[1] Dalhousie Univ, Div Cardiac Surg, Nova Scotia Hlth Author, Halifax, NS, Canada
[2] Dalhousie Univ, Sch Hlth Adm, Halifax, NS, Canada
[3] Univ British Columbia, Crit Care Med, Vancouver, BC, Canada
[4] Dalhousie Univ, Div Cardiol, Nova Scotia Hlth Author, Halifax, NS, Canada
[5] Maine Med Ctr, Dept Cardiovasc Surg, Portland, ME 04102 USA