98 - Small left ventricle in extreme of prematurity and postnatal growth

Poster Number: 98
Publication Number: 98.2089

Background: Preterm birth can significantly impact postnatal growth. Despite the effects of prematurity on cardiovascular health, heart development in preterm infants remains inadequately addressed. We described that extremes of prematurity were associated with smaller left cardiac dimensions at around 36 weeks of post-menstrual age (PMA). The current analysis investigates if this finding is inherent to the heart or or simply a result of an abnormal systemic growth.

Objective: To investigate if smaller left cardiac dimensions observed at around 36 weeks of PMA were related to growth, using various anthropometric parameters.

Design/Methods: Single-center retrospective cohort study in preterm infants < 29 weeks of gestational age (GA) admitted between February 2015 and September 2019. Left cardiac dimensions were measured at near term (34-426/7 weeks) and body weight and length - closest to the echocardiography - were retrieved. Weight to Length (WL) ratio, body mass index (BMI) and body surface area (BSA) were calculated. Fischer’s exact test was used to assess differences for categorical variables. Linear regression models were used to evaluate trends by GA groups. Multiple linear regression models were used to assess the association between left-sided cardiac dimensions and GA at birth adjusting for length, WL ratio, BMI and BSA at the time of echocardiography.

Results: A total of 205 infants < 29 weeks GA were included. Body weight, WL ratio, BMI, and BSA were similar between GA groups (Table 1). A patent ductus arteriosus (PDA) was found in 55 infants (27%) on near-term echocardiography, and size was similar among GA groups. GA at birth was associated with EDV/length, EDV/WL, EDV/BMI, EDV/BSA, LV length/BMI and LA diameter/BMI. In multilinear regression models, LV-EDV remained associated to GA after adjustment for WL ratio, BMI, and BSA. LV length and LA diameter were associated with GA at birth after adjustment for WL ratio and for BMI. Adjusting for the presence or absence of a PDA at near-term echocardiography did not alter the results of the regression models. EDV, EDV/Length ratio, EDV/BMI ratio and EDV/BSA ratio remained associated with GA at birth when adjusting for BPD. (Figure 1).

Conclusion(s): Left cardiac dimensions abnormal growth is highly associated with the degree of prematurity as it cannot be solely explained by altered postnatal growth. Future research using longitudinal echocardiographic evaluations to better elucidate risk factors directly associated with the trajectory of cardiac development are urgently needed.