Clopidogrel Use and Death/MI After Stent Implantation in a Diabetic Population

1. SCAI ‘07 Clopidogrel Use and Death/MI After Stent Implantation in a Diabetic Population Results from the SUNSET registry Somjot S. Brar, Simerjeet K. Brar, John Kim, Ray Zadegan, Michael Ree, In-lu A. Liu, Prakash Mansukhani, Vicken Aharonian, Ric Hyett, Albert Y-J. Shen Department of Cardiology Kaiser Permanente, Los Angeles & UCLA School of Medicine Kaiser Permanente

2. Disclosures • Research grant support from Boston Scientific • S. Brar, MD • A. Shen, MD Kaiser Permanente

3. Background • Death / MI reportedly increased with DES compared to BMS. • Two prior landmark analysis show increased death / MI in DES compared to BMS. • BASKET-LATE • Eisenstein et al. • Limited data in patients with diabetes. • Duration of clopidogrel after PCI remains unknown.

4. Study Questions • Is death / MI influenced by: • Clopidogrel duration? • Stent type (DES, BMS)? • Among patients taking clopidogrel for ≤ 6 months, is death / MI more frequent with DES compared to BMS? Kaiser Permanente

5. Methods • Study date: January 2002 – December 2005 • Study type: observational using the SUNSET registry • Population: • consecutive diabetic patients undergoing first PCI • No prior PCI or CABG • Multiple stent types not permitted • Insured members of a prepaid integrated health plan • Location: high volume tertiary care referral center (Los Angeles, CA) • Main outcomemeasure: death or MI at 18 months (545 days) post PCI Kaiser Permanente

6. Methods • Clopidogrel • pharmacy prescription records • Duration of clopidogrel calculated from index PCI • User: >6 months of clopidogrel use from index PCI date • Non-users: ≤6 months of use from the index PCI date • “Landmark” analysis • Excluded patients with events within first 6 months • Similar to an observational analysis from BASKET-LATE. Kaiser Permanente

7. Study Flow 749 diabetics underwent first revascularization Exclusion: 41 Death/MI/Revascularization 37 Clopidogrel usage unknown 671 event free from Death or MI at 6 months F/U to 18 months post PCI Kaiser Permanente

8. Four Study Groups: Stratified by Stent Type & Clopidogrel 671 Patients Clopidogrel / Stent type BMS (n=221) DES (n=450) Clopidogrel (-) N=74 Clopidogrel (+) N=147 Clopidogrel (-) N=127 Clopidogrel (+) N=323 Death or MI (18 months) Kaiser Permanente

9. Baseline Characteristics

10. Baseline Characteristics

11. Death / MI by Stent type(0d – 18mo) 20 20 p=0.05 15 15 Cumulative Incidence (%) 10 10 5 5 0 0 No. at Risk DES 498 469 459 320 BMS 251 237 225 218

12. Death / MI by Stent Type(6mo – 18mo) 10 p=0.08 6.2% Cumulative Incidence (%) 5 3.1% 0

13. Death / MI in BMS group(6mo – 18mo) 20 p=0.01 12.2% Cumulative Incidence (%) 10 3.5% 0

14. Death / MI in DES group(6mo – 18mo) 20 p=0.07 10 Cumulative Incidence (%) 5.5% 2.2% 0

15. Death / MI in Clopidogrel Non-Users (6mo – 18mo) 30 p=0.11 20 Cumulative Incidence (%) 12.2% 10 5.5% 0

16. Death / MI by Clopidogrel Duration(6mo – 18mo) 20 <9 months (n=314) 9-12 months (n=207) >12 months (n=150) 10 Cumulative Incidence (%) 7.3% (64% DES) p=0.0005 2.0% (69% DES) (71% DES) 1.0% 0 p= 0.27

17. Discussion • From index PCI date to 18 months, death / MI less with DES vs. BMS (p=0.05). • Landmark Analysis • Clopidogrel use was associated with less death / MI in both DES (p=0.07) and BMS groups (p=0.01). • Among clopidogrel non-users, death / MI less with DES vs. BMS (p=0.11). • Death / MI less with 9-12 mo and >12 mo. of clopidogrel use compared to ≤ 9 mo (p < 0.001). • Clopidogrel compliance by Rx records was 95% Kaiser Permanente

18. Conclusion • Extended clopidogrel use ( >6 mo) from the index PCI was associated with less death / MI in both DES and BMS groups. • Overall trend towards less death / MI in the DES group compared to the BMS group. • Among clopidogrel non-users, no difference in death / MI by stent type. Kaiser Permanente