The CHADS₂ (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, previous stroke/transient ischaemic attack (TIA) (double)) and more recently, the CHA₂DS₂-VASc (congestive heart failure, hypertension, age ≥75 years (double score), diabetes mellitus, previous stroke/TIA (double score), vascular disease, age 65–74 years, sex category (female)) scores are validated clinical prediction tools commonly used to estimate the stroke risk in atrial fibrillation (AF) patients. More recently, the focus has been on initially identifying those patients at ‘low risk’ (ie, CHA₂DS₂-VASc score=0 for men, 1 for women) who do not need any antithrombotic therapy. Subsequent to this step, effective stroke prevention can be offered to those patients with AF with ≥1 stroke risk factors.

The CHADS₂ and CHA₂DS₂-VASc scores represent clusters of common cardiovascular risk factors related to thromboembolism. Perhaps unsurprisingly, both scores have been reported to be associated with the incidence of stroke, thromboemblism and mortality, not only in patients with AF but also in general population or non-AF patient populations.

Mitchell et al1 show that the CHADS₂ and CHA₂DS₂-VASc scores could predict the incidence of stroke/TIA in a population of over 20 000 patients with acute coronary syndrome (ACS) without AF. Both scores had acceptable discrimination performance (CHADS₂ and CHA₂DS₂-VASc scores; …