Elevated Blood Pressure with Reduced Left Ventricular and Aortic Dimensions in Adolescents Born Extremely Preterm.

OBJECTIVE: To evaluate the long-term cardiovascular effects of extremely preterm birth in a cohort of adolescents followed prospectively, who were largely free from intrauterine growth restriction. STUDY DESIGN: Central blood pressures, aortic and cardiac dimensions, left ventricle (LV) function, pulse wave velocity, augmentation index, and microvascular reactive hyperemia were measured in 18-year-old subjects born extremely preterm at <28 weeks' gestation (n = 109) and term-born controls (n = 81). RESULTS: Compared with controls, preterm adolescents had higher systolic (124 ± 13 vs 118 ± 10 mm Hg, P = .002) and diastolic (72 ± 8 vs 67 ± 7 mm Hg, P < .001) blood pressures, but lower ascending aortic z-scores (0.13 ± 0.89 vs 0.42 ± 0.78, P = .02), LV diastolic (48.5 ± 4 vs 50.3 ± 4.5 mm, P = .007) and systolic (30.2 ± 3.5 vs 31.9 ± 4.0 mm, P = .003) diameters, and a reduced LV mass (130 ± 34 vs 145 ± 41 g, P = .01) and mass index (75 ± 14 vs 81 ± 16 g/m(2), P = .02). However, LV relative wall thickness, LV function, pulse wave velocity, augmentation index, and microvascular reactive hyperemia were similar. Within the ex-preterm group, there were no significant relationships between birthweight z-scores and any cardiovascular measures, once the latter were adjusted for current body size. CONCLUSIONS: Extremely preterm birth had relatively minor cardiovascular effects in late-adolescence, with increased blood pressures, decreased LV, and aortic size, but preserved LV function, macrovascular properties, and microvascular function. In utero growth was not independently related to cardiovascular function within the ex-preterm cohort.

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 ±â€Š11 vs. 105 ±â€Š10 mmHg; P < 0.001) and diastolic blood pressures (73 ±â€Š7 vs. 67 ±â€Š7 mmHg; 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 ±â€Š0.21 vs. -0.29 ±â€Š0.17 W/m/s × 10; P = 0.03), backward compression wave pressure change (9.0 ±â€Š3.5 vs. 6.6 ±â€Š2.5 mmHg; P = 0.001) and reflection index (0.44 ±â€Š0.15 vs. 0.32 ±â€Š0.08; 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.