CHA₂DS₂-VASc Score Calculator
Calculate CHA₂DS₂-VASc score to assess stroke risk in atrial fibrillation. Guides anticoagulation therapy decisions based on validated risk factors.
Select All That Apply
CHA₂DS₂-VASc Score
0 / 9
No antithrombotic therapy recommended
Low risk - anticoagulation not indicated for stroke prevention
Annual Stroke Risk
0%
Risk Category
Low
Stroke Risk by Score
| Score | Annual Risk | Recommendation |
|---|---|---|
| 0 | 0% | No therapy needed |
| 1 | 1.3% | Consider anticoagulation |
| 2 | 2.2% | Anticoagulation recommended |
| 3-4 | 3.2-4.0% | Anticoagulation recommended |
| ≥5 | 6.7-15% | Anticoagulation recommended |
Clinical Notes
- • Also assess bleeding risk (HAS-BLED score)
- • DOACs (dabigatran, rivaroxaban, apixaban, edoxaban) preferred over warfarin in most cases
- • Aspirin alone is not recommended for stroke prevention in AF
- • Left atrial appendage closure may be considered if anticoagulation contraindicated
Disclaimer: This calculator is for educational purposes only. Treatment decisions should be made by qualified healthcare providers considering individual patient factors, bleeding risk, and preferences.
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About This Calculator
The CHA₂DS₂-VASc score is the most widely used tool for estimating stroke risk in patients with atrial fibrillation (AF). It guides clinical decisions about anticoagulation therapy—medications that prevent blood clots but carry bleeding risks. This calculator helps assess which patients benefit most from treatment.
What is CHA₂DS₂-VASc? CHA₂DS₂-VASc is an acronym scoring system where each letter represents a stroke risk factor:
- Congestive heart failure (+1)
- Hypertension (+1)
- Age ≥75 (+2)
- Diabetes (+1)
- Stroke/TIA history (+2)
- Vascular disease (+1)
- Age 65-74 (+1)
- Sex category - female (+1)
Why is This Score Important? Atrial fibrillation increases stroke risk 5-fold. The irregular heartbeat allows blood to pool and form clots, which can travel to the brain. Anticoagulation dramatically reduces this risk but increases bleeding. CHA₂DS₂-VASc identifies who benefits most from treatment.
Clinical Guidelines: Current guidelines recommend anticoagulation for scores ≥2 in men or ≥3 in women. For related assessment, see our ASCVD Risk Calculator.
How to Use the CHA₂DS₂-VASc Score Calculator
- 1Review each risk factor checkbox carefully.
- 2Select all conditions that apply to the patient.
- 3Note that Age ≥75 and Age 65-74 are mutually exclusive.
- 4Check "Stroke/TIA" if there's any prior cerebrovascular event.
- 5Vascular disease includes MI, PAD, or aortic plaque.
- 6The score calculates automatically as you select factors.
- 7Review the annual stroke risk percentage.
- 8Consider the anticoagulation recommendation.
- 9Also assess bleeding risk (HAS-BLED score).
- 10Discuss treatment options with healthcare provider.
Understanding the Score Components
Each factor in CHA₂DS₂-VASc represents validated stroke risk.
C - Congestive Heart Failure (+1 point)
Includes:
- Symptomatic heart failure (any NYHA class)
- Reduced ejection fraction (<40%)
- Heart failure hospitalization
Heart failure causes blood stasis, promoting clot formation.
H - Hypertension (+1 point)
Defined as:
- Systolic BP >140 mmHg or diastolic >90 mmHg
- Currently on antihypertensive medication
Damages blood vessels and promotes atherosclerosis.
A₂ - Age ≥75 Years (+2 points)
The strongest age-related risk factor:
- Risk increases exponentially after 75
- Worth 2 points (not just 1)
- Present in most high-risk patients
D - Diabetes Mellitus (+1 point)
Includes:
- Type 1 or Type 2 diabetes
- Fasting glucose ≥126 mg/dL
- Currently on glucose-lowering therapy
Diabetes promotes vascular disease and hypercoagulability.
S₂ - Stroke/TIA/Thromboembolism (+2 points)
History of:
- Ischemic stroke
- Transient ischemic attack (TIA)
- Systemic embolism
Prior events dramatically increase recurrence risk.
Additional Score Components
Completing the CHA₂DS₂-VASc assessment.
V - Vascular Disease (+1 point)
Evidence of atherosclerosis:
- Prior myocardial infarction (MI)
- Peripheral arterial disease (PAD)
- Aortic plaque on imaging
- Prior arterial revascularization
A - Age 65-74 Years (+1 point)
Moderate age-related risk:
- Intermediate between younger and ≥75
- Only 1 point (vs 2 for ≥75)
- Cannot be scored with ≥75 (mutually exclusive)
Sc - Sex Category Female (+1 point)
Important considerations:
- Female sex alone (score = 1) does NOT require anticoagulation
- Acts as a risk modifier with other factors
- Controversial whether it's an independent risk factor
- Present because historical data showed increased risk
Maximum Score
Maximum: 9 points (not 10)
- Age ≥75 OR Age 65-74 (not both)
- All other factors can co-exist
Anticoagulation Guidelines
Translating score into treatment decisions.
