Predictors and Implications of Stent Thrombosis in Non-ST-Segment Elevation Acute Coronary Syndromes The ACUITY Trial

Background-The frequency, predictors, and consequences of stent thrombosis (ST) in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) have been incompletely studied. We sought to investigate the incidence, predictors, and clinical implications of ST occurring within 1 year after percutaneous coronary intervention in patients with NSTE-ACS. Methods and Results-The Acute Catheterization and Urgent Intervention Triage StrategY (ACUITY) trial was a large-scale, prospective, randomized trial of antithrombotic regimens in patients with NSTE-ACS. The present analysis includes 7162 patients in whom stents were implanted. At 1 year, definite/probable ST occurred in 146 patients (2.2%), including 94 definite and 52 probable events. There were 100 episodes (1.4%) of early ST (within the first 30 days) and 46 episodes (0.8%) of late ST (between 30 days and 1 year). The incidence of ST within 1 year was similar in patients treated with drug-eluting stents or bare metal stents (hazard ratio, 0.86; 95% confidence interval, 0.62-1.20; P=0.38) and was independent of procedural antithrombotic treatment. Patients with ST compared with those without ST had strikingly higher 1-year rates of cardiac mortality (32.4% versus 2.9%, P<0.0001), myocardial infarction (82.6% versus 7.6%, P<0.0001), and target vessel revascularization (79.6% versus 7.4%, P<0.0001). Independent predictors of 1-year definite/probable ST were insulin-treated diabetes mellitus, number of diseased vessels, and ST-segment deviation >= 1 mm. Conclusions-Compared with elective stent implantation, ST occurs with increased frequency in the first year after stent implantation in patients with NSTE-ACS, especially within the first 30 days, and is associated with marked increases in cardiac mortality and adverse events. Insulin-treated diabetes, number of diseased vessels, and dynamic ST-segment changes were independent predictors of 1-year ST in NSTE-ACS.