Arm-Leg Blood Pressure Gradient in Clinic to Predict Arch Hemodynamics and Ventricular Size after Coarctation Repair

Abstract

Objective: Patients with successfully repaired coarctation of the aorta (CoA) need continued follow-up due to risks of restenosis and abnormal arterial compliance, causing early onset hypertension/coronary artery disease. We hypothesize that subtle hemodynamic and structural abnormalities can be predicted in the clinic by an abnormal arm-leg blood pressure (BP) gradient (i.e. arm > leg systolic BP). Design: Uncomplicated CoA patients repaired between 1990 and 2007 with follow-up clinic visits documenting right arm and leg systolic BPs, along with a recent echocardiogram, were studied. Data included the Doppler peak instantaneous (PeakV) and mean velocities (MeanV) in the descending aorta along with measures of the proximal transverse arch (TA) diameter and left ventricular wall (LVPWd) thickness. Measurements were indexed by Z-scores. Patients were grouped by higher systolic BP in the leg (Group 1) or arm (Group 2). Results: Eighty-one patients met the criteria with 52 in Group 1 (median 12.5 years follow-up) and 29 in Group 2 (median 12 years follow-up). Group 2 group had significantly increased arm systolic BP Z-scores (p <0.01), PeakV (p <10-4 ), MeanV (p <10-6 ), and LVPWd (p <0.01) compared to Group 1. There was no difference, however, in arm diastolic BP (p =0.7) or TA diameter (p =0.5). These relationships held true even in otherwise “silent” patients without clinical hypertension. Conclusion: Abnormal arm-leg blood pressure gradients accurately identified CoA patients with elevated arch velocities and increased ventricular wall thickness years after repair. The arm-leg pressure measurements could more accurately select patients in need of further imaging studies and therapeutic interventions.