Abstract 13897: Native T1-mapping by Cardiac MRI as a Biomarker of Remodeling in Boys With Duchenne Muscular Dystrophy

• DOI: 10.1161/circ.142.suppl_3.13897
• Publication Date: 2021-05-10T16:18:27Z
• Authors: Seraina A Dual; Nyasha G Maforo; Doff B McElhinney; Ashley Prosper; Holden Wu; Shiraz A Maskatia; Pierangelo Renella; Nancy J Halnon; Daniel Ennis
• Keywords: 03 medical and health sciences; 0302 clinical medicine

Cardiac magnetic resonance (CMR) is an important tool to assess cardiac disease progression in boys with Duchenne muscular dystrophy (DMD), with native (pre-contrast) myocardial T1-mapping considered a possible biomarker of fibrosis. Due to its thin wall and highly trabeculated structure, the right ventricle (RV) remains understudied in DMD despite pre-clinical evidence of RV involvement. After determining the most robust method of obtaining RV-T1, we assessed the hypothesis that RV-T1 distinguishes healthy controls from boys with DMD. Boys with DMD (N=27) and age-matched healthy control boys (N=17) were prospectively enrolled for a 3T CMR exam (Skyra, Siemens). The CMR exam included standard functional imaging, LGE imaging, and native T1 maps acquired at diastasis. Native RV-T1 was evaluated in four regions of interest (ROIs): 1 pixel (px) along the RV centerline, 3px dilated RV centerline, a segment within the RV lateral wall, and the RV inferior wall (Figure 1). Robustness was assessed in controls only and was defined as an acceptable number of pixels, coefficient of variation (COV) per ROI, percentage of readable images, and lowest inter-observer variability across three observers. Subsequently, a t-test assessed the difference between boys with DMD and controls using the most robust RV ROI. Comparing the four ROIs, we found an average size of the ROI of 65, 196, 23, 25 px; a COV of 13.4%, 16.6%, 6.0%, 9.9%; and 75%, 75%, 93%, 81% of readable images. Intra-class correlation (0.75) was highest and both mean bias (20ms) and limits of agreement (100ms) were lowest for the RV 1px ROI. Using the 1px ROI, the RV-T1 was higher and more variable in boys with DMD compared to controls (1526 [1457,1650] ms vs. 1432 [1390,1486] ms; p<0.0001). Native RV-T1 is elevated in boys with DMD, if measured along a 1px centerline ROI. The methods described herein may enable using native RV-T1 as a biomarker of fibrosis in DMD and other pathologies. Correlation with functional indices is pending.