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Previous Volume 329:1370-1376 November 4, 1993 Number 19 Next

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ABSTRACT

Background Deep-vein thrombosis is a potentially life-threatening complication of total hip or knee replacement. There are few data on the effectiveness and safety of warfarin as compared with low-molecular-weight heparin as prophylaxis against this problem.

Methods We therefore performed a randomized, double-blind trial in 1436 patients to evaluate the effectiveness and safety of low-molecular-weight heparin (given subcutaneously once daily) as compared with adjusted-dose warfarin to prevent venous thrombosis after hip or knee replacement. Treatment with the drugs was started postoperatively. The primary end point was deep-vein thrombosis as detected by contrast venography (performed a mean of 9.4 days after surgery in each group).

Results Among the 1207 patients with interpretable venograms, 231 of 617 patients (37.4 percent) in the warfarin group and 185 of 590 patients (31.4 percent) in the low-molecular-weight-heparin group had deep-vein thrombosis (P = 0.03). The reduction in risk with low-molecular-weight heparin as compared with warfarin was 16 percent, and the absolute difference in the incidence of venous thrombosis was 6 percent in favor of low-molecular-weight heparin (95 percent confidence interval, 0.8 to 11.4 percent). The incidence of major bleeding was 1.2 percent (9 of 721 patients) in the warfarin group and 2.8 percent (20 of 715 patients) in the low-molecular-weight-heparin group (P = 0.04), and the absolute difference was 1.5 percent in favor of warfarin (95 percent confidence interval, 0.1 to 3.0 percent).

Conclusions Our data demonstrate that the small reduction in the incidence of venous thrombosis with low-molecular-weight heparin, as compared with warfarin, was offset by an increase in bleeding complications. Although the use of low-molecular-weight heparin is simpler, because it is administered subcutaneously without the need for monitoring, it may be more costly than warfarin. Warfarin is inexpensive, but the overall cost of its use is increased by the need to monitor the intensity of anticoagulation. At this time it is unclear which of these approaches is the most cost effective.

Source Information

From the Clinical Trials Unit, Faculty of Medicine, University of Calgary, Calgary, Alta., Canada (R.H., G.R., G.P., K.A., G.H., R.B.); Chedoke-McMaster Hospitals, Hamilton, Ont., Canada (D.R., F.S., A.P.); Ohio State University, Columbus (W.E., T.M.); Northwestern University, Chicago (D.G.); and LDS Hospital, Salt Lake City (C.G.E.).

Address reprint requests to Dr. Hull at the Department of Medicine, University of Calgary, 3330 Hospital Dr. NW, Calgary, AB T2N 4N1, Canada.

Full Text of this Article

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Low-Molecular-Weight Heparin vs. Warfarin for Prophylaxis against Deep-Vein Thrombosis
Hirsh J., Lotke P. A., Ecker M. L., Hull R. D., Pineo G. F.
Extract | Full Text  
N Engl J Med 1994; 330:862-863, Mar 24, 1994. Correspondence

