Stent malapposition occurred 17 days following percutaneous coronary intervention for a severe calcified lesion in acute myocardial infarction

The occurrence of stent malapposition and coronary artery aneurysm (CAA) during the early phase of drug-eluting stent (DES) implantation is rare. This report presents the case of a 55-year-old man who underwent DES implantation to the left circumflex artery with full-arc severe calcified lesion owing to inferior acute myocardial infarction. Coronary angiography and optical coherence tomography (OCT) at 17 days following percutaneous coronary intervention (PCI) revealed stent malapposition and CAA of diameter 6.5 mm in the distal part of the stented vessel. OCT findings at 5 months following PCI revealed a dilated CAA of diameter 7.5 mm and a luminal structure outside the stent. Based on these findings, it was suggested that the cause of CAA in the early phase following DES implantation to the severe calcified lesion was related to coronary sequelae of Kawasaki disease.