Association of CMR-based aortic pulse wave velocity and aortic distensibility with infrarenal aortic diameter and flow: Insights of a population-based study

Abstract Introduction Cardiovascular magnetic resonance (CMR)-based aortic stiffness (AS) parameters might predict development of aortic aneurysm and long-term outcomes associated with that disease. AS is a marker for structural and functional changes within the aortic vessel wall and can be quantified by both pulse wave velocity (PWV) and aortic distensibility (AD). Purpose The purpose of this study was to analyze possible associations of PWV and AD with the infrarenal aortic diameter and peak flow velocity in a population-based cohort who underwent CMR. Methods This study cohort consisted of 2,093 participants who were enrolled in a prospective epidemiological cohort study in Germany. Aortic PWV and AD of the ascending (AD AoAsc) and AD of the descending aorta (AD AoDesc) were measured using a 3 Tesla MRI scanner and a 2D phase-contrast velocity-encoding sequence. The maximum aortic diameter and the aortic peak flow velocity of the infrarenal aorta were quantified by standardized ultrasound measurement. Results The median age of this cohort was 66 [58, 71] years and 41.9% were female. The median aortic diameter was 18.1 [16.4, 19.9] mm and the median peak flow velocity was 98.6 [83.6,115.9] cm/s. Median PWV was 7.6 [6.2, 9.8] m/s, median AD AoAsc 0.4 [0.3, 0.6] 1/(10^3*kPa) and median AD AoDesc 0.4 [0.3, 0.6] 1/(10^3*kPa). Significant associations of aortic diameter with PWV (CI 0.044 [0.003, 0.085], p=0.037), AD AoASc (CI -0.535 [-0.955, -0.115], p=0.012) and AD AoDesc (CI -0.697 [-1.164, -0.230], p=0.003) as well as of peak flow velocity were found with PWV (CI -0.715 [-1.034, -0.396], p