CHA2DS2-VASc Score for Atrial Fibrillation Stroke Risk
Calculates stroke risk for patients with atrial fibrillation.
Darren Triller, Jennifer Glen, Tim Michalski
Provided by
Anticoagulation Forum- Helps with long-term stroke risk stratification for atrial fibrillation patients.
- The CHA2DS2-VASc score is one of several risk stratification schema that can help determine the 1 year risk of a thromboembolic (TE) event in a non-anticoagulated patient with non-valvular AF.
- The CHA2DS2-VASc score, among other risk stratification schema, can be used to provide an idea of a patient’s risk for thromboembolic (TE) event.
Summary
The CHA2DS2-VASc Score (Birmingham 2009) was developed after identifying additional stroke risk factors in patients with atrial fibrillation.
- Validation study included 1,084 patients with non-valvular AF, not on anticoagulation, over age 18 with EKG or Holter diagnosed AF in the ambulatory and hospital settings from 182 hospitals in 35 countries from 2003 to 2004 and had known thromboembolic status at 1 year from the Euro Heart Survey database.
- End point used was stroke or other thromboembolic event.
- Used previously developed Birmingham 2009 schema, under the acronym CHA2DS2-VASc.
- Study showed that as CHA2DS2-VASc score increased, rate of thromboembolic event within 1 year in non-anticoagulated patients with non-valvular AF increased as well.
- Considered score of 0 to be low risk for TE events (none seen in cohort at one year), score of 1 intermediate risk (0.6% rate at 1 year), and greater than 1 high risk (3% rate at 1 year).
Points to keep in mind:
- 31% of the patients in their original study group were lost to follow-up at one year and thus were not included in the analysis. These patients could have had thromboembolic events, causing them to be lost to follow-up.
- There was no statistically significant difference found between the CHA2DS2-VASc and CHADS₂ risk stratification schema in predicting TE events.
- None of the included patients were anticoagulated. Those at particularly high risk for a TE event may have been already anticoagulated by their PMD, potentially skewing the TE rates.
- A subsequent study examining the performance of CHA2DS2-VASc in predicting TE events on anticoagulated patients also identified CAD and smoking as potential additional risk factors for TE in this subset of patients. However, that study also did not show a statistical difference in the predictive avarious risk stratification abilities of the scores.
FORMULA
Addition of the selected points:
| Criteria | Points | |
|---|---|---|
| Age | <65 years old | 0 |
| 65-74 years old | +1 | |
| ≥75 years old | +2 | |
| Sex | Male | 0 |
| Female | +1 | |
| Congestive heart failure history | +1 | |
| Hypertension history | +1 | |
| Stroke/TIA/thromboembolism history | +2 | |
| Vascular disease history (prior MI, peripheral artery disease, or aortic plaque) | +1 | |
| Diabetes mellitus history | +1 |
FACTS & FIGURES
Interpretation:
| CHA₂DS₂-VASc Score | Risk of ischemic stroke | Risk of stroke/TIA/systemic embolism |
| 0 | 0.2% | 0.3% |
| 1 | 0.6% | 0.9% |
| 2 | 2.2% | 2.9% |
| 3 | 3.2% | 4.6% |
| 4 | 4.8% | 6.7% |
| 5 | 7.2% | 10.0% |
| 6 | 9.7% | 13.6% |
| 7 | 11.2% | 15.7% |
| 8 | 10.8% | 15.2% |
| 9 | 12.2% | 17.4% |
From Friberg 2012. Note the paradoxical decrease in risk between 7 and 8 points; this reflects the findings published in the study, but in general, assume increasing risk with higher scores.
.All questions & possible results
Default SectionTitle not visible
Age
Select one option:
- < 65
- 65 - 74
- ≥ 75
Sex
Select one option:
- Female
- Male
Congestive Heart Failure (CHF) history
Select one option:
- No
- Yes
Hypertension history
Select one option:
- No
- Yes
Stroke/TIA/thromboembolism history
Select one option:
- No
- Yes
Vascular disease history (prior MI, peripheral artery disease, or aortic plaque)
Select one option:
- No
- Yes
Diabetes history
Select one option:
- No
- Yes
Possible results
1 Points (out of 9)
Stroke risk was 2.2% per year in >90,000 patients (the Swedish Atrial Fibrillation Cohort Study) and 2.9% risk of stroke/TIA/systemic embolism.
One recommendation suggests a 0 score for men or 1 score for women (no clinical risk factors) is “low” risk and may not require anticoagulation; a 1 score for men or 2 score for women is “low-moderate” risk and should consider antiplatelet or anticoagulation; and a score ≥2 for men or ≥3 for women is “moderate-high” risk and should otherwise be an anticoagulation candidate.
3 Points (out of 9)
Stroke risk was 3.2% per year in >90,000 patients (the Swedish Atrial Fibrillation Cohort Study) and 4.6% risk of stroke/TIA/systemic embolism.
One recommendation suggests a 0 score for men or 1 score for women (no clinical risk factors) is “low” risk and may not require anticoagulation; a 1 score for men or 2 score for women is “low-moderate” risk and should consider antiplatelet or anticoagulation; and a score ≥2 for men or ≥3 for women is “moderate-high” risk and should otherwise be an anticoagulation candidate.
