Endothelial Dysfunction of Conduit Arteries in Patients with Repaired Coarctation of the Aorta

Adult patients with repaired coarctation of the aorta (r-CoA) show high prevalence of late hypertension, but the exact mechanisms of this phenomenon are unknown. Endothelial dysfunction has been implicated in this paradoxical hypertension. We evaluated the endothelial function of both conduit and resistance arteries by using flow-mediated dilation (FMD) and digital peripheral artery tonometry (PAT).Seventeen patients with r-CoA and one patient with repaired interrupted aortic arch (r-CoA group) aged 22.0 ± 6.9 years (5 females) underwent FMD of the right brachial artery, PAT of the right finger, blood marker tests, ambulatory blood pressure monitoring, echocardiography, carotid ultrasonography, and brachio-ankle pulse wave velocity measurement. The median age at aortic arch reconstruction was 2.0 months (interquartile range: 15 days to 7.0 years). Results were compared with 17 age-matched healthy subjects (control group).Eight (44%) patients of the r-CoA group were hypertensive (5 received antihypertensive drugs). Patients in the r-CoA group showed significantly lower FMD (3.8 ± 1.5 versus 6.6 ± 2.5%, P < 0.001), larger intima-media thickness (0.63 ± 0.17 versus 0.47 ± 0.09 mm, P = 0.001), and higher left ventricular mass index (91.4 ± 24.6 versus 73.4 ± 17.3 g/m², P = 0.017) than those in the control group. There were no significant differences in PAT (refractory hyperemia index, 1.86 ± 0.43 versus 1.99 ± 0.59, P = 0.48) and brachio-ankle pulse wave velocity between the two groups.Vascular dysfunction in r-CoA patients, particularly endothelial dysfunction, tends to occur more significantly in conduit arteries than in resistance arteries.