[1] Univ Ottawa, Heart Inst, Div Cardiac Surg, Ottawa, ON, Canada
[2] Univ Ottawa, Sch Epidemiol & Publ Hlth, Ottawa, ON, Canada
[3] Univ Ottawa, Dept Med, Ottawa, ON, Canada
[4] Univ Toronto, Sunnybrook Hlth Sci Ctr, Dept Surg, Div Cardiac Surg,Schulich Heart Ctr, Toronto, ON, Canada
[5] ICES formerly Inst Clin Evaluat Sci, Toronto, ON, Canada
[6] Ottawa Hosp, Res Inst, Ottawa, ON, Canada
[7] 40 Ruskin Ave, Ottawa, ON K1Y 4W7, Canada