Does intracoronary thrombus influence the outcome of high risk percutaneous transluminal coronary angioplasty? Clinical and angiographic outcomes in a large multicenter trial

Objectives. We sought to evaluate the impact of angiographically visible thrombus on short- and long-term clinical outcomes after percutaneous transluminal coronary angioplasty (PTCA). Background. Intracoronary thrombus is frequently seen on angiography in patients with acute ischemic coronary syndromes or complex lesion morphology, or both, and is often considered to predict a higher rate of complications in patients undergoing PTCA. Methods. Prospectively collected data from 2,099 patients undergoing high risk PTCA in the Evaluation of IIb/IIIa Platelet Receptor Antagonist 7E3 in Preventing Ischemic Complications (EPIC) trial were analyzed. In addition to aspirin and heparin, patients were randomized to receive either abciximab bolus and infusion, abciximab bolus alone or placebo. Based on an angiographic core laboratory interpretation, patients were classified into three groups: thrombus absent, thrombus possible or thrombus present. The primary end point at 30 days was the composite of death, myocardial infarction or urgent revascularization. The 6-month end point was the composite of death, myocardial infarction or any revascularization. Results. Although abrupt closure was most common in patients with thrombus present compared with thrombus absent or possible (13%, 10.0% and 7.4%, respectively), neither the 30-day nor the 6-month clinical end points were different among the three groups (9%, 11% and 11.7%, respectively, and 30%, 34% and 31%, respectively). Most notably, the benefit of treatment with abciximab was present in all three thrombus groups, and the magnitude of benefit was not different among the thrombus groups. Conclusions. In high risk patients undergoing percutaneous coronary revascularization, features of thrombus on the preprocedure angiogram do not indicate an augmented risk of adverse clinical outcomes. Abciximab therapy reduces the rate of adverse outcomes regardless of the presence of thrombus and should therefore not necessarily be reserved for patients whose angiograms have features of intraluminal thrombus.