Butt JH, Olesen JB, Gundlund A, et al. - Via an observational cohort study was conducted from January 1, 2000, through December 31, 2015, that involved 675 individuals with postoperative atrial fibrillation (POAF) and 2,025 matched individuals with nonvalvular atrial fibrillation (NVAF), researchers evaluated the long-term risk of thromboembolism in individuals acquiring new-onset POAF following isolated left-sided heart valve surgery in relation to individuals with nonsurgical, NVAF. In the adjusted analysis, the long-term risk of thromboembolism was comparable among people with POAF and NVAF. In comparison with no anticoagulation therapy, in individuals with POAF as well as with NVAF, oral anticoagulation therapy during follow-up was related to a lower risk of thromboembolic events. Hence, new-onset POAF following isolated left-sided heart valve surgery was related to a comparable long-term risk of thromboembolism as NVAF.