Increased Carotid Wall Stress in Vascular Ehlers-Danlos Syndrome

Abstract

Background— Vascular Ehlers-Danlos syndrome (vEDS), also known as EDS type IV, an inherited disorder of connective tissue, results from mutations in the gene encoding type III procollagen ( COL3A1 ). Affected patients are at risk for arterial dissection or rupture, the main cause of death. To understand the pathogenesis of the vascular lesions, we used a biomechanical approach and determined steady and pulsatile wall stress. Methods and Results— Sixteen patients with vEDS and 16 age-, gender-, and blood pressure–matched control subjects were included in this cross-sectional noninvasive study. Circumferential wall stress was determined under steady and pulsatile conditions at the site of an elastic (common carotid) and a muscular (radial) artery from the measurements of intima-media thickness and internal diameter with high-resolution echo-tracking systems and either mean blood pressure or pulse pressure, respectively. At the site of the carotid artery, steady circumferential wall stress was 43% higher in vEDS patients than in control subjects (68.9±14.3 versus 48.2±12.1 kPa, P <0.001), and pulsatile circumferential wall stress was 22% higher (28.2±7.7 versus 23.1±5.7 kPa, P <0.001). Carotid intima-media thickness was 32% lower (408±56 versus 598±171 μm, P <0.001) in vEDS patients, and internal diameter was not different between groups. Radial artery parameters were not significantly different between groups. Conclusions— In vEDS patients, an abnormally low intima-media thickness generates a higher wall stress than in control subjects at the site of an elastic artery, which may increase the risk of arterial dissection and rupture.