Central and Peripheral Arterial Stiffness in Patients After Surgical Repair of Tetralogy of Fallot: Implications for Aortic Root Dilation

Abstract

Background: Intrinsic histological abnormalities of the aorta and progressive aortic root dilation after surgical repair are documented in TOF patients. We sought to test the hypotheses that: 1.preferential stiffening of the central over the peripheral conduit arteries occurs in patients after surgical repair of tetralogy of Fallot (TOF); and 2.central arterial stiffening is related to aortic root dilation. Methods: The heart-femoral pulse wave velocity (PWV), femoral-ankle PWV, carotid augmentation index, and body surface area-adjusted aortic sinotubular dimension, were determined in 31 children after TOF repair and compared with those in 31 age-matched controls after left-to-right shunt repair. In addition, the PWVs and augmentation index were related to the sinotubular junction dimension. Results: When compared with controls, patients had significant greater heart-femoral PWV (666± 151 cm/s vs 587± 81 cm/s, p=0.021) and carotid augmentation index (−14.1± 17.0 % vs −25.2± 14.6 %, p=0.016), whereas the right (p=0.42) and left (p=0.25) femoral-ankle PWVs were similar between the two groups. The sinotubular junction z score of patients was significantly greater than that of controls (4.7± 1.5 vs 1.1± 1.4, p<0.001). Univariate analysis showed that sinotubular junction z score correlated positively with diastolic blood pressure (r=0.26, p=0.04), heart-femoral PWV (r=0.43, p=0.001), and carotid augmentation index (r=0.46, p=0.001). Multiple linear regression identified patient group (β =0.72, p<0.001) and heart-femoral PWV (β =0.26, p=0.007) (model R2=0.70) as significant determinants of sinotubular junction z score. Conclusions: Aortic stiffening occurs in patients after repair of TOF, which may contribute to progressive dilation of the aortic root in the long-term.