Impact of relative contraindications on the use, benefits, and risks of anticoagulant prophylaxis in atrial fibrillation: analysis of a claims database
Maneesha Mehra, Julia DiBello, Alan C. Fisher, Roger M. Mills
DOI: 10.4236/ojim.2011.13013   PDF    HTML     4,286 Downloads   8,795 Views   Citations


Background: Many individuals with atrial fibrillation (AF) do not receive recommended anticoagulant prophylaxis for stroke prevention. The study investigators attempted to assess whether the presence of relative contraindications (RCIs) to anticoagulation with warfarin might contribute to this, and to assess the risks and benefits of prophylaxis in patients with RCIs. Methods: Study investigators identified patients with established non-valvular AF and flutter in a claims database. Operationally defined RCIs included, in order of clinical severity: (1) prior intracranial hemorrhage; (2) gastrointestinal bleeding or esophageal varices; (3) neurological disorder; and (4) dizziness. Nonfatal events were attributed to warfarin if patients had an appropriate claim in the previous month. Results: A total of 67,082 AF patients were eligible for analysis, including 50,485 (75.3%) in the prevalent cohort. Warfarin exposure during the study period was 68% in the prevalent cohort. At baseline, 50.5% of prevalent cohort patients had one or more RCIs. Patients with RCI had higher prevalence of stroke risk factors (congestive heart failure, hypertension, age ≥ 75 years, diabetes mellitus, and prior stroke or transient ischemic attack) compared to those without RCI. Patients with RCIs often received warfarin and had lower rates of ischemic stroke than those who did not. Conclusions: These results suggest that RCIs do not account for underutilization of anticoagulant prophylaxis in AF patients. Further, the benefit/risk aspects of anticoagulation for stroke prophylaxis may be favorable for many patients with RCIs.

Share and Cite:

