Echocardiographic Assessment Of Patient-Prosthesis Mismatch After Mitral Valve Replacement

Objective:To explore the clinical significance of different evaluation methods of mitral valve mismatchMethods:A retrospective analysis of 166 patients（aged 56±11 years old,45 males and females）who underwent simple mitral valve mechanical valve replacement at Fujian Medical University Union Hospital from January 2016 to December 2019.All patients had complete clinical and echocardiographic follow-up（median16 months;range 15–months）.The effective orifice area（EOA）is measured by continuous equation（CE）,pressure half time（PHT）by echocardiography,and the reference value method is based on the EOA in vivo reference value reported in the literature and manufacturer’s instructions,and Using the effective orifice area index（EOAI）as an index,the patient-prosthesis mismatch（PPM）was defined as EOAI≤1.2cm²/m²,to calculate incidence and the patients were divided into two groups according to EOAI:no PPM group and PPM group,and the basic information,preoperative and postoperative echocardiographic results of the two groups were compared.Person correlation was to evaluate the relationship between EOAI_CE、EOAI_PHT and EOAI_R and the correlation with postoperative pulmonary systolic blood pressure.Pulmonary hypertension was defined as systolic pulmonary arterial pressure>40mm Hg.Comparing the preoperative and postoperative pulmonary hypertension rates in the no PPM group and the PPM group defined by the three methods,which method of evaluating PPM was more advantageous.Univariate linear regression analysis was used to test the linear relationship,and multiple regression analysis was used to analyze the statistically significant variables in the univariate analysis to analyze the predictive factors of postoperative pulmonary hypertension.Results:（1）The incidence of PPM in 166 patients was significantly different due to different calculation methods of EOA,ranging from 7%of PHT method,49%of EOA_Rmethod to 62%of CE method（p<0.05）.（2）At the time of PPM,only in the PPM group in the CE method,there was no downward trend in pulmonary systolic blood pressure（43±8mm Hg,p=0.001）.（3）Low correlation between EOAI_CEand EOAI_R（r<0.5,ICC<0.8）,poor correlation between EOAI_CE and EOAI_PHT,and EOAI_PHT and EOAI_R（both r<0.3,ICC<0.8）.（4）EOAI_CE was moderately negatively correlated with postoperative pulmonary systolic pressure（r=-0.658,p<0.001）,while EOAI_PHT and EOAI_R were not significantly correlated with postoperative pulmonary systolic pressure.（5）Only in EOAI_CE,it is more advantageous to evaluate the incidence of pulmonary hypertension in the no PPM group and the PPM group:the incidence of postoperative pulmonary hypertension in the no PPM group is significantly lower than before（24%vs62%,p<0.001）,while the PPM group has a downward trend not significant（61%vs72%,p=0.025）..（6）TR degree≥moderate,mitral valve EOAI_CE,and mean mitral valve pressure difference（MPG）were found to be predictors of postoperative pulmonary hypertension（p=0.002,p<0.001,p=0.001,p=0.003）.In contrast,EOAI_PHT and EOAI_Rwere not used as predictors of postoperative pulmonary hypertension（p=0.543,p=0.474）.Conclusion:（1）There are significant differences in the incidence of patient-prosthesis mismatch defined by the continuous equation,pressure half time and the reference method.（2）The continuous equation defines that patient-prosthesis mismatch is related to postoperative pulmonary systolic blood pressure,and has good clinical significance.（3）Patient-prosthesis mismatch is an independent predictor of postoperative pulmonary hypertension.