Analysis of 36 Reported Cases of Late Thrombosis in Drug-Eluting Stents Placed in Coronary Arteries

Drug-eluting stents (DESs) have decreased the incidence of in-stent restenosis. Within the past 2 years several cases on late stent thrombosis (LST) have been reported. This study analyzed and reviewed all published cases of LST in DESs to explore possible trends not previously reported. We applied a Medline search using the key word “drug eluting stents.” All 845 positive matches in March 2006 were screened for case reports of LST in DESs, defined as angiographic stent thrombosis ≥30 days after deployment. We included reported LSTs from randomized trials, observational registry reports, and letters to the editor if information regarding timing from stent deployment to clinical event, vessel, stent diameter and length, and antiplatelet regimen were available. There was no significant difference in the incidence of LST between sirolimus- and paclitaxel-eluting stents. Median time from stent deployment to clinical event was 242 days (total range 39 to 927). If aspirin and clopidogrel were discontinued, median time to clinical event was 7 days (3 to 150). In comparison, if only clopidogrel was discontinued, median time to clinical event was 30 days (14 to 690, p <0.0001). There was no significant difference in stent diameter and length between sirolimus- and paclitaxel-eluting stents. Forty-two percent of events occurred in relation to a surgical procedure for which the 2 antiplatelet agents or clopidogrel alone was discontinued. In conclusion, there was a strong association between occurrence of LST and cessation of dual antiplatelet therapy. Patients who continued on aspirin had a significant delay to the clinical event. Efforts should be made to maintain patients on aspirin during routine surgical procedures.