1. From the Institute for Clinical Evaluative Sciences (D.S.L., P.A., Z.C., J.H., J.V.T.), Toronto, Ontario, Canada; Toronto General Hospital (D.S.L., D.C.), Toronto, Ontario, Canada; Hamilton Health Sciences Centre (J.S.H.), Hamilton, Ontario, Canada; London Health Sciences Centre (A.D.K., R.Y.), London, Ontario, Canada; University of Ottawa Heart Institute (D.B.), Ottawa, Canada; Sunnybrook Health Sciences Centre (E.C., J.V.T.), Toronto, Ontario, Canada; St Michael's Hospital (P.D.), Toronto, Ontario...