Periprocedural Outcomes According to Timing of Clopidogrel Loading Dose in Patients Who Did Not Receive P2Y Inhibitor Pretreatment.

Background: In patients undergoing percutaneous coronary intervention (PCI), who did not receive P2Y inhibitor pretreatment, the optimal timing of P2Y inhibitor loading dose remains debated. We sought to examine whether the choice of administration of the clopidogrel loading dose before or after the start of PCI had an impact on periprocedural complications, including bleeding.

Methods And Results: The CHAMPION PHOENIX (A Clinical Trial Comparing Cangrelor to Clopidogrel Standard Therapy in Subjects Who Require Percutaneous Coronary Intervention) double-blind randomized trial compared cangrelor with clopidogrel loading dose at the time of PCI. Pretreatment with clopidogrel before randomization was not permitted per protocol. In the clopidogrel-only group (n=5438), a loading dose was given before (early load [EL]) or after the start of PCI (late load [LL]) according to physician choice. Overall, 3442 (63.3%) patients had EL and 1997 LL (36.7%). Median times were 5 minutes before and 20 minutes after the start of PCI, respectively. EL was more frequently used among patients with ST-segment-elevation myocardial infarction (84.4%) and non-ST-segment-elevation acute coronary syndromes (71.5%) than in stable patients (53.7%). At 48 hours, rates of the primary outcome of death, myocardial infarction, ischemia-driven revascularization, or stent thrombosis were similar (6.0% versus 5.4%) for EL versus LL, respectively (odds ratio [OR], 1.11 [95% CI, 0.87-1.41]; P=0.41), and remained so after adjustment for potential confounders, including clinical presentation (OR [95% CI], 1.39 [0.90-2.15]; P=0.14). Compared with clopidogrel, cangrelor consistently reduced the primary outcome in both EL (4.8% versus 6.0%; OR [95% CI], 0.80 [0.64-0.98]) and LL (4.3% versus 5.4%; OR [95% CI], 0.79 [0.59-1.06]; interaction P=0.99). Global Use of Strategies to Open Occluded Coronary Arteries severe/moderate bleeding rates were similar between treatment arms for both EL (OR [95% CI], 1.24 [0.58-2.66]) and LL (OR [95% CI], 2.53 [0.98-6.54]; interaction P=0.25).

Conclusions: In a nonrandomized comparison of patients with clopidogrel loading before or after the start of PCI, the rates of periprocedural PCI complications, including bleeding, were similar, as were the benefits of cangrelor, regardless of the timing.

Clinical Trial Registration: URL: https://www.clinicaltrials.gov . Unique identifier: NCT01156571.