Abstract 2002: 22q11.2 Deletion Status and the Risk of Aortic Root Dilation in Pediatric Patients With Tetralogy of Fallot
Background: Reported risk factors for aortic root dilation (ARD) in tetralogy of Fallot (TOF) include right aortic arch and pulmonary valve atresia, features seen in 22q11.2 deletion syndrome. This study examines whether 22q11.2 deletion is a risk factor for ARD in TOF.
Methods: TOF cases (n=184) were identified from research databases for whom deletion status was defined and echocardiograms performed between age 6 –19 years. Measurements at the level of the annulus, sinuses, and sinotubular junction were made by a single observer and analyzed as Z scores. No case had prior aortic root or valve repair.
Results: Of the 184 cases, 64% were male, 17% had 22q11.2 deletion, 42% had an aortic arch anomaly, and 12% had both a 22q11.2 deletion and aortic arch anomaly. TOF subtypes included pulmonary stenosis (70%), pulmonary atresia (23%), and absent pulmonary valve (7%). Echocardiograms were performed at an average age of 12 years (SD ± 3 yrs). In the total cohort, dilation of the aortic root (Z score >3) occurred at the aortic annulus (21%), sinuses (28%) and sinotubular junction (10%). Neither deletion status nor aortic arch anomalies were independently associated with ARD, but the combination of the two was a risk factor for aortic annular dilation with a Z score of 3.0 as compared to 1.7 in those with one or neither feature (p<0.02). Similarly, the sinuses were dilated in the subset with both features as compared to the rest of the cohort (Z score of 3.1 vs 2.0 respectively), but this was not statistically significant (p=0.15). Male sex (p<0.02) and pulmonary valve atresia (p<0.002) were additional risk factors for dilation of both the annulus and sinuses. There were no identified risk factors for dilation at the sinotubular junction. Of note, increasing age (p<0.011) was associated with a decrease in Z-score at all three aortic root measurements.
Conclusions: Pediatric TOF cases with 22q11.2 deletion and concurrent aortic arch anomalies have an increased risk of aortic annular dilation. Overall, in our total cohort, Z-scores decreased with age, but we speculate that a subset will develop progressive ARD as they enter adulthood. Further longitudinal study is needed to assess if patients with both 22q11.2 deletion and arch anomalies are at higher risk for progressive ARD over time.