Acute occlusion of the left internal mammary artery graft in the late postoperative period.

The left internal mammary artery (LIMA) graft used in coronary artery bypass grafting (CABG) reliably revascularizes the left anterior descending artery (LAD) and has excellent long-term patency. Here, we report a rare case of ST-elevation myocardial infarction caused by acute occlusion of the LIMA in the late postoperative period. A 62-year-old man who underwent CABG for a myocardial infarction 15 years previously was transferred to our hospital for the recurrence of acute anterior myocardial infarction. Emergent cardiac catheterization revealed complete occlusion from the mid-portion of the LIMA to the LAD. We successfully treated this patient with primary stent implantation to the culprit LIMA lesion using intravascular ultrasound guidance. <Learning Objective: The left internal mammary artery (LIMA) is commonly used as the conduit to bypass the left anterior descending artery (LAD) and has shown excellent long-term patency. However, we have experienced a rare case with acute myocardial infarction due to acute occlusion of LIMA in late postoperative period. We should carefully monitor, considering that the LIMA could possibly undergo arteriosclerotic changes.>.