miR−21 and NT-proBNP Correlate with Echocardiographic Parameters of Atrial Dysfunction and Predict Atrial Fibrillation

This study aimed to investigate the association of circulating biomarkers with echocardiographic parameters of atrial remodelling and their potential for predicting atrial fibrillation (AF). In patients with and without AF (n = 21 and n = 60) the following serum biomarkers were determined: soluble ST2 (sST2), Galectin−3 (Gal-3), N-terminal pro-brain natriuretic peptide (NT-proBNP), microRNA (miR)−21, −29a, −133a, −146b and −328. Comprehensive transthoracic echocardiography was performed in all participants. Biomarkers were significantly altered in patients with AF. The echocardiographic parameter septal PA-TDI, indicating left atrial (LA) remodelling, correlated with concentrations of sST2 (r = 0.249, p = 0.048), miR−21 (r = −0.277, p = 0.012), miR−29a (r = −0.269, p = 0.015), miR−146b (r = −0.319, p = 0.004) and miR−328 (r = −0.296, p = 0.008). In particular, NT-proBNP showed a strong correlation with echocardiographic markers of LA remodelling and dysfunction (septal PA-TDI: r = 0.444, p < 0.001, LAVI/a’: r = 0.457, p = 0.001, SRa: r = 0.581, p < 0.001). Multivariate Cox regressions analysis highlighted miR−21 and NT-proBNP as predictive markers for AF (miR−21: hazard ratio (HR) 0.16; 95% confidence interval (CI) 0.04–0.7, p = 0.009; NT-proBNP: HR 1.002 95%CI 1.001–1.004, p = 0.006). Combination of NT-proBNP and miR−21 had the best accuracy to discriminate patients with AF from those without AF (area under the curve (AUC)= 0.843). Our findings indicate that miR−21 and NT-proBNP correlate with echocardiographic parameters of atrial remodeling and predict AF, in particular if combined.