Abstract 14205: Aortic Vorticity, Helicity and Aortopathy in Adult Patients With Tetralogy of Fallot: Preliminary Study Using Four-dimensional Flow Magnetic Resonance Images

Abstract

Introduction and hypothesis: Flow hemodynamic parameters may relate to aortopathy in adults with tetralogy of Fallot. We aimed to employ quantitative analysis in the vorticity and helicity of the aortic root and the ascending aorta (AAo) in adults with tetralogy of Fallot (TOF), and to evaluate aortopathy and the relevant factors. Methods: Prospectively, 51 consecutive adults with TOF underwent 4 dimensional flow magnetic resonance imaging study for the assessment of vorticity and helicity of in the aortic root and AAo, wall shear stress (WSS), viscous energy loss (EL), and the left ventricular outflow tract - aortic root (LVOT-Ao) angle. Patients were divided into the two groups: dilated aortic root and/or AAo (indexed dimeter>25mm/cm2), Group A (15 patients); non-dilated aortic patients, Group B (36 patients). Ten age matched controls were also enrolled. Results: Group A showed acute LVOT-Ao angle, higher incidence of aortic regurgitation, and initial anatomy of pulmonary atresia, compared to Group B (P<0.0001, 0.02, 0.043). Group A showed greater vorticity at the level of Valsalva, AAo, and proximal arch, helicity, WSS, and EL than in Group B (P<0.001, <0.001, 0.049, 0.02, 0.026). Acute LVOT-Ao angle correlated with the diameter of the aortic root and AAo, vorticity, helicity, WSS, and EL (P=0.004, 0.023, 0.045, 0.004, 0.0004, 0.017). On a univariate logistic analysis, age, acute LVOT-Ao angle, AAo vorticity, AAo helicity, and maximum WSS were relevant factors of AAo dilatation (P=0.03, 0.02, 0.004, 0.03, 0.046). On a multivariate analysis, LVOT-Ao angle was the most important factor of AAo dilatation (odds ratio 0.66, 95%CI 0.46-0.95, P<0.024). Conclusions: TOF Adults with TOF presenting dilated AAo have greater vorticity, helicity, and acute LVOT-Ao angle. Flow eccentricity correlates with vorticity and helicity, which may affect the aortopathy in adults with TOF. AAo vorticity and helicity are also relevant factors of aortic dilatation, and these flow hemodynamic parameters may be adjunctive predictions of aortopathy in this population.