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Relationship between the Occurrence of Thromboembolism and INR Measurement Interval in Low Intensity Anticoagulation after Aortic Mechanical Valve Replacement

  • Rhie, Sang-Ho (Department of Thoracic and Cardiovascular Surgery, College of Medicine and Institute of Health Sciences, Gyeongsang National University) ;
  • Choi, Jun-Young (Department of Thoracic and Cardiovascular Surgery, College of Medicine and Institute of Health Sciences, Gyeongsang National University) ;
  • Jang, In-Seok (Department of Thoracic and Cardiovascular Surgery, College of Medicine and Institute of Health Sciences, Gyeongsang National University) ;
  • Kim, Jong-Woo (Department of Thoracic and Cardiovascular Surgery, College of Medicine and Institute of Health Sciences, Gyeongsang National University) ;
  • Lee, Chung-Eun (Department of Thoracic and Cardiovascular Surgery, College of Medicine and Institute of Health Sciences, Gyeongsang National University) ;
  • Park, Hyun-Oh (Department of Thoracic and Cardiovascular Surgery, College of Medicine and Institute of Health Sciences, Gyeongsang National University)
  • Received : 2010.09.28
  • Accepted : 2011.05.18
  • Published : 2011.06.05

Abstract

Background: We investigated changes in the International Normalized Ratio (INR) and its measurement interval in patients with thromboembolic events who were treated by low intensity anticoagulation therapy after isolated mechanical aortic valve replacement. Materials and Methods: Seventy-seven patients who underwent surgery from June 1990 to September 2006 were enrolled in the study and observed until August 2008. The patients were followed up at 4~8 week intervals and their warfarin (Coumadin)$^{(R)}$ dosage was adjusted aiming for a target range of INR 1.5~2.5. The rate of thromboembolic events was obtained. Changes in the mean INR and INR measurement interval were comparatively analyzed between the normal group (event free group, N=52) who had no anticoagulation-related complications and the thromboembolic group (N=10). Hospital records were reviewed retrospectively. Results: The observation period was 666.75 patient-years. Thromboembolic events occurred in 10 patients. The linearized occurrence rate of thromboembolism was 1.50%/patient-years. Actuarial thromboembolism-free rates were $97.10{\pm}2.02%$ at 5 years, $84.30{\pm}5.22%$ at 10 years, and $67.44{\pm}12.14%$ at 15 years. The percentages of INR within the target range and mean INR were not statistically significantly different for the normal and thromboembolic groups. However, the mean INR during the segmented period just before the events showed a significantly lower level in the thromboembolic group (during a 4 month period: normal group, $1.86{\pm}0.14$ vs. thromboembolic group, $1.50{\pm}0.28$, p<0.001). The mean intervals of INR measurement during the whole observation period showed no significant differences between groups, but in the segmented period just before the events, the interval was significantly longer in thromboembolic group (during a 6 month period: normal group, $49.04{\pm}9.47$ days vs. thromboembolic group, $65.89{\pm}44.88$ days, p<0.01). Conclusion: To prevent the occurrence of thromboembolic events in patients who receive isolated aortic valve replacement and low intensity anticoagulation therapy, we suggest that it would be safe to maintain an INR level above 1.8 and to measure the INR at least every 7~8 weeks.

