Abstract 15966: Abnormal Left Ventricular Strain Correlates With Left Ventricular Dysfunction but Not Aortic Pathology in Marfan Syndrome in Children

Abstract

Introduction: Cardiomyopathy has been described in some adults with Marfan syndrome (MFS), as demonstrated by low ejection fraction (EF) and abnormal left ventricular (LV) strain. Recent studies from our group show that LV dilation and decreased EF are common in children with MFS. However, LV strain remains understudied in children. Hypothesis: Abnormal strain is associated with lower EF, higher aortic root z-score and higher height-adjusted vertebral artery tortuosity index (VTI-h). In addition, abnormal strain with normal EF is associated with a subsequent decline in EF. Methods: Patients with MFS, defined as meeting Ghent 2010 criteria and a pathogenic FBN1 variant or ectopia lentis, <19 years of age at first cardiac magnetic resonance imaging study (CMR) from 2003-2018 were included. CMR LV circumferential and longitudinal strain were measured using feature tracking software. CMR aortic root Z-scores were calculated using both pediatric echocardiographic formulas and MRI reference data. VTI-h was measured using previously described methods. We evaluated initial CMR for associations between strain, EF, root z-scores, and VTI using Spearman correlation. A secondary analysis was performed limiting to patients with a normal EF on initial CMR, evaluating for associations between initial strain values and the outcomes of sustained normal EF versus development of low EF (<55%). Results: Of 31 included patients, median age at first CMR was 13.5 y (IQR 10.7-16.2 y). Worse circumferential strain was associated with lower EF (basal: rho = -0.586, p = 0.001; mid: rho = -0.573, p = 0.001; apical: rho = -0.406, p = 0.026), while longitudinal strain was not associated with EF (p = 0.063, 0.257, 0.260). Neither circumferential nor longitudinal strain were associated with aortic root z-score or VTI-h. Among patients with normal EF, initial circumferential strain was not different between patients who maintained normal EF or developed low EF. Conclusions: Worse LV circumferential strain was associated with lower EF in children with MFS, while longitudinal strain was not. Abnormal strain was not associated with aortic pathology or later development of reduced EF. This suggests that the cardiomyopathy seen in children with MFS is likely independent of aortic pathology.