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

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).

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.

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).

Our data demonstrate that LAVI and CKD significantly interact in a synergic manner in increasing AF risk.