2010;137:263 72. S4.1.1-6. Olesen JB, Torp-Pedersen C, Hansen ML, et al. The value of the CHA2DS2-VASc score for refining stroke risk stratification in patients with atrial fibrillation with a CHADS2 score 0 1: a nation- wide cohort study. Thromb Haemost. 2012;107:1172 9. S4.1.1-7. Mason PK, Lake DE, DiMarco JP, et al. Impact of the CHA2DS2-VASc score on anticoagulation recommendations for atrial fibrillation. Am J Med. 2012;125:e1 6. S4.1.1-8. Connolly SJ, Ezekowitz MD, Yusuf S, et al. Dabigatran versus warfarin in patients with atrial fibrillation. N Engl J Med. 2009;361:1139 51. S4.1.1-9. Patel MR, Mahaffey KW, Garg J, et al. Rivaroxaban versus warfarin in nonvalvular atrial fibrillation. N Engl J Med. 2011;365:883 91. S4.1.1-10. Granger CB, Alexander JH, McMurray JJV, et al. Apixaban ver- sus warfarin in patients with atrial fibrillation. N Engl J Med. 2011;365:981 92. S4.1.1-11. Giugliano RP, Ruff CT, Braunwald E, et al. Edoxaban versus warfarin in patients with atrial fibrillation. N Engl J Med. 2013;369:2093 104. S4.1.1-12. Matchar DB, Jacobson A, Dolor R, et al. Effect of home testing of international normalized ratio on clinical events. N Engl J Med. 2010;363:1608 20. S4.1.1-13. Ezekowitz MD, James KE, Radford MJ, et al. Initiating and maintain- ing patients on warfarin anticoagulation: the importance of moni- toring. J Cardiovasc Pharmacol Ther. 1999;4:3 8. S4.1.1-14. Hirsh J, Fuster V. Guide to anticoagulant therapy. Part 2: oral anti- coagulants. American Heart Association. Circulation. 1994;89: 1469 80. S4.1.1-15. Cannegieter SC, Rosendaal FR, Wintzen AR, et al. Optimal oral anti- coagulant therapy in patients with mechanical heart valves. N Engl J Med. 1995;333:11 7. S4.1.1-16. Acar J, Iung B, Boissel JP, et al. AREVA: multicenter randomized comparison of low-dose versus standard-dose anticoagulation in patients with mechanical prosthetic heart valves. Circulation. 1996;94:2107 12. CLINICAL STATEMENTS AND GUIDELINES S4.1.1-17. 