Washam JB, Hellkamp AS, Lokhnygina Y, Piccini JP, Berkowitz SD, Nessel CC, Becker RC, Breithardt G, Fox KAA, Halperin JL, Hankey GJ, Mahaffey KW, Singer DE, Patel MR. Efficacy and Safety of Rivaroxaban Versus Warfarin in Patients Taking Nondihydropyridine Calcium Channel Blockers for Atrial Fibrillation (from the ROCKET AF Trial). Am J Cardiol. 2017 Aug 15; 120(4):588-594.