Current Recommendations (2023 Guidelines)
| Score (Men) | Score (Women) | Recommendation |
|---|---|---|
| 0 | 1 (female only) | No anticoagulation |
| 1 | 2 | Consider anticoagulation |
| ≥2 | ≥3 | Anticoagulation recommended |
Anticoagulation Options
Direct Oral Anticoagulants (DOACs):
- Apixaban (Eliquis)
- Rivaroxaban (Xarelto)
- Dabigatran (Pradaxa)
- Edoxaban (Savaysa)
Generally preferred over warfarin due to:
- No routine monitoring needed
- Fewer drug/food interactions
- Lower intracranial bleeding risk
- Fixed dosing
Warfarin:
- Still used in some situations
- Requires INR monitoring (target 2.0-3.0)
- Preferred with mechanical heart valves
- More experience in severe renal disease
What About Aspirin?
Aspirin is NOT recommended for stroke prevention in AF.
Historical use was based on limited evidence. Modern trials show aspirin:
- Provides minimal stroke protection
- Has significant bleeding risk
- Is inferior to anticoagulation
Balancing Benefits and Risks
Anticoagulation decisions consider bleeding risk.
The Risk-Benefit Balance
Without anticoagulation:
- Higher stroke risk (varies by score)
- Strokes from AF tend to be severe
With anticoagulation:
- ~65% reduction in stroke risk
- Increased bleeding risk (~1-3% major bleeding/year)
HAS-BLED Score
Assesses bleeding risk on anticoagulation:
- Hypertension
- Abnormal renal/liver function
- Stroke history
- Bleeding history
- Labile INR
- Elderly (>65)
- Drugs/alcohol
Score ≥3 indicates high bleeding risk but does NOT contraindicate anticoagulation—just requires more caution.
High Bleeding Risk
Options for patients who can't take anticoagulation:
- Left atrial appendage closure (Watchman device)
- More frequent monitoring
- Lower dose DOACs in some cases
- Risk factor modification
Shared Decision Making
Discuss with patients:
- Their stroke risk (annual %)
- Their bleeding risk
- Medication preferences
- Lifestyle factors
- Personal values
Clinical Scenarios
Applying CHA₂DS₂-VASc in practice.
Case 1: Low Risk
65-year-old woman with new AF, no other risk factors.
- Score: 1 (female sex only)
- Recommendation: No anticoagulation
- Annual stroke risk: ~1.3%
Case 2: Intermediate Risk
68-year-old man with AF and hypertension.
- Score: 2 (age 65-74 + hypertension)
- Recommendation: Anticoagulation recommended
- Annual stroke risk: ~2.2%
Case 3: High Risk
78-year-old woman with AF, diabetes, and prior stroke.
- Score: 6 (age ≥75 [2] + female [1] + diabetes [1] + stroke [2])
- Recommendation: Anticoagulation strongly recommended
- Annual stroke risk: ~10%
Special Populations
Paroxysmal vs. Persistent AF: Same stroke risk—score applies equally.
Post-Ablation: May still need anticoagulation based on score.
Heart Failure: Counts even if EF normalized on treatment.
Evolution and Limitations
Understanding the score's context and alternatives.
From CHADS₂ to CHA₂DS₂-VASc
Original CHADS₂ (2001):
- CHF, Hypertension, Age ≥75, Diabetes, Stroke
- Maximum 6 points
- Less granularity at low scores
CHA₂DS₂-VASc (2010):
- Added vascular disease, age 65-74, female sex
- Better identifies truly low-risk patients
- Now the standard globally
Limitations
The score doesn't consider:
- Kidney function
- Type of AF (paroxysmal vs. persistent)
- Left atrial size
- Obesity
- Sleep apnea
- Biomarkers (troponin, BNP)
Overestimates risk in:
- Younger patients with only female sex
- Some Asian populations
Underestimates risk in:
- Patients with multiple risk factors in one category
Future Directions
Emerging tools include:
- Biomarker-enhanced risk scores
- Machine learning models
- Imaging-based risk assessment
- Genetic risk factors
Pro Tips
- 💡Maximum score is 9, not 10 (age categories are mutually exclusive).
- 💡Female sex alone (score = 1) does not require anticoagulation.
- 💡Score ≥2 in men or ≥3 in women generally indicates anticoagulation.
- 💡Paroxysmal and persistent AF have similar stroke risk.
- 💡Always assess bleeding risk (HAS-BLED) alongside CHA₂DS₂-VASc.
- 💡DOACs are generally preferred over warfarin for most patients.
- 💡Aspirin alone is NOT recommended for stroke prevention in AF.
- 💡Prior stroke/TIA adds 2 points—the highest individual factor.
- 💡Age ≥75 is worth 2 points; age 65-74 is worth 1 point.
- 💡Heart failure counts even if EF has normalized on treatment.
- 💡Reassess the score when clinical conditions change.
- 💡Treatment decisions should involve patient preferences and values.
Frequently Asked Questions
A score of 0 indicates very low stroke risk (~0% per year). Anticoagulation is not recommended as the bleeding risk would outweigh the benefit. This applies to men under 65 with AF but no other risk factors.
