CHARGE-AF risk score

CHARGE-AF risk score

CHARGE-AF risk score was developed to predict the risk of atrial fibrillation (AF) [1]. The derivation cohort for the development of the risk score combined participants of three community based studies from United States of America: Framingham Heart Study, Cardiovascular Health Study, and Atherosclerosis Risk in Communities Study (ARIC). The validation cohort comprised of two European studies: Age Gene/Environment Susceptibility‐Reykjavik (AGES) study and the Rotterdam Study.

CHARGE-AF risk score used multiple variables and gave them weightages. Age was taken per 5 year increment, height per 10 cm increment, weight per 15 Kg increment, systolic blood pressure per 20 mm Hg increment and diastolic blood pressure per 10 mm Hg increment. Other factors were smoking (current vs former/never), use of antihypertensive medication, diabetes, heart failure and myocardial infarction [2].

Calculation of the actual CHARGE-AF score is rather tough: 0.508 × age (5 year increments) + 0.248 × height (10 cm increments) + 0.115 × weight (15 Kg increments) + 0.197 × systolic blood pressure (20 mm Hg increments) – 0.101 × diastolic blood pressure (10 mm Hg increments) + 0.359 × current smoker + 0.349 × antihypertensive medication + 0.237 × diabetes + 0.701 × congestive heart failure + 0.496 × myocardial infarction [2].

The weightage coefficients were derived from the derivation cohorts. CHARGE-AF score has been shown to predict AF better than CHA₂DS₂-VASc risk score [2]. It may be noted that though CHA₂DS₂-VASc risk score was developed for prediction of stroke in AF, it has also been used to predict risk of atrial fibrillation.

References

1. Alonso A, Krijthe BP, Aspelund T, Stepas KA, Pencina MJ, Moser CB, Sinner MF, Sotoodehnia N, Fontes JD, Janssens AC, Kronmal RA, Magnani JW, Witteman JC, Chamberlain AM, Lubitz SA, Schnabel RB, Agarwal SK, McManus DD, Ellinor PT, Larson MG, Burke GL, Launer LJ, Hofman A, Levy D, Gottdiener JS, Kääb S, Couper D, Harris TB, Soliman EZ, Stricker BH, Gudnason V, Heckbert SR, Benjamin EJ. Simple risk model predicts incidence of atrial fibrillation in a racially and geographically diverse population: the CHARGE-AF consortium. J Am Heart Assoc. 2013 Mar 18;2(2):e000102.
2. Christophersen IE, Yin X, Larson MG, Lubitz SA, Magnani JW, McManus DD, Ellinor PT, Benjamin EJ. A comparison of the CHARGE-AF and the CHA2DS2-VASc risk scores for prediction of atrial fibrillation in the Framingham Heart Study. Am Heart J. 2016 Aug;178:45-54.