Hyperuricemia and the risk of ischemic stroke in patients with atrial fibrillation - Could it refine clinical risk stratification in AF?

Background: Although hyperuricemia has been reported to be a risk factor of stroke, the relationship between hyperuricemia and stroke in patients with atrial fibrillation (AF) remains uncertain. The goal of the present study was to investigate whether hyperuricemia could potentially refine clinical risk stratification in AF. Methods: This study used the "National Health Insurance Research Database" in Taiwan. A total of 7601 AF patients who did not receive antiplatelet agents or oral anticoagulants were identified as the study population. Hyperuricemia was defined as having at least one episode of gout attack necessitating long-term treatment with uric acid-lowering agents. The association between hyperuricemia and ischemic stroke was analyzed. Results: During the follow up of 3.0 +/- 2.7 years, 1116 patients (14.7%) experienced ischemic stroke with an annual rate of around 4.9%. Hyperuricemia significantly predicts stroke, with a hazard ratio (HR) of 1.280 after adjusting for CHA(2)DS(2)-VASc score and other comorbidities. Among the 376 patients with a CHA(2)DS(2)VASc score of 0, hyperuricemia can further stratify them into 2 groups with different stroke rates (7.1% versus 1.3%, p - 0.020). The adjusted HR of hyperuricemia in predicting ischemic stroke diminished from 7.491 for patients with a CHA2DS2-VASc score of 0 to 1.659 for those with a score of 3, and became insignificant for patients with a score >= 4. Conclusions: Hyperuricemia was a significant risk factor of stroke which could potentially refine the clinical risk stratification in AF. It deserves a prospective trial to investigate whether it would change the current strategy for stroke preventions using oral anticoagulants. (C) 2013 Elsevier Ireland Ltd. All rights reserved.