Platelet function testing to adjust antiplatelet therapy for elective coronary stenting: a landmark analysis of the ARCTIC trial

Abstract

Background: In the large randomized ARCTIC trial, platelet function monitoring with treatment adjustment in poor responders did not improve clinical outcome of patients undergoing coronary stenting as compared with standard antiplatelet therapy without monitoring. As randomization occurred early in the catheterization laboratory and most events were peri-procedural MI, we wondered whether results would differ when considering patients only after hospital discharge. Indeed, patients of the monitoring group were also monitored 2-4 weeks after randomization for their maintenance antiplatelet therapy taken for one year afterwards. Methods: The primary end point was the composite of death, myocardial infarction, stent thrombosis, stroke or urgent revascularization one year after stent implantation. A landmark analysis was performed from hospital discharge for the primary endpoint and the safety endpoints. Results: The results of this analysis for the primary endpoint outcome from discharge to end of follow-up is shown in the figure (p Log-Rank=0.058). The landmark analysis for major bleeding showed event rates of 1.8% vs. 2.8% in the monitored and control arms, respectively (HR [95% CI]: 0.64 [0.37; 1.10], p=0.11). The landmark analysis for major or minor bleeding showed event rates of 2.3% vs. 3.4% in the monitored and control arms, respectively (HR [95% CI]: 0.66 [0.41; 1.08], p=0.10). (figure presented) Conclusions: The results of the ARCTIC trial considered from hospital discharge, eliminating all the early events, fully confirm the main results of the study. The same trends were also observed with numerically more ischemic events and less bleedings in the group of patients allocated to the strategy of monitoring and treatment adjustment.