P135 - SYMMETRIC LEAFLET EXPANSION WITH MILD PROGRESSIVE LEAFLET TETHERING IS A NORMAL DEVELOPMENTAL FEATURE OF TRICUSPID VALVE MATURATION DURING YOUTH: A QUANTITATIVE THREE-DIMENSIONAL ECHOCARDIOGRAPHY (3DE) STUDY

Friday, October 28, 2022

3:40 PM – 3:50 PM EDT

Location: Room 201

Presenter(s)

Martha M. Moran

Clinical Fellow
Stollery Children's Hospital
University of Alberta
Edmonton, Alberta, Canada

First Author(s)

Martha M. Moran

Clinical Fellow
Stollery Children's Hospital
University of Alberta
Edmonton, Alberta, Canada

Author(s)

TA

Tuqa Al Lawati

Edmonton, Alberta, Canada

Senior Author(s)

NK

NEE S. KHOO

Associate Professor, Pediatric Cardiology, Department of Paediatrics, Faculty of Medicine & Dentistry
Edmonton, Alberta, Canada
TC

Timothy Colen

Assistant Professor
Division of Pediatric Cardiology, Department of Pediatrics, Stollery Children's Hospital, University of Alberta
Edmonton, Alberta, Canada

Author(s)

RT

Richard Thompson

Professor
Department of Biomedical Engineering,University of Alberta
Edmonton, Alberta, Canada
JG

Justin Grenier

Staff
Department of Biomedical Engineering, University of Alberta
Edmonton, Alberta, Canada

Senior Author(s)

LILY LIN

Pediatric Cardiologist
CPCA
University of Alberta
Edmonton, Alberta, Canada

Supervisor(s)

LILY LIN

Pediatric Cardiologist
CPCA
University of Alberta
Edmonton, Alberta, Canada

Background: Recent study on mitral valve development in healthy children suggest developmental differences between leaflets, with greater relative expansion of the anterior leaflet while maintaining annular saddle shape. To our knowledge, there is no published literature on developmental changes of the tricuspid valve (TV). In adult tricuspid valves, pathologic series suggest a qualitatively larger anterior leaflet with variability in the size of both posterior and septal leaflets. Using 3DE we aim to quantify developmental changes of the TV annulus and leaflets.

METHODS AND RESULTS: This cross-sectional study used prospectively acquired TV 3DE volumetric datasets in 51 healthy children between 0 and 18 years of age. Using a custom designed TV MATLAB software, annular dimensions, sphericity index (lateral width/anteroposterior annular dimension ratio) and bending angle were analyzed in mid-systole. TV leaflets were segmented into anterior (AL), septal (SL) and posterior (PL) to measure regional areas, prolapse and tethering volumes. Subjects were divided into 3 age groups: 0-5, 6-12 and 13-18 years. Between group comparison was performed using the Kruskal-Wallis test with significance at p< 0.05.
RESULTS
Between group comparisons for TV annulus and leaflet 3DE parameters were detailed in Table 1. With increasing age and size, TV annulus enlarged in both the anteroposterior and lateral dimensions. This annular growth occurred symmetrically such that annular sphericity index remained unchanged. Furthermore, the “saddle-shape” geometry of the annulus, quantified using the annular bending angle, was also maintained across groups. There was size-proportionate expansion of TV leaflets with increasing age (stable total leaflet area indexed by BSA). Individual leaflets also expanded symmetrically. There was no significant change in leaflet prolapse with increasing age, but a modest increase in leaflet tethering (p=0.01) was demonstrated. This progressive leaflet tethering was more pronounced in the AL and SL over PL.

Conclusion: Our study suggests that preservation of annular geometry occurred with normal TV maturation. Contrary to adult TV pathologic series, there was symmetric leaflets expansion during youth. Interestingly, there was also concurrent mild progressive leaflet tethering. Whether leaflet tethering is the result of physiologic differences in growth potential between leaflets and subvalve tensor apparatus or an adaptive biologic stimulus for leaflet growth, warrants further exploration.