Abstract 17169: Beyond CHA2DS2-VASc: Independent Predictors of Ischemic Stroke in Patients With Atrial Fibrillation

Factors outside of the CHA DS -VASc score also contribute to stroke risk, and patients prescribed anticoagulants still face a residual stroke risk. A multivariable model to predict stroke risk was built using data from patients treated for atrial fibrillation (AF) at Duke between 2009 and 2018. The model was then refined in patients presenting with incident AF at 7 hospitals within the larger PCORnet database. Of 43,896 patients with AF included in our multivariable model creation data set, median age was 71.6 years, 44.2% of patients were female, 17.4% were black, and median CHA DS -VASc was 3. DOAC was prescribed in 24.2%, warfarin in 28.7%, and 50.4% were not prescribed either anticoagulant. The 5-year incidence of ischemic stroke was 3.5%. In a multivariable model, patients who were black, had prior major bleeding, or who were prescribed aspirin or an SSRI were at increased risk for ischemic stroke regardless of type of anticoagulation, whereas lower eGFR did not increase the risk. The model was refined in the PCORnet database using 244,213 patients with incident AF, with additional identification of lower risk for patients with BMI >30 or recent cardiac surgery, and use of P2Y12 as a risk factor. Multivariable models showed substantial improvement in stroke prediction within both the Duke and PCORnet treatment cohorts, with improvement in C-indices to 69.6-75.7%, from baseline C-indices of 63.5%-68.7% for CHA DS -VASc alone among patients on DOAC, warfarin, or who were untreated. Lower BMI, prior major bleeding, antiplatelet (ASA or P2Y12) use, and black race were significantly associated with increased risk for ischemic stroke, independent of the commonly used CHA DS -VASc score. Future AF research should attempt to integrate these emerging risk factors with the existing CHA DS -VASc framework to improve the identification of patients at high risk of stroke and in greatest need of anticoagulation.

Duke Scholars

Author Larry Ronald Jackson II Medicine, Cardiology

Author Karen Chiswell