Invasive intracoronary flow assessment in a pediatric cohort of anomalous aortic origin of the right coronary artery (R-AAOCA): is it time to expand the assessment of coronary ischemia?

Background Anomalous aortic origin of a coronary artery (AAOCA) remains a leading cause of sudden cardiac death (SCD) in the young, particularly left-AAOCA. The more common right(R)-AAOCA, albeit rare, can also lead to SCD. Risk stratification remains a challenge, especially in patients with exertional symptoms and negative noninvasive studies under stress. Purpose We report outcomes in a pediatric cohort of R-AAOCA patients undergoing invasive intracoronary flow assessment (ICFA). Methods R-AAOCA patients underwent advanced imaging and functional assessment with non-invasive provocative stress studies (EST, perfusion imaging). Patients with exertional symptoms and negative noninvasive studies had cardiac catheterization for ICFA using coronary angiography (figure 1) and a Verrata pressure guide wire. ICFA was performed at baseline and under dobutamine stress. IVUS was performed in select cases. Instantaneous wave-free ratio (iFR) was considered abnormal if ≤0.85. Fractional flow reserve (FFR) was considered abnormal if <0.8. For patients undergoing surgery, repeat catheterization was performed at 3 months postoperatively. Results Our cohort included 30 patients (figure 2) with R-AAOCA, median age 14 (9-19) years and weight 57 (37-143) kg. Of these, 24 (80%) had an intramural course median length of 6 mm. Eight (27%) patients had abnormal ICFA and surgery was offered, 1 declined. Fourteen (47%) patients had negative ICFA and among these, surgery was not offered in 12/14 (86%) and 2/14 (14%) underwent surgery given exertional symptoms and shared decision making. One (3%) patient had incomplete data and surgery was performed based on shared decision making. In 7/30 (23%) patients, stable wire position in the distal R-AAOCA could not be obtained (most early in our experience); thus ICFA was not completed. No significant complications were encountered during or after cardiac catheterization. At 3 months post-operatively, 9/9 (100%) patients with pre-operative ICFA were scheduled for repeat study: 7 completed and 2 are pending. In those completed, data normalized/improved in 6/7 (86%) and could not be obtained in 1/7 (14%) due to wire position. In medium-term follow-up, 3-5 years after surgery, there is no evidence of ischemia or concerning symptoms. Conclusion Cardiac catheterization with ICFA plays an important role in the management of R-AAOCA, especially in those patients with concerning exertional symptoms and negative noninvasive studies. Of patients with negative ICFA data, most were not offered surgery. These procedures can be technically challenging in children, with a learning curve involved. Multicenter data are warranted to better characterize the role of ICFA in management decision making in R-AAOCA, as the current cut-off values derive from adult studies with coronary artery disease, a distinct condition from (R)-AAOCA in children.figure 1figure 2