Discussion
Anomalous aortic origin of coronary artery (AAOCA) reportedly occurs in 0.2% to 1.3% of patients undergoing CAG and are often encountered in clinical practice. The prevalence of the AAORCA was reportedly between 8% to 16% in AAOCA It is approximately six to 10 times more common than anomalous aortic origin of the left coronary artery (AAOLCA). AAOCA from opposite sinuses can cause sudden cardiac death in young people. When it originates in the opposite sinus and travels between the aorta and pulmonary artery trunk, it can cause ischemia. Its mechanism has been attributed to the enlargement of the aorta and pulmonary artery trunk, which interferes with coronary blood flow, especially during exercise. Acute AAD is lethal and requires emergency surgery. AMI occurs in 1–2% of patients with AAD and is due to extrinsic compression of the coronary ostium by an enlarged false lumen or occlusion by an intimal flap. Bypass surgery is required in most cases.
In this case, AAORCA from the left sinus of Valsalva was observed preoperatively, and there were findings of right ventricular infarction. A compressed RCA between the enlarged sinus of Valsalva and pulmonary artery trunk was assumed to cause AMI. This was supported by the resolution of ischemia after careful stump construction. There have been few reports of AAD complicated by AMI exhibiting a similar mechanism.
The necessity of bypass surgery in this case was debatable. The expert consensus recommended surgical intervention for symptomatic AAOCA and asymptomatic patients with AAOLCA. However, surgery for asymptomatic patients with AAORCA remains controversial. The possibility of the future enlargement of the sinus of Valsalva was considered in this case. Thus, bypass surgery may have been performed. As soon as the surgery began, parts were harvested for the bypass already. However, considering the urgency of the surgery, the short operating time required, and the possibility of PCI if the sinus enlarged postoperatively, bypass surgery was not performed. As a result, the right ventricular movement normalized, and there were no abnormal findings on the postoperative CAG.
This case illustrated that AAOCA from the opposite sinus of Valsalva could become symptomatic due to AAD, and early intervention should be initiated, especially in individuals with a high risk for AAD, such as bicuspid valve or Marfan syndrome patients. AAOCA from the opposite sinus of Valsalva combined with acute AAD may lead to AMI by a new mechanism.