Study On The Relationship Between Rho Kinase Expression And Fibrosis In Atrial Appendage Of Patients With Atrial Fibrillation

Objective:To understand the expression of Rho kinase and the degree of fibrosis in atrial appendage of patients with atrial fibrillation and analyze its significance.Methods:In this study,42 patients with heart valve disease who underwent thoracotomy at the Cardiothoracic Surgery Department of the First Affiliated Hospital of Wannan Medical College from September 2018 to October 2019 were included in the study.We collected general clinical data of patients such as gender,age,disease history,cardiac ultrasound,liver and kidney function,body mass index,etc.All patients were divided into 11 groups of sinus rhythm group and 31 cases of atrial fibrillation group according to the results of 12-lead surface electrocardiogram.All patients with atrial appendage tissue with a size of about 0.5×0.5×0.3 cm were removed during cardiac surgery.Immunohistochemical was used to detect Rho kinase expression in atrial appendage tissue.Masson staining was used to calculate the collagen volume fraction（CVF）of atrial appendage tissue.The Pearson method was used to test the correlation between Rho kinase expression and collagen volume fraction and some clinical data.Multivariate logistic regression analysis was used to analyze the factors affecting atrial fibrillation.Results:1.Comparison of general clinical data between the atrial fibrillation group and the sinus rhythm groupIn the atrial fibrillation group,Cr[（84.15±20.02）umol/L vs（63.10±15.28）umol/L,P=0.003],LAD[（58.45±9.35）mm vs（43.27±6.10）mm,P<0.01],LDH[（215.77±85.31）U/L vs（160.18±27.51）U/L,P=0.003],RALD[（58.32±7.75）mm vs（51.91±9.15）mm,P=0.030]Higher than the sinus rhythm group.2.Expression of Rho kinase in atrial appendage（atrium）tissues between the atrial fibrillation group and the sinus rhythm groupUnder light microscope,the positive expression of immunohistochemical Rho kinase showed brown particles in the cytoplasm of cardiomyocytes,and negative expression in the absence of brown particles.The expression of Rho kinase in the cytoplasm of myocardial cells in sinus rhythm group was mostly weakly positive,and the expression of Rho kinase in the cytoplasm of myocardial cells in AF group was mostly positive.The average optical density value of Rho kinase expression in the atrial fibrillation group（0.08722±0.02438）was significantly higher than that in the sinus rhythm group（0.04534±0.006316）（P<0.01）.3.Masson staining（collagen volume fraction）of atrial appendage（atrium）tissueAfter Masson staining,muscle fibers appear red,collagen fibers appear blue,and severe fibrosis is manifested as:a large number of blue collagen fibers are distributed around myocardial cells,and the cell structure is disordered.Mild fibrosis is manifested as:small distribution of blue collagen fibers between myocardial cells and a more ordered cell structure.The collagen volume fraction of atrial appendage tissue（34.78±9.82）in the atrial fibrillation group was significantly higher than that in the sinus rhythm group（14.08±2.75）（P<0.01）.4.Correlation analysis of Rho kinase expression with collagen volume fraction and left atrial diameter in atrial appendage（atrium）tissueThere was a linear correlation between the expression of Rho kinase and the degree of atrial appendage（atrium）fibrosis and the diameter of the left atrium.The correlation coefficient R_CVF=0.663、R_LAD=0.630（P<0.01）.5.Multivariate logistic regression analysis of atrial fibrillationLeft atrial diameter and atrial appendage（atrium）collagen volume fraction（CVF）were independent risk factors for atrial fibrillation（P<0.05）,The Rho kinase expression was not an independent risk factor for atrial fibrillation（P>0.05）.Conclusion:1.The expression of Rho kinase was significantly increased and atrial appendage（atrium）fibrosis was observed in patients’atrial appendage（atrium）with atrial fibrillation.2.The expression of Rho kinase in atrial appendage（atrium）was significantly positively correlated with atrial appendage（atrium）fibrosis and left atrial diameter.3.Abnormal expression of Rho kinase in atrial appendage（atrium）may play a role in the occurrence and development of atrial fibrosis.