Relation of renal function to risk for incident atrial fibrillation in women

Few prospective studies have explored the association between renal function and risk for incident atrial fibrillation (AF) in apparently healthy populations. A total of 24,746 women participating in the Women's Health Study who were free of cardiovascular disease and AF and provided blood samples at baseline were prospectively followed for incident AF from 1993 to 2010. AF events were confirmed by medical chart review. Estimated glomerular filtration rate (eGFR) was calculated from baseline creatinine using the Chronic Kidney Disease Epidemiology (CKD-EPI) equation. Cox models were used to estimate hazard ratios and 95% confidence intervals (CIs) for incident AF across eGFR categories controlling for AF risk factors. During a median of 15.4 years of follow-up, 786 incident AF events occurred. The multivariate-adjusted hazard ratios for incident AF across eGFR categories (<60, 60 to 74.9, 75 to 89, and ≥90 ml/min/1.73 m(2)) were 1.36 (95% CI 1.00 to 1.84), 0.90 (95% CI 0.71 to 1.14), 0.99 (95% CI 0.84 to 1.18) and 1.00, respectively, without evidence of a linear association (P for trend = 0.48). Similarly, there was no significant curvilinear association (quadratic p = 0.10) in multivariate analysis across categories. Compared to women with eGFRs ≥60 ml/min/1.73 m(2), the 1,008 women with eGFRs <60 ml/min/1.73 m(2) had a multivariate-adjusted hazard ratio for AF of 1.39 (95% CI 1.04 to 1.86, p = 0.03). In conclusion, no significant linear or curvilinear relation was observed between incident AF and less severe impairment of renal function in this large prospective cohort of women. However, a significant elevation in AF risk was observed at a threshold eGFR of <60 ml/min/1.73 m(2).