Increased aortic wave reflection contributes to higher systolic blood pressure in adolescents born preterm

Objective: To evaluate the wave reflection characteristics in the aortic arch and common carotid artery of ex-preterm adolescents and assess their relationship to central blood pressure in a cohort followed prospectively since birth. Methods: Central blood pressures, pulse wave velocity, augmentation index, microvascular reactive hyperemia, arterial distensibility, compliance and stiffness index, and also aortic and carotid wave intensity were measured in 18-year-olds born extremely preterm at below 28 weeks' gestation (n=76) and term-born controls (n=42). Results: Compared with controls, ex-preterm adolescents had higher central systolic (111±11 vs. 105±10mmHg; P<0.001) and diastolic blood pressures (73±7 vs. 67±7mmHg; P<0.001). Although conventional measures of arterial function and biomechanics such as pulse wave velocity and augmentation index were no different between groups, wave intensity analysis revealed elevated backward compression wave area (-0.39±0.21 vs. -0.29±0.17W/m 2 /s×10 4; P=0.03), backward compression wave pressure change (9.0±3.5 vs. 6.6±2.5mmHg; P=0.001) and reflection index (0.44±0.15 vs. 0.32±0.08; P<0.001) in the aorta of ex-preterm adolescents compared with controls. These changes were less pronounced in the carotid artery. On multivariable analysis, forward and backward compression wave areas were the only biomechanical variables associated with central systolic pressure. Conclusions: Ex-preterm adolescents demonstrate elevated wave reflection indices in the aortic arch, which correlate with central systolic pressure. Wave intensity analysis may provide a sensitive novel marker of evolving vascular dysfunction in ex-preterm survivors.