Ticagrelor versus clopidogrel in patients with acute coronary syndromes and a history of stroke or transient ischemic attack. - James SK; Storey RF; Khurmi NS; Husted S; Keltai M; Mahaffey KW; Maya J; Morais J; Lopes RD; Nicolau JC; Pais P; Raev D; et al. (Circulation, 2012)