Abstract
Studies have indicated varying mortality risks with timing of stent thrombosis (ST), but few have been adequately powered with prospective late follow-up. PROTECT randomized 8,709 subjects to either Endeavor zotarolimus-eluting or Cypher sirolimus-eluting stents. PROTECT Continued Access enrolled 1,018 patients treated with Endeavor zotarolimus-eluting stents. Subjects completed at least 4 and 3 years of follow-up, respectively. ARC-defined definite and probable ST events were stratified by time from index procedure: early (≤30 days), late (>30 and ≤360 days), and very late (>360 days). Rates of death and myocardial infarction were analyzed by ST timing. Median follow-up was 4.1 years. There were 184 ST events (1.9%): 61 early, 27 late, and 96 very late. Patient and procedural characteristics were similar between timing groups. There was no difference in dual-antiplatelet therapy use at discharge (97%) or 1 year (84%). Cardiac death in patients with ST at 4 years occurred in 32.1% compared with 2.5% in patients without ST (p <0.001). Combined rates of cardiac death and myocardial infarction did not differ according to ST timing, yet early ST was more commonly associated with cardiac death at 4 years than later ST (50.8% for early vs 18.5% for late vs 24.0% for very late; p <0.001). The relation between ST timing and outcomes did not differ between stent types. In conclusion, in prospective data, cardiac death was more common after early ST than later ST. Although ST remains infrequent, continued efforts to determine how to reduce ST, particularly within the first 30 days, are warranted. (The PROTECT trial is registered with ClinicalTrials.gov, number NCT00476957.).