Dual Left Anterior Descending Artery Arising From the Right Coronary Cusp With a Prepulmonic Course: A Case Report

Abstract

Dual left anterior descending artery (LAD) is an uncommon coronary anomaly that may be difficult to characterize with invasive angiography alone. We describe a 49-year-old man undergoing coronary angiography for acute coronary syndrome. Angiography showed mild ostial left main stem disease, mild mid-LAD disease, moderate mid-ramus intermedius disease, mild mid-left circumflex disease, and tight ostioproximal stenosis of the dominant right coronary artery (RCA). An anomalous LAD origin from the right coronary cusp was suspected. Coronary computed tomography angiography demonstrated dual LAD anatomy: a short native LAD arising from the left main stem, with mild proximal and moderate mid-vessel stenosis, terminating in the proximal anterior interventricular groove; and an accessory LAD arising separately from the right coronary cusp. The accessory LAD traversed anterior to the main pulmonary artery before entering the mid-anterior interventricular groove, consistent with a prepulmonic course. It had mild mid-segment disease, estimated at 28%, with a normal distal segment. Computed tomography coronary angiography established the benign course of the anomalous vessel and facilitated planning of revascularization for the severe RCA lesion. This case highlights the complementary role of coronary computed tomography angiography in defining anomalous coronary anatomy in patients with concomitant atherosclerotic coronary artery disease.