CHA2DS2-VASc Assessment of Thromboembolic Risk

Various scoring systems have been developed in order to define patients who may be at risk for the most serious outcome of atrial fibrillation, cerebrovascular events, ie, stroke. The scoring system that is prevalent in Europe and many other parts of the world is called CHA₂DS₂-VASc (Figure 4)[5][6][7] ; the 2 after the first A and the first S refer, of course, to the double points that these risk factors carry. The acronym is spelled out on the left of the Figure: Congestive heart failure and Hypertension score as 1 point each; Age ≥75 years is 2 points; Diabetes, 1 point; Stroke, transient-ischemic attack (TIA), or thromboembolism is 2 points; Vascular disease, Age range 65-74 years, 1 point; and finally when the Sex category is female, the risk factor adds 1 more point.

In the original derivation set from the European Heart Survey,[5] female gender carried a risk of 2.53 over males and vascular disease a risk of 2.27 over no disease. Looking at both the derivation set [5] and the later validation set [7] it can be seen that with a CHA₂DS₂-VASc score of 0 the risk of stroke ranges between 0 and roughly 1; for a score of 2, the risk is 2-4; and 3, 3-6, etc. Thus patients with a CHA₂DS₂-VASc score of 0 have very little risk of stroke or systemic embolism, but the risk increases dramatically as the CHA₂DS₂-VASc score increases. Camm J. Am J Med 2013; published on-line at http://education.amjmed.com/00000.

References

[5] 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;137:263-272.

[6] 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;41:2731-2738.

[7] Olesen JB, Lip GY, Hansen ML, et al. Validation of risk stratification schemes for predicting stroke and thromboembolism in patients with atrial fibrillation: nationwide cohort study. BMJ. 2011;342:d124.