Dr. Sun Receives AHA National Scientist Development Grant

Wei Sun, an assistant professor of Biomedical Engineering and Mechanical Engineering, was recently awarded an American Heart Association National Scientist Development grant of more than $300,000 in support of his work aimed at developing accurate biomechanical models that depict how human hearts respond to a heart valve repair procedure called percutaneous transvenous mitral annuloplasty.

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

According to Dr. Sun, 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, a 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, which is 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. A procedure called percutaneous transvenous mitral annuloplasty (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. Dr. Sun said 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 PTMA device.

Through a combination of experimental and computational studies, Dr. Sun hopes to better understand the mitral tissue-implant interaction. He and Dr. 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 failure modes.

Through the AHA project, Drs. Sun and Liang expect to improve their understanding of the biomechanics involved in PTMA treatment and aid in the rational development of novel minimally invasive valve repair devices.