Buy Article Permissions and Reprints Abstract

Objective Bronchopulmonary dysplasia (BPD) is the most common complication of preterm birth. Infants with BPD are at increased risk for pulmonary hypertension (PH). Cardiac catheterization is the gold standard for diagnosing PH, but cardiac catheterization is challenging to perform in small, sick, premature infants. The utility of echocardiography for diagnosing PH and predicting outcomes in extremely premature infants has not been clearly defined. Therefore, we sought to use predefined criteria to diagnose PH by echocardiogram and relate PH severity to mortality in extremely premature infants with BPD.

Study Design Echocardiograms from 46 infants born ≤28 weeks' postmenstrual age with a diagnosis of BPD were assessed for PH by three pediatric cardiologists using predefined criteria, and survival times among categories of PH patients were compared. A total of 458 echocardiograms were reviewed, and 15 (33%) patients were found to have at least moderate PH. Patients with at least moderate PH had similar demographic characteristics to those with no/mild PH.

Results Ninety percent of infants without moderate to severe PH survived to hospital discharge, compared with 67% of infants with at least moderate PH (p = 0.048). Patients with severe PH had decreased survival to hospital discharge (38%) compared with moderate (100%) and no/mild PH (90%) groups. Kaplan–Meier survival curves also differed among PH severity groups (Wilcoxon p < 0.001).

Conclusion Using predefined criteria for PH, premature infants with BPD can be stratified into PH severity categories. Patients diagnosed with severe PH by echocardiogram have significantly reduced survival.

Key Points

A composite score definition of PH by echocardiogram showed high inter- and intrarater reliability.

Infants with severe PH by echocardiogram had decreased survival rates.

Early diagnosis of PH by echocardiogram dictates treatment which may improve outcomes.

Keywords pulmonary hypertension - echocardiography - bronchopulmonary dysplasia - outcomes Authors' Contributions

R.D.T., A.W.M., and P.C.A.B. helped design the study, obtained echocardiogram data, and helped write the manuscript. R.A.G., J.S.L., C.P.H., M.M.L., and W.M.J. helped design the study, collected and interpreted the data, and wrote the manuscript. All authors approved the final manuscript as submitted and agreed to be accountable for all aspects of the work.

Ethical Approval

The study protocol was approved by The University of North Carolina at Chapel Hill Institutional Review Board and the Duke University Medical Center Institutional Review Board with a waiver of informed consent. Study was performed in accordance with the Declaration of Helsinki.

Publication History

Received: 02 November 2023

Accepted: 25 March 2024

Article published online:
02 May 2024

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