Angiographic stent thrombosis after routine use of drug-eluting stents in ST-segment elevation myocardial infarction: the importance of thrombus burden.

OBJECTIVES This study sought to investigate the impact of thrombus burden on the clinical outcome and angiographic infarct-related artery stent thrombosis (IRA-ST) in patients routinely treated with drug-eluting stent (DES) implantation for ST-segment elevation myocardial infarction (STEMI). BACKGROUND There are limited data for the safety and effectiveness of DES in STEMI. METHODS We retrospectively analyzed 812 consecutive patients treated with DES implantation for STEMI. Intracoronary thrombus burden was angiographically estimated and categorized as large thrombus burden (LTB), defined as thrombus burden > or =2 vessel diameters, and small thrombus burden (STB) to predict clinical outcomes. Major adverse cardiac events (MACE) were defined as death, repeat myocardial infarction, and IRA reintervention. RESULTS Mean duration of follow-up was 18.2 +/- 7.8 months. Large thrombus burden was an independent predictor of mortality (hazard ratio [HR] 1.76, p = 0.023) and MACE (HR 1.88, p = 0.001). The cumulative angiographic IRA-ST was 1.1% at 30 days and 3.2% at 2 years, and continued to augment beyond 2 years. It was significantly higher in the LTB compared with the STB group (8.2% vs. 1.3% at 2 years, respectively, p < 0.001). Significant independent predictors for IRA-ST were LTB (HR 8.73, p < 0.001), stent thrombosis at presentation (HR 6.24, p = 0.001), bifurcation stenting (HR 4.06, p = 0.002), age (HR 0.55, p = 0.003), and rheolytic thrombectomy (HR 0.11, p = 0.03). CONCLUSIONS Large thrombus burden is an independent predictor of MACE and IRA-ST in patients treated with DES for STEMI.