Original Research
4 June 2013

Aspirin Versus Low-Molecular-Weight Heparin for Extended Venous Thromboembolism Prophylaxis After Total Hip Arthroplasty: A Randomized Trial

Publication: Annals of Internal Medicine
Volume 158, Number 11

Abstract

Background:

The role of aspirin in thromboprophylaxis after total hip arthroplasty (THA) is controversial.

Objective:

To compare extended prophylaxis with aspirin and dalteparin for prevention of symptomatic venous thromboembolism (VTE) after THA.

Design:

Multicenter randomized, controlled trial with a noninferiority design based on a minimal clinically important difference of 2.0%. Randomization was electronically generated; patients were assigned to a treatment group through a Web-based program. Patients, physicians, study coordinators, health care team members, outcome adjudicators, and data analysts were blinded to interventions. (Current Controlled Trials: ISRCTN11902170)

Setting:

12 tertiary care orthopedic referral centers in Canada.

Patients:

778 patients who had elective unilateral THA between 2007 and 2010.

Intervention:

After an initial 10 days of dalteparin prophylaxis after elective THA, patients were randomly assigned to 28 days of dalteparin (n = 400) or aspirin (n = 386).

Measurements:

Symptomatic VTE confirmed by objective testing (primary efficacy outcome) and bleeding.

Results:

Five of 398 patients (1.3%) randomly assigned to dalteparin and 1 of 380 (0.3%) randomly assigned to aspirin had VTE (absolute difference, 1.0 percentage point [95% CI, −0.5 to 2.5 percentage points]). Aspirin was noninferior (P < 0.001) but not superior (P = 0.22) to dalteparin. Clinically significant bleeding occurred in 5 patients (1.3%) receiving dalteparin and 2 (0.5%) receiving aspirin. The absolute between-group difference in a composite of all VTE and clinically significant bleeding events was 1.7 percentage points (CI, −0.3 to 3.8 percentage points; P = 0.091) in favor of aspirin.

Limitation:

The study was halted prematurely because of difficulty with patient recruitment.

Conclusion:

Extended prophylaxis for 28 days with aspirin was noninferior to and as safe as dalteparin for the prevention of VTE after THA in patients who initially received dalteparin for 10 days. Given its low cost and greater convenience, aspirin may be considered a reasonable alternative for extended thromboprophylaxis after THA.

Primary Funding Source:

Canadian Institutes of Health Research.

