Platelet-Derived Growth Factor-A Overexpression Correlates with Atrial Fibrosis in the Patients with Atrial Fibrillation Secondary to Rheumatic Valvular Disease

Objective: To investigate the relationship between platelet-derived growth factor-A (PDGF-A) and atrial fibrosis in patients who have developed atrial fibrillation (AF) secondary to rheumatic valvular disease. Methods: 84 selected patients participated in the current study who have developed rheumatic heart disease and were going to have a cardiac surgical operation. In the current study, whole subjects were divided into two group, they were atrial fibrillation (AF) group (the quantity is thirty-nine) and sinus rhythm (SR) group (the quantity is forty-five). Before the operation, complete clinical data was available for the whole patients. During the operation, the right atrial tissue (0.3 - 0.5 mm3) was disserted from every patient. Right atrial fibrosis was observed by Masson staining and the distribution of PDGF-A in right atrium specimen was observed by immunohistochemistry. RT-PCR techniques were applied to admeasure the mRNA expressions of PDGF-A in patients’ atrial tissue. At the same time, western-Blot techniques were employed to admeasure the protein expressions of PDGF-A. Results: In baseline clinical characteristics, in both AF group and SR group, there was no apparently difference between them (P > 0.05); compared with SR group, the diameters of left atrium and right atrium in AF group were apparently increased (P < 0.05). The results of Masson staining revealed that the atrial tissue fibrosis was clearer in AF group, and collagen volume fraction in the AF group was evidently exceeding SR group (P < 0.05). The expressions of PDGF-A’s mRNA and protein from right atrial tissue in the AF group were evidently greater than SR group (P < 0.05). The mRNA and protein expressions of PDGF-A and the right atrium diameter go hand in hand. Conclusion: Atrial remodeling plays an important role in patients with valvular atrial fibrillation; PDGF-A in patients with AF was highly expressed in the right atrial, and was closely related with atrial fibrosis.