Abstract 2160: Adverse Aortic Remodelling in Children Post Palliation of Hypoplastic Left Heart Syndrome Assessed by Cardiovascular Magnetic Resonance Imaging
Introduction: The status of the reconstructed aorta in hypoplastic left heart syndrome (HLHS) is considered an important determinant for long-term prognosis. We assessed anatomy, elastic properties and late gadolinium enhancement (LGE) of the aorta as well as their impact on aortic valve competence and right ventricular (RV) function in HLHS patients post palliation by CMR imaging.
Methods: CMR was performed in 40 HLHS patients (age: 6.04+/− 2.22) and 10 controls (age: 7.3+/− 3.2). Aortic dimensions and distensibility were calculated at 5 different locations of the thoracic aorta using fast gradient echo cine imaging (TR/TE/α = 1.4/2.4 ms/65°, FOV 340 mm) at 3 Tesla (Philips, Achieva). Late enhancement imaging for viability assessment using an ECG triggered 3D inversion recovery sequence (TR/TE/α = 3.7/1.8 ms/15°; voxel size 1.17 × 1.27 × 10 mm) was applied. Additionally, aortic regurgitant (AR) fraction, and RV ejection fraction (RV-EF) were measured.
Results: Compared to controls, HLHS patients had increased diameters (aortic root: axial 27.97±3.34 vs. 22.26±2.96 mm, sagittal 26.10±2.90 vs. 19.91±3.63 mm; ascending aorta: axial 24.89±3.86 vs. 19.36±3.46 mm, sagittal 22.00±2.77 vs. 17.89±2.92 mm; p<0.05) and reduced distensibility (ascending aorta 4.13±2.42 vs.10.10±2.83 10−3 1/mmHg, aortic arch 5.44±3.57 vs. 9.15±2.07 10−3 1/mmHg; p<0.05) of the central aorta. Reduced distensibility in the ascending aorta correlated with decreased RV-EF (r=0.53, p<0.01) and LGE in the aortic root (r=0.72, p<0.01). Aortic LGE also correlated with decreased RV-EF (r=0.50, p<0.01). Increased diameters of the central aorta (aortic root: axial r=0.47, sagital r=0.51; p<0.05; ascending aorta: axial: r=0.66, sagittal: r=0.61; p<0.01) correlated with AR fraction.
Conclusions: Adverse aortic remodelling post palliation of HLHS is characterized by aortic dilatation and delayed gadolinium enhancement and associated with decreased RV-EF and aortic regurgitation due to unfavourable aortic-ventricular coupling. Therefore, patients at risk risk of adverse aortic remodelling may benefit from regular CMR follow-ups.