4D Flow MRI derived aortic pulse wave velocity and wall shear stress in Covid-19

This study aimed to investigate the changes in aortic pulse wave velocity (PWV) and wall shear stress (WSS) in COVID-19 using 4D Flow MRI.

Thirty-seven COVID-19 patients and 37 healthy controls underwent thoracic cardiovascular MRI. The PWV and WSS comparisons were performed using independent t-test. Peak velocity (PV)-peak WSS correlations in patients; aortic dimension-regional WSS correlations; PWV-age correlations were reported using Pearson correlation coefficient (r) analysis.

The global aortic PWV was higher in the patient group (p = 0.007). There was a positive correlation between patient age and PWV values (r = 0.650, p = 0.000). The patient ascending aorta (AAo) WSS levels were lower in the entire cohort, in the subgroup of ages between 50 and 70, and in the age/gender matched subgroup (p < 0.05 for all). Voxelwise 5 % PV was lower in the patient group (p = 0.005) and showed strong correlation with the 5 % peak WSS (r = 0.957). In the patient group there was a negative correlation between the maximal aortic dimension and AAo WSS (r = -0.398, p = 0.014) and aortic arch WSS (r = -0.388, p = 0.017).

The alterations to aortic stiffness in COVID-19 might be a late effect of the disease and should be confirmed in larger studies with longer follow-ups. The reasons behind the low AAo WSS levels in the COVID-19 group appears to be multifactorial and further work in larger cohorts eliminating the baseline aortic diameter and preexisting atherosclerotic risk factor differences is needed to validate our results and to establish reproducibility of the technique.