title: The investigator's dilemma.
authors.affiliation: Queen Elizabeth II Health Science Centre, Halifax, Nova Scotia.
authors.forename: Gregory M
authors.initials: GM
authors.lastname: Hirsch
mesh_terms: D001021:Aortic Valve / Q000601:surgery; D002170:Canada / Q000453:epidemiology; D003131:Combined Modality Therapy; D001026:Coronary Artery Bypass; D006349:Heart Valve Diseases / Q000401:mortality / Q000601:surgery; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D008943:Mitral Valve / Q000601:surgery; D016896:Treatment Outcome