1. Valve Science Center, Minneapolis Heart Institute Foundation, Abbott Northwestern Hospital, MN (L.T., M.G., A.A., R.G., S.M.B., H.N., D.W., W.R.P., R.B., J.R.L., K.M.H., B.S., K.M., P.S.).
2. Department of Cardiology, The Second Xiangya Hospital of Central South University, Changsha, China (L.T.).