154-LB: Cardiac MRI Findings in Young Adults with Childhood-Onset Type 2 Diabetes

Left ventricular (LV) hypertrophy and left atrial dilation are present at echocardiography in youth with T2D, however limited cardiac MRI data exist. We compared cardiac MRI findings in young adults with childhood- onset T2D (n=10) age 19-24 years, with published controls. History, physical exam and HbA1c were obtained. Hemodynamics were evaluated from cine imaging. For myocardial fibrosis, extracellular volume (ECV) fraction and native T1 relaxation times were assessed using a Modified Look-Locker Imaging sequence. Subjects were 8 females and 2 males, 7 black, 1 white, 1 mixed race and 1 Hispanic. Median (interquartile range IQR) age, diabetes duration, SBP, BMI and HbA1c were 19.9 (1.39) years, 7.8 (4.7) years, 121.5 (25) mmHg, 32.7 (9.5) kg/m2 and 10.3 (3.04)%, respectively. Subjects had a higher median (IQR) end systolic volume (ESV) index than published mean (SD) for healthy 20-29 year olds: 40.81 (5.74) ml/m2 vs. 29 (5.1) ml/m2 (p=0.007). However, they had lower LV mass index: 54.61 (9.01) g/m2 vs. 69 (8.1) g/m2 (p=0.01) and ejection fraction (EF): 50 (2.8)% vs. 66 (4.6)% (p=0.0049). Higher median (IQR) myocardial T1 of 1030.35 (44.6) msec vs. 965.6 (30.2) msec (p=0.005) and ECV fraction of 27.5 (1.5)% vs. 25 (3)% (p=0.012) were present. LV mass index directly correlated with HbA1c (rs= 0.69, p=0.03). Females had a higher median (IQR) ESV index of 40.81 (4.08) ml/m2 than published mean (SD) for females age 16-20 years of 29 (7.5) ml/m2 (p= 0.01), but lower EF of 50 (2.65)% vs. 64.3 (7.3)% (p= 0.01) and cardiac index of 3.08 (0.425) L/min/m2 vs. 3.85 (0.86) L/min/m2 (p= 0.01). ESV index positively correlated with HbA1c (rs=0.762, p=0.03). Males had a median (IQR) ESV index of 39.94 (25.7) ml/m2, LV mass index of 67.46 (13.9) g/m2 and EF of 54.95 (9.9)%. In this pilot study, young adult subjects with youth-onset T2D had a different myocardial phenotype compared to published normal values, characterized by undersized hearts relative to larger body size, poorer systolic performance and evidence for early onset myocardial fibrosis.