Objective: We investigated how does troponin level (TnT) affect the benefit achieved by abciximab in patients with acute coronary syndromes (ACS) undergoing percutaneous coronary intervention (PCI) after pretreatment with a high loading dose of clopidogrel.
Methods: The Intracoronary Stenting and Antithrombotic Regimen: Rapid Early Action for Coronary Treatment (ISAR-REACT 2) trial included 2,022 patients with non-ST elevation ACS undergoing PCI who were randomized to abciximab or placebo after pretreatment with 600 mg of clopidogrel. The patients were divided into groups with elevated TnT level (n = 1,049) and no elevated TnT level (n = 973). The primary end point of the trial was the composite of death, myocardial infarction and urgent reintervention at 30 days.
Results: In patients with elevated TnT level the incidence of the primary end point was 13.1% in the abciximab group Vs. 18.3% in the placebo group [relative risk (RR): 0.70; 95% confidence interval (CI), 0.52-0.95, P = 0.02]. The combined incidence of death or myocardial infarction was 12.9% in the abciximab group vs. 17.9% in the placebo group (RR: 0.71; 95% CI, 0.52-0.96, P = 0.03). In contrast, the incidence of the primary end point in patients with no elevated TnT level was identical in both treatment groups (4.6%). The risk of bleeding was not related to TnT level.
Conclusions: Baseline troponin level affects the benefit of abciximab in patients with ACS undergoing PCI after pretreatment with a high loading dose of clopidogrel. Abciximab reduces the risk of ischemic events only in patients with ACS and elevated troponin level.