P0419 - Variation in Recovery of Myocardial Strain in Infants with Coarctation Who Present with Left Ventricular Dysfunction

Background: Infants with delayed diagnosis of aortic coarctation who present with left ventricular (LV) dysfunction are typically treated with heart failure medications until their LV ejection fraction (EF) normalizes. LV strain is a measure of ventricular function that has been shown to be more reproducible than EF and to correlate with clinical outcomes in many patient populations. We aimed to determine the evolution in strain measurements from the initial echocardiogram to the first post-operative echocardiogram showing a normal LVEF in infants with coarctation and moderate-severe LV dysfunction at presentation.

Methods: We queried a tertiary care children’s hospital database (2010-2020) using surgical codes for coarctation repair with/without arch reconstruction. Inclusion criteria were age <6 months, no additional hemodynamically significant cardiac defects, and moderate-severe LV dysfunction (EF <40%). Analyses included descriptive statistics and paired t-test for comparison of continuous variables.

Results: Of the 21 infants with moderate-severe LV dysfunction at presentation, 12 were male (57%). The median age at diagnosis was 13 days (range 5-142 days). At presentation, the median LVEF was 32% (16-38%). LVEF normalized by a median of 6 days post-op (1-230 days). GLS was measured on 16/21 (76%) presentation echocardiograms and 14/21 (67%) follow-up studies. The median initial GLS was 6.9% (1.3 to 14.5%). At the first echocardiogram with a normal LVEF (≥55%; median 66, range 55-75%), the median GLS improved to 15.2% (p<0.001) but varied widely (7.3 to 27.3%) and 7/14 (50%) infants continued to have an abnormal GLS (<15.0%; median 11.7, range 7.3-14.8%).

Conclusion: LV GLS was abnormal in infants presenting with aortic coarctation and LVEF <40%. Although GLS improved by the first echocardiogram with normal LVEF, GLS remained abnormal in half of infants, suggesting variation in myocardial recovery that is not captured by LVEF alone. Further study is needed to determine if using LV GLS as a guide to adjust heart failure medicines improves the management of these infants.