Results of large phase 3 clinical trials of these agents in patients with AF have been recently published or will be reported soon (Table 8). Although ximelagatran is no longer approved for use by regulatory agencies because of concerns about severe liver toxicity, the Stroke Pre- vention Using an Oral Thrombin Inhibitor in Patients With AF (SPORTIF) III and V trials were a proof of principle that a direct thrombin inhibitor can achieve similar protection against stroke compared with war- farin (ie, ndings met the investigators prespeci ed noninferiority criterion) with no evidence of increased The Randomized Evaluation of Long-Term Anti- coagulation Therapy (RE-LY) trial reported the www.chestpubs.org CHEST / 141 / 2 / FEBRUARY, 2012 SUPPLEMENT e549S (Continued) Table [Sections Should Aspirin Plus Clopidogrel Rather Than Aspirin Be Used in Patients With AF? Quality Assessment Summary of Findings Risk of Bias Inconsistency Indirectness Imprecision Publication Bias Study Event Rates (%) Relative Effect CI) Estimation of Absolute Effects Time Frame No. 