Bronchopulmonary dysplasia and pulmonary hypertension: a meta-analysis

Pulmonary hypertension (PH) is a complication of bronchopulmonary dysplasia (BPD) but the true impact of PH in patients with BPD remains unclear. We sought to systematically review and meta-analyze incidence of PH in BPD and compare clinical outcomes of BPD patients with PH to those without PH in preterm infants.

Medline, Embase, PsychINFO and CINAHL were searched from January 2000 through December 2015. Cohort, case-control and randomized studies were included. Case-reports, case-series and letters to editors and studies with high risk of bias were excluded. Study design, inclusion/exclusion criteria, diagnostic criteria for BPD and PH and outcomes were extracted independently by two co-authors.

The pooled incidence of PH in patients with BPD (any severity) was 17% (95% confidence interval (CI) 12 to 21; 7 studies) and 24% (95% CI 17 to 30; 9 studies) in moderate-severe BPD. Patients with BPD have higher unadjusted odds of developing PH compared to those without BPD (odds ratio (OR) 3.00; 95% CI 1.18 to 7.66; 4 studies). Patients with BPD and PH were at higher odds of mortality (OR 5.29; 95% CI 2.07 to 13.56; 3 studies) compared with BPD without PH, but there was no significant difference in duration of initial hospitalization, duration of supplemental oxygen requirement or need for home oxygen. No studies included in this review reported on long-term pulmonary or neurodevelopmental outcomes.

PH occurs in one out of 4 to 5 preterm neonates with BPD. Patients with BPD and PH may have higher odds of mortality; however, there is urgent need for high quality studies that control for confounders and provide data on long-term outcomes.