Objectives: We sought to describe the incidence of late angiographic stent thrombosis (LAST) events in an unselected drug-eluting stent (DES) population.
Background: Concerns have been raised that LAST may be a potential limitation of DES.
Methods: We have previously reported the angiographic incidence of early stent thrombosis (1.0%) in this prospective cohort of 2,006 patients treated with either sirolimus-eluting stents (SES) (n = 1,017) or paclitaxel-eluting stents (PES) (n = 989). We continued long-term follow-up to determine the incidence of LAST events, defined as angiographically proven stent thrombosis associated with acute symptoms more than 30 days after DES implantation. All patients had at least 1 year of follow-up, mean duration 1.5 years.
Results: There were eight angiographically confirmed LAST events in seven patients: three with SES (at 2, 25, and 26 months) and five with PES (at 6, 7, 8, 11, and 14.5 months). Three cases were related to complete cessation of antiplatelet therapy, two cases occurred while patients were on aspirin therapy within one month of cessation of clopidogrel, and three cases occurred at a time when patients were apparently clinically stable on aspirin monotherapy. We observed no cases of LAST in patients who were on dual antiplatelet therapy. Two deaths occurred directly as a result of LAST.
Conclusions: Angiographically proven late stent thrombosis occurs with an incidence of at least 0.35% (95% confidence limits 0.17% to 0.72%) in patients treated with DES. Importantly, it may also occur when patients are stable on antiplatelet monotherapy.