Usefulness of CHA2DS2-VASc Score to Predict Stroke Risk Independent of Atrial Fibrillation

The CHA2DS2-VASc score is used to predict stroke risk among patients with atrial fibrillation (AF). We examined whether a CHA2DS2-VASc score predicts stroke risk among individuals without hospital-diagnosed AF and quantified the magnitude of the association in comparison to AF patients. We used data from population-based medical registries (1995 to 2005) covering all Danish hospitals to identify patients diagnosed with AF (n = 122,980). We matched ≤5 non-AF individuals (n = 612,723) to each AF patient on the individual risk factors included in the CHA2DS2-VASc score. We calculated 10-year absolute risk of ischemic and all-cause stroke in AF and non-AF individuals and compared the stroke risk between cohorts within strata of CHA2DS2-VASc scores using Cox regression. The 10-year risk of ischemic/all-cause stroke was 4.4%/8.8% among non-AF individuals and 6.2%/12% in AF patients, corresponding to a risk difference of 1.8% for ischemic stroke and 3.3% for all-cause stroke. In both cohorts, the stroke risk correlated with increasing CHA2DS2-VASc scores. However, in individuals with CHA2DS2-VASc scores ≥5 who were 2DS2-VASc score was associated with 10-year stroke risk also among individuals without hospital-diagnosed AF. In conclusion, primary prophylactic anticoagulation therapy may be relevant in male and younger non-AF individuals with CHA2DS2-VASc scores ≥5. These findings should be confirmed in clinical trials.