1. Department of Cardiovascular Medicine, The Cleveland Clinic Foundation, Cleveland, OH, USA.
2. Cardiology Division of Internal Medicine, Chungnam National University, Chungnam National University Hospital, Daejeon, Korea.
3. Pulmonary and Critical Care Medicine, The Cleveland Clinic Foundation, Cleveland, OH, USA.
4. Center for Heart Valve Disease, Bluhm Cardiovascular Institute, Northwestern Memorial Hospital, Chicago, IL, USA.