0 Points (out of 9)
Stroke risk was 0.2% per year in >90,000 patients (the Swedish Atrial Fibrillation Cohort Study) and 0.3% risk of stroke/TIA/systemic embolism.
One recommendation suggests a 0 score for men or 1 score for women (no clinical risk factors) is “low” risk and may not require anticoagulation; a 1 score for men or 2 score for women is “low-moderate” risk and should consider antiplatelet or anticoagulation; and a score ≥2 for men or ≥3 for women is “moderate-high” risk and should otherwise be an anticoagulation candidate.
7 Points (out of 9)
Stroke risk was 11.2% per year in >90,000 patients (the Swedish Atrial Fibrillation Cohort Study) and 15.7% risk of stroke/TIA/systemic embolism.
One recommendation suggests a 0 score for men or 1 score for women (no clinical risk factors) is “low” risk and may not require anticoagulation; a 1 score for men or 2 score for women is “low-moderate” risk and should consider antiplatelet or anticoagulation; and a score ≥2 for men or ≥3 for women is “moderate-high” risk and should otherwise be an anticoagulation candidate.
4 Points (out of 9)
Stroke risk was 4.8% per year in >90,000 patients (the Swedish Atrial Fibrillation Cohort Study) and 6.7% risk of stroke/TIA/systemic embolism.
One recommendation suggests a 0 score for men or 1 score for women (no clinical risk factors) is “low” risk and may not require anticoagulation; a 1 score for men or 2 score for women is “low-moderate” risk and should consider antiplatelet or anticoagulation; and a score ≥2 for men or ≥3 for women is “moderate-high” risk and should otherwise be an anticoagulation candidate.
6 Points (out of 9)
Stroke risk was 9.7% per year in >90,000 patients (the Swedish Atrial Fibrillation Cohort Study) and 13.6% risk of stroke/TIA/systemic embolism.
One recommendation suggests a 0 score for men or 1 score for women (no clinical risk factors) is “low” risk and may not require anticoagulation; a 1 score for men or 2 score for women is “low-moderate” risk and should consider antiplatelet or anticoagulation; and a score ≥2 for men or ≥3 for women is “moderate-high” risk and should otherwise be an anticoagulation candidate.
9 Points (out of 9)
Stroke risk was 12.2% per year in >90,000 patients (the Swedish Atrial Fibrillation Cohort Study) and 17.4% risk of stroke/TIA/systemic embolism.
One recommendation suggests a 0 score for men or 1 score for women (no clinical risk factors) is “low” risk and may not require anticoagulation; a 1 score for men or 2 score for women is “low-moderate” risk and should consider antiplatelet or anticoagulation; and a score ≥2 for men or ≥3 for women is “moderate-high” risk and should otherwise be an anticoagulation candidate.
8 Points (out of 9)
Stroke risk was 10.8% per year in >90,000 patients (the Swedish Atrial Fibrillation Cohort Study) and 15.2% risk of stroke/TIA/systemic embolism.
We realize that 8 points showed a lower risk than 7 points, these were the findings in the study, obviously one should assume all scores ≥7 have a risk >10%.
One recommendation suggests a 0 score for men or 1 score for women (no clinical risk factors) is “low” risk and may not require anticoagulation; a 1 score for men or 2 score for women is “low-moderate” risk and should consider antiplatelet or anticoagulation; and a score ≥2 for men or ≥3 for women is “moderate-high” risk and should otherwise be an anticoagulation candidate.
5 Points (out of 9)
Stroke risk was 7.2% per year in >90,000 patients (the Swedish Atrial Fibrillation Cohort Study) and 10.0% risk of stroke/TIA/systemic embolism.
One recommendation suggests a 0 score for men or 1 score for women (no clinical risk factors) is “low” risk and may not require anticoagulation; a 1 score for men or 2 score for women is “low-moderate” risk and should consider antiplatelet or anticoagulation; and a score ≥2 for men or ≥3 for women is “moderate-high” risk and should otherwise be an anticoagulation candidate.
2 Points (out of 9)
Stroke risk was 2.2% per year in >90,000 patients (the Swedish Atrial Fibrillation Cohort Study) and 2.9% risk of stroke/TIA/systemic embolism.
One recommendation suggests a 0 score for men or 1 score for women (no clinical risk factors) is “low” risk and may not require anticoagulation; a 1 score for men or 2 score for women is “low-moderate” risk and should consider antiplatelet or anticoagulation; and a score ≥2 for men or ≥3 for women is “moderate-high” risk and should otherwise be an anticoagulation candidate.
Literature
- Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation — Gregory Y H Lip 1, Robby Nieuwlaat, Ron Pisters, Deirdre A Lane, Harry J G M Crijns
- CHADS₂, CHA₂S₂DS₂-VASc, and long-term stroke outcome in patients without atrial fibrillation — George Ntaios, Gregory Y H Lip, Konstantinos Makaritsis, Vasileios Papavasileiou, Anastasia Vemmou, Eleni Koroboki, Paraskevi Savvari, Efstathios Manios, Haralampos Milionis, Konstantinos Vemmos
- Evaluation of risk stratification schemes for ischaemic stroke and bleeding in 182 678 patients with atrial fibrillation: the Swedish Atrial Fibrillation cohort study — Leif Friberg, Mårten Rosenqvist, Gregory Y H Lip
