Left ventricular diastolic function and respiratory outcomes in preterm infants: a retrospective study

Background The role of left ventricular (LV) diastolic pressure in the pathophysiology of bronchopulmonary dysplasia (BPD) is unclear. We evaluated the trajectory of echocardiographic parameters of LV diastolic function and the association with respiratory outcomes in preterm infants. Methods We retrospectively analysed measurements of LV diastolic function (E, e', A, Ee' and E/A ratios) in infants below 32 weeks' gestation (GA). We compared infants with and without BPD by two-way RM ANOVA. We considered Ee' ratio as a proxy of LV filling pressure and identified a cut-off value using ROC analysis. We divided infants using such threshold and compared respiratory outcomes between groups by Mann-Whitney or Chi-square tests. Results We included 72 infants. Ee' ratio at 28 days was significantly associated with the duration of respiratory support (beta (std. error) = 5.32 (1.82), p = 0.005) and BPD (beta = 0.27 (0.10), p = 0.008). Infants with Ee' ratio > 12 at 28 days had longer respiratory support, oxygen requirement, and higher BPD rates than infants with Ee' ratio <= 12. Conclusion LV diastolic function associated with elevated LV filling pressure may contribute to the pathophysiology of BPD. Serial echocardiographic measurements could identify infants at risk of worse respiratory outcomes. Impact In very preterm infants, we assessed the trajectory of left ventricular diastolic function by serial echocardiographic evaluations and evaluated its association with respiratory outcomes. On average, infants who developed bronchopulmonary dysplasia had higher ' at 28 postnatal days and 36 weeks postmentrual age than infants who did not develop the disease. Infants with elevated ' at 28 postnatal days, suggestive of elevated left atrial pressure, required longer respiratory support.

Automated summary

By evaluating the trajectory of left ventricular diastolic function through serial echocardiographic evaluations and its association with respiratory outcomes, we found that abnormalities in left ventricular diastolic function may contribute to the pathophysiology of bronchopulmonary dysplasia. Serial echocardiographic measurements could help identify infants at risk of worse respiratory outcomes.