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

Abstract

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.

Keywords: Case report; Computed tomography angiography; Coronary vessel anomalies; Percutaneous coronary intervention; ST elevation myocardial infarction; Single coronary artery ostium.

Figure 1

EKGs at arrival with standard leads showing anterior and inferior ST-segment elevation (A) and the right precordial leads showing right ventricle ST-segment elevation (B). Left coronary artery angiography showing the thrombotic occlusion (orange arrow) of the mid-segment of the left anterior descending (C). Final angiographic results of the primary percutaneous coronary intervention at the right coronary artery/mid-left anterior descending bifurcation with both fully patent coronary arteries (D). A three-dimensional reconstruction from the coronary computed tomography angiography depicting the single coronary artery ostium, the completely expanded stent at the bifurcation (white arrow) and its relationship with surrounding structures (E).

Figure 2

Right coronary artery ostium appearing from the mid-left anterior descending (orange arrow) after passing a guidewire to cross into the distal left anterior descending (A). After pre-dilation of the proximal left anterior descending, full visualization of the left anterior descending and the right coronary artery was achieved with some gain of antegrade flow (B).

Figure 3

Right coronary artery angiography obtained by selective right coronary artery microcatheter injection, allowing visualization of sub-occlusive thrombus in its mid-segment (A) followed by re-occlusion of both left anterior descending and right coronary artery from the bifurcation (B) occurring just before balloon dilation of the thrombotic mid-segment of the right coronary artery (likely occurring by local embolism).

Figure 4

Stent deployment (provisional single-stent strategy) in the proximal mid-left anterior descending.

Figure 5

Coronary computed tomography angiography at 4 days follow-up. The three-dimensional reconstructions after percutaneous coronary intervention showed good results (A and B) allowing the evaluation of the coronary pattern and the relationship with some of the surrounding structures.