Cardiovascular magnetic resonance assessment of aortic root dilatation in adult patients after tetralogy of fallot repair

Abstract

Purpose: Cardiovascular magnetic resonance (CMR) is an important tool in the follow-up of repaired tetralogy of Fallot (ToF). The dilatation of the aortic root (Ao dil) with risk of aneurysm and dissection is a recognized complication. We aimed to find possible predictors of Ao dil late after ToF repair. Methods: We included patients (pts) aged ≥ 18 years and we measured the maximal absolute diameter of the aortic root at the level of the sinuses of Valsalva (AoD), assessed by CMR, using SSFP cine sequences and angiography. We defined two groups: group 1 - with Ao dil (AoD ≥ 38 mm) and group 2 - without Ao dil (AoD < 38 mm). The CMR protocol included the evaluation of biventricular volumes and systolic function, and degree of pulmonary regurgitation. Exclusion criteria were: Associated heart disease congenital or acquired, genetic syndromes, unrepaired ToF, pregnancy, claustrophobia and contraindications for CMR. Results: We included 53 consecutive pts from March 2011 till December 2012 (mean age 32±10 years; 62% female); 46 pts (87%) were asymptomatic. The mean follow-up time since ToF repair was 23±7 years. In 29 pts (55%) an aortopulmonary (AP) shunt was done prior to complete ToF repair, with a median interval of 3 years. In 17 pts complete repair used a transannular patch. In 10 pts (19%; 9 male) we identified Ao dil. Only 3 out of 10 pts with right aortic arch had Ao dil. Male gender (p<0.0001), older age (39±12 vs 30±9 years; p=0.014), and higher body surface area (BSA 1.92±0.11 vs 1.65±0.19 m2; p<0.0001), left ventricle end-diastolic volume (LVEDV 170±41 vs 124±29 mL; p<0.0001), LVEDV indexed to BSA (LVEDV index 88±19 vs 75±14 mL/m2; p=0.023), left ventricle end-systolic volume (LVESV 76±26 vs 51±17 mL; p=0.022), LVESV indexed to BSA (39±12 vs 31±9 mL/m2; p=0.024) and left ventricle mass indexed to BSA (60±14 vs 52±9 g/m2; p<0.0001) were associated with Ao dil. None of the surgical variables studied (previous AP shunt, transannular patch, time to AP shunt, time between AP shunt and complete repair, time to complete repair) were significantly different between group 1 and 2. In multivariate analysis male gender was the only independent predictor of Ao dil (odds ratio 27.42, 95% confidence interval 1.95-386.48; p=0.014), after adjusting for age, previous AP shunt, follow-up time since ToF surgical repair and for LVEDV index. Conclusions: In this study male gender was the only independent predictor of aortic root dilatation late after ToF repair. In this context, CMR can be used in the screening of pts at risk of late Ao dil and therefore can contribute to prevent its potential complications.