Oral Anticoagulant Monitoring by Laboratory or Near-Patient Testing: What a Clinician Should Be Aware Of

A. Tripodi; W. G. M. Breukink-Engbers; A. M. H. P. van den Besselaar

doi:10.1055/s-2003-44460

Seminars in Vascular Medicine, Table of Contents

Semin Vasc Med 2003; 03(3): 243-254
DOI: 10.1055/s-2003-44460

Oral Anticoagulant Monitoring by Laboratory or Near-Patient Testing: What a Clinician Should Be Aware Of

A. Tripodi¹ , W. G.M. Breukink-Engbers² , A. M.H.P. van den Besselaar³

¹Bonomi Hemophilia and Thrombosis Centre, University and IRCCS Maggiore Hospital, Milan, Italy
²AntiStollingsCentrum Oost-Nederland (ASCON), Lichtenvoorde, The Netherlands
³Department of Haematology, Haemostasis and Thrombosis Research Centre, Leiden University Medical Centre, Leiden, The Netherlands

Abstract

ABSTRACT

Prothrombin time (PT) is the primary laboratory test for monitoring oral anticoagulant treatment but is influenced by preanalytical conditions and analytical variables, that is, thromboplastin reagents and instrumentation. Standardization and normalization of test results is mandatory. PT results should be transformed to International Normalized Ratio (INR) by calibration of the reagent/instrument system with International Reference standards according to World Health Organization guidelines. However, there is still uncertainty in the INR that is caused in part by calibration errors and in part by interaction between the PT reagent and various factors in the patient's specimen. These problems are highlighted in INR measurements performed with whole blood coagulation monitors. Each center should maintain an appropriate scheme of internal and external quality control for the laboratory INR measurement as well as the individual point-of-care coagulation monitors used by the center and patients for self-testing.

