Abstract 16381: Stiffened Dilated Ascending Aorta Independently Predicts Decreased Aerobic Exercise Capacity in Patients With Congenital Heart Disease After Biventricular Repair
Background: Several studies have reported aortic dilatation and increased stiffness of the aorta in patients with congenital heart disease (CHD), which shall deteriorate exercise capacity and be an important predictor of cardiovascular morbidity and mortality. However, the clinical significance of the aortic abnormalities has not been clarified in CHD patients.
Methods: One hundred and eighty-five postoperative CHD patients with biventricular repairs and 40 control subjects were included (15.9 +/- 6.0, and 15.6 +/- 4.4 years old, respectively). All CHD patients underwent cardiac catheterization with aortography and cardiopulmonary exercise testing (CPX). We measured the maximum and minimum diameters of the sinus of Valsalva (S), sinotubular junction (STJ), ascending aorta (AAo), descending aorta (DAo) from the cine-angiogram (standardized by body surface area), and calculated the stiffness parameters (β) of the AAo and DAo with the corresponding systolic and diastolic pressures. We also measured the cardiac index (CI), systolic (RVp, LVp), and end-diastolic pressures (RVedp, LVedp) of the right and left ventricles. Exercise capacity was quantitated by measurement of peak oxygen uptake (peak-VO2) during CPX.
Results: In comparison with the controls, patients after RV outflow tract reconstruction (RVOTR) mainly for tetralogy of Fallot and those after Ross procedure showed significant dilatation of the STJ and increased stiffness of the AAo (p<0.05, respectively). In CHD patients, peak-VO2 was correlated with CI (r= 0.43, p< 0.001), and was inversely correlated with RVp, S, STJ, AAo, β(AAo) (r=-0.55, -0.37, -0.42, -0.41, -0.35, respectively, all p< 0.05), but not with LVp, RVedp, LVedp, DAo or β(DAo). In the multivariable model, CI (p=0.001), RVp (p=0.002), STJ (p=0.02), β(AAo) (p=0.04) were independently correlated with peak-VO2.
Conclusion: In postoperative CHD patients with biventricular physiology, especially after RVOTR, the stiffened dilated ascending aorta as well as the low cardiac output and RV hypertension has a significant adverse impact on the diminished exercise capacity.
- © 2013 by American Heart Association, Inc.