Three-dimensional distensibility of the aorta derived from four-dimensional cardiovascular magnetic resonance in young and middle-aged adults with Marfan syndrome

Abstract

Background: Acute aortic syndromes in Marfan syndrome (MFS) often occur before reaching the surgical diameter threshold, highlighting the need for new imaging biomarkers.

Objectives: Aim was to compare cardiovascular magnetic resonance (CMR)-derived aortic three-dimensional (3D) distensibility and displacement in MFS patients with or without a history of aortic root surgery (RR or native) and healthy volunteers.

Methods: The participants underwent 3T CMR of the thoracic aorta using an accelerated non-contrast-enhanced, free breathing, 3D cine balanced steady state free precession sequence, with spatiotemporal resolution: (1.0 mm)(3)/similar to 33ms. A deep learning-based algorithm was used to obtain aorta segmentations. Non-rigid registration of these segmentations was subsequently used to calculate 3D distensibility and its separate components: 2-dimensional distensibility, longitudinal strain, and displacement in the ascending (AAo) and descending aorta (DAo). Results: Forty-seven volunteers, 51 native, and 33 RR MFS patients were included. AAo and DAo distensibility (10(-3)*mmHg(-1)) were different for healthy volunteers vs native vs RR patients (AAo: 5.1 +/- 1.4 vs 3.6 +/- 1.4 vs. 1.4 +/- 0.7, p<0.001, DAo: 3.2 +/- 1.1 vs. 2.5 +/- 0.9 vs 2.4 +/- 1.0, p=0.001). Sinotubular junction displacement (mm) was significantly higher for healthy volunteers vs native MFS vs RR MFS patients (10.3 +/- 1.3 vs 8.7 +/- 2.1 vs 5.7 +/- 1.6, p<0.001). In native patients, age (beta=-0.06 (95% CI:-0.10 to -0.01), p=0.014) and root diameter (beta=-0.1 (95% CI: -0.19 to -0.02), p=0.018) were negatively associated with AAo 3D distensibility, independent of male sex, body surface area, and aortic tortuosity index. Conclusion: Aortic 3D distensibility and displacement, derived from 4-dimensional CMR, were significantly diminished in MFS compared to volunteers and should be investigated longitudinally to assess their potential value in predicting aortic events and guiding therapy.