Characteristics of dyspnoea and associated clinical outcomes in the CHAMPION PHOENIX study

Dyspnoea may be induced by some reversibly-binding P2Y₁₂ inhibitors, including cangrelor and ticagrelor. Dyspnoea was not associated with any compromise to the efficacy of ticagrelor in the PLATO study. The CHAMPION PHOENIX study (NCT01156571) compared initial treatment with cangrelor versus initial treatment with clopidogrel in patients undergoing PCI. We investigated the incidence, characteristics, and associated clinical outcomes in patients with dyspnoea in CHAMPION PHOENIX. Adverse events (AEs) of dyspnoea to 48 hours were recorded in patients randomised to cangrelor or clopidogrel in CHAMPION PHOENIX. The composite primary endpoint of death, myocardial infarction, ischaemia-driven revascularisation, or stent thrombosis as well its individual components were assessed in patients who did or did not report dyspnoea. A total of 68 (1.2 %) cangrelor-treated patients and 18 (0.3 %) clopidogrel-treated patients reported dyspnoea (p<0.001). Most dyspnoea events in cangrelor-treated patients were considered mild (71 %) or moderate (28 %) and only one event was considered severe and led to discontinuation of cangrelor. The dyspnoea events in the clopidogrel-treated patients were mild (78 %) or moderate (22 %). Characteristics of dyspnoea were consistent with those seen in the CHAMPION programme as a whole. In the modified intention-to-treat population, rates of the composite primary outcome and its individual components were not affected by the presence of dyspnoea in cangrelor-treated patients. Cangrelor-related dyspnoea is transient, usually mild or moderate, and unlikely to lead to discontinuation of therapy. The occurrence of dyspnoea does not seem to be associated with any reduction in the efficacy of cangrelor compared with clopidogrel as initial therapy in PCI patients.