Background: Patients with repaired coarctation are at increased risk of hypertension and cardiovascular disease despite successful repair. We studied the function of conduit arteries in upper and lower limbs of patients late after successful coarctation repair and its relation to age at surgery.
Methods and results: Flow-mediated dilatation (FMD) and the dilatation after sublingual nitroglycerin (NTG, 25 microgram) were measured by using high-resolution ultrasound in the brachial artery in 64 coarctation patients (44 males and 20 females, aged 19+/-10 years; median age at operation 4 months) and 45 control subjects (28 males and 17 females, aged 19+/-10 years) and in the posterior tibial artery in 37 patients and 22 control subjects. Arterial stiffness was determined by pulse-wave velocity (PWV) of the brachioradial and femoral-dorsalis pedis tracts. Patients, compared with control subjects, had lower brachial FMD (7.16+/-3.4% versus 8.62+/-2.3%, respectively; P=0.02) and NTG (11.46+/-4.3% versus 13.21+/-4.6%, respectively; P=0.046) and higher brachioradial PWV (9.17+/-3.1 versus 8.06+/-1.9 m/s, respectively; P=0.05). In contrast, posterior tibial FMD, NTG, and lower limb PWV were comparable. Age (months) at the time of repair was related to brachioradial PWV (r=0.42, P=0.002) but not to brachial FMD or NTG.
Conclusions: Patients with repaired aortic coarctation have impaired conduit artery function, with abnormal responses to flow and NTG, and increased vascular stiffness confined to the upper part of the body. Early repair is associated with preserved elastic properties of conduit arteries, but reduced reactivity remains.