Novel fibro-inflammation markers in assessing left atrial remodeling in non-valvular atrial fibrillation

BACKGROUND Structural remodeling is associated with the fibroinflammatory process in the atrial extracellular matrix. In the present study we aimed to investigate whether serum levels of new circulating remodeling markers differ in patients with atrial fibrillation (AF) compared to patients with sinus rhythm. MATERIAL AND METHODS The study population included 52 patients diagnosed with non-valvular AF and 33 age-matched patients with sinus rhythm. Serum levels of Galectin-3, matrix metalloproteinase-9 (MMP-9), lipocalin-2 (Lcn2/NGAL), N-terminal propeptide of type III procollagen (PIIINP), Hs-Crp, and neutrophil-to-lymphocyte ratio (NLR) were measured. The left atrial volume (LAV) was calculated by echocardiographic method and LAV index was calculated. RESULTS Galectin-3, MMP-9, and PIIINP levels were significantly higher in AF patients except NGAL levels (1166 pg/ml (1126-1204) and 1204 pg/ml (1166-1362) p=0.001, 104 (81-179) pg/ml and 404 (162-564) pg/ml p<0.0001, and 1101 (500-1960) pg/ml and 6710 (2370-9950) pg/ml p<0.0001, respectively). The NLR and Hs-CRP levels were also higher in AF (2.1 ± 1.0 and 2.7 ± 1.1 p=0.02 and 4.2 ± 1.9 mg/L and 6.0 ± 4.7 mg/L p=0.04, respectively). In correlation analyses, NLR showed a strongly significant correlation with LAVi, but Hs-CRP did not (p=0.007 r=0.247, Pearson test and p=0.808 r=0.025, Pearson test, respectively). Moreover, Galectin-3, MMP-9, and PIIINP had a strong positive correlation with LAVi (p=0.021 r=640, Spearman test and p=0.004 r=0.319 Pearson test, and p=0.004 r=0.325 Pearson test, respectively). CONCLUSIONS Novel fibrosis and inflammation markers in AF are correlated with atrial remodeling. Several unexplained mechanisms of atrial remodeling remain, but the present study has taken the first step in elucidating the mechanisms involving fibrosis and inflammation markers.