Abstract:Objective:To investigate the diagnostic value of 3D-STE and 2D-STE in the diagnosis of right ventricular fibrosis in patients with end-stage heart failure. Methods:A total of 63 patients with end-stage heart failure who received heart transplantation in our hospital from July 2016 to March 2021 were selected. All patients underwent routine echocardiography, 3D-STE, 3D-STE and right heart catheterization coronary angiography. After heart transplantation, histopathological specimens of each patient were taken to detect the severity of RV myocardial fibrosis. According to the severity of myocardial fibrosis, the patients were divided into three groups: mild group, moderate group and severe group. Pearson correlation coefficient was used to evaluate the correlation between myocardial fibrosis and echocardiographic parameters. The optimal truncation value of each parameter was determined by ROC curve to detect the severity of myocardial fibrosis. Results:The mean value of myocardial fibrosis in mild group was (6.32±1.74) %, that in moderate group was (13.08±2.01) %, and that in severe group was (22.81±4.65) %, and the difference between groups was statistically significant (P < 0.05). RV length diameter, TAPSE, RVFAC, S "", left ventricular mass, RVSV, RVEF, 2D-RVFWLS and 3D-RVFWLS in mild group, moderate group and severe group were decreased gradually, with statistical significance (P < 0.05). Myocardial fibrosis was strongly negatively correlated with 3D-RVFWLS (r = -0.834, P = 0.000), moderately negatively correlated with 2D-RVFWLS(r = -0.651, P = 0.000), RVFAC (r = -0.465, P = 0.000), TAPSE (r = -0.473,P = 0.000), RVEF (r = -0.407, P = 0.000), right ventricular length diameter (r = -0.353, P = 0.000), S ""(r = -0.252, P = 0.000), RVEDV (r = -0.248, P = 0.000), RVSV (r = -0.364,P = 0.000), left ventricular mass (r = -0.305, P = 0.000) were weakly negative correlated, and had no significant correlation with other echocardiographic parameters. The optimal cut-off value of 3D-RVFWLS for the detection of severe RV myocardial fibrosis was 10.05%, the sensitivity was 85.33%, the specificity was 99.27%, and the AUC value was 0.91 (P = 0.000).The best cutoff value of 2D-RVFWLS in the detection of severe RV myocardial fibrosis was 10.31%, the sensitivity was 72.65%, the specificity was 80.46%, and the AUC value was 0.82 (P = 0.000).Other echocardiographic parameters have no diagnostic?value for severe RV myocardial fibrosis (AUC value was 0.21-0.42, P < 0.05). Conclusion:3D-RVFWLS is superior to 2D-RVFWLS and conventional echocardiographic indicators of right ventricular function in the evaluation of RV myocardial fibrosis in patients with end-stage heart failure, and 3D-RVFWLS May be the most reliable echocardiographic parameter to predict the severity of RV myocardial fibrosis in patients with end-stage heart failure.