Aortic arch shape after arch repair predicts exercise capacity: a multicentre analysis

Figure 1. (A) Location of measurements of the aorta at the root, sinotubular junction (STJ), ascending aorta (AAo), distal AAo measured proximal to the origin of the innominate artery, proximal transverse arch (prox), distal transverse arch (dist), isthmus, proximal descending aorta (DAo), and distal DAo at the level of the diaphragm. (B) Axial plane from phase contrast cardiac magnetic resonance imaging at the level of the right pulmonary artery demonstrating location of flow measurements at the AAo and DAo. %DAo flow was defined by DAo flow/AAo flow.

Figure 2. Distribution of patients from each of the four centres: Children’s National Hospital (CNH), Boston Children’s Hospital (BCH), Advocate Children’s Hospital (ACH), and University of Chicago Medical Center (UCMC), and exercise equipment used.

Figure 3. (A) Histogram of absolute peak oxygen consumption (VO2 max) among the cohort. (B) Histogram of % predicted VO2 max. The dashed line at 90% predicted VO2 max separates the groups of decreased capacity (n = 28) and normal exercise capacity (n = 30).

Figure 4. (A) Aorta size mismatch (DAAo/DDAo) negatively correlated with per cent predicted peak oxygen consumption (VO2 max). (B) A sub-analysis was performed on patients without evidence of arch obstruction by echocardiogram, defined by peak velocity < 2.2 m/s. The negative correlation of DAAo/DDAo and VO2 max was stronger in this group without arch obstruction. (C) DAAo/DDAo also negatively correlated with the ventilatory anaerobic threshold (VAT) as a percentage of predicted VO2 max. (D) Similar to peak exercise capacity, sub-analysis of patients without arch obstruction by echocardiogram demonstrated a stronger negative correlation between DAAo/DDAo and predicted VAT.

Figure 5. Per cent descending aorta (%DAo) flow positively correlated with per cent predicted peak oxygen consumption (VO2 max), i.e. more flow to the descending aorta at rest is associated with better exercise capacity.

Figure 6. The negative correlation of aorta size mismatch (DAAo/DDAo) with exercise capacity (VO2 max) is maintained in patients with a unicuspid or bicuspid aortic valve (r = −0.66, P < 0.0001). The correlation is not significant when assessing only patients with a tricuspid aortic valve (r = −0.33, P = 0.16).