Type of atrial fibrillation and outcomes in patients without oral anticoagulants

BACKGROUND: The effect of type of atrial fibrillation (AF) on adverse outcomes in Chinese patients without oral anticoagulants (OAC) was controversial. HYPOTHESIS: The type of AF associated with adverse outcomes in Chinese patients without OAC. METHODS: A total of 1358 AF patients without OAC from a multicenter, prospective, observational study was included for analysis. Univariable and multivariable Cox regression models were utilized. Net reclassification improvement analysis was performed for the assessment of risk prediction models. RESULTS: There were 896(66%) patients enrolled with non‐paroxysmal AF (NPAF) and 462(34%) with paroxysmal AF (PAF). The median age was 70.9 ± 12.6 years, and 682 patients (50.2%) were female. During 1 year of follow‐up, 215(16.4%) patients died, and 107 (8.1%) patients experienced thromboembolic events. Compared with the PAF group, NPAF group had a notably higher incidence of all‐cause mortality (20.2% vs. 9.4%, p < .001), thromboembolism (10.5% vs. 3.8%, p < .001). After multivariable adjustment, NPAF was a strong predictor of thromboembolism (HR 2.594, 95%CI 1.534–4.386; p < .001), all‐cause death (HR 1.648, 95%CI 1.153–2.355; p = .006). Net reclassification improvement analysis indicated that the addition of NPAF to the CHA(2)DS(2)‐VASc score allowed an improvement of 0.37 in risk prediction for thromboembolic events (95% CI 0.21–0.53; p < .001). CONCLUSIONS: In Chinese AF patients who were not on OAC, NPAF was an independent predictor of thromboembolism and mortality. The addition of NPAF to the CHA(2)DS(2)‐VASc score allowed an improvement in the accuracy of the prediction of thromboembolic events.