Anomalous Aortic Origin of a Coronary Artery

Abstract

Anomalous aortic origin of a coronary artery (AAOCA) is the second leading cause of sudden cardiac death in young athletes. The pathophysiology leading to sudden cardiac death, the specific risks associated with the different varieties of AAOCA, and the effects of different management strategies on the risk of sudden cardiac death are all unknown. This article describes the current knowledge of AAOCA, a proposed nomenclature for the different anatomic subtypes, the different modalities used to diagnose and characterize the disease, the available management strategies, and an algorithm used by the authors to diagnose and manage these patients.

Keywords: AAOCA; anomalous aortic origin of a coronary artery; coronary anomaly; sudden cardiac death.

Figure 1.

Topography map to identify the location of the coronary ostia. Each sinus is indicated by a number, and the radial location of the ostium within the sinus is indicated by a letter. The height of the ostium in the aortic root/ascending aorta is indicated by a Roman numeral. The normal location of the left main coronary ostium is 2b-I and the normal location of the right coronary ostium is 1b-I. © 2013 Texas Children's Hospital (reprinted with permission).

Figure 2.

Nomenclature for the relationship between two coronary ostia. Grade 1: two separate ostia; grade 2: separate but adjacent ostia; grade 3: common ostium with bifurcation within the aortic wall; grade 4: single coronary with bifurcation outside of the aortic wall. © 2018 The University of Texas Dell Medical School (reprinted with permission).

Figure 3.

Intraoperative image of a patient with an anomalous left coronary artery and a very thick intercoronary pillar (arrow). The intercoronary pillar likely plays an important role in the compression of the anomalous coronary artery that travels behind. © 2015 Texas Children's Hospital (reprinted with permission).

Figure 4.

Computerized tomographic angiography demonstrating an anomalous right coronary artery. (A) The anomalous right coronary arises from the left sinus and travels intramurally and in between the aorta and the pulmonary artery. (B) A virtual angioscopy shows a normal left coronary ostium (arrowhead) and the anomalous right coronary with a stenotic slit-like ostium arising just above and to the left of the intercoronary commissure. (C) The anomalous coronary (arrow) has an oval shape on its intramural segment compared to (D) the round shape of the distal coronary past its intramural segment. © 2014 Texas Children's Hospital (reprinted with permission). Ao: aorta; PA: pulmonary artery

Figure 5.

Algorithm for diagnosis and management of anomalous aortic origin of a coronary artery at Texas Children's Hospital. © 2018 Texas Children's Hospital (reprinted with permission). ALCA-R: anomalous left coronary from the right sinus; ALCx: anomalous left circumflex artery; ARCA-L: anomalous right coronary from the left sinus: CAP: Coronary Anomalies Program; CTA: computerized tomographic angiography; MRI: magnetic resonance imaging; IVUS: intravascular ultrasound; FFR: fractional flow reserve

1. ^a Consent obtained for participation in prospective Congenital Heart Surgeons' Society and Texas Children's Hospital databases.

2. ^b Additional studies may be performed depending on the clinical assessment.

3. ^c External echocardiograms do not need to be repeated if the study is deemed appropriate.

4. ^d CPET or stress cMRI are not necessary on patients who present with aborted sudden cardiac death. These studies may be deferred in young patients.

5. ^e An external CTA may be used if images can be uploaded and the study provides all necessary information to make a decision. These studies may be deferred in patients < 8 years unless there are clinical concerns.

6. ^f An intraseptal coronary is an abnormal vessel (usually a left coronary arising from the right sinus) that travels posteriorly into the septum below the level of the pulmonary valve.

7. ^g Unroofing if significant intramural segment, neo-ostium creation, or coronary translocation if intramural segment is behind a commissure, coronary translocation if short or no intramural segment. Surgical intervention will be offered for these patients between ages 10–35; other patients will be considered on a case-by-case basis. Aspirin will be administered for 3 months after surgery.

8. ^h Restriction from participation in all competitive sports and in exercise with moderate or high dynamic component (eg, soccer, swimming, tennis, basketball, football).

9. ⁱ Patient may be seen by outside primary cardiologist.

10. ^j Postoperative patients will be cleared for exercise and competitive sports based on findings at the third month postoperative visit, including results of CPET, stress cMRI, and CTA.

Figure 6.

Unroofing procedure for an anomalous right coronary artery from the left sinus. (A) The anatomy prior to unroofing. The left coronary ostium (small arrowhead) is large, round, and normal (2b-I). The right coronary ostium (large arrowhead) is stenotic and slit-like, just above and rightward to the intercoronary commissure (long arrow), located at 2a-II. The fine suture (small arrow) is placed transmurally and indicates the site where the right coronary arises out of the aorta externally. (B) The intramural segment has been unroofed. A medium-thickness intercoronary pillar (small arrow) can be seen. (C) The end results after placement of tacking sutures around the unroofed segment. The right coronary ostium (large arrowhead) is now wide open and away from the intercoronary pillar (small arrow). © 2018 Texas Children's Hospital (reprinted with permission).

Figure 7.

Diagram illustrating the result of unroofing an anomalous coronary artery with a long and a short intramural segment. (A) If a there is a long intramural segment, unroofing eliminates the intramural segment, enlarges the ostium, and effectively moves the ostium to the correct sinus. (B) On the contrary, if it the intramural segment is short, unroofing eliminates the intramural segment but the ostium remains arising from the incorrect sinus and the coronary may still be compressed between the thick intercoronary pillar and the pulmonary artery. In this case, coronary translocation may be a better alternative than unroofing. © 2016 Texas Children's Hospital (reprinted with permission). RCA: right coronary artery; PA: pulmonary artery; ALCA: anomalous left coronary artery