Modeling of the Tricuspid Valve and Right Ventricle in Hypoplastic Left Heart Syndrome With a Fontan Circulation

Abstract

Background: In hypoplastic left heart syndrome, tricuspid regurgitation (TR) is associated with circulatory failure and death. We hypothesized that the tricuspid valve (TV) structure of patients with hypoplastic left heart syndrome with a Fontan circulation and moderate or greater TR differs from those with mild or less TR, and that right ventricle volume is associated with TV structure and dysfunction. Methods: TV of 100 patients with hypoplastic left heart syndrome and a Fontan circulation were modeled using transthoracic 3-dimensional echocardiograms and custom software in SlicerHeart. Associations of TV structure to TR grade and right ventricle function and volume were investigated. Shape parameterization and analysis was used to calculate the mean shape of the TV leaflets, their principal modes of variation, and to characterize associations of TV leaflet shape to TR. Results: In univariate modeling, patients with moderate or greater TR had larger TV annular diameters and area, greater annular distance between the anteroseptal commissure and anteroposterior commissure, greater leaflet billow volume, and more laterally directed anterior papillary muscle angles compared to valves with mild or less TR (all P <0.001). In multivariate modeling greater total billow volume, lower anterior papillary muscle angle, and greater distance between the anteroposterior commissure and anteroseptal commissure were associated with moderate or greater TR ( P <0.001, C statistic=0.85). Larger right ventricle volumes were associated with moderate or greater TR ( P <0.001). TV shape analysis revealed structural features associated with TR, but also highly heterogeneous TV leaflet structure. Conclusions: Moderate or greater TR in patients with hypoplastic left heart syndrome with a Fontan circulation is associated with greater leaflet billow volume, a more laterally directed anterior papillary muscle angle, and greater annular distance between the anteroseptal commissure and anteroposterior commissure. However, there is significant heterogeneity of structure in the TV leaflets in regurgitant valves. Given this variability, an image-informed patient-specific approach to surgical planning may be needed to achieve optimal outcomes in this vulnerable and challenging population.

The Second Interstage Period Is Just as “Risky” as the First in HLHS

“…The tricuspid valve poses a major challenge in this patient population with ongoing efforts to better delineate abnormalities of the valve with concurrent improvement in surgical techniques. 8 Catheter-based interventions are likely to evolve as interventional cardiologists gain more expertise with the implantation of mitral valve clips. 9 However, a durable solution to this problem does not appear to be on the horizon.…”

Opportunities of 3-Dimensional Modeling and Quantitative Valve Analysis to Improve Valve Interventions

“…Nam et al 1 from the Children’s Hospital of Philadelphia present a comprehensive analysis of the geometric and anatomical factors of the tricuspid valve in single ventricle patients following a Fontan procedure with a focus on mechanisms of valve regurgitation. The authors are to be congratulated on this analysis and the very important body of work that has come out of the group led by Dr Jolly and collaborators on the enhancement and utilization of Slicer as an approach to segment, quantify and analyze AV valves in children.…”