Atrial appendage transcriptional profile in patients with atrial fibrillation with structural heart diseases

During the last few years DNA microarray studies of gene expression changes in human atrial tissues from patients with and without atrial fibrillation (AF) have been performed. For this purpose, tissue samples are usually collected from AF patients undergoing open heart surgery. These investigations have limitations associated with the unavoidable heterogeneity of compared groups which is due to the presence of various structural changes accompanying different sets of underlying heart diseases in both groups. It is thus reasonable to compare the atrial tissue samples from AF patients with those from individuals without signs of cardiovascular disease. To address this, we selected the atrial tissue samples from 12 AF patients (who underwent open heart surgery) and compared them with control atrial tissue samples from 10 individuals with no signs of cardiovascular diseases (those who died due to street accident). cDNA microarray method and reverse transcription-polymerase chain reaction (RT-PCR) analysis were used to identify genes which can discriminate between control and pathologically altered atrial tissues. Thirty-nine genes were found to be differentially expressed in pathologically altered tissues samples independently of the type of the underlying structural heart disease. These genes are involved in signal transduction, gene transcription regulation, cell proliferation, and apoptosis. The greatest alterations were observed for NOR1, DEC1, MSF, and Bcl2A1 genes (5 to 28-fold decrease, P < 0.05). Additional studies are needed to determine the specific role of each selected gene in pathophysiological changes leading to AF.