Late Coronary Stent Thrombosis

Introduced 20 years ago,1 coronary artery stents haveimproved the safety and particularly the efficacy of percu-taneous coronary interventions (PCIs).2 Abrupt vessel clo-sure, complicating 6 % to 8 % of balloon angioplasty proce-dures, was associated with a 5 % mortality, 40 % rate of myocardial infarction (MI), and 40 % rate of emergency coronary artery bypass grafting.3 Stents significantly reduced these adverse events (Figure 1).4,5 The reduction of restenosis afforded by bare metal stents (BMS) was modest (30 % to 40%). Repeat revascularization still occurred in 15 % to 20% of cases.6 Drug-eluting stents (DES) with antiproliferative drugs attached via polymers on the stent surface to minimize smooth muscle proliferation have reduced restenosis and rates of target lesion revascularization by 50 % to 70% compared with BMS across nearly all lesion and patient subsets.7 Initially8 and again more recently,9–16 safety con-