Visualization of CMR-based Anatomic Models in Virtual Reality to Evaluate Candidacy for Transcatheter Pulmonary Valve Replacement in Patients with Native of Surgically Repaired Right Ventricular Outflow Tracts (RF_SA_491)

Saturday, February 1, 2025

11:30 AM – 11:40 AM East Coast USA Time

Location: Blue Room PreFunction

Presenting Author(s)

HW

Hunter C. Wilson, MD

Assistant Professor of Pediatrics
Emory University

Co-Author(s)

Sassan Hashemi, MD

Research Scientist
Children's Healthcare of Atlanta
JK

James A. Kuo, MD

Assistant Professor of Pediatrics
Emory University School of Medicine
DK

Dennis Kim, MD, PhD

Professor of Pediatrics
Emory University
Timothy Slesnick, MD

Pediatric Cardiologist
Children's Healthcare of Atlanta
WM

William A. McEachern, MD

Assistant Professor of Pediatrics
Emory University/Children's Healthcare of Atlanta
RL

Ronald Allen Ligon, MD

Assistant Professor of Pediatrics
Emory University

Background: CMR with MRA is commonly used to support clinical indication for pulmonary valve replacement (PVR) in patients with significant pulmonary insufficiency. However, industry guidelines currently require additional cardiac CT (CCT) for “fit analysis” to evaluate candidacy for transcatheter pulmonary valve replacement (TPVR) using new valve technologies in patients with native or surgically repaired right ventricular outflow tracts (RVOTs). We aimed to 1) assess feasibility of generating 3-dimensional (3D) virtual RVOT models from clinical MRA datasets in patients undergoing consideration for TPVR; and, 2) compare determination of TPVR candidacy with visualization of RVOT and valve models in virtual reality (VR) compared to disposition suggested by industry fit analysis and ultimate clinical outcome of TPVR.

Methods: We included patients with native or surgically repaired RVOTs with clinically significant pulmonary insufficiency at our center with both CMR and CCT datasets and known TPVR outcome. Cardiac MRAs were completed in each patient on a 1.5T magnet with 0.2 mmol/kg gadolinium contrast administered to acquire a 1.2-1.4 mm isotropic IR-GRE dataset, gated to systole. Virtual models of patient RVOTs and left coronary systems were created using segmentation software. Virtual Medtronic Harmony TPV 25 mm™ and Edwards SAPIEN 3 valve with Alterra Adaptive Prestent™ valves were constructed using industry reported dimensions in 1:1 anatomic scale and visualized with RVOT models in VR. A congenital cardiologist with expertise in catheterization blinded to CCT fit analysis results and clinical outcome visualized the models and valves in VR and made determination of TPVR candidacy.

Results: 16 Patients (N=7 males, 44%) with mean age 16.1±3.0 years were identified. All CMR datasets were adequate for VR model creation. The mean time for model creation was 21.3±4.4 minutes (Figure). There were 15/16 (94%) of patients whose anatomies were felt to be amenable to TPVR when viewed in VR; one patient’s dataset was inconclusive. There were 3/16 (19%) “screen failures” of industry-derived fit analyses derived from CCT datasets. Of the cohort, 14/16 (88%) patients ultimately underwent TPVR (Table). One patient who passed both VR and industry screening did not undergo TPVR secondary to presence of an LPA stent (patient 7); one patient early in the institutional experienced passed VR screening but failed industry screening and was not offered TPVR (patient 14). Two patients who passed VR screening but not industry screening successfully underwent TPVR.

Conclusion: Generation of 3D models of clinical MRA datasets and visualization in a VR environment is feasible and allows for conceptualization of valve overlap with patient specific anatomy. VR-aided models may serve as an adjunct means of evaluating TPVR candidacy using new valve technologies but should be judiciously used in conjunction with other clinical and imaging data.

Right ventricular outflow tracts were segmented from MRA datasets and virtual models were created (Panel A). Scale virtual models of a Harmony TPV 25 mm™ valve (purple valve, left of panel) and Edwards SAPIEN 3 valve with Alterra Adaptive Prestent™ (green valve, right of panel) were built using industry specified dimensions (Panel B). The virtual Harmony TPV 25 mm™ valve is superimposed on a patient-specific 3D RVOT model to evaluate valve fit and candidacy for transcatheter pulmonary valve replacement (Panel C, left coronary artery system shown in yellow).
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