OPG/RANK/RANKL axis in stabilization of spontaneously restored sinus rhythm in permanent atrial fibrillation patients after mitral valve surgery.

OBJECTIVE To investigate the expression of the osteoprotegerin (OPG)/receptor activator of nuclear factor-ĸB (RANK)/RANK ligand (RANKL) axis in the stabilization of spontaneously restored sinus rhythm (SR) in permanent atrial fibrillation (AF) patients after mitral valve (MV) surgery and study its clinical significance. METHODS Clinical data, biopsies of right atrial appendages were collected from 135 permanent AF patients who spontaneously restored SR after conventional isolated MV replacement. A comparison was made between patients who had recurrence of AF within 7 days and patients with persistent SR for more than 7 days. RESULTS AF patients had an increased expression of RANK, RANKL, and the RANKL/OPG ratio compared to SR patients, and the degree of fibrosis was lower in SR compared to AF in the atria. Moreover, the expressions of RANK, RANKL, and the RANKL/OPG ratio were positively correlated with the degree of fibrosis. CONCLUSION These findings suggest that the OPG/RANK/RANKL axis plays important roles in the stabilization of restored SR after MV surgery by stimulating AF-related atrial remodeling in AF patients.