Early ventricular function assessed by speckle-tracking echocardiography (STE) in extremely preterm infants

Objectives To evaluate the relationship between early speckle-tracking echocardiography (STE)-derived longitudinal strain and conventional measures of ventricular systolic function in extremely preterm infants and assess their association with mortality before hospital discharge. Methods This retrospective cohort study included inborn infants born at less than 29 weeks of gestation admitted to a tertiary neonatal intensive care unit between October 2023 and December 2025. Standardised targeted neonatal echocardiography was performed within 72 hours of birth. Left ventricular (LV) and right ventricular (RV) longitudinal strain and conventional measures of ventricular function were evaluated in relation to mortality. Each measure was entered separately into multivariable models adjusted for gestational age and 5-min Apgar score, with bootstrap internal validation. Results Among 144 infants, 32 (22.2%) died before hospital discharge. Infants who died had less negative LV and RV longitudinal strain and lower conventional measures of LV and RV systolic function than survivors (all p < 0.001). LV strain correlated strongly with LV ejection fraction (r = −0.811) and fractional shortening (r = −0.868), while RV strain correlated strongly with RV fractional area change (r = −0.898) and RV output (r = −0.780) (all p < 0.001). All evaluated echocardiographic measures showed high apparent discrimination for mortality (AUC 0.910 to 0.955; all p < 0.001), without significant differences between strain and conventional measures, and remained associated with mortality after adjustment (optimism-corrected c-statistics 0.915 to 0.964). Conclusions STE-derived longitudinal strain was closely associated with conventional measures of ventricular systolic function, while both deformation-based and conventional measures were associated with mortality; these exploratory findings require external validation. STE may provide a complementary component of early neonatal haemodynamic assessment in extremely preterm infants.