Association of the respiratory severity score with bronchopulmonary dysplasia-associated pulmonary hypertension in infants born extremely preterm

Objective: To test the hypothesis that elevations in the respiratory severity score (RSS) are associated with increased probability of bronchopulmonary dysplasia-associated pulmonary hypertension (BPD-PH).Study design: Retrospective cohort study of infants born extremely preterm admitted to a BPD center between 2010 and 2018. Echocardiograms obtained >= 36 weeks' post-menstrual age (PMA) were independently adjudicated by two blinded cardiologists to determine the presence/absence of BPD-PH. Multivariable logistic regression estimated the association between RSS and BPD-PH.Result: BPD-PH was observed in 68/223 (36%) of subjects. The median RSS at time of echocardiography was 3.04 (Range 0-18.3). A one-point increase in the RSS was associated with BPD-PH, aOR 1.3 (95% CI 1.2-1.4), after adjustment for gestational age and PMA at time of echocardiography.Conclusion: Elevations in the RSS were associated with a greater probability of BPD-PH. Prospective studies are needed to determine the validity and performance of RSS as a clinical susceptibility/risk biomarker for BPD-PH.