# CHA₂DS₂-VASc Score Calculator (AFib Stroke Risk)
> Free CHA₂DS₂-VASc calculator for non-valvular atrial fibrillation stroke risk. Score + risk band + annual event rate. Based on Lip 2010 and the ACC/AHA/HRS 2019 AFib guideline. Clinician decision support.

## Overview

The CHA₂DS₂-VASc score estimates annual ischaemic stroke and systemic embolism risk in non-valvular atrial fibrillation. It assigns one or two points to congestive heart failure, hypertension, age, diabetes, prior stroke or thromboembolism, vascular disease, and sex category, for a total of 0–9. The ACC/AHA/HRS 2019 atrial fibrillation focused update incorporates CHA₂DS₂-VASc as the standard stratification tool for selecting patients who may benefit from oral anticoagulation. The score does not by itself dictate therapy — it is a decision-support input that clinicians integrate with bleeding risk, comorbid burden, valve status, and patient preferences.

## Who this is for

- Internal medicine and cardiology residents managing AF on rounds
- Hospitalists and emergency physicians making acute decisions
- Primary care attendings and APPs evaluating chronic AF

## How to interpret the result

| Score / band | Meaning |
|---|---|
| 0 | Low — anticoagulation often not recommended (men); women without other risk factors may also defer. |
| 1 | Borderline — guidelines suggest considering anticoagulation (men); discuss benefits and bleeding risk. |
| ≥ 2 (men) / ≥ 3 (women) | Anticoagulation is typically recommended pending bleeding risk assessment. |

## Cited source

**ACC/AHA/HRS 2019 Focused Update on Atrial Fibrillation** (2019) — ACC / AHA / HRS

_Primary publication:_ Lip GYH et al., Chest 2010 (refining stroke risk in AF)

## FAQs

### What CHA₂DS₂-VASc score warrants anticoagulation?

The ACC/AHA/HRS 2019 update suggests anticoagulation is typically reasonable at a CHA₂DS₂-VASc of ≥ 2 in men and ≥ 3 in women, after weighing bleeding risk. A score of 1 in men or 2 in women is a borderline range where shared decision-making applies. Always verify against the current guideline.

### Does CHA₂DS₂-VASc apply to valvular AF?

No. CHA₂DS₂-VASc was validated in non-valvular AF. Patients with mechanical heart valves or moderate-to-severe mitral stenosis are commonly anticoagulated regardless of score, per separate guideline recommendations.

### Should I use CHA₂DS₂-VASc for atrial flutter?

Most guidelines extend the CHA₂DS₂-VASc framework to atrial flutter because thromboembolic risk is presumed similar. Verify against the cited 2019 ACC/AHA/HRS update for the current language.

### Does CHA₂DS₂-VASc replace HAS-BLED?

No — they are complementary. CHA₂DS₂-VASc estimates stroke risk; HAS-BLED estimates major-bleeding risk on anticoagulation. Use both together when evaluating whether to start, continue, or pause anticoagulation.

### Is the CHA₂DS₂-VASc calculator a substitute for clinical judgement?

No. This tool is a decision-support aid only. It does not account for valve status, prior bleeding events, fall risk, frailty, drug interactions, or patient preferences. Final anticoagulation decisions are made by the clinician.

---
_Rounds AI is a citation-first clinical AI assistant. It supports clinical reasoning by surfacing cited information and is not a substitute for independent clinical judgement._