OBJECTIVE This study was designed to investigate the influence of aortic arch geometry on vascular remodeling after anatomically successful repair of coarctation of the aorta (CoA). BACKGROUND Abnormalities of the precoarctation vasculature are known to occur after CoA repair and appear related to adverse outcomes. The influence of aortic arch geometry on such abnormalities is unknown. METHODS Sixty-three postcoarctectomy subjects (age 15.9 +/- 6.3 years) were compared with 63 control volunteers. Aortic arch shape was characterized on magnetic resonance imaging using both qualitative classification, identifying 3 subtypes of arch geometry (Gothic, Crenel, Romanesque), and a quantitative index, height/width ratio (H/W) of the aorta. Using ultrasound, we measured carotid artery intima-media thickness (IMT) and stiffness index and distensibility, as well as right brachial artery flow-mediated dilation (FMD) and glyceryl trinitate (GTN)-induced dilatation, to assess the precoarctation vasculature of these subjects. RESULTS Gothic arch type was associated with higher carotid IMT and stiffness index, lower carotid distensibility (p < 0.001 for all), and lower brachial reactivity (FMD, p < 0.01; GTN response, p < 0.001) compared with Crenel and Romanesque geometries and with control subjects. The height/width ratio was also significantly related to these vascular abnormalities. Even in CoA subjects with Romanesque arch geometry, arterial function and stiffness parameters were significantly impaired compared with control subjects. CONCLUSIONS In young adult survivors of anatomically successful CoA repair, a gothic-type aortic arch with high H/W is associated with abnormal IMT, higher aortic stiffness index, and impaired arterial reactivity in the pre-CoA vasculature.