The aim of this study was to explore the clinical impact of transverse aortic arch hypoplasia (TAH) after stent implementation for isthmal coarctation of the aorta (CoA). From a retrospective chart review, 51 children (median age 11.1 years) were identified who had TAH and a CoA stent implanted between 10/1995 and 4/2015. Arm-leg cuff blood pressure measurements, echocardiographic arch imaging, and 24-h ambulatory blood pressure monitoring, prior to and after stent implantation, were reviewed. At catheterization, peak systolic gradients across the CoA's were 25 mmHg before and 4 mmHg after stent implantation. At a median 37-month follow-up, echocardiographic imaging showed no significant catch-up growth in the transverse arch (median z-score; proximal and distal arch -1.54 and -1.99 vs. -1.78 and -1.63, p = 0.13 and 0.90). A trend to increasing systolic blood pressure (SBP) differentials between the right and left arms was noted (11 mmHg [prior to]; 16 mmHg [follow-up], p = 0.09). Age-adjusted percentiles for right arm SBP decreased from 99.7% prior to, and 87.6% in follow-up (p < 0.001). The median time to re-intervention was 5.6 years (95% CI [2.8, 7.8]) and the proportion of children using anti-hypertensive in follow-up was not significantly different before the implantation (38% [prior to]; 45% [follow-up]). Elevated right arm blood pressure persists after successful stent implantation in the setting of associated TAH and there appears to be no catch-up growth of the transverse arch with time. Medical management can be difficult and approaches to surgical arch augmentation or stent implantation should be considered to avoid unilateral arm hypertension.