Rest and Dobutamine stress echocardiography in the evaluation of mid-term results of mitral valve repair in Barlow's disease

Clinical Impact of Computational Heart Valve Models

This paper provides a review of engineering applications and computational methods used to analyze the dynamics of heart valve closures in healthy and diseased states. Computational methods are a cost-effective tool that can be used to evaluate the flow parameters of heart valves. Valve repair and replacement have long-term stability and biocompatibility issues, highlighting the need for a more robust method for resolving valvular disease. For example, while fluid-structure interaction analyses are still scarcely utilized to study aortic valves, computational fluid dynamics is used to assess the effect of different aortic valve morphologies on velocity profiles, flow patterns, helicity, wall shear stress, and oscillatory shear index in the thoracic aorta. It has been analyzed that computational flow dynamic analyses can be integrated with other methods to create a superior, more compatible method of understanding risk and compatibility.

Stress echocardiographic assessment of mitral valve function repaired using rough-zone trimming

Background

We invented novel mitral valve repair technique; rough-zone trimming procedure (RZT) for anterior mitral valve prolapse. Prolapse site was resected in obtuse triangle shape and sutured edges to creates deep coaptation and improves regurgitation. Though it is simple and reproducible technique, functional mitral stenosis is a risk. Valve function and hemodynamics were investigated using dobutamine stress echocardiography (DSE) in patients after mitral valve repair using RZT.

Methods

Patients underwent RZT for the anterior mitral valve (AML, n = 10), quadrangular resection (QR) of the posterior mitral valve (PML; n = 4), RZT + QR of bileaflet valves (bileaflet; n = 4) and healthy individuals (control; n = 10) and were assessed by DSE (doses up to 20 μg/Kg/min). Echocardiographic data including mitral valve area (MVA), mitral valve mean pressure gradient (MVmeanPG), and systolic pulmonary artery pressure (sPAP) were measured at rest and at peak stress.

Results

Rest/stress MVA (cm²), MVmeanPG (mmHg) and sPAP (mmHg) were 2.8 ± 0.4 and 3.4 ± 0.3, 3.3 ± 1.1 and 7.4 ± 4.1, and 25.7 ± 4.7and 49.1 ± 4.1, respectively, in the AML group. Dobutamine stress increased all parameters but not to pathological levels. The results were similar to those of the other groups after mitral valve repair, whereas MVA was larger and MVmeanPG was lower in the control than in the AML group.

Conclusions

Valve repair using RZT does not pathologically obstruct the mitral valve, either at baseline or during dobutamine stress, and does not affect valve hemodynamics and reserve.

Mitral valve repair using multiple MitraClips®: a dobutamine stress echocardiography evaluation

AIMS

The haemodynamic effect of mitral valve (MV) repair using multiple MitraClips® (MC) has not been investigated. The aim of the study was to evaluate the stress performance of MV repair with MC.

METHODS AND RESULTS

Twenty consecutive patients (77±7 years, 13 men [65%]) after implantation of >2 MitraClips® were subsequently evaluated with dobutamine stress echocardiography (DSE). After MC implantation, mean transmitral pressure gradient (TPG) (3.3±0.8 mmHg vs. 4.0±0.6 mmHg; p<0.001) and mitral valve orifice area (2.9±0.3 cm2 vs. 3.9±0.4 cm2; p<0.001) were significantly increased during DSE showing a physiological behaviour effect of the MV. LVEF (41±18% vs. 46±21%; p<0.001) and systolic pulmonary artery pressure (42±11 mmHg vs. 44±12 mmHg; p=0.014) increased significantly. The degree of MR was stable during stress (p=0.68). At linear regression, only baseline peak TPG was related to stress mean TPG (p<0.001; Beta 0.816; 95% CI: 0.368-0.918).

CONCLUSIONS

MV repair using MitraClips® should be performed with the aim of maximal reduction of MR degree. MV repair using MC may not lead to pathological degrees of MV stenosis. Although the TPG is significantly increased during stress, it never reaches pathological levels and is always accompanied by a significant increase in MVOA. The degree of residual MR remains unchanged during maximal pharmacological stress.