Mehra, M. , DiBello, J. , Fisher, A. and Mills, R. (2011) Impact of relative contraindications on the use, benefits, and risks of anticoagulant prophylaxis in atrial fibrillation: analysis of a claims database. Open Journal of Internal Medicine, 1, 60-67. doi: 10.4236/ojim.2011.13013.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] Stroke Risk in Atrial Fibrillation Working Group (2008) Comparison of 12 risk stratification schemes to predict stroke in patients with nonvalvular atrial fibrillation. Stroke, 39, 1901-1910. doi:10.1161/STROKEAHA.107.501825
[2] Lip, G.Y., Nieuwlaat, R., Pisters, R. , Lane, D.A. and Crijns, H.J. (2010) Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the Euro Heart Survey on atrial fibrillation. Chest, 137, 263-272. doi:10.1378/chest.09-1584
[3] Gage, B.F., Waterman, A.D., Shannon, W., Boechler, M., Rich, M.W. and Radford, M.J. (2001) Validation of clinical classification schemes for predicting stroke: Results from the National Registry of Atrial Fibrillation. Journal of the American Medical Association, 285, 2864-2870. doi:10.1001/jama.285.22.2864
[4] Bristol-Myers Squibb (2010) Coumadin Prescribing Information.
[5] Aspinall, S.L., DeSanzo, B.E., Trilli, L.E. and Good, C.B. (2005) Bleeding risk index in an anticoagulation clinic. Assessment by indication and implications for care. Journal of General Internal Medicine, 20, 1008-1013. doi:10.1111/j.1525-1497.2005.0229.x
[6] Gage, B.F., Yan, Y., Milligan, P.E., et al. (2006) Clinical classification schemes for predicting hemorrhage: results from the National Registry of Atrial Fibrillation (NRAF). American Heart Journal, 151, 713-719. doi:10.1016/j.ahj.2005.04.017
[7] Go, A.S., Hylek, E.M., Phillips, K.A., Chang, Y., Henault, L.E., Selby, J.V., et al. (2001) Prevalence of diagnosed atrial fibrillation in adults: national implications for rhythm management and stroke prevention: the AnTicoagulation and Risk Factors in Atrial Fibrillation (ATRIA) Study. Journal of the American Medical Association, 285, 2370-2375. doi:10.1001/jama.285.18.2370
[8] Lin, P. (2005) Reviewing the reality: Why we need to change. European Heart Journal, 7, E15-E20.
[9] Walker, A.M. and Bennett, D. (2008) Epidemiology and outcomes in patients with atrial fibrillation in the United States. Heart Rhythm, 5, 1365-1372. doi:10.1016/j.hrthm.2008.07.014
[10] Singer, D.E., Albers, G.W., Dalen, J.E., et al. (2008) Antithrombotic therapy in atrial fibrillation: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th edition). Chest, 133, 546S-592S. doi:10.1378/chest.08-0678
[11] Lakshminarayan, K., Solid, C.A., Collins, A.J., Anderson, D.C. and Herzog, C.A. (2006) Atrial fibrillation and stroke in the general Medicare population: A 10-year perspective (1992 to 2002). Stroke, 37, 1969-1974. doi:10.1161/01.STR.0000230607.07928.17
[12] Waldo, A.L., Becker, R.C., Tapson, V.F., Colgan, K.J. (2005) Hospitalized patients with atrial fibrillation and a high risk of stroke are not being provided with adequate anticoagulation. Journal of the American College of Cardiology, 46, 1729-1736. doi:10.1016/j.jacc.2005.06.077
[13] Deplanque, D., Leys, D., Parnetti, L., et al. (2004) Stroke prevention and atrial fibrillation: reasons leading to an inappropriate management. Main results of the SAFE II study. British Journal of Clinical Pharmacology, 57, 798-806. doi:10.1111/j.1365-2125.2004.02086.x
[14] Lip, G.Y. and Tse, HF. (2007) Management of atrial fibrillation. Lancet, 370, 604-618. doi:10.1016/S0140-6736(07)61300-2
[15] Centers for Disease Control and Prevention (2011) Classification of Diseases, Functioning, and Disability.
[16] American Medical Association (2009) CPT 2010 Standard Edition (Current Procedural Terminology (CPT) Standard). American Medical Association Press, Chicago.
[17] Hart, R.G., Pearce, L.A. and Aguilar, M.I. (2007) Meta-analysis: Antithrombotic therapy to prevent stroke in patients who have nonvalvular atrial fibrillation. Annals of Internal Medicine, 146, 857-867.
[18] Go, A.S., Hylek, E.M., Borowsky, L.H., Phillips, K.A., Selby, J.V. and Singer, D.E. (1999) Warfarin use among ambulatory patients with nonvalvular atrial fibrillation: the AnTicoagulation and Risk Factors in Atrial Fibrillation (ATRIA) study. Annals of Internal Medicine, 131, 927-934.
[19] Fleiss, J., Levin, B. and Paik, M. (2003) Statistical methods for rates and proportions. 3rd Edition, John Wiley & Sons Inc., Hoboken. doi:10.1002/0471445428
[20] Koch, G., Atkinson, S. and Stokes, M. (1986) Poisson regression. In: Johnson, N.L. and Kotz, S., Eds. Encyclopedia of Statistical Sciences. John Wiley & Sons, Inc., Hoboken, 32-41.
[21] Stokes, M., Davis, C., Koch, G. (2009) Categorical data analysis using the SAS system. 2nd Edition, SAS Institute, Carey.
[22] Kowey, P.R., Reiffel, J.A., Myerburg, R., et al. (2010) Warfarin and aspirin use in atrial fibrillation among practicing cardiologist (from the AFFECTS Registry). American Journal of Cardiology, 105, 1130-1134. doi:10.1016/j.amjcard.2009.11.047
[23] Nieuwlaat, R., Capucci, A., Lip, G.Y., et al. (2006) Antithrombotic treatment in real-life atrial fibrillation patients: a report from the Euro Heart Survey on Atrial Fibrillation. European Heart Journal, 24, 3018-3026. doi:10.1093/eurheartj/ehl015
[24] Ansell, J., Hirsh, J., Hylek, E., Jacobson, A., Crowther, M. and Palareti, G. (2008) Pharmacology and manage- ment of the vitamin K antagonists: American College of Chest Physicians Evidence-Based Clinical Practice Gui- delines (8th edition). Chest, 133, 160S-198S. doi:10.1378/chest.08-0670
[25] Weitz, J.I., Hirsh, J. and Samama, M.M. (2008) New antithrombotic drugs: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th edition). Chest, 133, 234S-256S. doi:10.1378/chest.08-0673
[26] Connolly, S.J., Ezekowitz, M.D., Yusuf, S., et al. (2009) Dabigatran versus warfarin in patients with atrial fibrillation. New England Journal of Medicine, 361, 1139- 1151. doi:10.1056/NEJMoa0905561
[27] Patel M.R. (2010) Rivaroxaban-once daily, oral, direct factor Xa inhibition compared with vitamin K antagonism for prevention of stroke and Embolism Trial in Atrial Fibrillation: Rationale and design of the ROCKET AF study. American Heart Journal, 159, 340-347. doi:10.1016/j.ahj.2009.11.025
[28] Kolominsky-Rabas, P.L., Weber, M., Gefeller, O., Neundoerfer, B. and Heuschmann, P.U. (2001) Epidemiology of ischemic stroke subtypes according to TOAST criteria: incidence, recurrence, and long-term survival in ischemic stroke subtypes: A population-based study. Stroke, 32, 2735-2740. doi:10.1161/hs1201.100209
[29] Petty, G.W., Brown, R.D., Jr., Whisnant, J.P., Sicks, J.D., O’Fallon, W.M. and Wiebers, D.O. (2000) Ischemic stroke subtypes: A population-based study of functional outcome, survival, and recurrence. Stroke, 31, 1062-1068. doi:10.1161/01.STR.31.5.1062

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.