Heart valve surgery is performed to repair or replace heart valves that are damaged or dysfunctional. The heart has four one-way valves, each designed to keep blood moving in one direction as it flows through the four chambers of the heart. Under normal conditions each heart valve opens and closes as the heart alternatively contracts and relaxes, thereby causing the contraction of the heart to generate forward blood flow.
Heart valves may become dysfunctional because they don’t open adequately, which causes increased resistance to blood flowing through the valve (stenosis). Alternatively, some valves don’t close completely or have perforations in their leaflets, causing blood to leak backwards through the valve (regurgitation or insufficiency). Patients can have valve stenosis, regurgitation or a combination of the two, and on occasion more than one heart valve may be dysfunctional. As the degree of valve dysfunction gets worse, the heart’s ability to function as a pump becomes progressively inefficient, which ultimately leads to the development of congestive heart failure and death.
There are many different diseases which can lead to the development of heart valve stenosis and/or regurgitation. These include degenerative conditions such as calcific aortic stenosis or mitral valve prolapse, congenital abnormalities such as bicuspid aortic valve, infections such as rheumatic heart disease or bacterial endocarditis, diseases of the heart muscle such as ischemic heart disease or non-ischemic cardiomyopathy, and other less common diseases including cardiac tumors, radiation therapy, and the toxic effects of some drugs.
The diagnosis of heart valve disease is most commonly made using an echocardiogram, a non-invasive ultrasound test of the heart. An echocardiogram may be ordered for patients discovered to have a heart murmur on routine physical examination, or to evaluate the cause of symptoms or signs of congestive heart failure such as exertional shortness of breath. Other diagnostic tests are occasionally indicated to more clearly identify the cause of heart valve disease or the severity of dysfunction, including a transesophageal echocardiogram (TEE), cardiac catheterization, cardiac CT scan or cardiac MRI.
Heart valve repair or replacement is usually recommended once valve dysfunction becomes severe. Although symptoms of congestive heart failure may often be treated using medications, there are no good alternatives to surgical intervention for a severely dysfunctional heart valve, and without surgical correction many forms of heart valve disease will ultimately lead to progressive heart failure and death. Deciding when to proceed with surgical intervention depends upon a variety of factors including the patient’s symptoms and clinical presentation, which valve(s) are affected, the severity of valve dysfunction, the size and contractile function of the heart, whether the valve can be repaired or must be replaced, and the overall risks associated with surgery. The American College of Cardiology and the American Heart Association have jointly published guidelines designed to assist with this decision making process, although ultimately such decisions must be individualized to each patient’s particular circumstances and desires. The members of Triad Cardiac and Thoracic Surgeons (TCTS) work closely with each patient’s referring cardiologist to carefully review all treatment options, and many patients are evaluated by a team of physicians in the Multidisciplinary Heart Valve Clinic at the Moses Cone Heart and Vascular Center.
Once a decision has been made to proceed with surgery, a variety of surgical alternatives are discussed. Heart valve repair is often recommended as an alternative to valve replacement when technically feasible. Whether or not a patient’s valve may be repaired is primarily determined by which valve is dysfunctional and what disease process has caused it to fail. For example, patients with severe aortic stenosis always require valve replacement, whereas most patients with mitral regurgitation can undergo valve repair, particularly when the valve is leaking because of degenerative disease such as mitral valve prolapse. Successful mitral valve repair has been associated with improved heart function and long term patient survival despite low risk of late structural valve dysfunction requiring repeat surgery and no need for long term treatment with blood thinners. The likelihood of successful mitral valve repair has been linked to surgical experience and case volume, which is a particular strength of our program at TCTS. If a patient’s valve must be replaced, a decision is made ahead of time whether to replace it using a mechanical valve or a tissue valve. Mechanical heart valves typically have relatively low risk of structural failure but require life-long treatment using blood thinners (warfarin) due to the risk of blood clot formation and stroke. On the other hand, most tissue valves do not require treatment with blood thinners, but all tissue valves may eventually develop structural valve deterioration and failure, usually many years after surgery. Which type of valve is chosen depends upon a patient’s age, associated medical conditions, lifestyle and personal preference.
Alternative surgical approaches are often feasible for many patients requiring heart valve surgery. Both heart valve repair and replacement can be performed through small incisions in the chest using minimally-invasive techniques that avoid cutting the ribs or breast bone. In addition, under highly selected circumstances, some heart valve disorders can be corrected using catheter-based interventions performed while the heart is beating, such as transcatheter aortic valve replacement (TAVR). The risks associated with heart valve surgery and which surgical approach is recommended depend upon a variety of clinical variables that are carefully reviewed with each patient prior to surgery. Members of TCTS have extensive experience with all of these techniques, and we strive to incorporate other new, innovative techniques into our clinical practice once they have been demonstrated to be safe and efficacious by clinical investigators around the world. All surgical procedures are performed exclusively by members of TCTS as we do not have residents in surgical training at our institution.