Drug-eluting versus bare metal coronary stents: long-term human pathology. Findings from different coronary arteries in the same patient.

A 71-year-old woman underwent right coronary artery (RCA) bare metal stenting during an acute myocardial infarction. Seven months later the patient received a sirolimus-eluting stent as treatment for an 80% left anterior descending coronary artery (LAD) stenosis. She remained asymptomatic until she presented with unstable angina 16 months later. Angiography demonstrated subtotal occlusion of the left obtuse marginal branch. The LAD sirolimus-eluting stent showed 0% stenosis. The RCA stent showed 30% restenosis. The left obtuse marginal branch lesion was successfully stented, but the patient suffered a fatal stroke 24 hours after the coronary intervention. At autopsy the 16-month-old LAD sirolimus-eluting stent was widely patent with a minute thrombus near the ostium of a small side branch. The stent surface appeared free of any other irregularities. Scanning light microscopy showed mild neointimal thickening. Scanning electron microscopy showed > 80% endothelialization of the stent. The 24-month-old RCA bare metal stent showed mild to moderate neointimal growth with > 90% endothelialization.