CHAMPION PHOENIX Trial

Report from the (TCT) Scientific Symposium, 27 October – 1 November, San Francisco. Anti-clotting agent helps reduce the risk of intraprocedural events during percutaneous coronary intervention.

The clinical predictors and impact of intraprocedural stent thrombosis (IPST) in patients undergoing percutaneous coronary intervention (PCI) were examined in an angiographic study of the CHAMPION PHOENIX trial and presented at the 25th annual Transcatheter Cardiovascular Therapeutics (TCT) scientific symposium. Findings Published Simultaneously in the Journal of the American College of Cardiology

IPST, defined as new or worsening thrombus related to stent deployment at any time during PCI, is a relatively rare occurrence but has been linked to future ischemic events, including stent thrombosis and death, in previous trials. The CHAMPION PHOENIX trial comprised the largest independent angiographic core laboratory analysis of IPST to date and sought to determine the incidence, predictors, and clinical impact of IPST.

The prospective, double-blind, active-controlled trial randomized 11,145 patients to receive intravenous cangrelor or oral clopidogrel administered at the time of PCI. The primary efficacy endpoint was the composite rate of all-cause mortality, myocardial infarction (MI), ischemia-driven revascularization (IDR), or stent thrombosis (ST) in the 48 hours after randomization. The key secondary endpoint was the incidence of stent thrombosis at 48 hours. Both were significantly reduced by cangrelor, as previously reported in the New England Journal of Medicine.

An independent core laboratory (CRF) blinded to the treatment performed a frame-by-frame angiographic analysis in 10,939 of the randomized patients assessing the development of IPST. IPST occurred in 89 patients (0.8 percent), including 0.6 percent in the cangrelor arm (35/5,470) and 1.0 percent in the clopidogrel arm (54/5,469). Compared to patients without IPST, IPST was associated with a marked increase in death and ARC defined stent thrombosis at 48 hours (5.6 vs. 0.3 percent and 3.4 vs. 0.3 percent, respectively) and at 30 days (10.1 vs. 1.0 and 5.6 vs. 0.8 percent, respectively). After controlling for potential confounders, IPST remained a strong predictor of ischemic events, including death and stent thrombosis, at both time points. Compared to clopidogrel, the use of cangrelor at randomization was independently associated with freedom from IPST during PCI.

“In the large-scale CHAMPION PHOENIX trial, the occurrence of IPST was strongly predictive of subsequent adverse cardiovascular events,” said lead investigator Philippe Généreux, MD. Dr. Généreux is Director of the Angiographic Core Laboratory at the CRF Clinical Trials Center. The CRF Angiographic Core Lab conducted the analyses.

“The potent intravenous ADP antagonist cangrelor substantially reduces IPST, contributing to its beneficial effects at 48 hours and 30 days. This finding may have major implications when selecting the most potent antithrombotic treatment during PCI.”

“This trial is the largest study to specifically evaluate the incidence, predictors and impact of IPST on the early prognosis of patients undergoing elective, urgent, and emergent PCI,” added study co-chair, Deepak L. Bhatt, MD, MPH. Dr. Bhatt is Professor of Medicine at Harvard Medical School and Chief of Cardiology at VA Boston Healthcare System.

“The findings underscore the importance of preventing IPST, as well as close monitoring and optimal treatments, should IPST occur,” stated study co-chair, Robert A. Harrington, MD. Dr. Harrington is Professor of Medicine and Chairman of Medicine at Stanford.

The CHAMPION PHOENIX trial was funded by The Medicines Company. Dr. Généreux reported speaker fees from Abbott Vascular. Dr. Bhatt and Dr. Harrington reported research grants from The Medicines Company.