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Original article

Vol. 147 No. 3940 (2017)

Quality of vitamin K antagonist oral anticoagulation in 322 patients with atrial fibrillation – real-life data from a survey in Eastern Switzerland

  • Micha T. Maeder
  • Tabea König
  • Sanja Bogdanovic
  • Irene Schneider
  • Werner Eugster
  • Peter Ammann
  • Marius König
  • Jürg H. Beer
  • Hans Rickli
DOI
https://doi.org/10.4414/smw.2017.14503
Cite this as:
Swiss Med Wkly. 2017;147:w14503
Published
06.10.2017

Summary

AIM OF THE STUDY: To better appreciate the role of the non-vitamin K oral anticoagulants (NOACs) for patients with non-valvular atrial fibrillation in Switzerland we aimed to assess the quality of vitamin K antagonist (VKA) anticoagulation in daily practice.

METHODS: In a cross-sectional study, clinically stable patients on VKA treatment for non-valvular atrial fibrillation for at least 6 months, documentation of international normalised ratio (INR) values for at least 3 months and with at least two INR values were included. The percentage of INR values within the therapeutic range of 2.0 to 3.0 and the time in therapeutic range (TTR; Rosendaal method) and predictors for these measures of VKA anticoagulation quality were assessed.

RESULTS: We studied 332 patients (62% male, mean age 74 ± 9 years) with median (interquartile range) CHA2DS2Vasc and HAS-BLED scores of 4 (3–5) and 3 (2–4) points. The median number of INR values per patient was 8 (5–14), and the average interval between INR measurements was 20 (13–27) days. The percentage of INR values between 2.0 and 3.0 was 67% (50–83%). The median TTR was 69% (51–89%), and TTR ≥65% was found in 202 (61%) patients. Independent predictors of ≥80% INR values between 2.0 and 3.0 included a longer interval between INR measurements and the non-use of spironolactone. The non-use of amiodarone and spironolactone and a longer interval between INR measurements were the only independent predictors of a TTR ≥65%.

CONCLUSIONS: The quality of VKA anticoagulation in Switzerland is highly variable. Importantly, only 60% of patients achieve a TTR ≥65%, which is currently considered to be the minimal acceptable TTR required for VKA therapy. There are few clinical predictors of a good VKA anticoagulation quality. These data may represent a novel basis for decision making regarding the choice of anticoagulation for atrial fibrillation in Switzerland.

