CHA₂DS₂-VASc Score
Calculate stroke risk in patients with atrial fibrillation. This score guides anticoagulation decisions to prevent thromboembolic events.
About CHA₂DS₂-VASc
The CHA₂DS₂-VASc score estimates stroke risk in non-valvular atrial fibrillation. It refines the older CHADS₂ score by adding vascular disease, age 65-74, and female sex as risk factors. Higher scores indicate greater stroke risk and stronger indication for anticoagulation.
Scoring Criteria
Risk Stratification
Frequently Asked Questions
DOACs (apixaban, rivaroxaban, edoxaban, dabigatran) are preferred for most patients with non-valvular AF. Warfarin remains indicated for: mechanical heart valves, moderate-severe mitral stenosis, severe CKD (CrCl <15-30 mL/min depending on DOAC), or when DOACs are not affordable/available.
The HAS-BLED score assesses bleeding risk but should not be used to withhold anticoagulation. A high HAS-BLED score (≥3) identifies modifiable bleeding risk factors to address (uncontrolled BP, labile INR, concomitant drugs, alcohol). Studies show net clinical benefit favors anticoagulation even with high bleeding risk scores.
Yes. Current guidelines recommend using CHA₂DS₂-VASc for atrial flutter as well as atrial fibrillation. The thromboembolic risk appears similar, and anticoagulation recommendations are the same for both arrhythmias.
Female sex is a risk modifier that increases stroke risk when combined with other factors. However, female sex alone (score of 1 with no other risk factors) does not warrant anticoagulation. Guidelines recommend treating women with no other risk factors as low risk (equivalent to score 0).
Paroxysmal (intermittent), persistent, and permanent AF all carry similar stroke risk. Anticoagulation decisions should be based on CHA₂DS₂-VASc score regardless of AF pattern. Even brief episodes detected by devices (subclinical AF) may warrant anticoagulation if the score is elevated.
Important Considerations
- Contraindications: Assess for absolute contraindications to anticoagulation
- Renal function: Check CrCl for DOAC dosing; some require dose adjustment
- Drug interactions: Review for P-gp and CYP3A4 interactions with DOACs
- Patient preference: Shared decision-making is essential
Medical Disclaimer: This calculator is for educational purposes. Anticoagulation decisions require clinical judgment, consideration of bleeding risk, patient preferences, and contraindications. Always follow current guidelines and institutional protocols.
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