Impact of Intraprocedural Stent Thrombosis During Percutaneous Coronary Intervention Insights From the CHAMPION PHOENIX Trial (Clinical Trial Comparing Cangrelor to Clopidogrel Standard of Care Therapy in Subjects Who Require Percutaneous Coronary Intervention)

ObjectivesThis study sought to evaluate the clinical impact of intraprocedural stent thrombosis (IPST), a relatively new endpoint.BackgroundIn the prospective, double-blind, active-controlled CHAMPION PHOENIX (Clinical Trial Comparing Cangrelor to Clopidogrel Standard of Care Therapy in Subjects Who Require Percutaneous Coronary Intervention) trial, cangrelor significantly reduced periprocedural and 30-day ischemic events in patients undergoing percutaneous coronary intervention (PCI), including IPST.MethodsAn independent core laboratory blinded to treatment assignment performed a frame-by-frame angiographic analysis in 10,939 patients for the development of IPST, defined as new or worsening thrombus related to stent deployment at any time during the procedure. Adverse events were adjudicated by an independent, blinded clinical events committee.ResultsIPST developed in 89 patients (0.8%), including 35 of 5,470 (0.6%) and 54 of 5,469 (1.0%) patients in the cangrelor and clopidogrel arms, respectively (odds ratio: 0.65; 95% confidence interval: 0.42 to 0.99; p = 0.04). Compared to patients without IPST, IPST was associated with a marked increase in composite ischemia (death, myocardial infarction [MI], ischemia-driven revascularization, or new-onset out-of-laboratory stent thrombosis [Academic Research Consortium]) at 48 h and at 30 days (29.2% vs. 4.5% and 31.5% vs. 5.7%, respectively; p < 0.0001 for both). After controlling for potential confounders, IPST remained a strong predictor of all adverse ischemic events at both time points.ConclusionsIn the large-scale CHAMPION PHOENIX trial, the occurrence of IPST was strongly predictive of subsequent adverse cardiovascular events. The potent intravenous adenosine diphosphate antagonist cangrelor substantially reduced IPST, contributing to its beneficial effects at 48 h and 30 days. (Clinical Trial Comparing Cangrelor to Clopidogrel Standard of Care Therapy in Subjects Who Require Percutaneous Coronary Intervention [PCI] [CHAMPION PHOENIX]; NCT01156571