Very late stent thrombosis with bare-metal stent: identifying severe stent malapposition and underexpansion by intravascular ultrasound

A 60-year-old man with a history of implantation of two bare-metal stents 2 years prior presented to the emergency department with new-onset chest pain. He has been regularly taking angiotensin-converting enzyme inhibitors, beta blockers and aspirin. Aspirin was suspended for 10 days prior to the current hospitalization in order to perform surgery to remove a kidney tumor. He underwent coronary angiography, which revealed a right coronary artery with a distal intraluminal defect within the stents, suggesting thrombus. Intravascular ultrasound demonstrated a severe malapposition and underexpansion throughout the entire length of the stents containing thrombus. In this case, the mechanisms of very late stent thrombosis after bare-metal stent most likely were a combination of mechanical factors (severe stent undersizing during the index procedure) and pharmacological factors (aspirin discontinuation).