Abstract 18045: Mild Coarctation of the Aorta: To Touch or Not to Touch the Patient? Looking at Left Ventricular Function and Hemodynamics

Introduction: Coarctation of the aorta (COA) is an obstruction of the aorta distal to the left subclavian artery. A peak-to-peak trans-coarctation pressure gradient (P K dP) of greater than 20 mmHg warns of severe COA and the need for interventional/surgical repair. The optimal method and timing of the intervention remain uncertain especially when the severity of COA is mild (P K dP < 20 mmHg) and it is unclear if mild COA should be treated at all. Rosenthal (2001; J Am Coll Cardiol) suggested that treatment strategies for patients with mild COA may need to be redefined as transcatheter interventions emerge, and yet the risks and benefits of such interventions in patients with mild COA are unclear. The aim of this study is to investigate the effects of transcatheter intervention on hemodynamics of the aorta and left ventricle (LV) in eleven patients with mild COA. Methods. We used specially developed computational fluid dynamics and lumped parameter modeling framework along with highly-resolved particle image velocimetry data and clinical measurements (Doppler-echocardiography, cardiac catheterization, CT and MRI) in this study. Results . COA intervention can improve aortic hemodynamics to some extent (i.e., time-averaged wall shear stress, oscillating shear index, peak jet velocity and kinetic energy [all averaged in the descending aorta] were reduced by 20%, 13.3%, 26.7% and 25%, respectively). However there is no concomitant effect on the LV hemodynamics (i.e., stroke work, normalized stroke work and peak LV pressure were reduced by only 3.8%, 3.7% and 3.2%, respectively; arterial systemic compliance was also reduced by 17%; N=11; p < 0.05). Conclusion . Our computational approach can effectively model and predict clinical conditions. Herein one must question intervention for mild COA, as it has limited utility in reducing myocardial strain. Figure 1. Catheter data and results of lumped parameter modeling in patient No. 1.