Abstract
BACKGROUND: Patients with coarctation of aorta (COA) have arterial stiffening, and this is associated with impaired cardiac reserve and hypertensive systolic blood pressure (SBP) response during exercise. However, whether patients with COA have concomitant left ventricular (LV) stiffening and the potential impact of combined ventricular-arterial stiffening on exercise hemodynamics are unknown. METHODS: We studied 174 patients with repaired COA (aged 39 ± 11 years and male 103 [59%]) and 174 matched controls. Our study hypotheses are: (1) patients with COA have higher ventricular-arterial stiffness (end-systolic elastance [Ees] and arterial elastance [Ea]) as compared with controls; (2) ventricular-arterial stiffness was associated with LV stroke volume augmentation (ΔLVSV) and SBP augmentation (ΔSBP) during exercise among patients with COA. RESULTS: Despite similar systolic SBP, patients with COA had higher Ea (1.8 ± 0.4 vs 1.4 ± 0.4 mm Hg/mL, P < 0.001), higher Ees (2.41 ± 0.65 vs 2.17 ± 0.40 mm Hg/mL, P < 0.001), but similar Ea/Ees (0.87 ± 0.29 vs 0.83 ± 0.33, P = 0.2). ΔLVSV was 6.1 ± 1.4 mL/beat. Combined ventricular-arterial stiffness had a stronger correlation with ΔLVSV as compared with Ea alone (r = -0.53 vs r = -0.41, P = 0.006) and as compared with Ees alone (r = -0.53 vs r = -0.46, P = 0.02). ΔSBP was 48 ± 21 mm Hg. Combined ventricular-arterial stiffness had a stronger correlation with ΔSBP as compared with Ea alone (r = 0.57 vs r = 0.43, P < 0.001) and as compared with Ees alone (r = 0.57 vs r = -0.39, P < 0.001). CONCLUSION: Patients with COA had combined ventricular-arterial stiffening, and this was associated with impaired cardiac reserve and hypertensive SBP response during exercise. These findings provide foundation for further studies to determine whether drugs that reduce both ventricular and arterial stiffness will improve exercise capacity and hemodynamics in this unique population.