Congenital Heart Disease

1351726 - Discordant interpretation of left ventricular enlargement between echocardiography and cardiac magnetic resonance in pediatric patients with aortic/mitral regurgitation

Friday, January 27, 2023

1:54 PM – 2:06 PM

Location: Silver Pearl 3

Presenting Author(s)

AB

Anastasia Barros, MD

Pediatric resident
Children's National Medical Center, United States

Primary Author(s)

AB

Anastasia Barros, MD

Pediatric resident
Children's National Medical Center, United States

Co-Author(s)

Yue-Hin Loke, MD

Assistant Professor of Pediatrics
Children's National Hospital, Maryland, United States
Laura Olivieri, MD

Director, Noninvasive Cardiac Imaging
Children's Hospital of Pittsburgh of UPMC, United States
MU

Michelle Udine, MD

Advance Imaging Cardiologist
Children's National Medical Center, United States
CS

Chris Spurney, MD

Associate Director Cardiology Fellowship Program
Children's National Medical Center
Washington, District of Columbia, United States

Disclosure(s):

Yue Loke: No financial relationships to disclose

Background: Interpretation of left ventricular (LV) size is essential to the management of congenital heart disease in pediatric patients. Cardiac magnetic resonance (CMR) provides a reproducible assessment of LV end-diastolic volume (LVEDV), however, echocardiography (echo) is the front-line test for serial assessment of LV enlargement from aortic or mitral regurgitation (AR/MR). Echo assessment of LV size in pediatric patients either rely on linear left ventricular internal diastolic diameter (LVIDd) or five-sixth area length to calculate LVEDV (“bullet method”). Large normative pediatric datasets have been developed to interpret LV size for echo¹ and CMR^2,3; differences in interpretation between modalities have not been assessed in this population. In this study, we investigated the concordance of using LVIDd or bullet method of LVEDV by echo versus CMR measurements of LVEDV in interpreting LV size. We hypothesize that AR/MR patients will have a larger discordance in interpretation of LV enlargement between echo and CMR if only echo LVIDd is used.

Methods: A retrospective cohort of AR/MR pediatric patients (n=93, age=11.5±5.2, 39% female, BSA 1.3±0.5) and non-AR/MR patients (n=235, age=12.4±4.4, 41% female, BSA 1.4±0.5) with echo and CMR studies within 1 year were identified. The non-AR/MR cohort was comprised of pediatric patients with diagnoses of sickle cell disease, cardiomyopathy, heart transplant and rule out for myocarditis. LVEDV by CMR were obtained from clinical reports. For the AR/MR cohort, LVIDd was obtained from clinical reports and then echo imaging was independently reviewed to remeasure LVEDV by bullet method. The respective Z scores were re-calculated using normative data^1,2,3. Echo and CMR z-scores were compared by correlation coefficient. Receiver operative characteristic (ROC) analysis was performed for detection of moderate LV enlargement (CMR LVEDV z-score >3.5).

Results: The AR/MR cohort had more patients with moderate LV enlargement (28% vs. 6%) compared to the non-AR/MR cohort. AR/MR cohort had a mean indexed LVEDV of 110±33mL/m². AR/MR patients had lower correlation between echo and CMR z-scores compared to non-AR/MR, when using either LVIDd or LVEDV bullet method (r²=0.319 vs. r²=0.499, p=0.026 and r²= 0.227 vs. r²=0.499, p=0.008 respectively; Figure 1). With both LVIDd and LVEDV bullet method, AR/MR patients had lower AUC in ROC analysis when compared to non-AR/MR (AUC=0.826 vs. AUC=0.987, p=0.005 and AUC=0.826 vs. AUC=0.987, p= 0.0008; Figure 2).

Conclusion: Discordant interpretation of LV size by echo compared to CMR is worse in pediatric patients with AR/MR. This finding suggests non-uniform changes in LV geometry that continue to limit echo-based measurements to estimate the degree of LV enlargement. Further research should investigate other geometrical measurements to better define LV enlargement as a result of AR/MR.