C2HEST Score Calculator
Enter the age and select applicable conditions — the risk score for incident atrial fibrillation is calculated immediately.
Result
Score: —
Interpretation following Li et al., 2019: —
How to interpret the C2HEST score
The C2HEST score ranges from 0 to 8 points. Higher scores indicate a higher risk of developing atrial fibrillation. Both the original publication and the post-stroke validation use the same three risk categories. The observed AF incidence depends on the population and on how thyroid disease was counted:
| C2HEST score | Risk category | Hyperthyroidism only: AF incidence, general population* | Hypo- or hyperthyroidism: annual AF incidence after ischemic stroke† |
|---|---|---|---|
| 0–1 | Low risk | 0.34 per 1000 person-years | 3.19% |
| 2–3 | Medium risk | 2.60 per 1000 person-years | 7.15% |
| ≥4 | High risk | 15.98 per 1000 person-years | 14.64% |
* Derivation cohort of 471,446 people from the Chinese Yunnan Insurance Database (Li et al., Chest 2019). The values are labelled "%/year" in the article text; they correspond to the per-score incidences in Table 4 of the article, which are given per 1000 person-years.
† 240,459 patients after ischemic stroke in the French nationwide validation (Li et al., J Am Heart Assoc 2019), in which thyroid disease comprised hypo- and hyperthyroidism.
The score was developed in people without structural heart disease (rheumatic valvular heart disease or dilated cardiomyopathy). The authors regard patients with structural heart disease as being at high risk of atrial fibrillation independently of the score.
What is the C2HEST score?
The C2HEST score (Coronary artery disease / COPD, Hypertension, Elderly, Systolic heart failure, Thyroid disease) is a simple clinical score that estimates the risk of developing atrial fibrillation (AF). It was developed by Yan-Guang Li, Gregory Lip and colleagues and published in Chest in 2019.
The score was derived from 471,446 people in the Chinese Yunnan Insurance Database and externally applied to 451,199 people from the Korean National Health Insurance Service. Discrimination was good in the derivation cohort (AUC 0.75; 95% CI 0.73–0.77) and moderate in the Korean cohort (AUC 0.65; 95% CI 0.65–0.66). In both cohorts, C2HEST performed better than the CHADS2 and CHA2DS2-VASc scores for predicting incident AF.
Validation after ischemic stroke
In a French nationwide cohort of 240,459 patients hospitalised with ischemic stroke and without known AF, 14,095 patients developed AF during a mean follow-up of 7.9 ± 11.5 months. The C2HEST score had a C index of 0.734 (95% CI 0.732–0.736), which was better than that of the CHA2DS2-VASc score (0.703) and a modified Framingham risk score (0.720). The incidence of AF increased from 23.5 per 1000 patient-years at a score of 0 to 196.8 per 1000 patient-years at a score of ≥6.
In an Italian cohort of 132 patients with cryptogenic stroke or TIA who received an implantable cardiac monitor, AF was detected in 40 patients (30.3%). C2HEST reached an AUC of 0.704 (95% CI 0.609–0.799), compared with 0.671 for CHASE-LESS in the same cohort; a C2HEST score of 0 (threshold <1) identified patients unlikely to develop AF with a specificity of at least 85%.
Scoring table
| Letter | Risk factor | Points |
|---|---|---|
| C2 | Coronary artery disease | 1 |
| Chronic obstructive pulmonary disease | 1 | |
| H | Hypertension | 1 |
| E | Elderly (age ≥75 years) | 2 |
| S | Systolic heart failure | 2 |
| T | Thyroid disease: hyperthyroidism (original); hypo- or hyperthyroidism in the French post-stroke validation | 1 |
Limitations
- The score was derived in an Asian population without structural heart disease. Discrimination was lower in the Korean external cohort than in the derivation cohort.
- The derivation cohort and the large validation cohorts were based on insurance or hospital discharge databases, not on systematic rhythm monitoring. AF may have remained undetected in some patients.
- The score does not include stroke-specific variables such as stroke severity or echocardiographic findings.
- Hyperthyroidism is a potentially reversible cause of AF. The authors of the post-stroke validation note that including it may favour the detection of transient causes of AF.
The C2HEST score estimates a risk at group level. It does not replace rhythm monitoring and cannot rule out atrial fibrillation in an individual patient.
Frequently asked questions
What does C2HEST stand for?
C2: coronary artery disease and COPD (1 point each); H: hypertension (1 point); E: elderly, age ≥75 years (2 points); S: systolic heart failure (2 points); T: thyroid disease, i.e. hyperthyroidism (1 point).
What is a high C2HEST score?
A score of 4 points or more is classified as high risk. After ischemic stroke, the annual incidence of new atrial fibrillation in this group was 14.64% in the French validation cohort (thyroid disease counted as hypo- or hyperthyroidism).
Should hypothyroidism be counted?
In the original score only hyperthyroidism is counted. The French post-stroke validation used a broader item "thyroid disease" (hypo- or hyperthyroidism), which gave a slightly higher C index (0.734) than the sensitivity analysis with hyperthyroidism only (0.716). You can choose either definition in the calculator; the risk rates shown are then taken from the study that used that definition.
Can the score be used in patients with structural heart disease?
No. Patients with structural heart disease (rheumatic valvular heart disease or dilated cardiomyopathy) were excluded from the score development because they had a very high risk of atrial fibrillation (hazard ratio 26.07) and should be considered high-risk regardless of the score.
How does C2HEST differ from CHASE-LESS and AF-ESUS?
C2HEST was developed for the general population and later validated after ischemic stroke. CHASE-LESS and AF-ESUS were developed specifically for patients after ischemic stroke and embolic stroke of undetermined source and include stroke-related variables.
Related calculators
Reference
Li YG, Pastori D, Farcomeni A, et al. A simple clinical risk score (C2HEST) for predicting incident atrial fibrillation in Asian subjects: derivation in 471,446 Chinese subjects, with internal validation and external application in 451,199 Korean subjects. Chest. 2019;155(3):510–518. doi:10.1016/j.chest.2018.09.011
Li YG, Bisson A, Bodin A, et al. C2HEST score and prediction of incident atrial fibrillation in poststroke patients: a French nationwide study. J Am Heart Assoc. 2019;8:e012546. doi:10.1161/JAHA.119.012546
Pinnacchio G, et al. External validation of published scoring systems to predict incident atrial fibrillation after cryptogenic stroke/embolic stroke of undetermined source. J Am Heart Assoc. 2026;15(13):e047601. doi:10.1161/JAHA.125.047601
Written by Frederic Eberhardt, MD. Last reviewed: 13 October 2026