The percutaneous transcatheter mitral valve repair is an alternative therapy for severe symptomatic mitral regurgitation in patients with high surgical risk. Echocardiographic guidance, In addition to fluoroscopy is mandatory. Good echocardiographic knowledge of both the imager and the interventionist is essential for a clear communication during the procedure.
As standardized approach improves safety and helps to ensure the success of the procedure. This video shows our echocardiographic guidance, including views and measurements highlighting crucial steps during the intervention. Exclude pericardial effusion before transseptal puncture.
If a small pericardial effusion is present measure the maximal end-diastolic echolucent space in the four-chamber view with a focus on the right ventricle, a mid-oesophageal right ventricular inflow-outflow view, and the long axis view. Show the short axis view with focus on the left atrial appendage, sweep then at 40 to 60 degrees and rotate the probe anticlockwise to show the left upper pulmonary vein. Assess the flow in the right upper pulmonary vein by sweeping at 90 to 110 degrees.
Find the best intercommissural view at 50 to 70 degrees. Take a perpendicular view in the three segments with and without color doppler and measure the length of the posterior mitral leaflet. Then check the leaflet morphology again.
Assess the transmitral pressure gradient with continuous wave doppler in the long axis view at 120 to 140 degrees, take a 3D color doppler data set, or a wide sector zoom image with color and measure the 3D-vena contracta. Without color, use the 3D volume to measure the mitral valve area Show the 3D en-face surgical atrial view of the mitral valve Perform a 180 degree clockwise rotation into the 3D en-face surgical view to have a result and an equal sequence of segments in both views. Finally, take a bicaval view at 90 to 110 degrees with X-plane to show the aortic valve, for the transseptal puncture.
Show a bicaval view combined with a short access view, ensure the aortic valve is visible to avoid aortic injury. Make sure the puncture site is slightly superior and posterior. Once the transseptal needle leads to tenting of the interatrial septum, measure the puncture height in the 4 chamber view in mid-systole.
After transseptal puncture always exclude pericardial effusion in the 4 chamber view. Show a short access view with the focus on the left atrial appendage and pulmonary vein to visualize the entering of the stiff guidewire into the left upper pulmonary vein. Visualize the tenting advancement of the Steerable Guide Catheter with the dilator in the short access view with continuous 2D-echocardiography and fluoroscopic guidance to avoid injuries to the left atrial wall.
show the operator the short access view and the bicaval view to position the Steerable Guide Catheter, in the direction of the left ventricle, Take a 3D volume, including the interatrial septum, the left lateral ridge and the mitral valve, and ensure that the left lateral ridge is visible because protrusion of the clip delivery system is common. Otherwise, choose the short access view and the long axis view to ensure the clip delivery system does not have contact with the ridge in the leftatrial wall. Check that the clip delivery system is positioned perpendicularly to the coaptation line to guarantee a correct trajectory.
Show the intercommissural view in 2D at about 60 degrees to display the medial-lateral plane and the long axis view at 120 to 140 degrees to identify the anterior-posterior plane of the mitral valve. Take the 3D en-face view to show a perpendicular positioning of the arms to the coaptation line. In the event of poor image quality, show an intercommissural view combined with the long access view.
Choose the intercommissural view combined with the long axis view to visualize the advancing of the clip delivery system into the left ventricle. Verify in the 3D en-face view that the clip arms are still in the planned position, as a rotation of the clip while crossing the valve is frequent. Record the grasping of the leaflets in the intercommissural view, combined with the long axis view or in the long axis view only Ensure continuous visualization of leaflet insertion to avoid rolling of the leaflets or the chordae.
Rotate the TEE probe medially and laterally to the clip or use X-plane with color doppler, to find eccentric jets close to the clip. Measure the mean pressure gradient across the mitral valve Evaluate the PW flow in the pulmonary veins. Use the 3D en-face view of the mitral valve or a transgastric short axis view of the mitral valve to show the double orifice.
Finally, if the result is satisfactory check leaflet insertion in 2D. After releasing the clip from the clip delivery system, repeat the last five steps. Two randomized trials, MITRA-FR and COAPT, compared to the percutaneous edge to edge mitral valve repair with optimal medical therapy, assessing the efficacy and safety of the device in patients with systolic heart failure and severe secondary mitral regurgitation.
Although MITRA-FR did not show any significant benefit for the intervention group with respect to the composite endpoint at 12 months, COAPT showed significant superiority of the device in terms of mortality and rehospitalization rates compared to conservative treatment alone at 24 months. But there were relevant differences in the inclusion criteria of the two trials in the MITRA-FR trial mitral regurgitation was overall less severe and ventricular dilatation was more pronounced than in the COAPT trial. This may explain the different outcomes observed in these two trials.
In the CLASP study, another percutaneous edge to edge mitral valve repair device showed feasibility and acceptable safety in the treatment of severe mitral regurgitation. Furthermore, the study showed a significant reduction of severe mitral regurgitation as well as clinical and statistical, significant improvement in functional status, exercise capacity and quality of life. A critical appraisal of echocardiographic assessment of mitral regurgitation, especially a functional one is still to be done.
Due to missing validation of 2D vena contracta and EROA in multiple jets, neither 2D vena contracta nor EROA and regurgitant volume/fraction by PISA is recommended after edge to edge repair. Thresholds for 3D vena-contracta were first introduced in 2019. This parameter gained a relevant role for the quantification of valve regurgitation, but it is highly dependent on good image quality.
Therefore, semi-quantitative parameters as signal intensity of the continuous doppler of the mitral regurgitation jet, pulmonary vein flow pattern and mitral inflow pattern are still necessary. We use our step by step echo guidance during every intervention. In our opinion, an accurate echo-assessment is essential for a good result and to reduce complications during the procedure.
We hope this video can help both young and experienced cardiologists to have a better understanding of the echo-guidance during transcatheter edge-to-edge mitral valve repair.
