Renal disease and left atrial remodeling predict atrial fibrillation in patients with cardiovascular risk factors

Objectives: In this prospective population-based study, we tested the possible interaction between chronic kidney disease (CKD) and left atrium volume index (LAVI) in predicting incident atrial fibrillation (AF). Methods: We enrolled 3549 Caucasian subjects, 1829 men and 1720 women, aged 60.7 +/- 10.6 years, without baseline AF and thyroid disorders. Echocardiographic left ventricular mass and LAVI were measured. Renal function was calculated by estimated glomerular filtration rate (e-GFR). To test the effect of some clinical confounders on incident AF, we constructed different models including clinical and laboratory parameters. AF diagnosis was made by standard electrocardiogram or 24-h ECG-Holter, hospital discharge diagnoses, and by the all-clinical documentation. Results: During the follow-up (53.3 +/- 18.1 months), 546 subjects developed AF (4.5 events/100 patient-years). Progressors to AF were older, had a higher body mass index, blood pressure, LDL-cholesterol, glucose, cardiac mass, and LAVI, and had lower e-GFR. Hypertension, metabolic syndrome, diabetes, cardiac hypertrophy and CKD were more common among AF cases than controls. In the final Cox regression model, variables that remained significantly associated with AF were: cardiac hypertrophy (HR = 1.495, 95% CI = 1.215-1.841), renal disease (HR = 1.528, 95% CI = 1.261-1.851), age (HR = 1.586, 95% CI = 1.461-1.725) and LAVI (HR = 2.920, 95% CI = 2.426-3.515). The interaction analysis demonstrated a synergic effect between CKD and cardiac hypertrophy (HR = 4.040, 95% CI = 2.661-6.133), as well as between CKD and LAVI (HR = 4.875, 95% CI = 2.699-8.805). The coexistence of all three subclinical organ damages significantly increases the arrhythmic risk (HR = 7.185, 95% CI = 5.041-10.240). Conclusions: Our data demonstrate that LAVI and CKD significantly interact in a synergic manner in increasing AF risk. (C) 2014 Elsevier Ireland Ltd. All rights reserved.