Biomedical Engineer Studying Heart’s Response to Valve Repair

Engineering professor Wei Sun is developing accurate biomechanical models that depict how human hearts respond to a particular heart valve repair procedure.

Wei Sun, right, assistant professor of biomedical engineering and mechanical engineering, and graduate student Thuy Pham. Photo by Christopher LaRosa
Wei Sun, right, assistant professor of biomedical engineering and mechanical engineering, and graduate student Thuy Pham. Photo by Christopher LaRosa

Engineering professor Wei Sun was recently awarded an American Heart Association National Scientist Development grant of more than $300,000.

The grant will support his work to develop accurate biomechanical models that depict how human hearts respond to a heart valve repair procedure called percutaneous transvenous mitral annuloplasty (PTMA).

The research is an extension of ongoing work Sun has been conducting with Dr. Bruce Liang, a professor of cardiology at the UConn Health Center.

Through the American Heart Association project, the researchers expect to improve their understanding of the biomechanics involved in PTMA treatment, and to aid in the development of novel, minimally invasive valve repair devices.

Sun, an assistant professor of biomedical engineering and mechanical engineering, says approximately 300,000 heart valve surgeries are performed annually around the world – either whole valve replacement with an artificial heart valve or surgical valve repair. Both procedures require open-heart surgery with cardiopulmonary bypass, risky surgery that makes it desirable to develop less invasive, non-surgical techniques.

One type of heart disease is known as “mitral regurgitation,” a condition in which the mitral valve, located between the left atrium and the left ventricle, fails to close completely, allowing blood to leak backward into the heart. Mitral regurgitation limits the body’s ability to circulate blood efficiently.

PTMA, which involves minimally invasive insertion of a synthetic band or ring into the coronary sinus, was recently developed as an alternative to open heart surgery. A number of companies are developing experimental PTMA devices, and early clinical trials in humans were conducted in 2006 and 2007.

Sun says that dysfunctional performance and fatigue fracture were reported in the trials, possibly as a result of unknown biomechanical interactions between venous tissue, the mitral valve system, and the device.

Through a combination of experimental and computational studies, Sun hopes to better understand the mitral tissue-implant interaction. He and Liang will develop patient-specific computational models of the mitral valve using clinical cardiac images.

These models will be used to simulate PTMA device deployment and function under various conditions and to evaluate PTMA device failures.