(The CLEAR PLATELETS-2 Study) Bivalirudin With and Without Eptifibatide for Elective Stenting: A Pharmacodynamic Study of Platelet Reactivity in Relation to the Occurrence of Periprocedural Myocardial Infarction (The CLEAR PLATELETS-2 Study) Gurbel PA, Bliden KP, DiChiara J, Bassi A, Herzog WR, Gesheff TB, Tantry US. Sinai Center for Thrombosis Research, Sinai Hospital of Baltimore Baltimore, Maryland, U.S.A.

Dr. Paul A. Gurbel has received research grants and honoraria from: Haemoscope Astra Zeneca Schering Plough Medtronic Daiichi/Sankyo Lilly Sanofi-Aventis Boston Scientific Bayer Portola Disclosures

Background  The optimal antiplatelet and anticoagulant strategy for elective coronary stenting remains controversial.  Elective stenting is commonly performed in the presence of only aspirin and an anticoagulant, without clopidogrel pretreatment or GPIIb/IIIa inhibition.  In the CLEAR PLATELETS Study the addition of the GPIIb/IIIa inhibitor, eptifibatide to low or high loading dose clopidogrel + heparin administered at the time of stenting (no pretreatment) produced: - superior platelet inhibition and lower myocardial necrosis than 300 mg or 600 mg clopidogrel + heparin.  High platelet reactivity was associated with peri-procedural myocardial necrosis. (Threshold for MI ?) 1 1. Gurbel PA et al. Circulation. 2005;111:1153-9

 High periprocedural platelet reactivity and high platelet-fibrin clot strength are risk factors for short and long-term ischemic events. 1-3  It has been proposed that bivalirudin, a direct thrombin inhibitor, may be a superior antithrombotic agent compared to heparin for stenting. 4  There are no randomised data on platelet reactivity and clot characteristics in elective stent patients treated with bivalirudin vs. bivalirudin + eptifibatide. CLEAR PLATELETS-2 Objectives:  Compare in elective stenting the effect of: bivalirudin (B) + eptifibatide (E) vs. bivalirudin alone on: 1) platelet reactivity (aggregometry) 2) physical characteristics of clot (thrombelastography)  Relation of platelet reactivity to post-stent myonecrosis 1. Gurbel PA, et al. Circulation. 2005; 111: Gurbel PA, et al. J Am Coll Cardiol. 2005; 46: Bliden KP, et al. J Am Coll Cardiol. 2007; 49: Lincoff M, et al. JAMA. 2003; 289: Background

Methods Clopidogrel 600 mg in lab [clopidogrel naïve (n=128)] On 75 mg clopidogrel maintenance, no load (n=72) ASA 325 mg Bivalirudin (1mg/kg bolus; 2.5 mg/kg/hr) + Eptifibatide (n = 98) (180  g/kg bolus x 2, 2.0  g/kg/min infusion x 18h) Elective coronary stenting, open label, randomised, 2 center study (n = 200) - Sinai Hospital of Baltimore - University of Oklahoma Health Sciences Center - J Saucedo Exclusion Criteria: Blood Samples: Pre-PCI; 2 hrs, 6-8hrs and 18hrs post-PCI - Eptifibatide (n = 102) Bleeding diathesis, MI 2.0 mg/dl GPIIb/IIIa or anticoagulant use prior to the procedure

Methods: Laboratory Studies  Light Transmittance Aggregometry - (Chronolog) - PPACK tubes (75  M) - 5 and 20uM ADP, 15 and 25uM TRAP, 2ug/mL Collagen, 2mM AA  Flow Cytometry (FACScan, BD Biosciences) - PPACK tubes (75  M) - Non-stimulated and ADP-stimulated (1  M): P-selectin expression (% positive cells), Activated GPIIb/IIIa (MFI)  Thrombelastography (Haemoscope) - Maximum platelet - fibrin clot strength stimulated by kaolin (MA, mm) - Time to initial platelet-fibrin clot formation (R, min.)  Triage Meter (Biosite) - CKMB, Troponin-I, Myoglobin