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• Baughman, R. A., Kapoor, S. C., Agarwal, R. K., Kisicki, J., Catella-Lawson, F., FitzGerald, G. A. (1998). Oral Delivery of Anticoagulant Doses of Heparin : A Randomized, Double-Blind, Controlled Study in Humans. Circulation 98: 1610-1615 [Abstract] [Full Text]  
• White, R. H., Romano, P. S., Zhou, H., Rodrigo, J., Bargar, W. (1998). Incidence and Time Course of Thromboembolic Outcomes Following Total Hip or Knee Arthroplasty. Arch Intern Med 158: 1525-1531 [Abstract] [Full Text]  
• Agnelli, G., Piovella, F., Buoncristiani, P., Severi, P., Pini, M., D'Angelo, A., Beltrametti, C., Damiani, M., Andrioli, G. C., Pugliese, R., Iorio, A., Brambilla, G. (1998). Enoxaparin plus Compression Stockings Compared with Compression Stockings Alone in the Prevention of Venous Thromboembolism after Elective Neurosurgery. NEJM 339: 80-85 [Abstract] [Full Text]  
• KEATING, E. M. (1998). Instructional Course Lectures, The American Academy of Orthopaedic Surgeons - Current Options and Approaches for Blood Management in Orthopaedic Surgery*{{dagger}}. JBJS 80: 750-62 [Full Text]  
• Leclerc, J. R., Gent, M., Hirsh, J., Geerts, W. H., Ginsberg, J. S., for the Canadian Collaborative Group, (1998). The Incidence of Symptomatic Venous Thromboembolism During and After Prophylaxis With Enoxaparin: A Multi-institutional Cohort Study of Patients Who Underwent Hip or Knee Arthroplasty. Arch Intern Med 158: 873-878 [Abstract] [Full Text]  
• Hull, R. D., Pineo, G. F. (1998). Prophylaxis of Deep Vein Thrombosis and Pulmonary Embolism: Current Recommendations. CLIN APPL THROMB HEMOST 4: 96-104 [Abstract]  
• Agnelli, G. (1998). Postdischarge prophylaxis for venous thromboembolism among high-risk surgery patients. Vasc Med 3: 51-56 [Abstract]  
• Eriksson, B. I., Wille-Jorgensen, P., Kalebo, P., Mouret, P., Rosencher, N., Bosch, P., Baur, M., Ekman, S., Bach, D., Lindbratt, S., Close, P. (1997). A Comparison of Recombinant Hirudin with a Low-Molecular-Weight Heparin to Prevent Thromboembolic Complications after Total Hip Replacement. NEJM 337: 1329-1335 [Abstract] [Full Text]  
• Ewenstein, B. M. (1997). Antithrombotic Agents and Thromboembolic Disease. NEJM 337: 1383-1384 [Full Text]  
• Weitz, J. I. (1997). Low-Molecular-Weight Heparins. NEJM 337: 688-699 [Full Text]  
• FRANCIS, C. W., PELLEGRINI, V. D. JR., TOTTERMAN, S., BOYD, A. D. JR., MARDER, V. J., LIEBERT, K. M., STULBERG, B. N., AYERS, D. C., ROSENBERG, A., KESSLER, C., JOHANSON, N. A. (1997). Prevention of Deep-Vein Thrombosis after Total Hip Arthroplasty. Comparison of Warfarin and Dalteparin. JBJS 79: 1365-72 [Abstract] [Full Text]  
• Leclerc, J.R. (1997). State-of-the-Art Review: Low-Molecular Weight Heparin Prophylaxis in Surgical Patients. CLIN APPL THROMB HEMOST 3: 153-156  
• LIEBERMAN, J. R., WOLLAEGER, J., DOREY, F., THOMAS, B. J., KILGUS, D. J., GRECULA, M. J., FINERMAN, G. A., AMSTUTZ, H. C. (1997). The Efficacy of Prophylaxis with Low-Dose Warfarin for Prevention of Pulmonary Embolism following Total Hip Arthroplasty. JBJS 79: 319-25 [Abstract] [Full Text]  
• ERIKSSON, B. I., EKMAN, S., LINDBRATT, S., BAUR, M., BACH, D., TØRHOLM, C., KÄLEBO, P., CLOSE, P. (1997). Prevention of Thromboembolism with Use of Recombinant Hirudin. Results of a Double-Blind, Multicenter Trial Comparing the Efficacy of Desirudin (Revasc) with That of Unfractionated Heparin in Patients Having a Total Hip Replacement. JBJS 79: 326-33 [Abstract] [Full Text]  
• WOOLSON, S. T. (1996). Intermittent Pneumatic Compression Prophylaxis for Proximal Deep Venous Thrombosis after Total Hip Replacement. JBJS 78: 1735-40 [Abstract] [Full Text]  
• Geerts, W. H., Jay, R. M., Code, K. I., Chen, E., Szalai, J. P., Saibil, E. A., Hamilton, P. A. (1996). A Comparison of Low-Dose Heparin with Low-Molecular-Weight Heparin as Prophylaxis against Venous Thromboembolism after Major Trauma. NEJM 335: 701-707 [Abstract] [Full Text]  
• Prandoni, P., Goldhaber, S. Z., Piccioli, A., Girolami, A. (1996). State-of-the-Art Review : Prevention of Venous Thromboembolism in Major Orthopedic Surgery. CLIN APPL THROMB HEMOST 2: 153-157 [Abstract]  
• Hirsh, J., Hoak, J. (1996). Management of Deep Vein Thrombosis and Pulmonary Embolism : A Statement for Healthcare Professionals From the Council on Thrombosis (in Consultation With the Council on Cardiovascular Radiology), American Heart Association. Circulation 93: 2212-2245 [Full Text]  
• Poller, L., Thomson, J. M., MacCallum, P. K., Nicholson, D. A., Weighill, F. J., Lemon, J. G. (1995). Minidose Warfarin and Failure to Prevent Deep Vein Thrombosis After Joint Replacement Surgery Despite Inhibiting the Postoperative Rise in Plasminogen Activator Inhibitor Activity. CLIN APPL THROMB HEMOST 1: 267-273 [Abstract]  
• Weinmann, E. E., Salzman, E. W. (1994). Deep-Vein Thrombosis. NEJM 331: 1630-1641 [Full Text]  
• Hirsh, J., Lotke, P. A., Ecker, M. L., Hull, R. D., Pineo, G. F. (1994). Low-Molecular-Weight Heparin vs. Warfarin for Prophylaxis against Deep-Vein Thrombosis. NEJM 330: 862-863 [Full Text]  
• Clagett, G. P. (1994). Prevention of Venous Thromboembolism: An Update. PERSPECT VASC SURG ENDOVASC THER 7: 71-84  
• Verstraete, M. (1993). The Diagnosis and Treatment of Deep-Vein Thrombosis. NEJM 329: 1418-1420 [Full Text]