Proximal Left Main Coronary Artery Aneurysm Presenting as ST-Elevation Myocardial Infarction Treated by Stenting

Coronary artery aneurysm (CAA) is a rare cardiac anomaly with a reported incidence of 0.3-4.9% of patients who undergo coronary
angiography. The term is used when the coronary artery diameter exceeds more than 50% or 1.5 times the reference diameter. It can
be congenital or acquired. The commonest acquired cause in an adult is atherosclerosis and in a child is Kawasaki’s disease. The
commonest culprit vessel is the Right Coronary Artery (RCA), followed by Left Circumflex (LCx) and Left Anterior Descending
(LAD). Left main coronary aneurysms are extremely rare in clinical practice. Coronary angiography is the gold standard
procedure, both for diagnosis and treatment. We report a 49-year-old male who presented with anterior wall ST-Elevation
Myocardial Infarction (STEMI). The initial angiography showed LAD stent thrombosis, but when the second angiography was
done, there was spontaneous recanalization of the LAD. Coronary angiography was performed at our hospital, which revealed a
long left main coronary artery aneurysm measuring 9.8 mm—maximum diameter. This was treated with a size 5 × 24 mm
Begraft coronary stent.