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Clive Kearon


Professor, Medicine, McMaster University
Program Director, Clinician Investigator Program

Although his current clinical responsibilities primarily focus on the management of thromboembolic disorders, Dr. Clive Kearon originally qualified in Ireland, trained as a respirologist and obtained a Ph.D. from McMaster University for studies relating to respiratory and exercise physiology.  He is currently a Professor in the Department of Medicine, an Associated Member in the Department of Clinical Epidemiology and Biostatistics at McMaster University, a Consultant with the Clinical Thromboembolism Service at the Juravinski Site of Hamilton Health Sciences, and Program Director of the Clinician Investigator Program, at McMaster.  He was a Career  Investigator of the Canadian Institutes of Health Research and is now an Investigator of the Heart and Stroke Foundation of Canada.  Dr. Kearon is the recipient of two awards from the Canadian Institutes of Health Research for providing mentorship in the design and conduct of randomized controlled trials, and he is the recipient of the International Society on Thrombosis and Haemostasis’ 14th Biennial Investigator Recognition Award (2009).  Dr. Kearon is involved in the critical appraisal of the medical literature, the development of practice guidelines, and is the chairperson for the current American College of Chest Physicians’ guidelines for the treatment of venous thromboembolism.

Research Interests

Dr. Kearon’s research focuses on clinical trials designed to optimize the diagnosis and treatment of thromboembolic disease.  Diagnostic studies are evaluating the ability of D-dimer blood tests to exclude the presence of deep vein thrombosis and pulmonary embolism.  Treatment studies are evaluating new ways to use unfractionated heparin for the acute treatment of venous thrombosis; the optimal duration of anticoagulation in subgroups of patients who have either a high, or a low risk of recurrent venous thrombosis; and the catheter-directed thrombolysis for the acute treatment of deep vein thrombosis.

Dr. Kearon is also undertaking studies to identify the clinical importance, and the management implication, of the presence of biochemical abnormalities that are known to be associated with thromboembolism (“thrombophilia”).  Additional studies will elucidate, and compare, the pharmacology of different heparin preparations, and will, try to refine how patients with venous thromboembolism are selected to long-term therapy so as to maximize benefit and minimize harm from bleeding.

Dr. Kearon’s research is supported by the Heart and Stroke Foundation of Ontario, Canadian Institutes of Health Research, and the National Institute of Health.

Selected Publications

   1. Kearon C, Hirsh J.  Management of anticoagulation before and after elective surgery.  New Engl J Med 1997; 336(21):1506-1511.

   2. Kearon C, Julian JA, Newman T, Ginsberg J.  Noninvasive diagnosis of deep venous thrombosis.  Ann Intern Med 1998; 128(8):663-667.

   3. Kearon C, Ginsberg JS, Hirsh J.  The role of venous ultrasonography in the diagnosis of suspected deep vein thrombosis and pulmonary embolism.  Ann Intern Med 1998; 129:1044-1049.

   4. Kearon C, Gent M, Hirsh J, Weitz J, Kovacs MJ, Anderson DR, Turpie AG, Green D, Ginsberg JS, Wells P, MacKinnon B, Julian J.  A comparison of three months of anticoagulation with extended anticoagulation for a first episode of idiopathic venous thromboembolism.  N. Engl J Med 1999; 340:901-7.

   5. Kearon C, Ginsberg JS, Douketis J, Crowther M, Brill-Edwards P, Weitz JI, Hirsh J.  Management of suspected deep vein thrombosis in outpatients using clinical assessment and D-dimer testing.  Ann Intern Med 2001; 135:108-111.

   6. Kearon C, Ginsberg JS, Kovacs MJ, Anderson DR, Wells P, Julian JA, MacKinnon B, Weitz JI, Crowther MA, Dolan S, Turpie AGG, Geerts W, Solymoss S, van Nguyen P, Demers C, Kahn SR, Kassis J, Rodger M, Hambleton J, Gent M, (ELATE) Investigators).  Comparison of low-intensity with conventional-intensity warfarin therapy for long-term prevention of recurrent venous thromboembolism.  New Engl J Med 2003; 349:631-639.

