CHA2DS2-VASc Score

Overview

Atrial fibrillation substantially increases the risk of ischemic stroke, but that risk varies widely between patients depending on their comorbidities and demographics. The CHA2DS2-VASc score was introduced by Lip and colleagues in 2010 as a refinement of the earlier CHADS2 score, adding three additional risk factors — vascular disease, age 65–74 years, and female sex — to better identify truly low-risk patients who can safely avoid anticoagulation, as well as to more accurately stratify risk across the full range of AF patients.

The score is calculated from eight clinical variables, each contributing 0, 1, or 2 points, for a maximum of 9 points. It is now the standard tool recommended by European and American cardiology guidelines to guide the decision to initiate oral anticoagulation in patients with non-valvular atrial fibrillation.

Scale / Variables

Risk Factor	Criterion	Points
C	Congestive heart failure / LV dysfunction	1
H	Hypertension	1
A2	Age ≥ 75 years	2
D	Diabetes mellitus	1
S2	Prior stroke, TIA, or thromboembolism	2
V	Vascular disease (prior MI, PAD, or aortic plaque)	1
A	Age 65–74 years	1
Sc	Sex category (female)	1

Total score ranges from 0 to 9 points, the sum of all applicable criteria.

Interpretation

Score	Annual Stroke Risk
0	0.2%
1	0.6%
2	2.2%
3	3.2%
4	4.8%
5	7.2%
6	9.7%
7	11.2%
8	10.8%
9	12.2%

Risk estimates from the Friberg et al. 2012 Swedish Atlas cohort (182,678 patients with atrial fibrillation).

Per the 2020 ESC atrial fibrillation guidelines, anticoagulation guidance based on the score is sex-specific:

• Men: score 0 — no antithrombotic therapy needed; score 1 — consider anticoagulation, individualize; score ≥ 2 — anticoagulation recommended.
• Women: score 1 — no antithrombotic therapy needed; score 2 — consider anticoagulation, individualize; score ≥ 3 — anticoagulation recommended.

Female sex alone (without any other risk factor) is not considered an independent indication for anticoagulation.

Literature

Lip GYH, Nieuwlaat R, Pisters R, Lane DA, Crijns HJGM. 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(2):263–272.

Friberg L, Rosenqvist M, Lip GYH. Evaluation of Risk Stratification Schemes for Ischaemic Stroke and Bleeding in 182,678 Patients With Atrial Fibrillation: The Swedish Atlas Cohort Study. Eur Heart J. 2012;33(12):1500–1510.