Implications of different criteria for percutaneous coronary intervention-related myocardial infarction on study results of three large phase III clinical trials: The CHAMPION experience.

AIMS: The purpose of this study was to test whether different results between Cangrelor versus standard therapy to acHieve optimal Management of Platelet InhibitiON (CHAMPION) PCI/PLATFORM and PHOENIX trials are due in part to different definitions of percutaneous coronary intervention (PCI)-related myocardial infarction (MI). METHODS AND RESULTS: In patients with acute coronary syndrome (ACS), the definition of MI was identical in CHAMPION PCI and PLATFORM and did not require an assessment of baseline cardiac biomarker status, while in PHOENIX specific MI criteria were associated with different patient presentations. The same MI criteria were used in PCI, PLATFORM, and PHOENIX for patients with stable angina. Logistic regression assessed the effect of cangrelor on MI (PCI- and non-PCI related) in the combined PCI/PLATFORM population and in PHOENIX. Consistency of cangrelor's effect in PCI/PLATFORM and in PHOENIX in patients with stable angina and in those with an ACS (with or without ST elevation) was evaluated. Overall, the incidence of PCI-related MI at 48 h was 6.3% in PCI/PLATFORM and 4.0% in PHOENIX. In patients with ACS, MI incidence was 6.4% in PCI/PLATFORM and 1.7% in PHOENIX, and 6.3% and 5.6%, respectively in stable angina patients. Cangrelor's effect on PCI-related MI differed between PCI/PLATFORM (odds ratio (OR) 1.03, 95% confidence interval (CI) 0.90-1.17) and PHOENIX (OR 0.80, 95% CI 0.66-0.98) with pINT=0.04. This difference was mostly evident in patients with ACS ( pINT= 0.06) while the effect was consistent in patients with stable angina ( pINT=0.81). Results were similar when all MIs were analyzed. CONCLUSIONS: The definition of PCI-related MI has important implications for event rates, treatment effect, and study results. This illustrates the importance of a rigorous assessment of PCI-related MI in clinical trials of patients with an ACS.

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).

OBJECTIVES: This study sought to evaluate the clinical impact of intraprocedural stent thrombosis (IPST), a relatively new endpoint. BACKGROUND: In 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. METHODS: An 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. RESULTS: IPST 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. CONCLUSIONS: In 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).

Safety and efficacy of cangrelor, an intravenous, short-acting platelet inhibitor in patients requiring coronary artery bypass surgery.

OBJECTIVE: Oral P2Y12 platelet receptor inhibitors are a cornerstone of reducing complications in patients with acute coronary syndromes or coronary stents. Guidelines advocate discontinuing treatment with P2Y12 platelet receptor inhibitors before surgery. Cangrelor, a short-acting, reversible, intravenously administered P2Y12 platelet inhibitor is effective in achieving appropriate platelet inhibition in patients who are awaiting coronary artery bypass grafting (CABG) and require P2Y12 inhibition. The objective of this study was to assess the effects of preoperative cangrelor on the incidence of perioperative complications, which are currently unknown. METHODS: Patients (n = 210) requiring preoperative clinical administration of thienopyridine therapy were randomized in a multicenter, double-blinded study to receive cangrelor or placebo while awaiting CABG after discontinuation of the thienopyridine. Optimal platelet reactivity, which was defined as <240 P2Y12 platelet reaction units, was measured with serial point-of-care testing (VerifyNow). Pre- and postoperative outcomes, bleeding values, and transfusion rates were compared. To quantify potential risk factors for bleeding, we developed a multivariate logistic model. RESULTS: The differences between the groups in bleeding and perioperative transfusion rates were not significantly different. The rate of CABG-related bleeding was 11.8% (12/102) in cangrelor-treated patients and 10.4% (10/96) in the placebo group (P = .763). Transfusion rates for the groups were similar. Serious postoperative adverse events for the cangrelor and placebo groups were 7.8% (8/102) and 5.2% (5/96), respectively (P = .454). CONCLUSIONS: Compared with placebo, bridging patients with cangrelor prior to CABG effectively maintains platelet inhibition without increasing post-CABG complications, including bleeding and the need for transfusions. These data suggest cangrelor treatment is a potential strategy for bridging patients requiring P2Y12 receptor inhibition while they await surgery.

Effect of platelet inhibition with cangrelor during PCI on ischemic events.

