Pediatric Heart Disease
Sandra Kikano, MD
Clinical Fellow
Vanderbilt University Medical Center, United States
Sandra Kikano, MD
Clinical Fellow
Vanderbilt University Medical Center, United States
Simon Lee, MD
Assistant Professor of Pediatrics
Nationwide Children's Hospital
Columbus, Ohio, United States
Debra Dodd, MD
Professor of Clinical Pediatrics, and Medical Director, Pediatric Heart Transplant Program
Vanderbilt University Medical Center, United States
Justin Godown, MD
Associate Professor of Pediatrics, Associate Director of Pediatric Heart Transplantation
Vanderbilt University Medical Center, United States
David Bearl, MD, MA
Assistant Professor, and Medical Director of the Ventricular Assist Device Program
Vanderbilt University Medical Center, United States
Maryanne Chrisant, MD
Medical Director, Pediatric Cardiac Transplant, Heart Failure and Cardiomyopathy
Joe DiMaggio Children's Hospital, United States
Kak-Chen Chan, MD
Medical Director, Complex Pediatric Cardiac Specialty Services
Joe DiMaggio Children's Hospital, United States
Deipanjan Nandi, MD, MSc
Assistant Professor of Pediatrics
Nationwide Children's Hospital, United States
Kimberly Crum, RN
Clinical Research Nurse
Vanderbilt University Medical Center, United States
Kristen George-Durrett, BSc
Research MRI Technologist
Vanderbilt University Medical Center
Nashville, Tennessee, United States
Lazaro Hernandez, MD
Medical Director, Advanced Cardiac Imaging
Joe DiMaggio Children's Hospital
Hollywood, Florida, United States
Jonathan H. Soslow, MD, MSc
Associate Professor of Pediatrics, and Director, Pediatric Cardiac Imaging Research Center
Vanderbilt University Medical Center
Nashville, United States
In pediatric heart transplant (PHT) patients, cardiac catheterization with endomyocardial biopsy (EMB) and coronary angiography is standard practice for the diagnoses of acute rejection (AR) and cardiac allograft vasculopathy (CAV). However, EMB and angiography are costly and invasive. We hypothesized that cardiac magnetic resonance (CMR) can non-invasively detect AR and CAV in PHT.
Methods:
Patients were enrolled at three tertiary care children’s hospitals. Prospective enrollment occurred as part of a funded multicenter research study at 2 sites; retrospective data collection was performed at all 3 sites to supplement enrollment. Data were collected from surveillance EMB or EMB at the time of clinical concern for a unique episode of AR. AR was defined as an abnormal EMB necessitating a change in immunosuppressives. CAV diagnosis was determined based on coronary angiography. Patients were excluded if they had a diagnosis of AR and CAV simultaneously, had CMR obtained >7 days from AR diagnosis, had EMB negative AR, or if they could not undergo contrasted, unsedated CMR. CMR data included standard volumes, global longitudinal and circumferential strain (GLS, GCS) measured using feature tracking, native T1, T2 and extracellular volume (ECV) mapping, and left ventricular (LV) filling curves to assess diastology. Normative values from each magnet were obtained to generate native T1 and T2 z-scores. Kruskall-Wallis testing was used to compare groups: 1. No AR or CAV (Healthy) 2. AR 3. CAV. Wilcoxon rank sum testing was used to compare subgroup analyses for significant values.
Results:
Fifty-nine patients met inclusion criteria (mean age 17 years [15-19]) with 10 (17%) having AR, and 11 (19%) with CAV. Patients with CAV were older in age and had increased time since transplant; there were otherwise no significant demographic differences between the groups. Patients with AR had worse left ventricular ejection fraction (LVEF) (p=0.001) and larger LV end systolic and diastolic volumes. GCS was worse in patients with AR (p=0.054) and CAV (p=0.019), compared to Healthy patients. ECV and T2 z-scores in all locations were elevated in patients with AR when compared to CAV and Healthy. Native T1 z-scores were also elevated in AR compared with the other groups. Diastolic markers were not significantly different between the groups.
Conclusion:
CMR findings can differentiate CAV and AR from Healthy PHT patients. In this cohort, CAV subjects have normal global function (LVEF) but abnormal GCS which may suggest early subclinical dysfunction. CAV subjects also have normal parametric mapping. AR patients have abnormal function (LVEF and GCS) and tissue characteristics consistent with edema, with elevated ECV, native T1 and T2 z-scores. Characterization of these patterns may assist in informing standardization of CMR findings and help determine diagnostic differences in PHT patients.