Longitudinal assessment of cardiac function in extremely low birth weight children at 7 and 11 years of age: implications for adult medicine

Abstract

Background: The long-term impact of extreme prematurity on cardiac structure and function has not been fully evaluated.

Aims: The aim of the study was to assess cardiac condition at 11 years of age in a local cohort of extremely low birth weight (ELBW) children born between 2002 and 2004 and to compare it to a previous study in the same group at 7 years of age.

Methods: Sixty-four children with ELBW (median birth weight of 890 g) and 36 children born at full term underwent echocardiography and physical examination.

Results: M-mode echocardiography parameters, expressed as z-scores for body surface area (mean [SD]), showed significant differences in left ventricular end-diastolic dimension (–1.01 [0.91] vs 0.35 [0.71]; P < 0.001), left ventricular end-systolic dimension (–0.29 [0.92] vs 0.57 [0.65]; P < 0.001), aorta dimension (0.63 [1.14] vs 1.63 [1.30]; P < 0.001), and left atrial dimension (–1.75 [0.97] vs –0.01 [0.86]; P < 0.001) between the study group and controls at 11 years of age. Fractional shortening (FS) and ejection fraction (EF) were higher in the ELBW children than in their full-term counterparts (33.6 [5.5] vs 30.8 [4.34]; P = 0.009 and 0.63 [0.07] vs 0.58 [0.06]; P = 0.005, respectively) at a mean age of 11 years.

Conclusions: The ELBW children had smaller hearts than full-term controls at both 7 and 11 years of age. The FS and EF were elevated in the group of 11-year-old ELBW children. We observed comparable progress in cardiac growth (approximately 20%) in premature and full-term children over a 4-year study period.