Derrick Y Tam1, Harindra C Wijeysundera2, Stephen E Fremes1. 1. Division of Cardiac Surgery, Department of Surgery, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada. 2. Division of Cardiology, Department of Medicine, Schulich Heart Centre, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada.