Primary Percutaneous Coronary Intervention for ST-Elevation Myocardial Infarction in a Patient with a Single Coronary Artery Arising from the Right Aortic Sinus

Case Report. A 53-year-old male presented with chest pain due to an acute inferior ST-elevation myocardial infarction and was transferred to our institution for immediate coronary angiography. This revealed a single coronary artery arising from the right aortic sinus. The right coronary artery (RCA) had an apparently normal course but gave rise to the left anterior descending (LAD) and the left circumflex (LCx) arteries in its proximal segment. The RCA was subtotally occluded in the mid vessel with thrombolysis in myocardial infarction (TIMI) grade 1 antegrade flow (panel A). The left coronary artery (LCA)was free of significant obstructive disease. Primary percutaneous coronary intervention (PPCI) was performed utilising an Export aspiration thrombectomy device (Medtronic, Inc., Minneapolis, Minnesota), which restored TIMI grade 3 flow into the distal vessel. This revealed a tight stenosis in the mid segment of the RCA (panel B and inset) which was treated by implantation of a 3.0 mm diameter bare-metal stent (panel C).

Subsequent coronary computed tomography showed the relation between the anomalous coronary circulation and the great vessels (panel D). The RCA is dominant and follows a normal course in the right atrioventricular (AV) groove. The LAD traverses the anterior surface of the right ventricle before entering the anterior interventricular groove. The LCx has an acute takeoff from the proximal RCA and runs posteriorly between the aorta and pulmonary artery (interarterial course) to reach the left AV groove.

Discussion. The incidence of coronary artery anomalies is 0.6–1.3%.¹ An anomalous origin of the LCA from the right aortic sinus is rare, comprising approximately 3% of all coronary artery anomalies.² Most coronary artery anomalies have little clinical significance. The presence of an interarterial course of the LCA, however, has been linked to cases of sudden death, the postulated mechanism being ischaemia-driven arrhythmia due to extrinsic compression of the LCA.³

To our knowledge, this is the first reported case of PPCI in a patient with a single coronary artery. The increasing availability of PPCI means that more patients with coronary artery anomalies will undergo this procedure. This case illustrates that PPCI can be performed safely in this setting, but careful guide catheter manipulation is required to minimize the risk of iatrogenic coronary dissection, which might have potentially serious hemodynamic consequences and also be technically challenging to treat.

References

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2. Moodie DS, Gill C, Loop FD, Sheldon WC. Anomalous left main coronary artery originating from the right sinus of Valsalva: Pathophysiology, angiographic definition, and surgical approaches. J Thorac Cardiovasc Surg 1980;80:198–205.
3. Shirani J, Roberts WC. Solitary coronary ostium in the aorta in the absence of other major congenital cardiovascular anomalies. J Am Coll Cardiol 1993;21:137–143.