The Value of a Specialized Program for the Management of Oral Anticoagulation

Summary

Oral anticoagulation has proven to be an effective and useful therapy for over 50 years for patients at risk for thromboembolism, but recent evidence suggests that many patients are not only poorly managed, but therapy is withheld from a significant number of individuals because of the fear of complications and the labor intensiveness of treatment.

Over the last decade several developments have occurred that may increase and improve the use of oral anticoagulation by effectively lowering the risk/benefit profile. Among these have been the standardization of the prothrombin time using the International Normalized Ratio leading to more appropriate and standardized therapy, and a number of consensus conferences in the United States and throughout the world focusing on indications for anticoagulation. Less has occurred in a coordinated fashion to substantially improve the management of oral anticoagulation until very recently. There is now accumulating evidence showing that a coordinated and focused approach to the management of therapy by specialized programs significantly improves clinical outcomes by improving therapeutic control, lessening the frequency of hemorrhage or thrombosis and decreasing the use of medical resources leading to more cost-effective therapy. Furthermore, with the development of new technologies for the measurement of prothrombin times (capillary whole blood PTs or point-of-care testing) allows for novel models of management including patient self-testing and patient self-management. These latter concepts are beginning to be popularized in several regions, especially Germany, Canada and the United States.

The focus of the presentation will be to comment on the barriers to more effective and widespread use of anticoagulation and to summarize advances in the management of therapy including the concept of anticoagulation management services, patient self-testing and patient self-management.

Keywords

Anticoagulation - monitoring - warfarin - anticoagulation clinics

• REFERENCES

• 1 Kutner M, Nixon G, Silverstone F. Physicians’ attitudes toward oral anticoagulants and antiplatelet agents for stroke prevention in elderly patients with atrial fibrillation. Arch Intern Med 1991; 151: 1950-3.
• 2 McCrory DC, Matchar DB, Samsa G, Sanders LL, Pritchett ELC. Physician attitudes about anticoagulation for nonvalvular atrial fibrillation in the elderly. Arch Intern Med 1995; 155: 277-81.
• 3 Loeliger EA, Poller L, Samama M, Thomson JM, Van den Besselaar AMHP, Vermy-len J, Verstraete M. Questions and answers on prothrombin time standardization in oral anticoagulant control. Thromb Haemost 1985; 54: 515-7.
• 4 Dalen JE, Hirsh J. Fourth ACCP Consensus Conference on Antithrombotic Therapy. Chest 1995; 108 suppl 225S-522S.
• 5 Ansell JE, Hughes R. Evolving models of warfarin management: Anticoagulation clinics, patient self-monitoring and patient self-management. Am Heart J 1996; 132: 1095-100.
• 6 Ansell J, Patel N, Ostrovsky D, Nozzolillo E, Peterson AM, Fish L. Long-term patient self-management of oral anticoagulation. Arch Intern Med 1995; 155: 2185-9.
• 7 Fihn SD, McDonell M, Martin D. et al. Risk factors for complications of chronic anticoagulation: a multicenter study. Ann Intern Med 1993; 118: 511-20.
• 8 Cannegieter SC, Rosendaal FR, Wintzen AR, van der Meer FJM, Vandenbroucke JP, Briet E. Optimal oral anticoagulant therapy in patients with mechanical heart valves. N Engl J Med 1995; 33: 11-7.
• 9 Landefeld CS, Goldman L. Major bleeding in outpatients treated with warfarin: incidence and prediction by factors known at the start of outpatient therapy. Arn J Med 1989; 87: 144-52.
• 10 Petitti DB, Strom BL, Melmon KL. Duration of warfarin anticoagulant therapy and the probabilities of recurrent thromboembolism and hemorrhage. Am J Med 1986; 81: 255-9.
• 11 Gitter MJ, Jaeger TM, Petterson TM, Gersh BJ, Silverstein MD. Bleeding and thromboembolism during anticoagulant therapy: A population-based study in Rochester, Minnesota. Mayo Clin Proc 1995; 70: 725-33.
• 12 Davis FB, Estruch MT, Samson-Cervera EB. et al. Management of anticoagulation in outpatients: experience with an anticoagulation service in a municipal hospital setting. Arch Intern Med 1977; 137: 197-202.
• 13 Fofar JC. A seven year analysis of haemorrhage in patients on long-term anticoagulant treatment. Br Heart J 1979; 42: 128-32.
• 14 Errichetti AM, Holden A, Ansell J. Management of oral anticoagulant therapy: Experience with an anticoagulation clinic. Arch Intern Med 1984; 144: 1966-8.
• 15 Conte RR, Kehoe WA, Nielson N, Lodhia H. Nine-year experience with a pharmacist-managed anticoagulation clinic. Am J Hosp Pharm 1986; 43: 2460-4.
• 16 Petty GW, Lennihan L, Mohr JP. et al. Complications of long-term anticoagulation. Ann Neurol 1988; 23: 570-4.
• 17 Charney R, Leddomado E, Rose DN, Fuster V. Anticoagulation clinics and the monitoring of anticoagulant therapy. Int J Cardiol 1988; 18: 197-206.
• 18 Bussey HI, Rospond RM, Quandt CM, Clark GM. The safety and effectiveness of long-term warfarin therapy in an anticoagulation clinic. Pharmacotherapy 1989; 9: 214-9.
• 19 Kornblit P, Senderoff J, Davis-Ericksen M, Zenk J. Anticoagulation therapy: patient management and evaluation of an outpatient clinic. Patient Education 1990; 15 (08) 21-32.
• 20 Seabrook GR, Karp D, Schmitt DD, Bandyk DF. An outpatient anticoagulation protocol managed by a vascular nurse-clinician. Am J Surg 1990; 160: 501-4.
• 21 Van der Meer FJ, Rosendaal FR, Vanden-brouke JP, Briet E. Bleeding complications in oral anticoagulant therapy: an analysis of risk factors. Arch Intern Med 1993; 153: 1557-62.
• 22 Hamilton GM, Childers RW, Silverstein MD. Does clinic management of anticoagulation improve the outcome of prosthetic valve patients. Clin Res 1985; 33: 832A.
• 23 Cohen IA, Hutchison TA, Kirking DM, Shue ME. Evaluation of a pharmacist-managed anticoagulation clinic. J Clin Hosp Pharm 1985; 10: 167-75.
• 24 Garabedian-Ruffalo SM, Gray DR, Sax MJ. et al. Retrospective evaluation of a pharmacist-managed warfarin anticoagulation clinic. Am J Hosp Pharm 1985; 42: 304-8.
• 25 Cortelazzo S, Finazzi G, Viero P. et al. Thrombotic and hemorrhagic complications in patients with mechanical heart valve prostheses attending an anticoagulation clinic. Thromb Haemost 1993; 69: 316-20.
• 26 Wilt VM, Gums JG, Amhed OI, Moore LM. Outcome analysis of a pharmacist-managed anticoagulation service. Pharmacotherapy 1995; 15: 732-9.
• 27 Bussey HI, Chiquette E, Amato MG. Anticoagulation clinic care versus routine medical care: A review and interim report. J Thromb Thrombolys 1996; 2: 315-9.
• 28 Gray DR, Garabedian-Ruffalo SM, Chretien SD. Cost-justification of a clinical pharmacist-managed anticoagulation clinic. Drug Intell Clin Pharm 1985; 19: 575-80.
• 29 Lee YP, Schommer JC. Effect of a pharmacist-managed anticoagulation clinic on warfarin-related hospital readmissions. Am J Health-Sys Pharm 1996; 53: 1580-3.