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References

1.
Collins RScrimgeour AYusuf SPeto R. Reduction in fatal pulmonary embolism and venous thrombosis by perioperative administration of subcutaneous heparin. Overview of results of randomized trials in general, orthopedic, and urologic surgery. N Engl J Med. 1988;318:1162-73. [PMID: 3283548]
2.
Geerts WHBergqvist DPineo GFHeit JASamama CMLassen MRet alAmerican College of Chest Physicians. Prevention of venous thromboembolism: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest. 2008;133:381S-453S. [PMID: 18574271]
3.
Planes AVochelle NDarmon JYFagola MBellaud MHuet Y. Risk of deep-venous thrombosis after hospital discharge in patients having undergone total hip replacement: double-blind randomised comparison of enoxaparin versus placebo. Lancet. 1996;348:224-8. [PMID: 8684199]
4.
White RHRomano PSZhou HRodrigo JBargar W. Incidence and time course of thromboembolic outcomes following total hip or knee arthroplasty. Arch Intern Med. 1998;158:1525-31. [PMID: 9679793]
5.
Bergqvist DBenoni GBjörgell OFredin HHedlundh UNicolas Set al. Low-molecular-weight heparin (enoxaparin) as prophylaxis against venous thromboembolism after total hip replacement. N Engl J Med. 1996;335:696-700. [PMID: 8703168]
6.
Dahl OEAndreassen GAspelin TMüller CMathiesen PNyhus Set al. Prolonged thromboprophylaxis following hip replacement surgery—results of a double-blind, prospective, randomised, placebo-controlled study with dalteparin (Fragmin). Thromb Haemost. 1997;77:26-31. [PMID: 9031444]
7.
Lassen MRBorris LCAnderson BSJensen HPSkejø Bro HPAndersen Get al. Efficacy and safety of prolonged thromboprophylaxis with a low molecular weight heparin (dalteparin) after total hip arthroplasty—the Danish Prolonged Prophylaxis (DaPP) Study. Thromb Res. 1998;89:281-7. [PMID: 9669750]
8.
Hull RDPineo GFFrancis CBergqvist DFellenius CSoderberg Ket al. Low-molecular-weight heparin prophylaxis using dalteparin extended out-of-hospital vs in-hospital warfarin/out-of-hospital placebo in hip arthroplasty patients: a double-blind, randomized comparison. North American Fragmin Trial Investigators. Arch Intern Med. 2000;160:2208-15. [PMID: 10904465]
9.
Comp PCSpiro TEFriedman RJWhitsett TLJohnson GJGardiner GA Jret alEnoxaparin Clinical Trial Group. Prolonged enoxaparin therapy to prevent venous thromboembolism after primary hip or knee replacement. Enoxaparin Clinical Trial Group. J Bone Joint Surg Am. 2001;83-A:336-45. [PMID: 11263636]
10.
O'Donnell MLinkins LAKearon CJulian JHirsh J. Reduction of out-of-hospital symptomatic venous thromboembolism by extended thromboprophylaxis with low-molecular-weight heparin following elective hip arthroplasty: a systematic review. Arch Intern Med. 2003;163:1362-6. [PMID: 12796074]
11.
Skedgel CGoeree RPleasance SThompson KO'brien BAnderson D. The cost-effectiveness of extended-duration antithrombotic prophylaxis after total hip arthroplasty. J Bone Joint Surg Am. 2007;89:819-28. [PMID: 17403806]
12.
Hull RDPineo GFStein PDMah AFMacIsaac SMDahl OEet al. Extended out-of-hospital low-molecular-weight heparin prophylaxis against deep venous thrombosis in patients after elective hip arthroplasty: a systematic review. Ann Intern Med. 2001;135:858-69. [PMID: 11712876]
13.
Eikelboom JWQuinlan DJDouketis JD. Extended-duration prophylaxis against venous thromboembolism after total hip or knee replacement: a meta-analysis of the randomised trials. Lancet. 2001;358:9-15. [PMID: 11454370]
14.
Anderson FA JrHirsh JWhite KFitzgerald RH JrHip and Knee Registry Investigators. Temporal trends in prevention of venous thromboembolism following primary total hip or knee arthroplasty 1996-2001: findings from the Hip and Knee Registry. Chest. 2003;124:349S-356S. [PMID: 14668417]
15.
Rahme EDasgupta KBurman MYin HBernatsky SBerry Get al. Postdischarge thromboprophylaxis and mortality risk after hip-or knee-replacement surgery. CMAJ. 2008;178:1545-54. [PMID: 18519902]
16.
Eriksson BIBorris LCFriedman RJHaas SHuisman MVKakkar AKet alRECORD1 Study Group. Rivaroxaban versus enoxaparin for thromboprophylaxis after hip arthroplasty. N Engl J Med. 2008;358:2765-75. [PMID: 18579811]
17.
Wolowacz SERoskell NSPlumb JMCaprini JAEriksson BI. Efficacy and safety of dabigatran etexilate for the prevention of venous thromboembolism following total hip or knee arthroplasty. A meta-analysis. Thromb Haemost. 2009;101:77-85. [PMID: 19132192]
18.
Collaborative overview of randomised trials of antiplatelet therapy—III: Reduction in venous thrombosis and pulmonary embolism by antiplatelet prophylaxis among surgical and medical patients. Antiplatelet Trialists' Collaboration. BMJ. 1994;308:235-46. [PMID: 8054013]
19.
Prevention of pulmonary embolism and deep vein thrombosis with low dose aspirin: Pulmonary Embolism Prevention (PEP) trial. Lancet. 2000;355:1295-302. [PMID: 10776741]
20.
Hirsh J. Low dose aspirin reduced DVT and pulmonary embolism but increased post-operative bleeding requiring transfusion in hip surgery patients. ACP J Club. 2001;134:13.
21.
Johanson NALachiewicz PFLieberman JRLotke PAParvizi JPellegrini Vet al. American academy of orthopaedic surgeons clinical practice guideline on prevention of symptomatic pulmonary embolism in patients undergoing total hip or knee arthroplasty. J Bone Joint Surg Am. 2009;91:1756-7. [PMID: 19571100]
22.
Fraser JDAnderson DR. Venous protocols, techniques, and interpretations of the upper and lower extremities. Radiol Clin North Am. 2004;42:279-96. [PMID: 15136017]
23.
Goldhaber SZ. Pulmonary embolism. Lancet. 2004;363:1295-305. [PMID: 15094276]
24.
World Health Organization. Cerebrovascular Disorders: A Clinical and Research Classification. Geneva: World Health Organization; 1978. WHO offset publication no. 43.
25.
Boersma EHarrington RAMoliterno DJWhite HThéroux PVan de Werf Fet al. Platelet glycoprotein IIb/IIIa inhibitors in acute coronary syndromes: a meta-analysis of all major randomised clinical trials. Lancet. 2002;359:189-98. [PMID: 11812552]
26.
Tissue plasminogen activator for acute ischemic stroke. The National Institute of Neurological Disorders and Stroke rt-PA Stroke Study Group. N Engl J Med. 1995;333:1581-7. [PMID: 7477192]
27.
Horan TCGaynes RPMartone WJJarvis WREmori TG. CDC definitions of nosocomial surgical site infections, 1992: a modification of CDC definitions of surgical wound infections. Infect Control Hosp Epidemiol. 1992;13:606-8. [PMID: 1334988]
28.
Jameson SSCharman SCGregg PJReed MRvan der Meulen JH. The effect of aspirin and low-molecular-weight heparin on venous thromboembolism after hip replacement: a non-randomised comparison from information in the National Joint Registry. J Bone Joint Surg Br. 2011;93:1465-70. [PMID: 22058295]

