MRI in preterm infants detects indicators of pulmonary vascular disease

Key takeaways:

• Evaluating pulmonary artery flow and cardiac function with MRI revealed parameters that detect bronchopulmonary dysplasia-related pulmonary vascular disease.
• This method does not require sedation of infants.

A cardiopulmonary MRI conducted during unsedated sleep aided in early detection of pulmonary vascular disease in preterm infants with bronchopulmonary dysplasia, according to results published in European Respiratory Journal.

“As pulmonary vascular disease (PVD) significantly determines long-term morbidity and mortality, mainly through its later, often undetected progression into [pulmonary hypertension] and unexplained cardiac death in adulthood, its early identification is a prerequisite for adequate monitoring strategies in at-risk infants,” Friederike Häfner, doctoral student at the Institute for Lung Health and Immunity and Comprehensive Pneumonology Center with the CPC-M bioArchive at Helmholtz Zentrum Munich, and colleagues wrote. “However, timely PVD diagnosis remains a major challenge after preterm birth due to non-discriminatory clinical signs and lack of diagnostic tools.”

With advanced MRI, Häfner and colleagues evaluated sleeping babies born at less than 32 weeks of gestation — 36 with mild bronchopulmonary dysplasia (BPD), 26 with moderate/severe BPD and 28 with no BPD — without sedating them to see how elements of pulmonary artery flow and cardiac function are linked to BPD-related PVD.

Based on the data from those infants with BPD-associated PVD, researchers trained a pulmonary artery flow model to detect variations, which they then applied to the group with mild BPD in order to assess their risk for developing PVD.

Overall, researchers identified four abnormalities/parameters that differentiated infants with moderate/severe BPD vs. no BPD — high net forward volume (ratio right-over-left), low mean relative area change, high right end-diastolic volume normalized to body surface area (RV EDV/BSA) and postmenstrual age — with a high area under the curve (leave-1-out AUC, 0.88; 95% CI, 0.78-0.98), sensitivity (0.8; 95% CI, 0.35-1) and specificity (0.81; 95% CI, 0.57-0.95).

Their model that used all four of these parameters performed better than models that only used one of the parameters, according to the researchers.

Of the above parameters, infants with moderate/severe BPD and infants with prolonged oxygenation had high net forward volume (P = .048; P = .02) and RV EDV/BSA (P = 2.2 x 10^-3; P = 1 x 10^-3), according to researchers. Elevated RV EDV/BSA was also found in infants who experienced longer mechanical ventilation (P = 2 x 10^-3).

In the cohort of infants with mild BPD, the pulmonary artery flow model found a heightened risk for pulmonary vascular disease with prolonged measures of mechanical ventilation duration (P = 2.2 x 10^-4) and oxygen supplementation (P = 6 x 10^-4), both of which indicate lung injury, researchers noted.

Lastly, researchers sought to see how well their statistical model correlated with echocardiographic and MRI measures that signal pulmonary vascular pathology and observed a relationship between the included abnormalities and unfavorable outcomes, such as elevated right ventricular afterload shown through right ventricular-arterial coupling (P = .016), pulmonary artery midsystolic notching (P = .015) and right ventricular cardiac index (P = 1.67 x 10^-8).

“Future studies are needed to carefully track the identified, early signs of lung vascular pathology into (pre)school age and adulthood in order to delineate their potential to predict mortality in this high-risk patient cohort,” Häfner and colleagues wrote.

Reference:

• Take a deep breath: early detection of vascular disease in chronic lung disease of premature infants. https://www.helmholtz-munich.de/en/newsroom/news-all/artikel/take-a-deep-breath-early-detection-of-vascular-disease-in-chronic-lung-disease-of-premature-infants. Published Sept. 7, 2023. Accessed Sept. 18, 2023.