Piccini JP, Hellkamp AS, Washam JB, Becker RC, Breithardt G, Berkowitz SD, Halperin JL, Hankey GJ, Hacke W, Mahaffey KW, Nessel CC, Singer DE, Fox KA, Patel MR. Response by Piccini et al to Letters Regarding Article, "Polypharmacy and the Efficacy and Safety of Rivaroxaban Versus Warfarin in the Prevention of Stroke in Patients With Nonvalvular Atrial Fibrillation". Circulation. 2016 Jul 12; 134(2):e7-8.