Dilated hypertrophy: a distinct pattern of cardiac remodeling in preterm infants

Area of Science:

• Neonatal cardiology
• Pediatric cardiovascular research
• Fetal development and cardiac outcomes

Background:

• Preterm birth leads to cardiac remodeling in young adults, characterized by altered cardiac shape, size, and impaired function.
• The long-term effects and patterns of cardiac remodeling due to prematurity are not well understood.
• This study investigates cardiac changes in preterm infants at 36 weeks postmenstrual age.

Purpose of the Study:

• To compare left ventricle (LV) geometry and function in preterm infants at 36 weeks postmenstrual age (PMA) with term-born, gestation-matched infants.
• To establish the natural history and pattern of cardiac remodeling in infants born preterm.
• To identify specific echocardiographic parameters indicative of cardiac alterations in this population.

Main Methods:

• Prospective echocardiographic assessment of LV end-diastolic volume index (LV EDVI), LV mass index (LVMI), relative wall thickness (RWT), and sphericity index (SI).
• Classification of LV geometry using the Gaasch method.
• Assessment of LV function included ejection fraction (EF), longitudinal strain (LS), mitral annular systolic motion (s'), and estimated LV filling pressure (E/e').

Main Results:

• Eighty-three preterm infants (23-29 weeks gestation) and 40 term-born infants were analyzed.
• Preterm infants showed higher LV EDVI, LVMI, SI, LS, s', and E/e' compared to controls.
• LV geometry in preterm infants included normal (55.4%), physiological enlargement (23%), and dilated hypertrophy (21.6%). RWT and EF were comparable between groups.

Conclusions:

• At 36 weeks PMA, preterm infants display significantly dilated, hypertrophied, and more spherical left ventricles.
• Impaired diastolic function was observed in preterm infants compared to term-born controls.
• These findings highlight early cardiac remodeling in preterm infants, impacting both structure and diastolic function.