KEYWORDS

Oral anticoagulation - International Normalized Ratio - near-patient testing

Full Text

References

REFERENCES

1 Hirsh J, Dalen J E, Anderson D R, Poller L, Bussey H, Ansell J, Deykin D. Oral anticoagulants: mechanism of action, clinical effectiveness, and optimal therapeutic range. Chest . 2001; 119 8S-21S
2 WHO Expert Committee on Biological Standardization. Guidelines for thromboplastins and plasma used to monitor oral anticoagulant therapy. World Health Organization Technical Report Series, 1999; No. 889
3 van den Besselaar A H P M, Aillaud M F, Denson K WE. et al . Influence of three types of automated coagulometers on the international sensitivity index (ISI) of rabbit, human and recombinant human tissue factor preparations. Thromb Haemost . 1999; 81 66-70
4 Poller L, van den Besselaar A H P M, Jespersen J, Tripodi A, Houghton D. The European Concerted Action on Anticoagulation (ECAA): field studies of coagulometers effects on the ISI of ECAA thromboplastins. Thromb Haemost . 1998; 80 615-623
5 Johnston M, Harrison L, Moffat K, Willan A, Hirsh J. Reliability of the international normalized ratio for monitoring the induction phase of warfarin: comparison with the prothrombin time ratio. J Lab Clin Med . 1996; 128 214-217
6 Hyers T M, Agnelli G, Hull R D, Morris T A, Samama M, Tapson V, Weg J G. Antithrombotic therapy for venous thromboembolic disease. Chest . 2001; 119 176S-193S
7 van den Besselaar A H P M, Meeuwisse-Braun J. Enzymatic elimination of heparin from plasma for activated partial thromboplastin time and prothrombin time testing. Blood Coag Fibrinol . 1993; 4 635-638
8 Tripodi A. The risk of heparin-neutralizing substances. Am J Clin Pathol . 1999; 111 566
9 Della Valle P, Crippa L, Safa O. et al . Potential failure of the international normalized ratio (INR) system in the monitoring of oral anticoagulation in patients with lupus anticoagulants. Ann Med Intern . 1996; 147 10-14
10 Moll S, Ortel T L. Monitoring warfarin therapy in patients with lupus anticoagulants. Ann Intern Med . 1997; 127 177-185
11 Lawrie A S, Purdy G, Mackie I J, Machin S J. Monitoring oral anticoagulation therapy in lupus anticoagulant positive patients with the anti-phospholipid syndrome. Br J Haematol . 1997; 98 887-892
12 Robert A, Le Querrec A, Delahousse B. et al . Control of oral anticoagulation in patients with the antiphospholipid syndrome. Influence of the lupus anticoagulant on international normalized ratio. Thromb Haemost . 1998; 80 99-103
13 Tripodi A, Chantarangkul V, Clerici M, Negri B, Galli M, Mannucci P M. Laboratory control of oral anticoagulant treatment by the INR system in patients with the antiphospholipid syndrome and lupus anticoagulant. Results of a collaborative study involving nine commercial thromboplastins. Br J Haematol . 2001; 115 672-678
14 Rapaport S I, Le D T. Thrombosis in the antiphospholipid antibody syndrome. N Engl J Med . 1995; 333 665
15 Lassen J F, Brandslund I, Antonsen S. International Normalized Ratio for prothrombin times in patients taking oral anticoagulants: critical difference and probability of significant change in consecutive measurements. Clin Chem . 1995; 41 444-447
16 Jacobs P. Concentration of citrate anticoagulant. Am J Clin Pathol . 1973; 60 941
17 Chantarangkul V, Tripodi A, Clerici M, Negri B, Mannucci P M. Assessment of the influence of citrate concentration on the International Normalized Ratio (INR) determined with twelve reagent-instrument combinations. Thromb Haemost . 1998; 80 258-262
18 Lottin L, Woodhams B J, Saureau M C, Robert A, Aillaud M F, Arnaud E, Martinoli J L. The clinical relevance of the citrate effect on International Normalized Ratio determinations depends on the reagent and instrument combination used. Blood Coagul Fibrinolysis . 2001; 12 399-404
19 van den Besselaar A H P M, Chantarangkul V, Tripodi A. A comparison of two sodium citrate concentrations in two evacuated blood collection systems for prothrombin time and ISI determination. Thromb Haemost . 2000; 84 664-667
20 van den Besselaar A H P M, van Dam W, Sturk A, Bertina R M. Prothrombin time ratio is reduced by magnesium contamination in evacuated blood collection tubes. Thromb Haemost . 2001; 85 647-650
21 Vadher B D, Lloyd M, Parker N, Patterson D LH. Effect of sample storage on the International Normalized Ratio. Br J Haematol . 1997; 97 936-937
22 Hernández A G, Martín de Segovia M J, Villanueva J R. Refrigerated stored specimens are not reliable for delayed INR determination. Br J Haematol . 1997; 98 781-782
23 Froom P, Abramova D, Bar-El M, Barak M. Reliability of delayed prothrombin time INR determinations in a central laboratory using off-site blood sampling. Clin Lab Haematol . 2001; 23 189-192
24 Baglin T, Luddington R. Reliability of delayed INR determination: implications for decentralized anticoagulant care with off-site blood sampling. Br J Haematol . 1997; 96 431-434
25 Brigden M L, Graydon C, McLeod B, Lesperance M. Prothrombin time determination. The lack of need for a discard tube and 24-hour stability. Am J Clin Pathol . 1997; 108 422-426
