Background: Mild transverse aortic arch (TAA) hypoplasia is common after coarctation treatment, but is considered benign in the absence of an arm-leg systolic blood pressure (SBP) difference. Hypertension (HTN) is a common long-term morbidity after successful coarctation treatment. We examined whether mild TAA hypoplasia after coarctation treatment is associated with late systemic HTN. Methods and Results: We retrospectively reviewed 92 patients (median age, 19.9 years; range, 4.9 to 57.8; 60% male) 14.1±10.3 years after successful coarctation treatment (surgery in 63, stent in 16, and balloon dilation in 13), excluding those with resting right arm-leg blood pressure gradient >20 mm Hg, atypical coarctation, and major associated heart defects. Minimum body-surface area (BSA)-adjusted TAA cross-sectional area (CSA) was calculated from cardiac magnetic resonance (CMR) images. On follow-up, 38 of 92 (41%) patients had systemic HTN using standard criteria. Systemic HTN was independently associated with smaller TAA CSA/BSA (P=0.006; odds ratio [OR], 6.41 per 0.5 cm2/m2 decrease), higher age at CMR (P=0.03; OR, 1.57 per 5-year increase), and in a subset (n=61), higher arm-leg SBP difference during exercise (P=0.05; OR, 1.03 per 1-mm-Hg increase). Lower ratio of TAA diameter/descending aorta diameter was associated with a larger increase in right arm SBP during peak exercise (P=0.006; r2=0.11). Conclusions: Persistent mild aortic arch hypoplasia, even in the absence of an arm-leg SBP difference at rest, is associated with late systemic HTN. Further studies should be undertaken to determine whether more-aggressive arch reconstruction at initial repair can reduce the incidence of systemic HTN.
