Wang KKP, Liu W, Chew STH, et al. - Researchers conducted this prospective cohort study to determine the incidence and significance of new-onset atrial fibrillation as a risk factor for long-term stroke and mortality after cardiac surgery. Between 2008 and 2012, 3,008 patients who underwent coronary artery bypass grafting and/or valve surgery were studied. Using a multivariate logistic regression model after adjustment for potential confounders, new-onset atrial fibrillation was analyzed as a risk factor for postoperative stroke. Postoperative stroke was more common in patients with new-onset atrial fibrillation and patients with both preoperative and postoperative atrial fibrillation than in patients without atrial fibrillation. After cardiac surgery, new-onset atrial fibrillation is a substantial risk factor for long-term stroke and mortality. To lessen the risk of postoperative stroke and mortality, this condition may need to be closely monitored and treated.