Left main-like bifurcation primary percutaneous coronary intervention case report: anomalous right coronary artery ostium from the left anterior descending.

Background: A single coronary artery ostium (SCAO) is estimated to be present in 0.066% of the general population. The proximal coronary course and the relationship with surrounding structures are related to malignant vs. benign prognoses. We present a case of SCAO with the right coronary artery (RCA) arising from the mid-left anterior descending (LAD), complicated by anterior and inferior STEMI because of acute thrombotic occlusion at the bifurcation and its percutaneous management.

Case Summary: A 56-year-old male was admitted with sudden onset of resting chest pain. His ECG showed an anterior, inferior, and right ventricular STEMI. Via trans-radial access, coronary angiography showed significant stenoses at the left main and the circumflex but also a thrombotic occlusion at the proximal segment of the LAD while no RCA was seen. After crossing the LAD occlusion, the dominant RCA appeared from the mid-LAD. A provisional stent technique was performed achieving good results. Coronary computed tomography angiography showed an SCAO congenital anomaly with a patent stent in the bifurcation accompanied by diffuse coronary artery disease causing mild stenosis of the left main, proximal, and distal circumflex.

Discussion: The RCA arising from the mid-LAD with pre-pulmonic course has been described in only 37 cases. One reported an LAD/RCA bifurcation treatment with two stents technique in a stable scenario. The present is the first case reported of an acute thrombotic occlusion of an LAD/RCA bifurcation clinically resulting in a left main equivalent STEMI treated successfully with primary percutaneous coronary intervention using a bifurcation technique.