A population-based cohort study was conducted using administrative data from a local health authority in the Campania Region (~1,000,000 inhabitants). NVAF was defined as one or more claims for atrial fibrillation (ICD-9-CM code 427.31) between July, 2013 and June, 2014 where none of the claims were associated with cardioversion or cardiac ablation during the identification period and there was no evidence of valve-related diagnoses or procedures. The cohort was classified according to the first drug dispensing during 6 months from the discharge date. Patients were categorized in low ischemic stroke (CHA2DS2-VASc) (LR, score=0), moderate-risk (MR, score=1), high-risk (HR, score≥2).Multivariable logistic regression was used to evaluate the associations between ischemic stroke and bleeding (HAS-BLED) risk with the choice of non-vitamin K antagonist oral anticoagulants (NOACs) versus vitamin K antagonists (VKAs) therapy.  RESULTS: A total of 1,963 patients were identified: 4.9% LR, 7.6% MR and 87.5% HR patients. Overall, 36.4% of patients were not treated (LR: 56.7%, MR: 55.0%, HR: 33.7%patients). Among patients treated, VKA in monotherapy was prescribed to 26.7% of the patients (LR: 23.8%, MR: 26.9%, HR: 26.8%), aspirin in monotherapy to 27.5% (LR: 31.0%, MR: 34.3%, HR: 27.0%), NOAC in monotherapy to 19.3% (LR: 23.8%, MR: 17.9%, HR: 19.2%), other antiplatelet in monotherapy to 19.4% (LR: 16.7%, MR: 13,4%, HR: 19.8%), and associations to 7.1% (LR: 4.8%, MR: 7.5%, HR: 7.2%). The ischemic stroke and bleeding risks were not significantly associated with the choice of anticoagulant drug. CONCLUSIONS:

High proportion of NVAF patients with moderate or high stroke risk did not receive antithrombotic therapy as recommended by guidelines. Moreover, aspirin was commonly prescribed even in HR patients. The risk stratification did not influence the choice of anticoagulant drug.