Effect of Upstream Clopidogrel Treatment in Patients With ST-Segment Elevation Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

Study Questions:

What are the long-term clinical outcomes of upstream clopidogrel treatment in patients undergoing primary percutaneous coronary intervention (PCI) for ST-segment elevation myocardial infarction (STEMI)?


All patients who underwent PCI for STEMI in Sweden between 2003 and 2008 were identified from the national Swedish Coronary Angiography and Angioplasty Registry (SCAAR). Patients with concomitant warfarin treatment and patients not having received aspirin upstream were excluded, leaving 13,847 patients for the analysis. Groups were compared for death and MI during 1 year of follow-up using Cox regression models with adjustment for differences in baseline characteristics by propensity score methods.


The combined primary endpoint of death or MI during 1-year follow-up occurred in 1,325 of 9,813 patients with upstream clopidogrel and in 364 of 4,034 patients without upstream treatment. After propensity score adjustment, a significant relative risk reduction (hazard ratio [HR], 0.82; 95% confidence interval [CI], 0.73-0.93) in death/MI at 1 year was observed. The secondary endpoint of total 1-year death was significantly reduced (HR, 0.76; 95% CI, 0.64-0.90), while the incidence of 1-year MI did not show any significant reduction (HR, 0.90; 95% CI, 0.77-1.06). Similar results were observed in multivariate analysis on top of propensity scoring and in sensitivity analyses excluding patients without clopidogrel and aspirin at discharge.


The authors concluded that upstream clopidogrel treatment prior to arrival at the catheterization lab is associated with a reduction in the combined risk of death or MI as well as death alone in patients with STEMI treated with primary PCI.


This large observational study indicates a potential beneficial effect of early administered clopidogrel in patients with STEMI treated with primary PCI. The composite endpoint of death/MI as well as death alone was decreased in patients administered clopidogrel upstream compared with periprocedural administration. The benefits were shown both at 30 days as well as 1 year for both endpoints. Despite the limitations of an observational study, these findings appear to support current guideline recommendations regarding as early as possible clopidogrel administration in the setting of STEMI.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Interventions and Imaging, Angiography, Nuclear Imaging

Keywords: Myocardial Infarction, Follow-Up Studies, Sweden, Coronary Angiography, Risk Reduction Behavior, Catheterization, Angioplasty, Balloon, Coronary, Percutaneous Coronary Intervention

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