Predicting stroke in patients without atrial fibrillation

Abstract Background Only few studies in selected cohorts have examined whether the CHA2DS2‐VASc score can predict the risk of atrial fibrillation and thromboembolic events in patients without atrial fibrillation. Materials and methods Patients with coronary angiography performed between 2004 and 2012 were grouped according to CHA2DS2‐VASc score. We excluded patients with atrial fibrillation, anticoagulant therapy and follow‐up <30 days. The endpoints were atrial fibrillation and a composite of ischaemic stroke, transient ischaemic attack and systemic embolism. Event rates per 100 person‐years were estimated for each CHA2DS2‐VASc score (0, 1, 2, 3, 4, and >4). Incidence rate ratios were calculated using low‐risk patients (CHA2DS2‐VASc score 0 in males or 1 in females) as reference. Results In total, 78 233 patients were included with group sizes varying between 8299 (CHA2DS2‐VASc >4) and 19 882 (CHA2DS2‐VASc 2). An increasing CHA2DS2‐VASc score was significantly associated with a future diagnosis of atrial fibrillation (P for trend <0.0001) and an incremental risk of ischaemic stroke, transient ischaemic attack, systemic embolism (P for trend <0.0001) and all‐cause death (P for trend <0.0001). Patients with a CHA2DS2‐VASc score of 3 had a rate of ischaemic stroke/transient ischaemic attack/systemic embolism of 1.30 per 100 person‐years. Conclusions Among patients undergoing coronary angiography, the CHA2DS2‐VASc score predicted a future diagnosis of atrial fibrillation and the composite risk of ischaemic stroke, transient ischaemic attack or systemic embolism in patients without atrial fibrillation. A CHA2DS2‐VASc score of 3 was associated with a risk that would justify prophylactic oral anticoagulation treatment in a patient with atrial fibrillation.