1. 수요저널 2015. 5. 13 우종신

3. ACC/AHA Guideline Focused Update 2011 Class I 1. After PCI, use of aspirin should be continued indefinitely. (Level of Evidence : A) 2. The duration of P2Y12 inhibitor therapy after stent implantation : a. In patients receiving a stent (BMS or DES) during PCI for ACS, P2Y12 inhibitor therapy should be given for at least 12 months. Options include clopidogrel 75 mg daily, prasugrel 10 mg daily, and ticagrelor 90 mg twice daily. (Level of Evidence: B) b. In patients receiving DES for a non-ACS indication, clopidogrel 75 mg daily should be given for at least 12 months if the patient is not at high risk of bleeding. (Level of Evidence: B)

4. Duration of Dual Antiplatelet Therapy after Implantation of Drug-Eluting Stents The use of dual antiplatelet therapy > 12 months after DES implantation was not significantly more effective than aspirin monotherapy in reducing the rate of myocardial infarction or death from cardiac causes. Park SJ NEJM 2010

5. Dual-antiplatelet treatment beyond 1 year after drug-eluting stent implantation (ARCTIC-Interruption): a randomised trial No apparent benefit but instead harm with extension of DAPT beyond 1 year after stenting with DES when no event has occurred within the first year after stenting Primary end-point: death, MI, stent thrombosis, Stroke, or urgent revascularization Safety endpoint: major and minor STEEPLE bleeding

6. PROlonging Dual antiplatelet treatment after Grading stent-induced Intimal hyperplasia studY Our study failed to show that prolonging DAPT for 24 months is superior to a 6-months duration of Tx in patients receiving 1 or 2 generation DES or at least 1 month after BMS.

7. ESC Guideline 2014

9. Study flow

10. Co-Primary Effectiveness End Point Stent Thrombosis

11. Co-Primary Effectiveness End Point MACCE

12. Co-Primary Effectiveness End Points & Components: 12-30 Months

14. PLATO (PLATelet inhibition and patients Outcomes) study Rate of stroke for Ticagrelor was not different from clopidogrel (1.3% vs 1.1% ), P=0.225. 024681012 6 4 3 2 1 0 Clopidogrel Ticagrelor 4.0 5.1 7 5 Months After Randomisation Cardiovascular Death Cumulative Incidence (%) ARR=1.1% RRR=21% NNT=91 P=0.001 HR: 0.79 (95% CI, 0.69–0.91) Months After Randomisation 024681012 6 5 4 3 2 1 0 7 Cumulative Incidence (%) Clopidogrel Ticagrelor 5.8 6.9 Myocardial Infarction ARR=1.1% RRR=16% Calculated NNT=91 P=0.005 HR: 0.84 (95% CI, 0.75–0.95) Ticagrelor reduced the combined risk of CV death, MI, or stroke by 16% vs. Clopidogrel

15. Prevention of Cardiovascular Events in Patients With Prior Heart Attack Using Ticagrelor Compared to Placebo on a Background of Aspirin

16. Primary Endpoint

17. Bleeding

18. Conclusion Prolonged duration of dual antiplatelet therapy (DAPT) may increase bleeding risk as well as cost and inconvenience DAPT trial did not answer the question, but left us with uncertainty high risk group  extended duration of DAPT beyond 12 month - complex PCI (bifurcation lesion, left main lesion, long lesion) - imperfect PCI procedure (stent malapposition, residual stenosis) - a history of stent thrombosis - morbidities with higher thrombogenicity - implantation of first generation DES