Distal Transverse Arch to Left Carotid Artery Ratio Helps to Identify Infants With Aortic Arch Hypoplasia

Abstract

Aortic coarctation (CoA) with concomitant aortic arch hypoplasia (AAH) is associated with an increased risk of hypertension after surgical repair. The differentiation of CoA with or without AAH may be critical to delineate the ideal surgical approach that best ameliorates postoperative hypertension. Since 2000, we have defined CoA with AAH when the diameter of the distal transverse aortic arch is equal to or less than the diameter of the left carotid artery. We hypothesized that, based on our definition, aortic tissue from infants having CoA with AAH would demonstrate distinct genetic expression patterns as compared with infants having CoA alone. From 6 infants (AAH, 3; CoA, 3), an Affymetrix 1.0 genome array identified genes in the coarctation/arch region that were differentially expressed between infants having CoA with AAH versus CoA alone. Reverse transcription polymerase chain reaction validated genetic differences from a cohort of 21 infants (CoA with AAH, 10; CoA, 11). To evaluate the clinical outcomes based on our definition of CoA with AAH, we reviewed infants repaired using this algorithm from 2000 to 2010. Microarray data demonstrated genes differentially expressed between groups. Reverse transcription polymerase chain reaction confirmed that CoA with AAH was associated with an increased expression of genes involved in cardiac and vascular development and growth, including hepsin, fibroblast growth factor-18, and T-box 2. The clinical outcomes of 79 infants (AAH, 26; CoA, 53) demonstrated that 90.1% were free of hypertension at 13 years when managed with this surgical strategy. These findings provide evidence that the ratio of the diameter of the distal transverse arch to the left carotid artery may be helpful to identify CoA with AAH and, when used to delineate the surgical approach, may minimize hypertension.