The correlation between the coaptation height of mitral valve and mitral regurgitation after mitral valve repair

A total of 20 patients were treated with the MV at Capital medical university affiliated Beijing anzhen hospital between Sep 2014 and Jun 2015. Transesophageal echocardiography (TEE) assessment assessment were routinely performed before the intervention to assess LVEF, mitral valve morphology and mitral regurgitation grade, and evaluation of factors that may contraindicate the procedure. Transthoracic echocardiographic (TTE) examination was performed after the operation. This study was approved by the ethics committee of Capital medical university affiliated Beijing Anzhen hospital. The informed consent was obtained form all the included patients.

All operations included in this study were performed via a median sternotomy approach. Cardiopulmonary bypass was established by ascending aortic and bicaval cannulation. The aorta was cross-clamped and cardiac asystole was achieved using intermittent antegrade and retrograde cardioplegia. Posterior leaflet prolapse was primarily repaired by leaflet resection. The resection size and shape were determined by a surgeon in charge of each case. Neochordal placement was added if necessary. Ring annuloplasty was performed in all cases. The type of ring was chosen based on surgeon’s preference. The size of ring was determined by sizing the area of anterior leaflet using prosthetic sizers made by each manufacturer.

The surgical procedures with prosthetic ring annuloplasty were performed in all patients. Prosthetic ring annuloplasty was performed in 5 cases with 30-mm prosthetic ring (Edwards physio 2), 8 cases with 32-mm prosthetic ring (Edwards 5200), 5 cases with 34-mm prosthetic ring (Edwards physio 2) and 2 cases with 36-mm prosthetic ring (Edwards physio 4450).

TTE was performed using commercially available ultrasound systems (E33; Philips, Netherlands) equipped with an S5–1 transducer, and 2D, M-mode and Doppler data were acquired with the patient in the left lateral decubitus position. Transthoracic echocardiography was performed at 3 months and 12 months postoperatively. TEE with X7-2 t transducer was applied. The TEE view for the measurement was 3-chamber view and the middle square of mitral apparatus in short axis (Fig. 1). Mitral valve short-axis dimension (MVd) and Coaptation height (CH) at endsystole were measured (Fig. 1). The coaptation height was defined as the length between the free edge of the leaflet and the anterior and posterior lobes to left atrial surface level at end-systole stage. Carpentier typing was used to unify the mitral leaflet partition. The posterior lobe is divided into three leaves, the lateral fan as P1, the middle fan leaf as P2 and the medial fan leaf as P3. The corresponding anterior lobe was also divided into three parts, the lateral 1/3 part as A1, the middle 1/3 as A2, the medial 1/3 as A3. 20 cases in the operation room under anesthesia were examined by TEE.The Height of the corresponding section were set. The A2P2 was measured by four chamber view of the middle esophagus. The A1P1 was measured by five chamber view of the middle esophagus. The A3P3 was measured by deep esophageal short four chamber view showing coronary sinus. Three cardiac cycles were selected to measure the corresponding height. The mitral regurgitation grade was determined according to the following scale: 0, no or trivial mitral regurgitation; 1+, mild; 2+, mild to moderate mitral regurgitation; 3+, moderate to severe mitral regurgitation; and 4+, severe mitral regurgitation. The coaptation height (the longest coaptation height of the anterior and posterior leaflets) was measured in early systole.

The mean age of all patients was 52.45 ± 14.26 years and 11 patients (55%) were women. In the 20 cases studied, mitral regurgitation was degree 1 in 2 patients, degree 2 in 4 cases, and degree 3 in 14 cases before the operation. All patients had a posterior middle scallop prolapse, the mean LVEF was 62.75 ± 7.94%. All patients underwent MVP with prosthetic ring. Pre-operative and operative data are shown in Table 1. In the 20 cases studied, mitral regurgitation was 0 in 14 patients, 1 in 3 cases, and 2 in 3 cases 12 months after the operation.

Table 1 shows the preoperative and postoperative values of EF, MVd. The values of LVEF and MVd were not significantly changed. However, MVd showed only increase trend after the surgery. In Fig. 2, CH of A1P1, A2P2, A3P3 was increased significantly. Among those stated index, the average values of CH (A1P1, A2P2, A3P3) after heart resuscitation showed a statistically significant negative correlation with degree of mitral regurgitation 12 months after the operation. (p < 0.05 r = 0.81) (Fig. 3).