Impact of valve-sparing aortic root replacement on aortic fluid dynamics and biomechanics in patients with syndromic heritable thoracic aortic disease

ABSTRACT: Background: Patients with syndromic heritable thoracic aortic diseases (sHTAD) who underwent prophylactic aortic root replacement are at high risk of distal aortic events, but the underlying mechanisms remain unclear. This prospective, longitudinal study evaluates the impact of valve-sparing aortic root replacement (VSARR) on aortic fluid dynamics and biomechanics in these patients. Methods: Sixteen patients with Marfan or Loeys-Dietz syndrome underwent two time-resolved three-dimensional phase-contrast cardiovascular magnetic resonance (4D flow CMR) studies before (sHTAD-preSx) and after VSARR (sHTAD-postSx). Two matched cohorts of 40 healthy volunteers (HV) and 16 sHTAD patients without indication for aortic root replacement (sHTAD-NSx) with available 4D flow CMR were included for comparison. In-plane rotational flow (IRF), systolic flow reversal ratio (SFRR), wall shear stress (WSS), pulse wave velocity (PWV), and aortic strain were analyzed in the ascending (AscAo) and descending aorta (DescAo). Results: All patients with sHTAD presented altered hemodynamics and increased stiffness (p