Abstract
With the advent of new oral anticoagulants, the place of warfarin for stroke prevention in patients with atrial fibrillation needs re-evaluation. Warfarin is difficult to use, because of large individual differences in response and metabolism, many significant interactions with drugs and foods, and fluctuations in vitamin K absorption. It requires frequent blood testing and dose adjustments, so with good reason patients and physicians are eager for the newer agents that are easier to use. However, the purchase price of the new anticoagulants is so high that warfarin will remain in widespread use. It is important therefore for physicians to know how to use it well. Anticoagulants work much better for stroke prevention in atrial fibrillation than do antiplatelet agents; physicians need to understand the concept of red thrombus (for which anticoagulants are required) versus white thrombus—platelet aggregates—which are the target of antiplatelet agents. Stroke from atrial fibrillation increases steeply with age, and the elderly benefit disproportionately from anticoagulation. It is still necessary for physicians to know how to use warfarin, and to use it better than it has been used in the past.
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Boston Collaborative Drug Surveillance Program (1972) Interaction between chloral hydrate and warfarin. A report from the Boston Collaborative Drug Surveillance Program, Boston Universtiy Medical Center. N Engl J Med 286:53–55. doi:10.1056/NEJM197201132860201
Bang H, Mazumdar M, Spence JD (2006) Tutorial in biostatistics: analyzing associations between total plasma homocysteine and B vitamins using optimal categorization and segmented regression. Neuroepidemiology 27:188–200
Caplan LR, Fisher M (2007) The endothelium, platelets, and brain ischemia. Rev Neurol Dis 4:113–121
Connolly SJ, Eikelboom JW, Ng J, Hirsh J, Yusuf S, Pogue J, de Caterina R, Hohnloser S, Hart RG (2011) Net Clinical Benefit of Adding Clopidogrel to Aspirin Therapy in Patients With Atrial Fibrillation for Whom Vitamin K Antagonists Are Unsuitable. Ann Intern Med 155:579–586. doi:10.1059/0003-4819-155-9-201111010-00004
del Zoppo GJ, Eliasziw M (2011) New options in anticoagulation for atrial fibrillation. N Engl J Med 365:952–953. doi:10.1056/NEJMe1107516
Deykin D (1967) Thrombogenesis. N Engl J Med 276:622–628
Eerenberg ES, Kamphuisen PW, Sijpkens MK, Meijers JC, Buller HR, Levi M (2011) Reversal of rivaroxaban and dabigatran by prothrombin complex concentrate: a randomized, placebo-controlled, crossover study in healthy subjects. Circulation 124:1573–1579. doi:10.1161/CIRCULATIONAHA.111.029017
Fisher CM (1959) Observations of the fundus oculi in transient monocular blindness. Neurology 9:333–347
Gladstone DJ, Bui E, Fang J, Laupacis A, Lindsay MP, Tu JV, Silver FL, Kapral MK (2009) Potentially preventable strokes in high-risk patients with atrial fibrillation who are not adequately anticoagulated. Stroke 40:235–240
Holbrook AM, Pereira JA, Labiris R, McDonald H, Douketis JD, Crowther M, Wells PS (2005) Systematic overview of warfarin and its drug and food interactions. Arch Intern Med 165:1095–1106. doi:10.1001/archinte.165.10.1095
House AA, Eliasziw M, Cattran DC, Churchill DN, Oliver MJ, Fine A, Dresser GK, Spence JD (2010) Effect of B-vitamin therapy on progression of diabetic nephropathy: a randomized controlled trial. JAMA 303:1603–1609. doi:10.1001/jama.2010.490
Hylek EM, Frison L, Henault LE, Cupples A (2008) Disparate stroke rates on warfarin among contemporaneous cohorts with atrial fibrillation: potential insights into risk from a comparative analysis of SPORTIF III versus SPORTIF V. Stroke 39:3009–3014
