Natural History of the Aortic Root in Tetralogy of Fallot After Repair

Abstract Background Aortic root dilation is described in tetralogy of Fallot (TOF) but few studies have examined the longitudinal trajectory of aortic root size over time. This study aims to evaluate changes in aortic root dimension across age in patients with repaired TOF and examine associated clinical characteristics. Methods Retrospective single-center study of TOF patients derived from a historical research cohort with up to 4 serial echocardiograms. Aortic dimensions at the annulus, sinus, and sinotubular junction (STJ) were measured and converted to Pediatric Heart Network Z-scores. Fractional polynomial regression models were fitted to describe aortic size across age after adjusting for age, sex, elevated blood pressure, and aortic valve morphology. Association of clinical variables with aortic size were examined using multivariate regression models. Results There were 126 patients (35% female, age 12.0 years [range 8.0 – 18.9] at first echo) with 426 echocardiograms. Age at last echo was 19.4 years [range 10.4 – 26.9]. Aortic annulus size was stable, whereas sinus and STJ size progressively increased with age. Male sex and pulmonary atresia were associated with increase in aortic root dimensions whereas age at repair, 22q11.2 deletion, and arch anomaly were not. Conclusions In children and young adults with TOF, the aortic annulus, sinus, and STJ are dilated compared to healthy peers. Aortic size was stable at the annulus but there was progressive increase beyond that associated with somatic growth at the sinus and most notably at the STJ. Male sex and pulmonary atresia were associated with increased aortic root dimensions.