Role of Early Pulmonary Hypertension as a Risk Factor for Late Pulmonary Hypertension in Extremely Preterm Infants.

OBJECTIVE: The evidence on the role of early pulmonary vascular disease (PVD) in the development of late pulmonary hypertension (PH) in the extremely preterm infants is limited. Objectives were to determine the incidence of early and late PH in extreme preterm infants and to evaluate the role of early PH as a risk factor for development of clinically detected late PH. METHODS: It was a retrospective analysis of early echocardiograms (day of life 5-14) in preterm infants, 22 to 27 weeks' gestation, admitted to the University of Iowa NICU between July 01, 2012 to June 30, 2015. Late echocardiograms performed for clinical suspicion of PH were also analyzed. RESULTS: A total of 154 infants were included in the study. Early PH was diagnosed in 31 (20%) infants. Twenty-four (16%) infants were evaluated for clinically suspected PH. Eight (5%) infants were diagnosed with late PH. Infants with early PH had echocardiograms performed earlier than infants without the evidence of early PH. Early PH was not associated with the development of late PH (p = 0.99). CONCLUSION: Early PH is common among extremely preterm infants (20%). Five percent of infants had clinically detected late PH. Infants with early PH had echocardiograms performed earlier than infants without the evidence of early PH. Early PH was not associated with the development of clinically detected late PH.