This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kornberg, A. Articles by Marder, V. J. Search for Related Content PubMed PubMed Citation Articles by Kornberg, A. Articles by Marder, V. J.

Circulation, Vol 88, 454-460, Copyright © 1993 by American Heart Association

ARTICLES

Comparison of native prothrombin antigen with the prothrombin time for monitoring oral anticoagulant prophylaxis

A Kornberg, CW Francis, VD Pellegrini Jr, KR Gabriel and VJ Marder
Department of Medicine, University of Rochester School of Medicine and Dentistry, NY 14642.

BACKGROUND. Oral anticoagulation is most frequently monitored using the prothrombin time, but an alternative approach is measurement of native, fully carboxylated, prothrombin antigen (NPA). We have correlated results of the prothrombin time and NPA with development of venous thrombosis or bleeding complications in a clinical trial of warfarin prophylaxis following total hip arthroplasty to determine the potential value of NPA measurement for monitoring oral anticoagulation. METHODS AND RESULTS. Patients in one arm of a prospective, randomized trial received warfarin prophylactically beginning 10 to 14 days before total hip arthroplasty in a dose adjusted to prolong the international normalized ratio (INR) to 1.5 on the day of surgery and 2.5 after surgery. NPA was measured by ELISA, and the prothrombin time was measured using rabbit brain thromboplastin. Samples were tested from 97 patients, and data from 81 patients who had adequate venography were analyzed to correlate test results with occurrence of thrombosis. The prothrombin time and INR were less sensitive than NPA to the lowest intensities of anticoagulation, with the prothrombin time index increasing from 1.0 to 1.3 and the INR increasing from 1.0 to 2.0, whereas the NPA concentration decreased fourfold, from 200 to 50 micrograms/mL. There was little correlation between either the prothrombin time index or the INR and the development of thrombosis, whereas NPA concentrations were significantly higher on the day of surgery and on postoperative days 1, 3, 5, and 7 in patients who developed venous thrombosis. Higher concentrations of NPA were associated with an increased risk of venous thrombosis, but there was no relation between thrombosis and the prothrombin time index or INR. There was no significant correlation between surgical blood loss and prothrombin time index, INR, or NPA concentration. However, patients who received the largest number of transfusions on the day of surgery had significantly lower NPA concentrations than patients who required no transfusion. CONCLUSIONS. These results indicate that the NPA concentration more accurately reflects the antithrombotic effect of warfarin than does prothrombin time and may be superior in monitoring prophylactic oral anticoagulation.

This article has been cited by other articles:

				T. P. Moyer, D. J. O'Kane, L. M. Baudhuin, C. L. Wiley, A. Fortini, P. K. Fisher, D. M. Dupras, R. Chaudhry, P. Thapa, A. R. Zinsmeister, et al. Warfarin Sensitivity Genotyping: A Review of the Literature and Summary of Patient Experience Mayo Clin. Proc., December 1, 2009; 84(12): 1079 - 1094. [Abstract] [Full Text] [PDF]

				A. Lazo-Langner, R. Villa-Marquez, D. Hernandez-Hernandez, S. Rojas-Maya, and J. Piedras Intrahospital Correlation of the International Normalized Ratio Clinical and Applied Thrombosis/Hemostasis, April 1, 2009; 15(2): 220 - 224. [Abstract] [PDF]

				J. Ansell, J. Hirsh, E. Hylek, A. Jacobson, M. Crowther, and G. Palareti Pharmacology and Management of the Vitamin K Antagonists: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition) Chest, June 1, 2008; 133(6_suppl): 160S - 198S. [Abstract] [Full Text] [PDF]

				J. Ansell, J. Hirsh, L. Poller, H. Bussey, A. Jacobson, and E. Hylek The Pharmacology and Management of the Vitamin K Antagonists: The Seventh ACCP Conference on Antithrombotic and Thrombolytic Therapy Chest, September 1, 2004; 126(3_suppl): 204S - 233S. [Abstract] [Full Text] [PDF]

				J. Hirsh, V. Fuster, J. Ansell, and J. L. Halperin American Heart Association/American College of Cardiology Foundation guide to warfarin therapy J. Am. Coll. Cardiol., May 7, 2003; 41(9): 1633 - 1652. [Full Text] [PDF]

				J. Hirsh, V. Fuster, J. Ansell, and J. L. Halperin American Heart Association/American College of Cardiology Foundation Guide to Warfarin Therapy Circulation, April 1, 2003; 107(12): 1692 - 1711. [Full Text] [PDF]

				J. Hirsh, J. E. Dalen, D. R. Anderson, L. Poller, H. Bussey, J. Ansell, and D. Deykin Oral Anticoagulants: Mechanism of Action, Clinical Effectiveness, and Optimal Therapeutic Range Chest, January 1, 2001; 119 (2009): 8S - 21S. [Full Text] [PDF]

				J. Ansell, J. Hirsh, J. Dalen, H. Bussey, D. Anderson, L. Poller, A. Jacobson, D. Deykin, and D. Matchar Managing Oral Anticoagulant Therapy Chest, January 1, 2001; 119 (2009): 22S - 38S. [Full Text] [PDF]

				J. Hirsh and L. Poller The International Normalized Ratio: A Guide to Understanding and Correcting Its Problems Arch Intern Med, February 14, 1994; 154(3): 282 - 288. [Abstract] [PDF]