1. Bedside monitoring to adjust antiplatelet therapy for Coronary stenting
N Engl J Med Nov 29;367:2100-9
Prof. Soo-Joong Kim / R3 Yu Ho Lee

2. Introduction Aspirin, clopidogrel Platelet reactivity test
Play a central role in the treatment of percutaneous coronary intervention (PCI)
One third of patients have inadequate platelet inhibition
Platelet reactivity test
Shown prognostic value during antiplatelet therapy in patients undergoing coronary stenting
Unknown whether individualized antiplatelet therapy can improve the long-term clinical outcome

3. Introduction ARCTIC study
The Assessment by a Double Randomization of a Conventional Antiplatelet Strategy versus a Monitoring-guided Strategy for Drug-Eluting Stent Implantation and of Treatment Interruption versus Continuation One Year after Stenting
Evaluated a strategy of systematic platelet-function monitoring
for the purpose of adjusting treatment in patients with a poor response to aspirin, thienopyridine (clopidogrel or prasugrel) as compared with a conventional approach

4. Methods Study patients Inclusion criteria Randomized, open-label study
38 centers in France
Inclusion criteria
Patients scheduled to undergo drug-eluting stent implantation
Exclusion criteria
PCI for ST-segment elevation
The planned use of glycoprotein IIb/IIIa inhibitors
Long-term anti-coagulation therapy
Bleeding diathesis

5. Methods Randomization and treatment strategies
Monitoring group : platelet-function evaluation with adjustment of antiplatelet drugs and doses
Conventional-treatment group : conventional treatment without platelet-function assessment
In the monitoring group..
Platelet-function measurements were performed for aspirin, P2Y12 inhibitors
Repeated measurements 2 to 4 weeks after stent implantation
Platelet-function Monitoring : VerifyNow assay (Accumetrics)

6. Methods
VerifyNow Assay

7. Methods Aspirin reaction unit (ARU) ARU > 550
 High platelet reactivity
P2Y12 reaction unit (PRU)
PRU > 235 or inhibition < 15%
 High platelet reactivity

8. Methods Before stent implantation
Patients with high Aspirin reaction unit (ARU)
Administration of intravenous aspirin
Patients with high P2Y12 reaction unit (PRU)
Administration of glycoprotein IIb/IIIa inhibitors
Additional loading dose of clopidogrel (at a dose of > 600mg) or prasugrel (60mg) before the procedure
Daily maintenance dose of 150mg of clopidogrel or 10mg of prasugrel after the procedure

9. Methods At 14 to 30 days after stent implantation
Patients with high P2Y12 reaction unit (PRU) during treatment with clopidogrel
Switched to prasugrel 10mg or 75mg increase in maintenance dose of clopidogrel

10. Methods Primary end points Main secondary efficacy end points
Composite of death from any cause
Myocardial infarction
Stroke or transient ischemic attack (TIA)
Urgent coronary revascularization
Stent thrombosis
Main secondary efficacy end points
Composite of stent thrombosis and urgent revascularization
Main safety end points
Major bleeding event

11. Methods Statistical analysis
Primary and secondary end points : Cox model for survival analysis
Nongaussian variables : summarized as medians, compared with Mann-Whitney test
Frequency comparison : Chi-square test

12. Results

13. Results

14. Results

15. Results

16. Results

17. Results

18. Conclusion
Our data do not support the routine use of platelet- function testing in patients undergoing coronary stenting