   7. Kearon C,  Ginsberg JS, Douketis J, Crowther MA, Turpie AG, Bates SM, Lee A, Brill-Edwards P, Finch T, Gent M.  A randomized trial of diagnostic strategies after normal proximal vein ultrasonography for suspected deep venous thrombosis:  D-dimer testing compared with repeated ultrasonography. Ann Inter Med 2005; 142:490-496.

   8. McCrae S, Huyen T, Schulman S, Ginsberg J, Kearon C.  Effects of patient’s sex on risk of recurrent venous thromboembolism:  a meta-analysis.  The Lancet 2006; 368:371-378.

   9. Kearon C, Ginsberg JS, Douketis J, Turpie AG, Bates SM, Lee  AY, Crowther MA, Weitz JI, Brill-Edwards P, Wells P, Anderson DR, Kovacs MJ, Linkins L-A, Julian JA, Bonilla LR, Gent M for the Canadian Pulmonary Embolism Diagnosis Study (CANPEDS) Group.  An evaluation of D-Dimer in the diagnosis of pulmonary embolism: A randomized trial.  Ann Intern Med 2006; 144(11):  812-821.

  10. Kearon C, Ginsberg JS, Julian JA, Douketis J, Solymoss S, Ockelford P, Jackson S, Turpie AG, MacKinnon B, Hirsh J, Gent M, (for the Fixed-Dose Heparin (FIDO) Investigators.  Comparison of fixed-dose weight-adjusted unfractionated heparin and low-molecular-weight heparin for acute treatment of venous thromboembolism.  JAMA 2006; 296(8):935-942.

  11. O’Donnell MJ, Kearon C, Johnson J, Robinson M, Zondag M, Turpie I, Turpie AG.  Brief Communication:  Preoperative anticoagulant activity after bridging low-molecular-weight heparin for temporary interruption of warfarin.  Ann Intern Med 2007; 146:184-187.

  12. Kearon C, Kahn SR, Agnelli G, Goldhaber S, Raskob GE, Comerota AJ.  Antithrombotic therapy for venous thromboembolic disease.  ACCP Evidence-Based Clinical Practice Guidelines (8th Edition).  Chest 2008; 133:454S-545S.

  13. Kearon C, Julian JA, Kovacs MJ, Anderson DR, Wells P, MacKinnon B, Weitz JI, Crowther MA, Dolan S, Turpie AG, Geerts W, Solymoss S, van Nguyen P, Demers C, Kahn SR, Kasis J, Rodger M, Hambleton J, Gent M, Ginsberg JS for the ELATE Investigators. Influence of thrombophilia on risk of recurrent venous thromboembolism whle on warfarin:  results from a randomized trial.  BLOOD 2008; 112(12):4432-4436.

  14. Andreou ER, Koru-Sengul T, Linkins L, Bates SM, Ginsberg JS, Kearon C.  Differences in clinical presentation of deep vein thrombosis in men and women.  J Thromb Haemost  2008; 6:1713-1719.

  15. Crowther MA, Ageno W, Garcia D, Wang L, Witt DM, Clark NP, Blostein MD, Kahn SR, Vesely SK, Schulman S, Kovacs MJ, Rodger MA, Wells P, Anderson D, Ginsberg J, Selby R, Siragusa S, Silingardi M, Dowd MB, Kearon C.  Oral vitamin K versus placebo to correct excessive anticoagulation in patients receiving warfarin.  Ann Intern Med. 2009; 150:293-300.

  16. Arnold D, Anderson J, Kearon C.  Pre-operative Risk Assessment for Bleeding and Thromboembolism (“Rational Testing” Series).  BMJ 2009; 339:692-694.

  17. Couturaud F, Leroyer C, Julian JA, Kahn SR, Ginsberg JS, Wells PS, Douketis JD, Mottier D, Kearon C.  Factors that predict risk of thrombosis in relatives of patients with unprovoked venous thromboembolism.  Chest2009 JUL 10. [Epub ahead of print].