Relation of kidney function and albuminuria with atrial fibrillation (from the Heart and Soul Study)

Atrial fibrillation (AF) is common in end-stage renal disease, but the relation between more modest decrements in kidney function or albuminuria with AF is uncertain. Among 956 outpatients with coronary artery disease, kidney function was assessed using 3 methods (cystatin C-based estimated glomerular filtration rate [eGFR(cys)], creatinine-based eGFR [eGFR(Cr)], and the urinary albumin/creatinine ratio [ACR]) and prevalent AF using surface electrocardiography. Multivariate logistic regression was used to evaluated the association of each measure of kidney function with AF. The mean eGFR(cys) was 71 +/- 23 ml/min/1.73 m(2), and the median ACR was 10 mg/g (interquartile range 6 to 19). Forty subjects (4%) had prevalent AF. Compared to participants with eGFR(cys) in the highest tertile (eGFR(cys) >79), those with eGFR(cys) in the lowest tertile (eGFR(cys) <62) had more than threefold greater odds of AF (odds ratio [OR] 3.43, 95% confidence interval [CI] 1.18 to 9.97) after multivariate adjustment for traditional cardiovascular disease risk factors. This association remained significant with further adjustment for ACR (OR 3.37, 95% 1.02 to 11.14). Results were similar for eGFR(Cr) but did not reach statistical significance (OR 1.59, 95% CI 0.57 to 4.40). Participants with ACRs in the highest tertile (ACR >15 mg/g) had more than fourfold greater odds of AF compared to participants in the lowest ACR tertile (ACR <7 mg/g); an association that remained significant after adjustment for eGFR(cys) (OR 4.36, 95% CI 1.45 to 13.05) or eGFR(Cr) (OR 4.61, 95% CI 1.56 to 13.66). In conclusion, among outpatients with coronary artery disease, lower eGFR(cys) and higher ACR were associated with prevalent AF, independent of each other.