Effects of morphologic restenosis, defined by MRI after coarctation repair, on blood pressure and arm-leg and Doppler gradients.

Ten years after coarctation repair, 36 adolescents and young adults were studied in order to evaluate the relationship of anatomy at the resection site to blood pressure and arm-leg and Doppler gradients. The patients underwent magnetic resonance imaging (MRI), exercise testing, and continuous wave (CW) Doppler echocardiography. On MRI, residual narrowing at the resection site was measured as 1-(phi anastomosis/ phi descending aorta) and expressed as percent stenosis. Residual stenosis on MRI was negatively correlated with the leg pressure at rest (P = 0.0003) and during exercise (P = 0.002). Residual stenosis correlated positively with the arm-leg gradient at rest (P < 0.0001) and during exercise (P < 0.0001) and with the peak CW Doppler gradient across the anastomosis (P < 0.0001). However, residual stenosis was not related to the systolic blood pressure of the arm at rest or during exercise. The systolic arm pressures did not differ between patients with residual stenosis of less than 30% (group I), patients with residual stenosis of equal to or greater than 30% but less than 45% (group II), and patients with residual stenosis of equal to or greater than 45% (group III). In conclusion residual anatomic stenosis influences blood pressure in the legs, the arm-leg gradient, and the Doppler gradient across the anastomosis. Arm hypertension late after coarctation repair seems not to be related to residual stenosis, and the benefit of reintervention in these patients remains questionable.