Prediction of Atrial Fibrillation in a Racially Diverse Cohort: The Multi‐Ethnic Study of Atherosclerosis (MESA)

Abstract

BackgroundExisting equations for prediction of atrial fibrillation (AF) have been developed and validated in white and African‐American populations. Whether these models adequately predict AF in more racially and ethnically diverse populations is unknown.Methods and ResultsWe studied 6663 men and women 45 to 84 years of age without AF at baseline (2000–2002) enrolled in the Multi‐Ethnic Study of Atherosclerosis (MESA). Of these, 38% were non‐Hispanic whites, 28% non‐Hispanic African Americans, 22% Hispanics, and 12% Chinese Americans. AF during follow‐up was ascertained from hospitalization discharge codes through 2012. Information collected at baseline was used to calculate predicted 5‐year risk of AF using the previously published simple CHARGE‐AF model, which only includes clinical variables, and a biomarker‐enriched CHARGE‐AF model, which also considers levels of circulating N‐terminal of the prohormone B‐type natriuretic peptide and C‐reactive protein. For comparison purposes, we also assessed performance of the 10‐year Framingham AF model. During a mean follow‐up of 10.2 years, 351 cases of AF were identified. The C‐statistic of the CHARGE‐AF models were 0.779 (95% CI, 0.744–0.814) for the simple model and 0.825 (95% CI, 0.791–0.860) for the biomarker‐enriched model. Calibration was adequate in the biomarker‐enriched model (χ2=7.9; P=0.55), but suboptimal in the simple model (χ2=25.6; P=0.002). In contrast, the 10‐year Framingham score had a C‐statistic (95% CI) of 0.746 (0.720–0.771) and showed poor calibration (χ2=57.4; P<0.0001).ConclusionThe CHARGE‐AF risk models adequately predicted 5‐year AF risk in a large multiethnic cohort. These models could be useful to select high‐risk individuals for AF screening programs or for primary prevention trials in diverse populations.

Lifetime Risk of Atrial Fibrillation by Race and Socioeconomic Status

“…8 The same results have been found in different cohorts. [22][23][24][25][26][27][28] Complementing previous studies, we now show that AAs have lower lifetime risk of AF than whites, despite higher prevalence of AF risk factors. However, notwithstanding their lower lifetime risk, still 1 in 5 AAs in ARIC were estimated to develop AF during their lifetime, certainly not a trivial figure.…”

Predicting Atrial Fibrillation and Its Complications

“…For instance, in the CHARGE-AF pooled analysis, which included five separate cohorts, B-type natriuretic peptides but not C-reactive protein helped in risk reclassification of individuals, as measured by the net reclassification index (NRI). 16 Similar observations have been made in the FHS, 22 the Malmö Diet and Cancer Study, 18 the MESA cohort, 8 and in the Gutenberg Health Study. 17 …”

“…This score was subsequently validated in four different cohorts: the Age, Gene/Environment Susceptibility-Reykjavik (AGES) study, Atherosclerosis Risk in Communities (ARIC) study, Cardiovascular Health Study (CHS), and the Multi-Ethnic Study of Atherosclerosis (MESA). 6–8 In these external cohorts, the discrimination of the model was acceptable, ranging from 0.67 in African American participants in CHS to 0.75 in the racially diverse MESA cohort. In most populations, however, the model required recalibration to adjust the predicted probabilities to the actual risk of AF in the different cohorts.…”

“…13 Similarly, the CHARGE-AF model had good discrimination in the MESA cohort (C-statistic 0.78, 95%CI 0.74, 0.81), but also overestimated AF risk, particularly among those with the highest observed risk. 8 …”

“…However, these scores perform worse than AF-specific predictive models (as assessed with c-statistics, for example) and are not adequately calibrated to predict AF, failing to provide estimates of actual predicted AF risk over a particular time period. 8 …”