1352648 - Very preterm birth with or without preceding fetal growth restriction is associated with a spherical left ventricle in adolescence

Both preterm birth and low birth weight associate with increased risk for development of hypertension and future cardiovascular disease. However, recent studies suggest a limited effect on cardiac morphology and function in adolescence, showing normal cardiac pumping and lack of left ventricular hypertrophy after very or extremely preterm independent of birth weight deviation (1,2).

Shape analysis is suggested to be a sensitive method for assessment of cardiac morphology and function. Alterations in left ventricular shape has been shown to be a predictor of cardiovascular disease (3).The aims of this study were therefore to investigate whether left ventricular shape is altered in adolescents born very preterm with or without preceding fetal growth restriction (FGR).

Methods:

Adolescents born very preterm due to early onset FGR, verified with fetal doppler velocimetry, and two control groups with appropriate birth weight for gestational age (AGA), one delivered at similar gestation and one born at term, underwent CMR. Principle component analysis (PCA) was applied to find the modes of variation that best explain the left ventricular shape variability within the whole dataset for end-diastole, end-systole, and for the combination of both. The combined analysis examines the shape change between end-diastole and end-systole, indicative of function. Manually delineated left ventricular volumes from all groups were used as input and were included in the PCA analysis whereafter shape statistics for each group were computed.

Results:

Seventy adolescents were included (13–16 years; 51% girls; Table 1). The first mode corresponded visually to sphericity and explained 30% of shape variability in end-diastole, 34% in end-systole, and 26% in end-diastole and end-systole combined. Figure 1 shows shape differences between groups. The preterm FGR group showed an increased median [IQR] sphericity in comparison to the term AGA group for end-diastole (36 [0 to 60] vs -42 [-82 to 8]; p=0.01) and for end-diastole and end-systole combined (27 [-23 to 94] vs -51 [-119 to 11]; p=0.01). The preterm AGA group showed increased sphericity as compared to the term AGA group at end-diastole (30 [-56 to 115] vs -42 [-82 to 8]; p=0.04), at end-systole (57 [-29 to 89] vs -30 [-79 to 34]; p=0.03), and for end-diastole and end-systole combined (44 [-50 to 145] vs -51 [-119 to 11]; p=0.02). No group differences were observed for left ventricular mass or ejection fraction (all p≥0.33) (Table 1).

Conclusion:

Adolescents born very preterm with or without preceding FGR showed an increased left ventricular sphericity, without alterations in left ventricular mass or ejection fraction. This suggests that increased sphericity may serve as a potential prognostic biomarker of future cardiovascular disease in this cohort, currently showing no signs of cardiac dysfunction using standard clinical measurements.