Aortic Root Dilatation and Aortic-Related Complications in Children After Tetralogy of Fallot Repair

BACKGROUND: The study objective was to assess the severity, progression rate, and risk factors for aortic root dilatation (ARD) in pediatric tetralogy of Fallot (TOF) and to study its relationship to complications including aortic regurgitation. METHODS AND RESULTS: Seven hundred sixty-eight TOF patients were studied with echocardiography (median age at repair 6.1 months; interquartile range, 4.5-11.3 months) and compared with 304 controls. Five hundred ninety-two (77%) had usual TOF, 41 (5.3%) TOF-type double outlet right ventricle, and 135 (17.6%) TOF with pulmonary atresia. Median follow-up was 3.7 years (interquartile range, 0.5-6.9 years, total follow-up 3002 patients-years). Aortic root dimensions were enlarged at TOF diagnosis and during follow-up. Mean aortic valve annulus Z score at first postoperative echo was 3.3±2.7, associated with TOF type (TOF<TOF double outlet right ventricle<TOF/pulmonary atresia; P<0.0001). Mean maximum aortic valve diameter Z score during follow-up was 4.6±2.5. Overall, there was no rapid progression of ARD or ascending aorta dimensions during follow-up, with a marginal mean decrease of aortic valve annulus Z score during follow-up of 0.092 Z score unit per year (SE=0.010; P<0.0001). Ascending aorta showed a mean marginal increase of 0.041 Z score unit per year (SE=0.008; P<0.0001) during follow-up. No predictors of increased rate of progression were identified. ARD increase (>1 Z score unit per year) was observed in <1% of patients. Of the 768 patients, only 3 (0.39%) developed moderate/severe aortic regurgitation and 2 required aortic surgery for subvalvar aortic stenosis and aortic dissection, respectively. CONCLUSIONS: ARD is common before and after TOF repair, but our data suggest that aortic root dimensions remain stable in the majority of pediatric TOF patients. Progressive ARD and aortic-related complications are distinctly uncommon during childhood.