- See also: Atrial fibrillation anticoagulation
The CHA2DS2-VASc score [Congestive heart failure, Hypertension, Age ≥75 years (doubled), Diabetes mellitus, Stroke (doubled), Vascular disease, Age 65–74 years, Sex category] predicts clinical risk of stroke and thromboembolism in atrial fibrillation.
The CHA2DS2-VASc score has been recommended in the 2010 European Society of Cardiology (ESC) guidelines  which promotes a risk factor based approach to stroke prevention, and de-emphasises the artificial stratification into low/moderate/high risk, given the poor predictive value of these 3 categories.
Indeed, the CHA2DS2-VASc score is more inclusive of 'stroke risk modifier' risk factors and has been validated in several large independent cohorts  . Of note, the most recent validation study used nationwide data on 73,538 hospitalized non-anticoagulated patients with AF, whereby in ‘low risk’ subjects (score=0), the rate of thromboembolism per 100 person-years was 1.67 (95%CI 1.47 to 1.89) with CHADS2 and 0.78 (0.58 to 1.04) with the CHA2DS2-VASc score, at 1 year follow-up . Thus, those categorised as ‘low risk’ using the CHA2DS2-VASc score were ‘truly low risk’ for thromboembolism, and the CHA2DS2-VASc score performed better than CHADS2 in identifying these 'low risk' patients. The c-statistics at 10 years follow-up were 0.812 (0.796 to 0.827) with CHADS2 and 0.888 (0.875 to 0.900) with the CHA2DS2-VASc score, respectively - thus, the CHA2DS2-VASc score also performed better than CHADS2 in predicting ‘high risk’ patients.
|Feature||Score if present|
|Congestive Heart Failure||1|
|Age ≥ 75 years||2|
|Age between 65 and 74 years||1|
|Vascular disease (previous MI, peripheral arterial disease or aortic plaque)||1|
Anticoagulation based on the CHA2DS2-VASc score
The following treatment strategies are recommended in the table below based on the European Society of Cardiology guidelines:
|0||Low||No antithrombotic therapy (or Aspirin)||No antithrombotic therapy (or Aspirin 75-325mg daily)|
|1||Moderate||Oral anticoagulation (or aspirin)||Oral anticoagulation, whether as warfarin INR to 2.0-3.0, or one of the new oral anticoagulation drugs (eg. dabigatran) [or aspirin 75-325mg daily, depending on factors such as patient preference]|
|2 or greater||High||Oral anticoagulation||Oral anticoagulation, whether as Warfarin INR to 2.0-3.0, or one of the new oral anticoagulation drugs (eg. dabigatran), unless contraindicated (e.g. clinically significant GI bleeding, etc)|
Assessment of Bleeding Risk with Anticoagulation
The decision to anticoagulate a patient should also be based upon an assessment of the risk of bleeding using a score such as the HAS-BLED score.
- Lip GY, Nieuwlaat R, Pisters R, Lane DA, Crijns HJ. 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. Chest. 2010 Feb; 137(2):263-72.(Link to article – subscription may be required.)
- Camm AJ, Kirchhof P, Lip GY, Schotten U, Savelieva I, Ernst S, Van Gelder IC, Al-Attar N, Hindricks G, Prendergast B, Heidbuchel H, Alfieri O, Angelini A, Atar D, Colonna P, De Caterina R, De Sutter J, Goette A, Gorenek B, Heldal M, Hohloser SH, Kolh P, Le Heuzey JY, Ponikowski P, Rutten FH. Guidelines for the management of atrial fibrillation: the Task Force for the Management of Atrial Fibrillation of the European Society of Cardiology (ESC). Eur Heart J. 2010 Oct;31(19):2369-429.
- Van Staa TP, Setakis E, Di Tanna GL, Lane DA, Lip GY. A comparison of risk stratification schema for stroke in 79884 atrial fibrillation patients in general practice. J Thromb Haemost. 2010 Oct 1. doi: 10.1111/j.1538-7836.2010.04085.x.[Epub ahead of print] PubMed PMID: 21029359.
- Lip GY, Frison L, Halperin JL, Lane DA. Identifying Patients at High Risk for Stroke Despite Anticoagulation. A Comparison of Contemporary Stroke Risk Stratification Schemes in an Anticoagulated Atrial Fibrillation Cohort. Stroke. 2010 Oct 21. [Epub ahead of print] PubMed PMID: 20966417
- Olesen JB, Lip GY, Hansen ML, Hansen PR, Tolstrup JS, Lindhardsen J, Selmer C, Ahlehoff O, Olsen AM, Gislason GH, Torp-Pedersen C. Validation of risk stratification schemes for predicting stroke and thromboembolism in patients with atrial fibrillation: nationwide cohort study. BMJ. 2011 Jan 31;342:d124. doi: 10.1136/bmj.d124.