Methods: Clinical Outcomes In-hospital and up to 12 month ischemic and bleeding events Definition of Ischemic Events: - Death (secondary to cardiovascular cause) - MI (symptoms and Tn I >ULN and/or CKMB > 3x ULN) - Stroke - Definite stent thrombosis (angiographically documented) - Any unplanned coronary intervention Bleeding Events – TIMI Major (intracranial, a fall in Hgb>5g/dL or a fall in Hct of >15%) 1 – TIMI Minor (fall in Hgb of 3-5g/dL or a fall in Hct of 9-15%) 1 1. Bovill EG, et al. Ann Intern Med. 1991;115:

Results: Patient Demographics

Results: Procedural Characteristics

Results: Aggregation 5  M ADP-Induced Aggregation (%) 20  M ADP-Induced Aggregation (%) + p<0.05, 600 mg C+B vs. 75 mg C+B * p<0.001, B+E vs. E

Results:Aggregation 25 uM TRAP-Induced Aggregation (%) 2 ug/ml Collagen-Induced Aggregation (%) + p<0.05, 600 mg C+B vs. 75 mg C+B * p<0.001, B+E vs. E

Results: Thrombelastography Baseline2 hr6-8hr18 hr 600mg C+B600mg C+B+E * * Baseline2 hr6-8hr18 hr 75mg C+B75mg C+B+E (mm) Baseline2 hr6-8 hr18 hr 600mg C+B600mg C+B+E Baseline2 hr6-8 hr18 hr 75mg C+B75mg C+B+E (min) Platelet-Fibrin Clot Strength Time to Initial Platelet-Fibrin Clot Formation Clopidogrel Naïve Chronic Clopidogrel Clopidogrel Naïve Chronic Clopidogrel * p<0.05

ADP-Stimulated P-Selectin Expression ADP-Stimulated GPIIb/IIIa Expression Results- Flow Cytometry * p<0.001 Clopidogrel Naive Chronic Clopidogrel C+B C+B+E Positive Cells (%) Baseline18 hr ** C+BC+B+E Baseline18 hr Mean Fluorescence Intensity Clopidogrel Naive Chronic Clopidogrel C+B C+B+E Baseline18 hr * * * C+BC+B+E Baseline18 hr * p<0.001

Relation of Platelet Reactivity (5  M ADP) to Myocardial Necrosis CKMB Mean Post-Treatment Aggregation (%) NL>1-3 ULN>3X ULN p< p=0.8

Relation of Myonecrosis Marker Release to Treatment Patient (%) p=0.04 p= Myoglobin (>2XULN), % Troponin-I (>ULN), % 75C+B+E600C+B+E75C+B600C+BCardiac Marker

Relation of Platelet-Fibrin Clot Strength to Myocardial Necrosis CKMB Clot Strength (mm) NL (>1-3X ULN)(>3X ULN) p=0.04 p=0.02 p=NS ~ 25% greater clot strength

Relation of Platelet-Fibrin Clot Strength (G) to MA Clot Strength Increases: ~ 1.8x Between MA 62- MA 74 (MI range) ~ 4.0x Between MA 50- MA 80 (total range) Data on file from Haemoscope Corp

Results: Clinical Outcomes

Conclusions 1) Eptifibatide + bivalirudin = 1) superior platelet inhibition irrespective of agonist 2) lower platelet-fibrin clot strength (most pronounced in clopidogrel naïve) These 2 properties may explain lower periprocedural Ischemic events in patients treated with eptifibatide + bivalirudin vs. bivalirudin. 2) CLEAR PLATELETS 2 further supports a link between high platelet reactivity and the occurrence of post-stent infarction. 3) The addition of eptifibatide may reduce periprocedural MI in selected patients with high platelet reactivity on bivalirudin + clopidogrel therapy 4) Selection of patients for adjunctive GPIIb/IIIa blockade may be facilitated in future studies by individualized platelet function measurements- ? Target pt. with high on-clopidogrel treatment platelet reactivity In elective stenting in clopidogrel naïve and chronic clopidogrel treated pts: