ACUITY Analysis Indicates Increased 1-Year Risk of Stent Thrombosis in Non–ST-Segment Elevation ACS

October 25, 2011—Tullio Palmerini, MD, et al published finding from the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial online ahead of print in Circulation: Cardiovascular Interventions. The ACUITY trial was a large-scale, prospective, randomized trial of antithrombotic regimens in patients with non–ST-segment elevation acute coronary syndrome (NSTE-ACS).

According to the investigators, the frequency, predictors, and consequences of stent thrombosis in patients with NSTE-ACS have been incompletely studied; therefore, they sought to investigate the incidence, predictors, and clinical implications of stent thrombosis occurring within 1 year after percutaneous coronary intervention in patients with NSTE-ACS.

As detailed in Circulation: Cardiovascular Interventions, the present analysis includes 7,162 patients in whom stents were implanted. At 1 year, definite/probable stent thrombosis occurred in 146 patients (2.2%), including 94 definite and 52 probable events. There were 100 episodes (1.4%) of early stent thrombosis (within the first 30 days) and 46 episodes (0.8%) of late stent thrombosis (between 30 days and 1 year). The incidence of stent thrombosis 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 = .38) and was independent of procedural antithrombotic treatment. Patients with stent thrombosis compared with those without stent thrombosis had strikingly higher 1-year rates of cardiac mortality (32.4% vs 2.9%; P < .0001), myocardial infarction (82.6% vs 7.6%; P < .0001), and target vessel revascularization (79.6% vs 7.4%; P < .0001). Independent predictors of 1-year definite/probable stent thrombosis were insulin-treated diabetes mellitus, number of diseased vessels, and ST-segment deviation ≥ 1 mm.

The investigators concluded that compared with elective stent implantation, stent thrombosis 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 stent thrombosis in NSTE-ACS.