Study Evaluates Predictors of Stent Thrombosis After PCI for STEMI

October 15, 2012—Bruce Brodie, MD, et al published findings from a study that sought to evaluate the frequency and predictors of stent thrombosis after stenting for ST-segment elevation myocardial infarction (STEMI). The investigators found that stent thrombosis after primary percutaneous coronary intervention is relatively frequent and continues to increase out to 5 years; new strategies are needed to prevent stent thrombosis in STEMI patients, and targeted therapies are needed in patients identified at highest risk. The study was published in the Journal of the American College of Cardiology: Cardiovascular Interventions (2012;5:1043–1051).

According to the investigators, the background of the study is that stent thrombosis remains a major concern with STEMI patients treated with primary percutaneous coronary intervention. Consecutive patients (N = 1,640) undergoing stenting for STEMI were prospectively enrolled in the investigators' database and followed for 1 to 15 years. Bare-metal stents were implanted from 1995 to 2002, and drug-eluting and bare-metal stents were implanted from 2003 to 2009. Stent thrombosis was defined as definite or probable.

The investigators reported that their database population had a high-risk profile, including a high incidence of Killip class III to IV (11.5%) and STEMI due to stent thrombosis (10.2%). Stent thrombosis occurred in 124 patients, including 42 with early stent thrombosis (0 to 30 days), 35 with late stent thrombosis (31 days to 1 year), and 47 with very late stent thrombosis (> 1 year). The frequency of stent thrombosis was 2.7% at 30 days, 5.2% at 1 year, and 8.3% at 5 years. Independent predictors of early or late stent thrombosis were STEMI due to stent thrombosis (hazard ratio [HR]: 4.38; 95% confidence interval [CI], 2.27–8.45), small stent size (HR: 2.44; 95% CI, 1.49–4), Killip class III to IV (HR: 2.39; 95% CI, 1.3–4.4), and reperfusion time ≤ 2 h (HR: 2.09; 95% CI, 1.03–4.24). Use of a drug-eluting stent was the only independent predictor of very late ST (HR: 3.73; 95% CI, 1.81–7.88), the investigators stated in Journal of the American College of Cardiology: Cardiovascular Interventions.