AIM  To explore the correlation between microRNA-328 and atrial remodeling and the intervention effect of spironolactone by studying the expression of microRNA-328 (miRNA-328) and the changes of left atrial diameter (LAD) in patients with persistent atrial fibrillation.

  METHODS  By 2016 European Guidelines for the Management of Atrial Fibrillation, 48 patients with persistent atrial fibrillation after 1.5 years of regular drug treatment from the Department of Cardiology of our hospital were selected as the experimental group and 40 healthy subjects under normal physical examination in the same period were selected as the control group. The relative expression of miRNA-328 was detected by real-time fluorescence quantitative PCR and the left ventricular ejection fraction (LVEF) and left ventricular ejection fraction (LAD) were measured by Doppler echocardiography. The patients with persistent atrial fibrillation in the experimental group were treated with spironolactone for 6 months (20mg,1 times/day). The electrocardiogram, liver and kidney functions and serum potassium were detected every month to find out whether the liver and kidney functions were abnormal and whether the serum potassium was elevated. Six months later, Doppler echocardiography, electrocardiogram and miRNA-328 quantitative detection were performed again.

  RESULTS  The expression level of serum miRNA-328 in persistent atrial fibrillation group was significantly higher than that in control group. There was a positive correlation between serum miRNA-328 expression and LAD in persistent atrial fibrillation group (r = 0.333, P<0.05). After correction by partial correlation analysis, there was still a positive correlation between them (r = 0.449, P<0.05). After taking spironolactone for 6 months, the values of miRNA-328 and LAD were significantly lower than those before taking spironolactone.

  CONCLUSION  The expression of miRNA-328 in serum of patients with persistent atrial fibrillation suggests that it may participate in the process of atrial remodeling in patients with persistent atrial fibrillation and has diagnostic value. It can be used as a biological marker for early warning and clinical diagnosis of persistent atrial fibrillation and it may also become a new target for the treatment of persistent atrial fibrillation in the future. The decrease of LAD and miRNA-328 expression after the intervention of spironolactone suggests that spironolactone can reverse atrial remodeling, which provides theoretical support for improving the clinical application of atrial remodeling in patients with persistent atrial fibrillation and indicates that spironolactone may become a new method for the prevention and treatment of atrial fibrillation.