Histological validation of cardiovascular magnetic resonance T1 mapping markers of myocardial fibrosis in paediatric heart transplant recipients

• Published in: Journal of cardiovascular magnetic resonance 2017-02, Vol.19 (1), p.10-10, Article 10
• Main Authors: Ide, Seiko, Riesenkampff, Eugenie, Chiasson, David A, Dipchand, Anne I, Kantor, Paul F, Chaturvedi, Rajiv R, Yoo, Shi-Joon, Grosse-Wortmann, Lars
• Format: Article
• Language: English
• Subjects: Adolescent; Age Factors; Analysis; Biomarkers - analysis; Biopsy; Cardiomyopathies - diagnostic imaging; Cardiomyopathies - etiology; Cardiomyopathies - pathology; Cardiomyopathies - physiopathology; Care and treatment; Case-Control Studies; Child; Child, Preschool; Collagen - analysis; Contrast Media - administration & dosage; Female; Fibrosis; Gadolinium DTPA - administration & dosage; Heart diseases; Heart transplantation; Heart Transplantation - adverse effects; Humans; Infant; Magnetic resonance imaging; Magnetic Resonance Imaging, Cine; Male; Myocardium - chemistry; Myocardium - pathology; Observer Variation; Pilot Projects; Predictive Value of Tests; Prospective Studies; Reproducibility of Results; Severity of Illness Index; Transplant Recipients; Treatment Outcome; Ventricular Remodeling
• ISSN: 1097-6647; 1532-429X
• DOI: 10.1186/s12968-017-0326-x

Adverse fibrotic remodeling is detrimental to myocardial health and a reliable method for monitoring the development of fibrotic remodeling may be desirable during the follow-up of patients after heart transplantation (HTx). Quantification of diffuse myocardial fibrosis with cardiovascular magnetic resonance (CMR) has been increasingly applied and validated histologically in adult patients with heart disease. However, comparisons of CMR findings with histological fibrosis burden in children are lacking. This study aimed to compare native T1 times and extracellular volume fraction (ECV) derived from CMR with the degree of collagen on endomyocardial biopsy (EmBx), and to investigate the association between myocardial fibrosis and clinical as well as functional markers in children after HTx. EmBx and CMR were performed on the same day. All specimens were stained with picrosirius red. The collagen volume fraction (CVF) was calculated as ratio of stained collagen area to total myocardial area on EmBx. Native T1 values and ECV were measured by CMR on a mid-ventricular short axis slice, using a modified look-locker inversion recovery approach. Twenty patients (9.9 ± 6.2 years of age; 9 girls) after HTx were prospectively enrolled, at a median of 1.3 years (0.02-12.6 years) post HTx, and compared to 24 controls (13.9 ± 2.6 years of age; 12 girls). The mean histological CVF was 10.0 ± 3.4%. Septal native T1 times and ECV were higher in HTx patients compared to controls (1008 ± 32 ms vs 979 ± 24 ms, p