OBJECTIVETo analyze the clinical date of 4 patients who developed very late stent thrombosis after implantation of sirolimus eluting stents.

METHODSFrom Oct. 2002 to Aug. 2006, 835 sirolimus eluting stents were implanted in 612 patients. From Jan. 2006 to Aug. 2006, very late thrombosis in sirolimus eluting stents occurred in 4 patients (0.65%), and which caused acute myocardial infarction in anterior wall. Emergency percutaneous coronary interventions (PCIs) were performed in 4 patients immediately after re-admission. The clinical date of the 4 cases were analyzed retrospectively.

RESULTSThese 4 patients were male with the age of 40-69 years. Very late stent thrombosis occurred 31-37 months after successful implantation of sirolimus eluting stents. Application of clopidogrel was stopped 7-12 months after first stents implantation. Aspirin was continued in 3 patients, while the other patient discontinued taking aspirin 18 moths before thrombosis occurred. Emergency coronary angiogram showed that sirolimus eluting stents in LADs were all occlude by thrombosis with TIMI 0 flow. All 4 patients survived after successfully primary PCIs.

CONCLUSIONSOur report presents evidence of very late thrombosis in sirolimus eluting coronary stents, and more careful and prolonged flow-up was required in patients after implantation of drug eluting stents.