Information & Authors

Information

Published In

cover image Annals of Internal Medicine
Annals of Internal Medicine
Volume 158Number 114 June 2013
Pages: 800 - 806

History

Published online: 4 June 2013
Published in issue: 4 June 2013

Keywords

Authors

Affiliations

David R. Anderson, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Michael J. Dunbar, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Eric R. Bohm, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Etienne Belzile, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Susan R. Kahn, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
David Zukor, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
William Fisher, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Wade Gofton, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Peter Gross, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Stephane Pelet, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Mark Crowther, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Steven MacDonald, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Paul Kim, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Susan Pleasance, BScN
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Nicki Davis, BSc
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Pantelis Andreou, PhD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Philip Wells, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Michael Kovacs, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Marc A. Rodger, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Tim Ramsay, PhD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Marc Carrier, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Pascal-Andre Vendittoli, MD
From Dalhousie University, Halifax, Nova Scotia; University of Manitoba, Winnipeg, Manitoba; Université Laval, Québec City, Québec; McGill University and Montréal University, Montréal, Québec; University of Ottawa, Ottawa, Ontario; McMaster University, Hamilton, Ontario; and University of Western Ontario, London, Ontario, Canada.
Note: All authors had full access to the study data. Dr. Anderson takes full responsibility for the integrity of the data and the accuracy of the data analysis.
Acknowledgment: The authors thank the members of the EPCAT study group (see the Appendix).
Financial Support: By grant MCT-82948 from the Canadian Institutes for Health Research and by Pfizer Pharmaceuticals Canada. In-kind support was provided by Bayer HealthCare. Dr. Kahn is a recipient of a National Research Scholar Award from the Fonds de la Recherche en Santé du Québec.
Reproducible Research Statement: Study protocol, statistical code, and data set: For details, contact Dr. Anderson ([email protected]).
Corresponding Author: David Anderson, MD, Department of Medicine, Capital Health, 1276 South Park Street, Room 442, Bethune Building, VG Site, Halifax, Nova Scotia B3H 2Y9, Canada; e-mail, [email protected].
Current Author Addresses: Dr. Anderson: Department of Medicine, Capital Health, 1276 South Park Street, Room 442, Bethune Building, VG Site, Halifax, Nova Scotia B3H 2Y9, Canada.
Dr. Dunbar: Queen Elizabeth II Health Sciences Centre, Suite 4822, Halifax Infirmary, 1796 Summer Street, Halifax, Nova Scotia B3H 3A7, Canada.
Dr. Bohm: Concordia Joint Replacement Group, Suite 300–1155, Concordia Avenue, Winnipeg, Manitoba R2K 2M9, Canada.
Dr. Belzile: Centre Hospitalier Universitaire Québec, Pavillon Hotel Dieu de Québec, Service de Chirurgie Orthopedique, 11 Côte du Palais, Québec, Québec G1R 2J6, Canada.
Dr. Kahn: Centre for Clinical Epidemiology and Community Studies, Jewish General Hospital, 5790 Côte-des-Neiges, Room H-485, Montréal, Québec H3S 1Y9, Canada.
Dr. Zukor: Department of Orthopedics, SMBD Jewish General Hospital, 3755 Chemin de la Côte Ste-Catherine, Montréal, Québec H3T 1E2, Canada.