26 Ridyard J, Bhavnani M, Seal L H. Laboratory control of oral anticoagulant therapy: preservation of prothrombin time specimens using a polypropylene collection system. Clin Lab Haematol . 1998; 20 369-372
27 Leeming D R, Craig S, Stevenson K J, Taberner D A. The determination of INR in stored whole blood. J Clin Pathol . 1998; 51 360-363
28 Woodhams B, Girardot O, Blanco M J, Colesse G, Gourmelin Y. Stability of coagulation proteins in frozen plasma. Blood Coagul Fibrinolysis . 2001; 12 229-236
29 Poller L, Keown M, Shepherd S A, Shiach C R, Tabeart S. The effects of freeze drying and freeze drying additives on the prothrombin time and the international sensitivity index. J Clin Pathol . 1999; 52 744-748
30 van den Besselaar A H P M. Precision and accuracy of the International Normalized Ratio in oral anticoagulant control. Haemostasis . 1996; 26 248-265
31 Preston F E. Quality control and oral anticoagulation. Thromb Haemost . 1995; 74 515-520
32 van den Besselaar A H P M. Field study of lyophilised plasmas for local prothrombin time calibration in the Netherlands. J Clin Pathol . 1997; 50 371-374
33 Loeliger E A, van den Besselaar A H P M, Lewis S M. Reliability and clinical impact of the normalization of the prothrombin times in oral anticoagulant control. Thromb Haemost . 1985; 53 148-154
34 Tomenson J A. A statistician's independent evaluation. In: van den Besselaar AMHP, Gralnick HR, Lewis SM, eds. Thromboplastin Calibration and Oral Anticoagulant Control Boston, MA: Martinus Nijhoff 1984: 87-108
35 Attermann J. Monitoring oral anticoagulant therapy: measuring coagulant activity. Ph.D. thesis. Faculty of Health Sciences, University of Aarhus, 2000
36 Macik B G. Designing a point-of-care program for coagulation testing. Arch Pathol Lab Med . 1995; 119 929-938
37 Ruzicka K, Kapiotis S, Quehenberger P. et al . Evaluation of bedside prothrombin time and activated partial thromboplastin time measurement by coagulation analyzer CoaguChek Plus;rM in various clinical settings. Thromb Res . 1997; 87 431-440
38 Kitchen S, Preston F E. Monitoring oral anticoagulant treatment with the TAS near-patient test system: comparison with conventional thromboplastins. J Clin Pathol . 1997; 50 951-956
39 van den Besselaar A H P M, Breddin K, Lutze G. et al . Multicenter evaluation of a new capillary blood prothrombin time monitoring system. Blood Coagul Fibrinolysis . 1995; 6 726-732
40 Andrew M, Ansell J L, Becker D M. et al . Point-of-care prothrombin time measurement for professional and patient self-testing use. Am J Clin Pathol . 2001; 115 288-296
41 Zweig S E, Meyer B G, Sharma S. et al . Membrane-based, dry-reagent prothrombin time tests. Biomed Instrum Technol . 1996; 30 245-256
42 Tripodi A, Arbini A A, Chantarangkul V. et al . Are capillary whole blood coagulation monitors suitable for the control of oral anticoagulant treatment by the International Normalized Ratio?. Thromb Haemost . 1993; 70 921-924
43 Tripodi A, Chantarangkul V, Mannucci P M. Near-patient testing devices to monitor oral anticoagulant therapy. Br J Haematol . 2001; 113 847-852
44 Poller L, Keown M, Chauhan N. et al . European Concerted Action on Anticoagulation (ECAA): multicentre international sensitivity index calibration of two types of point-of-care prothrombin time monitor systems. Br J Haematol . 2002; 116 844-850
45 Attermann J, Kynde K, Hasenkam J M. Precision of patients' measurements of the international normalized ratio (INR) using a patient operated whole blood home coagulometer. Thromb Res . 1998; 92 287-291
46 Taborski U, Müller-Berghaus G. State-of-the-art patient self-management for control of oral anticoagulation. Semin Thromb Hemost . 1999; 25 43-47
47 Havrda D E, Hawk T L, Marvin C M. Accuracy and precision of the CoaguChek S versus laboratory INRs in a clinic. Ann Pharmacother . 2002; 36 769-774
48 van den Besselaar A H P M. Accuracy, precision, and quality control for point-of-care testing of oral anticoagulation. J Thromb Thrombolysis . 2001; 12 35-40
49 Bland J M, Altman D G. Comparing methods of measurement: why plotting difference against standard method is misleading. Lancet . 1995; 346 1085-1087
50 Gosselin R, Owings J T, White R H. et al . A comparison of point-of-care instruments designed for monitoring oral anticoagulation with standard laboratory methods. Thromb Haemost . 2000; 83 698-703
51 Biasiolo A, Rampazzo P, Furnari O, Filippi B, Pengo V. Comparison between routine laboratory prothrombin time measurements and fingerstick determinations using a near-patient testing device (Pro-Time;rM). Thromb Res . 2000; 97 495-498
52 Fairweather R B, Ansell J, van den Besselaar A H P M. et al . College of American Pathologists Conference XXXI on laboratory monitoring of anticoagulant therapy. Laboratory monitoring of oral anticoagulant therapy. Arch Pathol Lab Med . 1998; 122 768-781
53 Mörsdorf S, Erdlenbruch W, Taborski U. et al . Training of patients for self-management of oral anticoagulant therapy: standards, patient suitability, and clinical aspects. Semin Thromb Hemost . 1999; 25 109-115
54 Poller L, Keown M, Chauhan N. et al . European Concerted Action on Anticoagulation. Use of plasma samples to derive international sensitivity index for whole-blood prothrombin time monitors. Clin Chem . 2002; 48 255-260