1. Division of Cardiovascular Surgery, Department of Surgery, University of British Columbia, Vancouver, BC, Canada
2. Division of Cardiothoracic Surgery, Michael E. DeBakey Department of Surgery, Baylor College of Medicine and the Texas Heart Institute, Houston, TX, USA
3. Divison of Cardiothoracic Surgery, Department of Surgery, Washington University School of Medicine at Barnes-Jewish Hospital, St. Louis, MO, USA
4. Department of Thoracic and Cardiovascular Surgery, University of Texas MD Anderson Cancer Center, Houston, TX, USA