Atrial fibrillation is one of the most common arrhythmias encountered in clinical practice, associated with a higher risk of cardioembolic stroke and systemic embolism. Oral anticoagulant therapy is needed to prevent stroke, based on a structured risk assessment of each patient, to decide whether this therapy should be prescribed. The selection of the optimal therapy for patients with atrial fibrillation is sometimes difficult, because of the lack of a proper prediction of benefits and risks. To facilitate this decision, the 2020 European Society of Cardiology Guidelines for the diagnosis and management of atrial fibrillation recommend the use of CHA2DS2-VASc (Congestive heart failure, Hypertension, Age(3) 75 years, Diabetes mellitus, Stroke, Vascular disease, Age 65-74 years, Sex category – female) and HAS-BLED (Hypertension, Abnormal renal/liver function, Stroke, Bleeding history or predisposition, Labile INR, Elderly > 65 years, Drugs/Alcohol concomitantly) scores(1). These scores take into consideration only clinical variables, that can limit their power of prediction and calibration. Due to the heterogeneity of the population of patients with atrial fibrillation, recent research has focused on identifying new biomarkers for a better prediction of an individualized risk of stroke. Cardiac troponins are sensitive and specific biomarkers of myocardial damage. The first study showing that circulating troponin I (hsTnI) level is associated with mortality and morbidity in patients with atrial fibrillation was performed on hospitalized patients(2). Another study confirmed these results in a group of stable patients with atrial fibrillation on chronic anticoagulant treatment, in whom elevated hsTnT levels were associated with a worse prognosis(3). Increased myocyte wall stress leads to a higher synthesis and release of B-type natriuretic peptide (BNP) and NT-proBNP (the stable portion of the prohormone proBNP). Natriuretic peptides are independent predictors of new-onset atrial fibrillation in patients with ST segment elevation myocardial infarction(4). In a sub-study of RE-LY trial, NT-proBNP was a predictor of thromboembolic events and cardiovascular mortality.
Higher levels of D-dimers and beta-thromboglobulin may predict thromboembolic events in patients with non-valvular atrial fibrillation(6). D-dimers are markers of thrombogenesis. RE-LY and ARISTOTLE substudies described the correlation between the levels of D-dimers and the risk of stroke, cardiovascular death and major hemorrhagic events outcomes(5). In ARISTOTLE substudy, D-dimers levels were related to stroke, major bleeding, and mortality, independent of the oral anticoagulant treatment(7). A multi marker strategy may improve and refine the risk stratification in patients with atrial fibrillation. The ABC-stroke risk score has been validated in some studies as a better tool for predicting stroke and systemic embolism in patients with atrial fibrillation(8). This score includes two blood biomarkers, NT-proBNP and cardiac troponin-hs, and two clinical variables, age and prior stroke.
The ABC-stroke risk score includes only four variables: Age, Biomarkers (troponin and NT-proBNP), prior stroke as Clinical history. This is a dynamic score, that can increase or decrease and may allow a better selection of treatment in various clinical settings and a more appropriate risk stratification and decision support. Very important, the two biomarkers included in the ABC-score are widely available. As the treatment of cardiovascular diseases, including atrial fibrillation, is moving towards more personalized healthcare, the utilization of scores such as ABC-stroke risk score may contribute to a better therapeutic decision-making and better outcomes.
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