Dynamics of renal function in patients with atrial fibrillation: interrelations with systemic fibrosis and arterial stiffness

The aim was to study the dynamics of renal function in relation to the fibrosis activity and the arterial stiffness in young and middle-aged patients with atrial fibrillation (AF). Materials and methods. 50 young and middle-aged men with AF were examined. The average age was 53.0 (48.0-58.0). The serum levels of creatinine and cystatin C (Cys C) were determined and the glomerular filtration rate (eGFR) was calculated initially and after 12 months. The activity of systemic fibrosis was assessed by serum metalloproteinase-2 (MMP-2) and transforming growth factor-s1 (TGF-s1) determining. To assess systemic vascular stiffness central aortic pressure and pulse wave velocity (PWV) were measured. Results. Renal impairment defined as eGFR decrease by more than 10 ml/min/1.73 m 2 or to the level below than 60 ml/min/1.73 m 2 throughout the year was registered in 10 (20.0 %) patients. The concentration of MMP-2 and TGF-s1 was higher in the subgroup with the eGFR decline compared to the patients without renal function impairment (21.1 (17.4-25.9) and 16.5 (13.0-19.2) ng/ml (p = 0.038); 3.01 (0.09-17.4), and 0.08 (0-1.3) ng/ml (p = 0.041). Central aortic pulse pressure was also higher in the patients with eGFR decline (45.5 (42.0-49.0) and 38.0 (31.0-41.0) mmHg; p = 0.036). The PWV levels did not differ in the subgroups. Conclusion. The renal function impairment throughout a follow-up period of 12 months was registered in 20.0 % of young and middle-aged patients with AF. This subgroup of AF patients was characterized by increased activity of systemic fibrosis and vascular stiffness in terms of matrix metalloproteinase-2, transforming growth factor-s1 and central aortic pulse pressure levels.