Dr. Greg Hare


Dr. Hare is one of IMPART associate members. He is a Staff Anesthesiologists and Professor of Anesthesia and Physiology at St. Michael’s Hospital at the University of Toronto. His clinical focus is to develop multimodal and inter-professional approaches to optimize patient outcomes through patient blood management strategies and clinical trials related to anemia, transfusion therapy, and cardiovascular outcomes.

The long term research goals of his basic science research are to define mechanisms of anemia-induced cardiovascular morbidity and mortality, to optimize perioperative hemostasis and to design novel treatment strategies to prevent these adverse outcomes. Translational studies have identified integrative adaptive cellular (nNOS and HIF) and physiological mechanisms which promote organism survival during acute anemia. Current clinical research focuses on translational approaches to identify patient specific biomarkers of anemia-induced tissue hypoxia and to assess whether treatment of preoperative anemia can reduce morbidity and mortality associated with both anemia and red blood cell transfusions. Participation in  large randomized clinical trials to assess  important outcome in cardiovascular anesthesiology including the optimal use of antifibrinolytic agents to prevent acute blood loss and determination of the optimal hemoglobin threshold to transfuse patients undergoing cardiac surgery (TRICSIII).

The overall goal of Dr. Hare’s research is to reduce morbidity and mortality associated with acute and chronic anemia and RBC transfusion in perioperative patients with cardiovascular disease.



  1. Mazer, CD, Whitlock, RP, Fergusson, DA, Belley-Cote, E, Connolly, K, Khanykin, B et al.. Six-Month Outcomes after Restrictive or Liberal Transfusion for Cardiac Surgery. N. Engl. J. Med. 2018; :. doi: 10.1056/NEJMoa1808561. PubMed PMID:30146969 .
  2. Shehata, N, Mistry, N, da Costa, BR, Pereira, TV, Whitlock, R, Curley, GF et al.. Restrictive compared with liberal red cell transfusion strategies in cardiac surgery: a meta-analysis. Eur. Heart J. 2018; :. doi: 10.1093/eurheartj/ehy435. PubMed PMID:30107514 .
  3. McAuliffe, N, Nicholson, S, Rigamonti, A, Hare, GMT, Cusimano, M, Garavaglia, M et al.. Awake craniotomy using dexmedetomidine and scalp blocks: a retrospective cohort study. Can J Anaesth. 2018;65 (10):1129-1137. doi: 10.1007/s12630-018-1178-z. PubMed PMID:29978278 .
  4. Hare, GMT, Han, K, Leshchyshyn, Y, Mistry, N, Kei, T, Dai, SY et al.. Potential biomarkers of tissue hypoxia during acute hemodilutional anemia in cardiac surgery: A prospective study to assess tissue hypoxia as a mechanism of organ injury. Can J Anaesth. 2018;65 (8):901-913. doi: 10.1007/s12630-018-1140-0. PubMed PMID:29696581 .
  5. Mistry, N, Mazer, CD, Sled, JG, Lazarus, AH, Cahill, LS, Solish, M et al.. Red blood cell antibody-induced anemia causes differential degrees of tissue hypoxia in kidney and brain. Am. J. Physiol. Regul. Integr. Comp. Physiol. 2018;314 (4):R611-R622. doi: 10.1152/ajpregu.00182.2017. PubMed PMID:29351418 PubMed Central PMC5966813.
  6. Garg, AX, Shehata, N, McGuinness, S, Whitlock, R, Fergusson, D, Wald, R et al.. Risk of Acute Kidney Injury in Patients Randomized to a Restrictive Versus Liberal Approach to Red Blood Cell Transfusion in Cardiac Surgery: A Substudy Protocol of the Transfusion Requirements in Cardiac Surgery III Noninferiority Trial. Can J Kidney Health Dis. 2018;5 :2054358117749532. doi: 10.1177/2054358117749532. PubMed PMID:29326843 PubMed Central PMC5757433.
  7. Mazer, CD, Whitlock, RP, Fergusson, DA, Hall, J, Belley-Cote, E, Connolly, K et al.. Restrictive or Liberal Red-Cell Transfusion for Cardiac Surgery. N. Engl. J. Med. 2017;377 (22):2133-2144. doi: 10.1056/NEJMoa1711818. PubMed PMID:29130845 .
  8. Kei, T, Mistry, N, Tsui, AKY, Liu, E, Rogers, S, Doctor, A et al.. Experimental assessment of oxygen homeostasis during acute hemodilution: the integrated role of hemoglobin concentration and blood pressure. Intensive Care Med Exp. 2017;5 (1):12. doi: 10.1186/s40635-017-0125-6. PubMed PMID:28251580 PubMed Central PMC5332316.
  9. Levin, DN, Dulberg, Z, Chan, AW, Hare, GM, Mazer, CD, Hong, A et al.. A randomized-controlled trial of nabilone for the prevention of acute postoperative nausea and vomiting in elective surgery. Can J Anaesth. 2017;64 (4):385-395. doi: 10.1007/s12630-017-0814-3. PubMed PMID:28160217 .
  10. Kosinski, PD, Croal, PL, Leung, J, Williams, S, Odame, I, Hare, GM et al.. The severity of anaemia depletes cerebrovascular dilatory reserve in children with sickle cell disease: a quantitative magnetic resonance imaging study. Br. J. Haematol. 2017;176 (2):280-287. doi: 10.1111/bjh.14424. PubMed PMID:27905100 .