Quantitative in vivo assessment of human mitral valve coaptation area after undersized ring annuloplasty repair for ischemic mitral regurgitation

Objectives

Long-term outcomes of mitral valve repair procedures to correct ischemic mitral regurgitation remain unpredictable, due to an incomplete understanding of the disease process and the inability to reliably quantify the coaptation zone using echocardiography. Our objective was to quantify patient-specific mitral valve coaptation behavior from clinical echocardiographic images obtained before and after repair to assess coaptation restoration and its relationship with long-term repair durability.

Methods

To circumvent the limitations of clinical imaging, we applied a simulation-based shape-matching technique that allowed high-fidelity reconstructions of the complete mitral valve in the systolic configuration. We then applied this method to an extant database of human regurgitant mitral valves before and after undersized ring annuloplasty to quantify the effect of the repair on mitral valve coaptation geometry.

Results

Our method was able to successfully resolve the coaptation zone into distinct contacting and redundant regions. Results indicated that in patients whose regurgitation recurred 6 months postrepair, both the contacting and redundant regions were larger immediately postrepair compared with patients with no recurrence (P < .05), even when normalized to account for generally larger recurrent valves.

Conclusions

Although increasing leaflet coaptation area is an intuitively obvious way to improve long-term repair durability, this study has implied that this may not be a reliable target for mitral valve repair. This study underscores the importance of a rigorous understanding of the consequences of repair techniques on mitral valve behavior, as well as a patient-specific approach to ischemic mitral regurgitation treatment within the context of mitral valve and left ventricle function.

Left ventricular vortex analysis by high-frame rate blood speckle tracking echocardiography in healthy children and in congenital heart disease

Background

High-frame rate blood speckle tracking (BST) echocardiography is a new technique for the assessment of intracardiac flow. The purpose of this study was to evaluate the characteristics of left ventricular (LV) vortices in healthy children and in those with congenital heart disease (CHD).

Methods

Characteristics of LV vortices were analyses based on 4-chamber BST images from 118 healthy children (median age 6.84 years, range 0.01-17 years) and 43 children with CHD (median age 0.99 years, range 0.01-14 years). Both groups were compared after propensity matching. Multiple linear regression was used to identify factors that independently influence vortex characteristics.

Results

Feasibility of vortex imaging was 93.7% for healthy children and 95.6% for CHD. After propensity matching, there were no overall significant differences in vortex distance to apex, distance to interventricular septum (IVS), height, width, sphericity index, or area. However, multiple regression analysis revealed significant associations of LV morphology with vortex characteristics. Furthermore, CHD involving LV volume overload and CHD involving LV pressure overload were both associated with vortices localized closer to the IVS.

Conclusions

LV vortex analysis using high-frame rate BST echocardiography is feasible in healthy children and in those with CHD. As they are associated with LV morphology and are modified in some types of CHD, vortices might yield diagnostic and prognostic value. Future studies are warranted to establish applications of vortex imaging in the clinical setting.