1 The American Association for Thoracic Surgery, Beverly, Mass; and the Division of Cardiovascular Surgery, Toronto General Hospital, Research Institute and the University of Toronto, Toronto, Ontario, Canada.
2 The American Association for Thoracic Surgery, Beverly, Mass; and the Division of Cardiovascular Surgery, Toronto General Hospital, Research Institute and the University of Toronto, Toronto, Ontario, Canada. Electronic address: rweisel@uhnresearch.ca.