Objective To investigate the changing tendency of mitral valve coaptation area and coaptation index of moderate mitral regurgitation （MR） in a dog experiment，and provide evidence for predicting long-term surgical results. Methods Real-time three-dimensional transesophogeal echocardiography （RT-3D-TEE） images were obtained in 15 dogs via Philips IE33 echocardiography system，and animal experiment model was established. RT-3D-TEE images were taken by gradually narrowing the ascending aorta and increasing left ventricular pressure till moderate MR. Original data were analyzed using Philips Qlab 7.0 three-dimensional quantification software，and mitral valve coaptation area and coaptation index were calculated. Specimen coaptation index of the mitral leaflets was calculated after the animal experiment. Cutoff values of coaptation index and left ventricular pressure were calculated by receiver operating characteristic （ROC） curve. Results There was statistical difference in coaptation area （198±50）mm2 vs. （123±36）mm2，P＜0.05） and coaptationindex （0.25±0.06 vs. 0.13±0.03，P＜0.05） between non-MR state and MR status of the 15 dogs. The area under the ROC curve of coaptation index and moderate MR was 0.879±0.019 with 95% CI 0.843 to 0.916，and the cutoff value was 0.213（P＜0.05）. The area under the ROC curve of left ventricular pressure and moderate MR was 0.882±0.021 swith 95% CI 0.840 to 0.923，and the cutoff value was 225 （P＜0.05）. There was no statistical difference between specimen mitral valve area and early-diastolic mitral leaflet area，specimen coaptation area and coaptation area，specimen coaptation index and coaptation index （P＞0.05）. Early-diastolic mitral leaflet area was significantly correlated with specimen mitral valve area （r=0.937，P＜0.05）. Coaptation area was significantly correlated with specimen coaptation area （r=0.917，P＜0.05）. Coaptation index was significantly correlated with specimen coaptation index （r=0.946，P＜0.05）. The correlation of coaptation index and specimen coaptation index was higher than those of coaptation area and specimen coaptation area，and earlydiastolic mitral leaflet area and specimen mitral valve area. Conclusions Both coaptation area and coaptation index significantly decrease in MR status. Coaptation index can more precisely reflect MR degree，and provide reference for prognosis of mitral valve repair. RT-3D TEE can accurately measure mitral valve coaptation area and coaptation index.
Objective To analyze the echocardiographic characteristics of above grade 3+ mitral regurgitation (MR) patients by 3D transesophageal echocardiography (3D-TEE) in transcatheter edge-to-edge repair (TEER) and compare the intervention rate of TEER treatment in patients with different risk stratification. Methods We retrospectively analyzed the clinical data of 91 patients with above grade 3+ MR in Anzhen Hospital between June 2021 and April 2022. There were 45 males and 46 females aged 66.5±15.9 years. According to pathogenesis, the patients were divided into different anatomical groups and risk stratification groups. There were 34 patients in a simple degenerative group (simple DMR group), 28 patietns in a complex disease group (Complex group), 14 patients in a simple ventricular functional reflux group (simple VFMR group), 9 patients in a simple atrial functional reflux group (simple AFMR group), and 6 patients in a mixed functional reflux group (mixed FMR group). All patients were examined with a unified standard of transthoracic echocardiography (TTE) and 3D-TEE to compare the characteristic three-dimensional structural changes of the mitral valve in each group. According to the three partition strategy of preoperative anatomical evaluation of TEER, the risk stratification was conducted for the enrolled patients, which was divided into three regions from light to heavy: green area, yellow area, and red area. TEER treatment intervention rate of patients with different risk stratification was calculated. Results Ant leaf angle and post leaf angle were negative in the simple DMR and Complex groups, and non-planar angle, prolapse height and prolapse volume were higher than those of the other groups (P=0.000). Ant leaf angle and post leaf angle were positive in the VFMR group and the mixed FMR group. Anterior and posterior (AP) diameter of valve ring (P=0.036), tenting height and tenting volume were higher than those of other groups (P=0.000). AP diameter, tenting height and tenting volume were changed mildly in patients with simple AFMR. MR patients in red and yellow zone achieved a 28.1% TEER intervention rate.Conclusion Standardized TTE and TEE examinations are crucial for the qualitative and quantitative diagnosis of MR in the echo core-lab. 3D-TEE mitral valve parameter can help determine the exact pathogenesis of MR and to improve the interventional rate of challenging MR patients.