Bedside Monitoring to Adjust Antiplatelet Therapy for Coronary Stenting
What is the efficacy of systematic platelet function monitoring for the purpose of adjusting treatment in patients with a poor response to aspirin, thienopyridine (clopidogrel or prasugrel), or both, as compared with a conventional approach in which similar treatment was given to all patients, without platelet-function assessment?
The ARCTIC trial investigators randomly assigned 2,440 patients scheduled for coronary stenting at 38 centers to a strategy of platelet-function monitoring, with drug adjustment in patients who had a poor response to antiplatelet therapy, or to a conventional strategy without monitoring and drug adjustment. The primary endpoint was the composite of death, myocardial infarction, stent thrombosis, stroke, or urgent revascularization 1 year after stent implantation. For patients in the monitoring group, the VerifyNow P2Y12 and aspirin point-of-care assays were used in the catheterization laboratory before stent implantation and in the outpatient clinic 2-4 weeks later.
In the monitoring group, high platelet reactivity in patients taking clopidogrel (34.5% of patients) or aspirin (7.6%) led to the administration of an additional bolus of clopidogrel, prasugrel, or aspirin along with glycoprotein IIb/IIIa inhibitors during the procedure. The primary endpoint occurred in 34.6% of the patients in the monitoring group, as compared with 31.1% of those in the conventional-treatment group (hazard ratio, 1.13; 95% confidence interval [CI], 0.98-1.29; p = 0.10). The main secondary endpoint, stent thrombosis or any urgent revascularization, occurred in 4.9% of the patients in the monitoring group and 4.6% of those in the conventional-treatment group (hazard ratio, 1.06; 95% CI, 0.74-1.52; p = 0.77). The rate of major bleeding events did not differ significantly between groups.
The authors concluded that there were no significant improvements in clinical outcomes with platelet-function monitoring and treatment adjustment for coronary stenting, as compared with standard antiplatelet therapy without monitoring.
This large randomized study suggests that platelet-function monitoring with adjustment of antiplatelet therapy as needed before and after stent implantation did not reduce the rate of cardiovascular events, as compared with a conventional treatment strategy without measurement of the effect of antiplatelet drugs. Overall, these and other data including the TRILOGY ACS Platelet Function Substudy data, do not support the routine use of platelet-function testing in patients undergoing coronary stenting.
Keywords: Myocardial Infarction, Stroke, Platelet Aggregation Inhibitors, Drug-Eluting Stents, Catheterization
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