found that that women have a greater risk for cardiac complications – but not death - compared with men. Earlier studies suggested that women had a higher mortality rate than men following aortic valve replacement.
Mechanical valves are constructed of high performance carbon and titanium. They are extremely durable so the chance that you will need a future re-operation to replace the valve is small. But, if you choose a mechanical valve, you will have to take medication to prevent clots from forming on the valve that would block blood flow to the brain or other organ systems. Because of the need for anti-coagulation medication, a mechanical valve is not an appropriate choice for women of childbearing age.
Tissue valves are native valves that are harvested from a pig or cow, then treated and processed to make them safe for human use. In some cases, a tissue valve may be retrieved from a human donor, but these are rare.
Tissue valves are an excellent choice for older people and women of childbearing age because they do not usually require anticoagulant therapy. The downside of these valves is that they tend to degrade over time and may require a re-operation.
At Cleveland Clinic, our surgeons prefer tissue valves in patients over the age of 60 years and mechanical valves under the age of 50. Healthy women in their 50s should consider mechanical valves since many can expect another 30 years of life.
Valve Surgery Without Large Incisions
Heart surgery does not always mean a large incision. Minimally invasive surgery is performed through a small incision, often using specialized surgical instruments. The incision is about 3 to 4 inches instead of the 8- to 10-inch incision required for traditional surgery. Keyhole approaches or port-access, and robot-assisted techniques are also available for some types of valve surgery. These approaches allow for minimal scarring, and other benefits, such as decreased length of stay, reduced risk of infection, and less blood loss.
Repairing valves without surgery
Percutaneous balloon valvotomy has revolutionized the treatment of mitral valve stenosis. More than 80 percent of all patients who undergo balloon valvotomy for mitral stenosis are women.
This non-surgical technique involves passing a deflated balloon through the femoral artery to the mitral valve. At the valve, the balloon is inflated against the valve ring to widen the opening.
This is an effective option for pregnant women with mitral valve stenosis because it is safer for the baby than open heart surgery, which requires cardiopulmonary bypass. However, radiation exposure during the procedure is a concern, and appropriate shielding of the uterus must be used. As an alternative to X-ray guidance, the procedure can be performed with transesophageal echocardiographic guidance, which reduces radiation risk.
Older patients may have less improvement in function after Percutaneous balloon valvotomy compared with younger women, but it is a well-tolerated option for those who cannot undergo open heart surgery.
Cardiologists and surgeons are currently researching other percutaneous approaches to treat both mitral and aortic valve disease. Investigators are hopeful that these procedures may increase options for patients with valve disease in the future.
When selecting a center for treatment of heart valve disease, experience counts. Surgeons at large, busy heart centers treat more patients and are more likely to have the skill and experience necessary to perform a valve repair so that you will not need a replacement. At major heart centers, only about 5 percent of operations for mitral valve prolapse are replacements.
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- Duncan AI, Lin J, Koch CG, Gillinov AM, Xu M, Starr NJ. The impact of gender on in-hospital mortality and morbidity after isolated aortic valve replacement. Anesth Analg. 2006 Oct;103(4):800-8.
- Gillinov AM, Cosgrove DM. Percutaneous heart valve repair and replacement. Endovascular Today 2004;3:31-4.
- Shaw TR, Sutaria N, Prendergast B. Clinical and haemodynamic profiles of young, middle aged and elderly patients with mitral stenosis undergoing mitral balloon valvotomy. Heart 2003 Dec;89(12):1430-6.
- Wilcken DEL, Hickey AJ. Lifetime risk for patients with mitral valve prolapse of developing severe valve regurgitation requiring surgery. Circulation 1998;78:10-14.
Websites of Interest
Reviewed by Dr. Mina Chung and Dr. A. Marc Gillinov