Advanced imaging and intervention in congenital heart disease

Abstract

Background. Even after successful repair for coarctation of the aorta (CoA) abnormal blood flow patterns can be expected due to aortic narrowing, a changed aortic geometry after repair, or generalized aortopathy, all of which may have a negative impact on left ventricular (LV) performance. The aim of this study is to investigate the relationship between aortic haemodynamics assessed by four-dimensional flow (4D flow) cardiac magnetic resonance imaging (CMR) and LV performance in CoA patients. Methods.CoA patients with a clinical indication for CMR underwent additional 4D flow acquisition. Wall shear stress, oscillatory shear index, vorticity, viscous dissipation, energy loss, kinetic energy and velocity angle were assessed for several aortic segments at peak-systole. Global pulse wave velocity (PWV) was assessed for the entire aorta, as well as LV ejection fraction, volumes, and mass.Results. A total of 17 CoA patients were included. Increased velocity angle in the ascending aorta was correlated with decreased LV mass (p = 0.0445). Energy loss at the CoA site and increased degree of vorticity in the descending aorta were correlated with increased LV end-diastolic and end-systolic volume (p = 0.0499, p = 0.0461, respectively). PWV was correlated with LV mass and LV end-systolic volume (p = 0.0385, p = 0.0397, respectively). Apart from energy loss the CoA site, all correlations remained significant after correction for age. Conclusion.Adverse aortic-ventricular interaction in CoA patients was demonstrated by abnormal aortic haemodynamics by 4D flow assessment and was associated with impaired LV performance. 4D flow CMR may provide novel parameters to assess aorticventricular interaction in patients with CoA.