For a study, researchers determined how often de novo atrial fibrillation (>90 days after surgery) is in people who had never had it before. Between 2004 and 2014, 2261 patients received mitral valve surgery; 1288 (57%) had no history of atrial fibrillation, and 930 patients had rhythm information more than 90 days after surgery. The multi-state model used a semi-competing hazard to assess de novo atrial fibrillation and death probabilities. The Fine–Gray model was used to identify univariable and multivariable risk factors for atrial fibrillation. De novo atrial fibrillation occurred in 14% and 23% of people after five and ten years, respectively. Older age, more difficult surgeries, tricuspid regurgitation, and congestive heart failure were univariable risk variables (all P<.05). Atrial fibrillation was less common in patients with degenerative mitral regurgitation (hazard ratio [HR], 0.4; 95% confidence interval [CI], 0.24-0.65; P<.001). tricuspid valve surgery (HR, 1.80; 95% CI, 1.22, 2.65; P=.003), aortic valve surgery (HR, 1.49; 95 % CI, 1.03-2.17; P=.035), and older age (HR, 1.03; 95% CI, 1.02-1.05; P<.001) were all multivariable risk factors for de novo atrial fibrillation.

Overall survival was unaffected by de novo atrial fibrillation (P=.41). Researchers found greater warfarin use (P<.001) and a clear trend toward an elevated risk of stroke (P=.055) among individuals who developed de novo atrial fibrillation. After mitral surgery, de novo atrial fibrillation develops gradually and is linked to a high risk of stroke. A trial to reduce atrial fibrillation in high-risk patients could be conducted.