The Impact of Bronchopulmonary Dysplasia on the Maturation of Preterm Infants' Right Ventricular Mechanics Over the First Year of Life: A Prospective Strain-Echocardiography Cohort.

Abstract

Bronchopulmonary dysplasia (BPD) is frequent in very-preterm infants, yet its effects on right-ventricular (RV) maturation during the first post-natal year remains unclear. We aimed to investigate RV mechanics among preterm with and without BPD, using conventional echocardiogram and speckle-tracking derived strain, throughout this period. We prospectively enrolled 118 infants born < 32 weeks' gestation who were scanned at 36 weeks post-menstrual age (PMA), as well as at 1-month and 1-year corrected age (CA). Seventy-two infants met BPD criteria and 46 served as controls. Pattern-mixture models, adjusted for sex, birth-weight z-score, and respiratory support, analyzed trajectories of RV global longitudinal strain (RVGLS). Conventional RV dimensions and functional measurements were comparable between groups at all visits. RVGLS increased in controls (+ 4.4 ± 1.2%) but remained unchanged in BPD (- 0.2 ± 1.3%), yielding a significant group-by-time interaction (β = - 5.8%, 95% CI - 9.3 to - 2.4; p = 0.001). At 1-year CA, mean RVGLS was lower in BPD than controls (24.3 ± 4.1% vs 28.7 ± 4.6%; p < 0.001). Oxygen dependency at 36 weeks PMA (β = - 5.8%; p = 0.001) and invasive ventilation > 2 days (β = - 2.8%; p = 0.012) independently predicted worse RVGLS, whereas high-frequency oscillatory ventilation was associated with improvement (β =  + 4.9%; p = 0.043). BPD may disrupt the normal maturation of RV mechanics during the first postnatal year. RVGLS identifies subclinical dysfunction undetectable by conventional echocardiography and may serve as an early biomarker to guide cardiopulmonary interventions in this high-risk population.