Keywords

References

  1. Hirsh J, Guyatt G, Albers GW, Harrington R, Schünemann HJ, American College of Chest Physician. Antithrombotic and thrombolytic therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest 2008;133(6 Suppl):110S-2S. https://doi.org/10.1378/chest.08-0652
  2. Butchart EG, Lewis PA, Grunkemeier GL, Kulatilake N, Breckenridge IM. Low risk of thrombosis and serious embolic events despite low-intensity anticoagulation. Experience with 1,004 Medtronic Hall valves. Circulation 1988;78(3 Pt 2):I66-77.
  3. Horstkotte D, Schulte HD, Bircks W, Strauer BE. Lower intensity anticoagulation therapy results in lower complication rates with the St. Jude Medical prosthesis. J Thorac Cardiovasc Surg 1994;107:1136-45.
  4. Kim CW, Kim YT. Anticoagulation Management after Mitral Valve Replacement with the St. Jude Medical Prosthesis. Korean J Thorac Cardiovasc Surg 1998;31:1172-82.
  5. Jeong SC, Kim MJ, Song CM, Kim WS, Shin YC, Kim BY. Low-intensity oral anticoagulation versus high-intensity oral anticoagulation in patients with mechanical bileaflet prosthetic heart valves. Korean J Thorac Cardiovasc Surg 2008;41:430-8.
  6. Yu HC, Chan TY, Critchley JA, Woo KS. Factors determining the maintenance dose of warfarin in Chinese patients. QJM 1996;89:127-35. https://doi.org/10.1093/qjmed/89.2.127
  7. Gan GG, Teh A, Goh KY, Chong HT, Pang KW. Racial background is a determinant factor in the maintenance dosage of warfarin. Int J Hematol 2003;78:84-6. https://doi.org/10.1007/BF02983247
  8. You JH, Chan FW, Wong RS, Cheng G. Is INR between 2.0 and 3.0 the optimal level for Chinese patients on warfarin therapy for moderate-intensity anticoagulation? Br J Clin Pharmacol 2005;59:582-7. https://doi.org/10.1111/j.1365-2125.2005.02361.x
  9. Dang MT, Hambleton J, Kayser SR. The influence of ethnicity on warfarin dosage requirement. Ann Pharmacother 2005;39:1008-12. [Epub 2005 Apr 26] https://doi.org/10.1345/aph.1E566
  10. Kim JW, Rhie SH, Kim YC, Yang JH, Jang IS, Choi, JY. Acceptability of low intensity anticoagulation therapy after mechanical heart valve replacement. Korean J Thorac Cardiovasc Surg 2009;42:193-200.
  11. Anonymous (1983). "33: Expert Committee on Biological Standardization. Requirements for thromboplastins and plasma used to control oral anticoagulant therapy". World Health Organ Tech Rep Ser. pp. 81-105.
  12. Edmunds LH Jr. Thrombotic and bleeding complications of prosthetic heart valves. Ann Thorac Surg 1987;44:430-45. https://doi.org/10.1016/S0003-4975(10)63816-7
  13. Ikonomidis JS, Kratz JM, Crumbley AJ 3rd, et al. Twenty-year experience with the St Jude Medical mechanical valve prosthesis. J Thorac Cardiovasc Surg 2003;126:2022-31. https://doi.org/10.1016/j.jtcvs.2003.07.005
  14. Aagaard J, Tingleff J. Fifteen years' clinical experience with the CarboMedics prosthetic heart valve. J Heart Valve Dis 2005;14:82-8.
  15. Emery RW, Krogh CC, Arom KV, et al. The St. Jude Medical cardiac valve prosthesis: a 25-year experience with single valve replacement. Ann Thorac Surg 2005;79:776-82. discussion 782-3. https://doi.org/10.1016/j.athoracsur.2004.08.047
  16. Tominaga R, Kurisu K, Ochiai Y, et al. A 10-year experience with the Carbomedics cardiac prosthesis. Ann Thorac Surg 2005;79:784-9. https://doi.org/10.1016/j.athoracsur.2004.08.067
  17. Spiliopoulos K, Haschemi A, Parasiris P, Kemkes BM. Sorin BicarbonTM bileaflet valve: a 9.8-year experience. Clinical performance of the prosthesis after heart valve replacement in 587 patients. Interact Cardiovasc Thorac Surg 2008;20. [Epub ahead of print]
  18. Torella M, Torella D, Chiodini P, et al. LOWERing the INtensity of oral anticoaGulant Therapy in patients with bileaflet mechanical aortic valve replacement: results from the "LOWERING-IT" Trial. Am Heart J 2010;160:171-8. https://doi.org/10.1016/j.ahj.2010.05.005
  19. Lidstone V, Janes S, Stross P. INR: Intervals of measurement can safely extend to 14 weeks. Clin Lab Haematol 2000;22:291-3. https://doi.org/10.1046/j.1365-2257.2000.00315.x

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