CHA₂DS₂-VASc Score
Estimate annual stroke risk in atrial fibrillation (AF) using the CHA₂DS₂-VASc score. Guide anticoagulation decisions and assess perioperative thromboembolism risk based on ESC 2020 guidelines.
Based on: ESC 2020
Input
Clinical reasoning
A 76-year-old woman with hypertension and heart failure. No prior stroke, diabetes, or vascular disease.
Should anticoagulation be initiated?
A 67-year-old male, newly diagnosed AF. No hypertension, diabetes, stroke history, vascular disease, or heart failure.
Should anticoagulation be initiated?
Overview
CHA₂DS₂-VASc score for stroke risk stratification in non-valvular atrial fibrillation (AF). Calculates annual stroke risk and provides anticoagulation guidance based on ESC 2020 guidelines.
Evidence Summary
The CHA₂DS₂-VASc score was developed by Lip et al. (2010) as a refinement of the original CHADS₂ score, adding vascular disease, age 65–74, and female sex as additional risk modifiers. The score stratifies stroke risk in non-valvular AF and informs anticoagulation decisions.
The ESC 2020 AF guidelines recommend anticoagulation for men with CHA₂DS₂-VASc ≥ 2 and women with CHA₂DS₂-VASc ≥ 3 (net clinical score ≥ 2). Female sex alone (score 1 in women) does not independently confer stroke risk and is not an indication for anticoagulation.
| Male | Female | |
|---|---|---|
| Low (no anticoag.) | Score 0 | Score 1 (sex only, net 0) |
| Consider anticoag. | Score 1 | Score 2 (net 1) |
| Anticoag. recommended | Score ≥ 2 | Score ≥ 3 (net ≥ 2) |
What this score decides — and what it does not
CHA₂DS₂-VASc answers whether stroke risk justifies anticoagulation. It does not assess whether anticoagulation is safe to give — that requires parallel bleeding risk evaluation with HAS-BLED. For borderline cases (net score 1, moderate risk), the score does not mandate a prescription: it identifies patients who need individualized risk-benefit discussion. A high score is clinical evidence for anticoagulation, not an automatic order.