Conductance catheterization compared to cardiac MRI environment in acquisition of pressure and volume loops for the physiological assessment of ventricular functionality (RF_FR_347)

Friday, January 31, 2025

11:40 AM – 11:50 AM East Coast USA Time

Location: Blue Room PreFunction

Presenting Author(s)

MG

Maria Gusseva, PhD

Postdoctoral Researcher
UT Southwestern Medical Center

Primary Author(s)

MG

Maria Gusseva, PhD

Postdoctoral Researcher
UT Southwestern Medical Center

Co-Author(s)

Daniel A. Castellanos, MD

Assistant Professor of Pediatrics
Boston Children's Hospital
PH

Peter E. Hammer, PhD

Scientist
Boston Children’s Hospital
Sunil J. Ghelani, MD

Assistant Professor of Pediatrics
Boston Children's Hospital
RC

Ryan Callahan, MD

Cardiologist
Children’s Hospital of Philadelphia
Tarique Hussain, MD, PhD

Professor
UT Southwestern
RC

Radomir Chabiniok, MD, PhD

Assistant Professor
UT Southwestern Medical Center
NT

Nikhil Thatte, MD

Boston Children's Hospital

Background: Pressure Volume Loops (PVL) can be obtained via conductance catheterization (C-Cath) or by combining fluid-filled catheter (FFcath) pressure with cardiac MRI data¹. C-Cath remains the gold-standard for dynamic PVL acquisition but is limited by need for specialized equipment and unreliable volumetry^2,3, while FFcath+MRI can suffer from time-synchronization (Tsyn) errors leading to nonphysiological PVL shapes⁴. Congenitally corrected transposition of the great arteries (ccTGA) is a unique physiology often treated with anatomic double switch operation. Subpulmonary left ventricular (LV) Pressure-Volume loops (PVLs) energetics can help in assessment for LV preparedness for surgery, in particular with measurement of biventricular stroke work (SW). This study compares C-cath, FFcath+MRI, and model-derived PVL metrics in patients with ccTGA.

Methods: Patients with ccTGA who underwent a diagnostic conductance catheter were included. C-cath LV PVLs were recorded. Routine FFcath pressures were recorded in the LV and pulmonary artery. MRI was performed 1-2 days prior to C-cath. LV volumes were segmented using a motion tracking algorithm⁵to obtain LV time-vs-volume curves. FFcath and MRI data were used to build patient-specific biomechanical models of LVs to obtain model-derived PVLs^6,7. Parameters of the mechanical laws were calibrated such that simulated pressure and volume corresponded to the measured LV end-systolic volume (ESV), end-diastolic volume (EDV) and peak systolic pressure⁸.For each patient three types of PVLs were obtained: 1) C-cath, 2) FFcath+MRI⁴, and 3) model-derived. SW, maximum time derivative of LV pressure (max(dP/dt)), maximum time-varying elastance (E_max) and the time of E_max(t_max) were obtained for all PVLs. Linear regressions and the relationship between max(dP/dt)/EDV=E_max/t_max⁹were used to compare the quality of PVL signals between different methods.

Results:

Figure 1 shows PVLs in patients by all PVL methods. Mean bias ± standard deviation between C-cath and FF-cath+MRI PVLs for EDV, ESV, and PSP were 2.81±3.16 ml, -3.91±4.52 ml, and -9.08±6.69 mmHg, respectively (Table 1). C-cath vs. FFcath+MRI PVLs show considerable variability in major functional indicators. Model-derived max(dP/dt) had a stronger relationship with data-derived E_max/t_max compared to data-derived max(dP/dt) (Figure 2).

Conclusion:

Our data shows that cardiac MRI based model-derived PVLs can provide reliable PVLs in this unique physiology, and more accurate max(dP/dt) estimations than C-cath or FFcath methods. The reliability of C-cath volumetric assessment remains to be explored in human left and right ventricles. Model-derived PVLs may allow for derivation of PVL metrics in centers without specialized equipment for C-cath measurement.