[1] Sunnybrook Hlth Sci Ctr, Div Cardiol, Toronto, ON M4N 3M5, Canada
[2] Univ Toronto, Dept Med, Toronto, ON, Canada
[3] Vancouver Hosp, Div Cardiol, Vancouver, BC, Canada
[4] Univ British Columbia, Dept Med, Vancouver, BC, Canada
[5] McMaster Univ, Hlth Sci Ctr, Dept Clin Epidemiol & Biostat, Hamilton, ON L8N 3Z5, Canada