1. From the Department of Medicine, Echocardiography, and Noninvasive Cardiology Service, Montreal Heart Institute (F.P.M.), Montreal, Canada; Division of Clinical Epidemiology, McGill University Health Center (P.B., L.J.), Montreal, Canada; Divisions of Cardiology, Interventional Cardiology and Clinical Epidemiology, Jewish General Hospital (M.J.E.), Montreal, Canada, and Department of Cardiology, Quebec Heart and Lung Institute (S.R.), Quebec City, Canada.