Dr. Fisher: McGill University Health Centre, 1650 Cedar Avenue, B5.158.7, Montréal, Québec, H3G 1A4, Canada.
Dr. Gofton: Ottawa Hospital Civic Campus, Suite J153, 1053 Carling Avenue, Ottawa, Ontario K1Y 4E9, Canada.
Dr. Gross: TaARI, David Braley CVSRI-5th Floor, 247 Barton Street East, Hamilton, Ontario L8L 2X2, Canada.
Dr. Pelet: Departement d’orthopedie, CHA-Pavillon Enfant-Jesus, 1401, 18eme Rue, Québec, Québec G1J 1Z4, Canada.
Dr. Crowther: Room L-301, St Joseph's Hospital, 50 Charlton Avenue East, Hamilton, Ontario L8N 4A6, Canada.
Dr. MacDonald: London Health Sciences Centre, University Hospital, 339 Windermere Road, London, Ontario N6A 5A5, Canada.
Dr. Kim: Ottawa Hospital General Campus, 501 Smyth Road, Room W1650, Box 502, Ottawa, Ontario K1H 8L6, Canada.
Ms. Pleasance: Queen Elizabeth II Health Sciences Centre, Capital Health Centre for Clinical Research, 5790 University Avenue, Room 132, Halifax, Nova Scotia B2H 1V7, Canada.
Ms. Davis: 21 Robertson Avenue, Gander, Newfoundland A1V 1Y1, Canada.
Dr. Andreou: Department of Community Health and Epidemiology, Dalhousie University, 5790 University Avenue, Room 414, Halifax, Nova Scotia B3H 1V7, Canada.
Dr. Wells: Ottawa Hospital General Campus, LM 12 Box 206, 501 Smyth Road, Ottawa, Ontario K1H 8L6, Canada.
Dr. Kovacs: Victoria Hospital, 800 Commissioners Road East, Room A2-401, London, Ontario N6A 4G5, Canada.
Dr. Rodger: Ottawa Hospital General Campus, 501 Smyth Road, W6120, Box 201, Ottawa, Ontario K1H 8L6, Canada.
Dr. Ramsay: Ottawa Hospital General Campus, Box 201b, 501 Smyth Road, Ottawa K1H 4E9, Canada.
Dr. Carrier: Division of Hematology and CEP, Ottawa Hospital General Campus, 501 Smyth Road, Box 201A, Ottawa, Ontario K1H 8L6, Canada.
Dr. Vendittoli: Hospital Maisonneuve-Rosemont, 5415 boul L’Assomption, Montréal, Québec H1T 2M4, Canada.
Author Contributions: Conception and design: D. Anderson, M.J. Dunbar, E.R. Bohm, E. Belzile, D. Zukor, W. Fisher, S. Pleasance, P. Wells, M. Kovacs, M.A. Rodger, P.A. Vendittoli.
Analysis and interpretation of the data: D. Anderson, M.J. Dunbar, E.R. Bohm, W. Fisher, P. Kim, N. Davis, P. Andreou, P. Wells, M. Kovacs, M. Carrier.
Drafting of the article: D. Anderson, M.J. Dunbar, E. Belzile, W. Fisher, M. Crowther, P. Kim, S. Pleasance, P. Wells, M. Kovacs, P.A. Vendittoli.
Critical revision of the article for important intellectual content: D. Anderson, E.R. Bohm, E. Belzile, S. Kahn, W. Fisher, P. Gross, S. Pelet, S. Pleasance, P. Wells, M. Kovacs, M.A. Rodger, T. Ramsay, M. Carrier, P.A. Vendittoli.
Final approval of the article: D. Anderson, M.J. Dunbar, E.R. Bohm, E. Belzile, S. Kahn, D. Zukor, W. Fisher, W. Gofton, P. Gross, S. Pelet, S. MacDonald, P. Kim, S. Pleasance, P. Andreou, P. Wells, M. Kovacs, M.A. Rodger, T. Ramsay, M. Carrier, P.A. Vendittoli.
Provision of study materials or patients: M.J. Dunbar, E.R. Bohm, E. Belzile, S. Kahn, D. Zukor, W. Fisher, W. Gofton, P. Gross, S. Pelet, M. Crowther, S. MacDonald, P. Kim, M. Kovacs.
Statistical expertise: N. Davis, P. Andreou, T. Ramsay.
Obtaining of funding: D. Anderson, E.R. Bohm, E. Belzile, S. Kahn, S. Pelet, S. Pleasance, P. Wells, M.A. Rodger, M. Carrier.
Administrative, technical, or logistic support: E.R. Bohm, S. Pelet, M. Crowther, P. Kim, S. Pleasance, N. Davis.
Collection and assembly of data: S. Kahn, D. Zukor, S. Pelet, S. MacDonald, P. Kim, N. Davis, M. Rodger, M. Carrier, P.A. Vendittoli.

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David R. Anderson, Michael J. Dunbar, Eric R. Bohm, et al. Aspirin Versus Low-Molecular-Weight Heparin for Extended Venous Thromboembolism Prophylaxis After Total Hip Arthroplasty: A Randomized Trial. Ann Intern Med.2013;158:800-806. [Epub 4 June 2013]. doi:10.7326/0003-4819-158-11-201306040-00004

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