Not All Stroke Estimates from CHA₂DS₂-VASc Scores Are Created Equal

We have largely moved beyond CHADS₂ to CHA₂DS₂-VASc, which more accurately predicts the risk for stroke in patients with nonvalvular atrial fibrillation (AF). U.S. and European medical societies agree that most individuals with a CHA₂DS₂-VASc of ≥2 should be anticoagulated and that those with CHA₂DS₂-VASc of 0 can avoid anticoagulation. There is controversy about treatment in patients with a CHA₂DS₂-VASc of 1. But published stroke rates vary greatly among different populations stratified by CHA₂DS₂-VASc scores. In four recent studies, the yearly incidence of stroke found in untreated patients with CHA₂DS₂-VASc of 2 was 0.8% in ATRIA, 2.2% in SPORTIF and in a Swedish national cohort, and 3.7% in a Danish cohort. Using Markovian-model probabi…