Late angiographic stent thrombosis of polymer based paclitaxel eluting stent

The drug eluting stent (DES) has largely abolished the risk of in-stent restenosis and repeat revascularisation compared with the bare metal stent (BMS). In some parts of the world, DES implantation has been adopted as a default strategy for percutaneous coronary intervention in many centres. However, this enthusiasm was recently weakened by the occurrence of a severe adverse event, late angiographic stent thrombosis (LAST).1,2 This newly described entity was presumed to be related to delayed endothelialisation of the implanted DES. We report a case series of LAST involving the polymer based paclitaxel eluting stent (Taxus, Boston Scientific Corporation), all of which occurred after discontinuation of clopidogrel. Importantly, we found that both DES and BMS can be susceptible to LAST when antiplatelet treatment is discontinued. Patient 1 was a 44 year old man who underwent percutaneous coronary stent implantation for evolved myocardial infarction in September 2002. A 3.0 mm (diameter) × 24 mm (length) Taxus stent was implanted in the proximal left anterior descending coronary artery (LAD). Treatment for six months with aspirin (100 mg/day) and clopidogrel (75 mg/day), followed by life long aspirin (100 mg/day), was recommended. The patient was compliant with antiplatelet treatment but continued to smoke. He remained well until 13 months later when he was readmitted with acute anterior myocardial infarction. Emergency coronary angiography showed a totally occluded proximal LAD at the site of the previously implanted Taxus stent. Intravascular ultrasound (IVUS) showed only mild in-stent neointimal hyperplasia, suggesting primarily a thrombotic event. The stent was well expanded except for a small segment at the proximal stent edge. No stent malapposition or edge stenosis was noted. Balloon dilatation was performed with the elective use of eptifibatide. The patient made an uneventful recovery and was discharged four days after the procedure. Patient 2 was a 76 …