Biomarkers and atrial fibrillation: is it prime time yet?

Atrial fibrillation (AF) is a global epidemic with increasing burden on healthcare systems.1 AF is associated with increased risk of thromboembolic stroke, heart failure, cognitive dysfunction and mortality. In improving prognosis, the focus of management revolves around stroke prevention with clinical scores developed to identify people with increased stroke risk. The CHADS2 and CHA2DS2-VASc scores are the most commonly used scores, with the latter being better able to discriminate low-risk subjects.2 However, both the risk scores have a modest predictive value for identifying high-risk subjects for stroke with C statistics ranging from 0.60 to 0.80 (median 0.683) for CHADS2 and 0.64–0.79 (median 0.673) for CHA2DS2-VASc suggesting further scope for improvement.3 The C statistics of 1 means perfect discrimination and 0.5 means random chance. C statistics from 0.7 to 0.8 are considered to be of intermediate predictive value and those from 0.8 to 0.9 are considered to be of excellent predictive value. More recently, attention has been drawn to ways that can improve the predictive value of these clinical stroke risk scores. Renal impairment, although associated with increased risk of AF and stroke, does not significantly improve the predictive value.4 This can be explained by the increased association of renal impairment with conditions that already constitute these clinical scores. Echocardiographic parameters, for example, systolic dysfunction on transthoracic echocardiogram5 and spontaneous echo contrast and left atrial appendage velocity on …