Abstract 14726: Performance of the Novel Biomarker-Based ABC-Stroke Risk Score Over Time in Patients With Atrial Fibrillation
Introduction: The ABC-stroke risk score (Age, Biomarkers [troponin and NT-proBNP], and Clinical history of prior stroke) is a novel biomarker-based model for patients with atrial fibrillation (AF). In the derivation cohort of 14,701 AF patients in the ARISTOTLE trial the ABC-stroke performed better than the CHA2DS2VASc score. We now evaluated the performance of the ABC-stroke score over time.
Methods: The ARISTOTLE trial evaluated the effect of randomized treatment with apixaban or warfarin in patients with AF for the primary endpoint of stroke or systemic embolism during a median of 1.8 years follow-up. In the biomarker substudy, 4,796 patients provided plasma samples for central biomarker analyses both at entry and after 2 months. Immunoassays were used to measure levels of cardiac troponin (cTn) I, cTnT, and NT-proBNP. C-indices and calibration plots were used to evaluate the ABC-stroke risk score over time.
Results: The changes in biomarker levels after 2 months were small (median cTnT +2.8%, NT-proBNP +13.5%) and intraindividual correlation were high (0.88 and 0.82, respectively). Based on 8,702 person-years of follow-up and 96 adjudicated stroke or systemic embolic events after the blood sampling at 2 months, the ABC-stroke score at 2 months achieved a c-index of 0.70 (95% CI 0.65, 0.76) compared to 0.70 (0.65, 0.75) at baseline. The ABC-stroke score at 2 months remained well calibrated using predefined risk classes (Fig). Repeated measurements of cardiac biomarker levels did not provide incremental information to the risk prediction obtained at baseline.
Conclusions: The biomarker-based ABC-stroke risk score is consistent and remains well calibrated with similar good predictive performance when retested after 2 months. The ABC-stroke risk score seem to provide reliable and important prognostic information at different time-points. Whether biomarker retesting at a later time point would add additional prognostic information requires further investigation.
Author Disclosures: The Disclosure Block has exceeded its maximum limit. Please call Tech support at (217) 398-1792 for more information.
- © 2016 by American Heart Association, Inc.