Unexpected Dual Left anterior Descending artery as a source of percutaneous Coronary Revascularization Failure

A 61-year-old man was referred for transcatheter coronary angiography because of stable angina and a positive bicycle stress test. His medical history was unremarkable besides mild hypercholesterolemia. The angiogram showed occlusion of the distal left anterior descending artery (LAD), with a severe ostial lesion of the second diagonal branch (Figure 1A). The left circumflex and the right coronary artery (Figure 1B) presented no significant lesion. The second diagonal branch was successfully dilated with a 2-mm balloon, while recanalization of the LAD occlusion was unsuccessful. In order to plan a second attempt, a preprocedural coronary CT angiography was performed to identify the course and caliber of the LAD and better characterize the occluded segment and assess side branch as well as bridging collaterals. Surprisingly, the CT scan showed a double LAD anomaly. The anomalous distal LAD originated from the right coronary sinus with a prevascular course easily appreciated in the 3D reconstructions (Figures 2A, B). This anomaly, classified as type IV by Spindola-Franco et al., is an uncommon and rare among congenital coronary artery anomalies and is usually asymptomatic (1). Because the vessel had a separated ostium just above the origin of the right coronary artery, it was not identified during selective coronary angiography. The presented case clearly demonstrates the potential role of CT to help understand failure of percutaneous coronary interventions as well as its potential role to plan optimally recanalization of coronary chronic total occlusions.