BACKGROUND: The intensity of antiplatelet therapy during percutaneous coronary intervention (PCI) is an important determinant of PCI-related ischemic complications. Cangrelor is a potent intravenous adenosine diphosphate (ADP)-receptor antagonist that acts rapidly and has quickly reversible effects. METHODS: In a double-blind, placebo-controlled trial, we randomly assigned 11,145 patients who were undergoing either urgent or elective PCI and were receiving guideline-recommended therapy to receive a bolus and infusion of cangrelor or to receive a loading dose of 600 mg or 300 mg of clopidogrel. The primary efficacy end point was a composite of death, myocardial infarction, ischemia-driven revascularization, or stent thrombosis at 48 hours after randomization; the key secondary end point was stent thrombosis at 48 hours. The primary safety end point was severe bleeding at 48 hours. RESULTS: The rate of the primary efficacy end point was 4.7% in the cangrelor group and 5.9% in the clopidogrel group (adjusted odds ratio with cangrelor, 0.78; 95% confidence interval [CI], 0.66 to 0.93; P=0.005). The rate of the primary safety end point was 0.16% in the cangrelor group and 0.11% in the clopidogrel group (odds ratio, 1.50; 95% CI, 0.53 to 4.22; P=0.44). Stent thrombosis developed in 0.8% of the patients in the cangrelor group and in 1.4% in the clopidogrel group (odds ratio, 0.62; 95% CI, 0.43 to 0.90; P=0.01). The rates of adverse events related to the study treatment were low in both groups, though transient dyspnea occurred significantly more frequently with cangrelor than with clopidogrel (1.2% vs. 0.3%). The benefit from cangrelor with respect to the primary end point was consistent across multiple prespecified subgroups. CONCLUSIONS: Cangrelor significantly reduced the rate of ischemic events, including stent thrombosis, during PCI, with no significant increase in severe bleeding. (Funded by the Medicines Company; CHAMPION PHOENIX ClinicalTrials.gov number, NCT01156571.).

Quantification of the effect of clopidogrel on enzymatic infarct size related to a percutaneous coronary intervention in patients with acute coronary syndromes: insights from the CHAMPION percutaneous coronary intervention trial.

OBJECTIVES: Using data from the CHAMPION percutaneous coronary intervention (PCI), we determined the relationship between clopidogrel started at least 5 days before PCI (maintenance of clopidogrel) and PCI-related enzymatic infarct size. BACKGROUND: Clopidogrel is recommended in patients with acute coronary syndrome (ACS) managed with PCI, but its effect on PCI-related myonecrosis in contemporary patients has not been quantified. PATIENTS AND METHODS: Patients with ACS (with or without ST-segment elevation) who underwent PCI and had at least three creatine kinase-MB (CK-MB) samples after PCI were included. Enzymatic infarct size was defined as the peak CK-MB concentration indexed by its upper limit of normal. Associations between maintenance clopidogrel and enzymatic infarct size were explored using multivariable linear regression (with and without missing data imputation) and propensity score analysis using inverse probability weighting. RESULTS: Of 8877 patients randomized, 6327 (71.3%) were included (median age 61 years, 73% male, 13% ACS with ST-segment elevation). Of these 6327 patients, 2015 (31.8%) were on maintenance clopidogrel. After multivariable adjustment, maintenance clopidogrel was associated with a reduction in enzymatic infarct size {ß=-0.63; 47% decrease in peak CK-MB [95% confidence interval (CI) 35, 56%]}. Multivariable linear regression with multiple imputations and inverse probability weighting propensity score analysis yielded similar results, with maintenance clopidogrel associated with 44% (95% CI 33, 53%) and 29% (95% CI 24, 33%) infarct size reductions. CONCLUSION: In this subgroup analysis of modern ACS patients, clopidogrel maintenance was independently associated with smaller enzymatic infarct size after PCI. These results are consistent with previous observations suggesting a benefit of clopidogrel on the procedural outcome and quantify this benefit.

Rationale and design of the Cangrelor versus standard therapy to acHieve optimal Management of Platelet InhibitiON PHOENIX trial.

BACKGROUND: Despite robust efficacy in the reduction of ischemic events in patients who require percutaneous coronary intervention (PCI), current P2Y(12) inhibitors have limitations. In particular, they require hours to be effective, and they can only be administered orally. Cangrelor is an intravenous, potent, and reversible P2Y(12) inhibitor with fast onset and offset of action. We designed CHAMPION PHOENIX to evaluate the efficacy and safety of cangrelor in patients with atherosclerosis undergoing PCI. TRIAL DESIGN: The CHAMPION PHOENIX is a randomized, double-blind, double-dummy, superiority trial comparing cangrelor with clopidogrel standard of care in approximately 10,900 patients who have not previously received a P2Y(12) inhibitor and who require PCI, including patients with stable angina and with acute coronary syndromes (with or without ST-segment elevation). The primary objective of the study is to demonstrate that cangrelor will reduce the incidence of the composite of death, myocardial infarction (MI), ischemia-driven revascularization, or stent thrombosis in the 48 hours after randomization compared with clopidogrel without excessive periprocedural bleeding. The key secondary objective is to demonstrate that cangrelor will reduce the incidence of stent thrombosis. Myocardial infarction will be defined according to the universal MI definition, adapting the definition of PCI-related (type 4a) MI. Bleeding will be assessed according to the thrombolysis in myocardial infarction, GUSTO, and Bleeding Academic Research Consortium (BARC) scales. CONCLUSION: The CHAMPION PHOENIX may establish the role of cangrelor in the care of patients who require PCI across the spectrum of stable and unstable coronary diseases in the setting of current treatment strategies.