ABC Stroke Risk Score Calculator

ABC Stroke Risk Score: Explanation and Clinical Context The ABC (Age, Biomarkers, Clinical History) Stroke Risk Score is a validated biomarker-based model designed to estimate the individual 1-year risk of ischemic stroke or systemic embolism in patients with atrial fibrillation. It was developed and validated using data from the ARISTOTLE and RE-LY trials (Hijazi et al., Circulation 2016;133:268–277). Unlike traditional models such as CHA2DS2-VASc, the ABC model integrates circulating biomarkers that reflect myocardial stress and injury—namely high-sensitivity cardiac troponin T (hs-cTnT) and N-terminal pro–B-type natriuretic peptide (NT-proBNP)—together with age and prior stroke or TIA history.

This approach provides a more accurate, dynamic, and biologically relevant risk estimation. In the original derivation cohort, the model achieved a C-statistic of 0.68, outperforming CHA2DS2-VASc (0.62). The continuous nature of this model allows for recalculation as biomarkers change over time, offering a personalized assessment that reflects the patient’s current cardiovascular status.

Predicted risk categories are generally interpreted as follows: Low Risk (<1.5%/year), Intermediate Risk (1.5–3.0%/year), and High Risk (>3.0%/year). Clinically, the ABC Stroke Risk Score supports decision-making on anticoagulation by quantifying stroke risk more precisely. It can also be paired with the ABC Bleeding Risk Score to balance thromboembolic versus bleeding hazards in patients with atrial fibrillation.