References

  1. Kirchhof P, Benussi S, Kotecha D, Ahlsson A, Atar D, Casadei B, et al. 2016 ESC Guidelines for the management of atrial fibrillation developed in collaboration with EACTS. Eur Heart J. 2016;37(38):2893-962. https://doi.org/10.1093/eurheartj/ehw210
  2. Connolly SJ, Ezekowitz MD, Yusuf S, Eikelboom J, Oldgren J, Parekh A, et al. Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med. 2009;361(12):1139-51. https://doi.org/10.1056/NEJMoa0905561
  3. Patel MR, Mahaffey KW, Garg J, Pan G, Singer DE, Hacke W, et al. Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med. 2011;365(10):883-91. https://doi.org/10.1056/NEJMoa1009638
  4. Granger CB, Alexander JH, McMurray JJ, Lopes RD, Hylek EM, Hanna M, et al. Apixaban versus warfarin in patients with atrial fibrillation. N Engl J Med. 2011;365(11):981-92. https://doi.org/10.1056/NEJMoa1107039
  5. Giugliano RP, Ruff CT, Braunwald E, Murphy SA, Wiviott SD, Halperin JL, et al. Edoxaban versus warfarin in patients with atrial fibrillation. N Engl J Med. 2013;369(22):2093-104. https://doi.org/10.1056/NEJMoa1310907
  6. Wieloch M, Sjalander A, Frykman V, Rosenqvist M, Eriksson N, Svensson PJ. Anticoagulation control in Sweden: reports of time in therapeutic range, major bleeding, and thrombo-embolic complications from the national quality registry AuriculA. Eur Heart J. 2011;32(18):2282-9. https://doi.org/10.1093/eurheartj/ehr134
  7. Sjogren V, Grzymala-Lubanski B, Renlund H, Friberg L, Lip GY, Svensson PJ, et al. Safety and efficacy of well managed warfarin. A report from the Swedish quality register Auricula. Thromb Haemost. 2015;113(6):1370-7. https://doi.org/10.1160/TH14-10-0859
  8. Dlott JS, George RA, Huang X, Odeh M, Kaufman HW, Ansell J, et al. National assessment of warfarin anticoagulation therapy for stroke prevention in atrial fibrillation. Circulation. 2014;129(13):1407-14. https://doi.org/10.1161/CIRCULATIONAHA.113.002601
  9. Baker WL, Cios DA, Sander SD, Coleman CI. Meta-analysis to assess the quality of warfarin control in atrial fibrillation patients in the United States. J Manag Care Pharm. 2009;15(3):244-52. https://doi.org/10.18553/jmcp.2009.15.3.244
  10. Ansell J, Hollowell J, Pengo V, Martinez-Brotons F, Caro J, Drouet L. Descriptive analysis of the process and quality of oral anticoagulation management in real-life practice in patients with chronic non-valvular atrial fibrillation: the international study of anticoagulation management (ISAM). J Thromb Thrombolysis. 2007;23(2):83-91. https://doi.org/10.1007/s11239-006-9022-7
  11. Mearns ES, Kohn CG, Song JS, Hawthorne J, Meng J, White CM, et al. Meta-analysis to assess the quality of international normalized ratio control and associated outcomes in venous thromboembolism patients. Thromb Res. 2014;134(2):310-9. https://doi.org/10.1016/j.thromres.2014.05.035
  12. Ageno W, Gallus AS, Wittkowsky A, Crowther M, Hylek EM, Palareti G, et al. Oral anticoagulant therapy: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest. 2012;141(2 Suppl):e44S-88S.
  13. Apostolakis S, Sullivan RM, Olshansky B, Lip GY. Factors affecting quality of anticoagulation control among patients with atrial fibrillation on warfarin: the SAMe-TT(2)R(2) score. Chest. 2013;144(5):1555-63. https://doi.org/10.1378/chest.13-0054
  14. Rosendaal FR, Cannegieter SC, van der Meer FJ, Briet E. A method to determine the optimal intensity of oral anticoagulant therapy. Thromb and Haemost. 1993;69(3):236-9.
  15. Gallagher AM, Setakis E, Plumb JM, Clemens A, van Staa TP. Risks of stroke and mortality associated with suboptimal anticoagulation in atrial fibrillation patients. Thromb Haemost. 2011;106(5):968-77. https://doi.org/10.1160/TH11-05-0353
  16. Weitz JI, Semchuk W, Turpie AG, Fisher WD, Kong C, Ciaccia A, et al. Trends in Prescribing Oral Anticoagulants in Canada, 2008-2014. Clin Ther. 2015;37(11):2506. https://doi.org/10.1016/j.clinthera.2015.09.008
  17. Freeman JV, Zhu RP, Owens DK, Garber AM, Hutton DW, Go AS, et al. Cost-effectiveness of dabigatran compared with warfarin for stroke prevention in atrial fibrillation. Ann Inter Med. 2011;154(1):1-11. https://doi.org/10.7326/0003-4819-154-1-201101040-00289
  18. Harrington AR, Armstrong EP, Nolan PE, Jr., Malone DC. Cost-effectiveness of apixaban, dabigatran, rivaroxaban, and warfarin for stroke prevention in atrial fibrillation. Stroke. 2013;44(6):1676-81. https://doi.org/10.1161/STROKEAHA.111.000402
  19. Pletscher M, Plessow R, Eichler K, Wieser S. Cost-effectiveness of dabigatran for stroke prevention in atrial fibrillation in Switzerland. Swiss Med Wkly. 2013;143:w13732.
  20. Prochaska JH, Gobel S, Keller K, Coldewey M, Ullmann A, Lamparter H, et al. Quality of oral anticoagulation with phenprocoumon in regular medical care and its potential for improvement in a telemedicine-based coagulation service--results from the prospective, multi-center, observational cohort study thrombEVAL. BMC Med. 2015;13:14. https://doi.org/10.1186/s12916-015-0268-9
  21. Schein JR, White CM, Nelson WW, Kluger J, Mearns ES, Coleman CI. Vitamin K antagonist use: evidence of the difficulty of achieving and maintaining target INR range and subsequent consequences. Thromb J. 2016;14:14. https://doi.org/10.1186/s12959-016-0088-y
  22. O'Reilly RA. Spironolactone and warfarin interaction. Clin Pharmacol Ther. 1980;27(2):198-201. https://doi.org/10.1038/clpt.1980.31
  23. Pokorney SD, Simon DN, Thomas L, Gersh BJ, Hylek EM, Piccini JP, et al. Stability of International Normalized Ratios in Patients Taking Long-term Warfarin Therapy. JAMA. 2016;316(6):661-3. https://doi.org/10.1001/jama.2016.9356
  24. Beer JH. Vitamin K antagonists are hard to beat by the price - are they? Some answers, new questions and the GPs dilemma. Swiss Med Wkly. 2013;143:w13739.