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

Abstract

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. 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 <28weeks' gestation (n=109) and term-born controls (n=81). Compared with controls, preterm adolescents had higher systolic (124±13 vs 118±10mm Hg, P=.002) and diastolic (72±8 vs 67±7mm 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±4.5mm, P=.007) and systolic (30.2±3.5 vs 31.9±4.0mm, P=.003) diameters, and a reduced LV mass (130±34 vs 145±41g, P=.01) and mass index (75±14 vs 81±16g/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. 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.