Juurlink DN (2007) Drug interactions with warfarin: what clinicians need to know. CMAJ 177:369–371
Man-Son-Hing M, Nichol G, Lau A, Laupacis A (1999) Choosing antithrombotic therapy for elderly patients with atrial fibrillation who are at risk for falls. Arch Intern Med 159:677–685
Poli D, Antonucci E, Cecchi E, Marcucci R, Liotta AA, Cellai AP, Lenti M, Gensini GF, Abbate R, Prisco D (2005) Culprit factors for the failure of well-conducted warfarin therapy to prevent ischemic events in patients with atrial fibrillation: the role of homocysteine. Stroke 36:2159–2163
Rombouts EK, Rosendaal FR, Van Der Meer FJ (2007a) Daily vitamin K supplementation improves anticoagulant stability. J Thromb Haemost 5:2043–2048
Rombouts EK, Rosendaal FR, van der Meer FJ (2007b) Daily vitamin K supplementation improves anticoagulant stability. J Thromb Haemost 5:2043–2048
Samsa GP, Matchar DB, Goldstein LB, Bonito AJ, Lux LJ, Witter DM, Bian J (2000) Quality of anticoagulation management among patients with atrial fibrillation: results of a review of medical records from 2 communities. Arch Intern Med 160:967–973
Schwarz UI, Ritchie MD, Bradford Y, Li C, Dudek SM, Frye-Anderson A, Kim RB, Roden DM, Stein CM (2008) Genetic determinants of response to warfarin during initial anticoagulation. N Engl J Med 358:999–1008
Sellers EM, Koch-Weser J (1970) Potentiation of warfarin-induced hypoprothrombinemia by chloral hydrate. N Engl J Med 283:827–831. doi:10.1056/NEJM197010152831601
Sellers EM, Koch-Weser J (1971) Kinetics and clinical importance of displacement of warfarin from albumin by acidic drugs. Ann N Y Acad Sci 179:213–225
Spence JD (2006) Nutrition and stroke prevention. Stroke 37:2430–2435
Spence JD (2007) Homocysteine-lowering therapy: a role in stroke prevention? Lancet Neurol 7:830–838
Spence D (2009a) Mechanisms of thrombogenesis in atrial fibrillation. Lancet 373:1006–1007
Spence JD (2009b) Stroke: atrial fibrillation, stroke prevention therapy and aging. Nat Rev Cardiol 6:448–450
Spence JD, Stampfer MJ (2011) Understanding the complexity of homocysteine lowering with vitamins: the potential role of subgroup analyses. JAMA 306(23):2610–2611
Spence JD, Bang H, Chambless LE, Stampfer MJ (2005) Vitamin intervention for stroke prevention trial: an efficacy analysis. Stroke 36:2404–2409
van Ryn J, Stangier J, Haertter S, Liesenfeld KH, Wienen W, Feuring M, Clemens A (2010) Dabigatran etexilate–a novel, reversible, oral direct thrombin inhibitor: interpretation of coagulation assays and reversal of anticoagulant activity. Thromb Haemost 103:1116–1127. doi:10.1160/TH09-11-0758
van Walraven C, Hart RG, Connolly S, Austin PC, Mant J, Hobbs FD, Koudstaal PJ, Petersen P, Perez-Gomez F, Knottnerus JA, Boode B, Ezekowitz MD, Singer DE (2009) Effect of age on stroke prevention therapy in patients with atrial fibrillation: the atrial fibrillation investigators. Stroke 40:1410–1416. doi:10.1161/STROKEAHA.108.526988
Vogiatzoglou A, Oulhaj A, Smith AD, Nurk E, Drevon CA, Ueland PM, Vollset SE, Tell GS, Refsum H (2009) Determinants of plasma methylmalonic acid in a large population: implications for assessment of vitamin B12 status. Clin Chem 55:2198–2206
Wolf PA, Abbott RD, Kannel WB (1991) Atrial fibrillation as an independent risk factor for stroke: the Framingham Study. Stroke 22:983–988
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Spence, J.D. Atrial fibrillation and stroke prevention: is warfarin still an option? Yes. J Neural Transm 120, 1447–1451 (2013). https://doi.org/10.1007/s00702-012-0941-5
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DOI: https://doi.org/10.1007/s00702-012-0941-5