Kristin Newby and the EARLY-ACS investigators Upstream Clopidogrel Use and the Efficacy and Safety of Early Eptifibatide Treatment in Patients with Acute Coronary Syndrome: an Analysis from the EARLY-ACS Trial Tracy Wang, MD, MHS, MSc on behalf of Jennifer White, Pierluigi Tricoci, Robert Giugliano, Uwe Zeymer, Robert Harrington, Gilles Montalescot, Stefan James, Frans Van de Werf, Paul Armstrong, Eugene Braunwald, Robert Califf, Kristin Newby and the EARLY-ACS investigators

The EARLY ACS trial was funded by Schering-Plough The EARLY ACS trial was funded by Schering-Plough. These analyses were funded by research grant support from Merck & Co., Inc. Wang: BMS/Sanofi, Schering Plough, The Medicines Co, Heartscape, Canyon Pharmaceuticals, Lilly/Daiichi Sankyo White, Zeymer: nothing to disclose Giugliano: Schering Plough, Merck, Daiichi Sankyo, BMS, Sanofi Tricoci: Research grants from Merck Harrington: Schering Plough, others at www.dcri.duke.edu/research/coi.jsp. Montalescot: BMS, Boston Scientfic, Centocor, Cordis, Lilly, Fédération Française de Cardiologie, Fondation de France, Guerbet Medical, INSERM, ITC Edison, Medtronic, Pfizer, Sanofi-Aventis Group, Société Française de Cardiologie; Accumetrics, Astra-Zeneca, Bayer, Boehringer-Ingelheim, Daiichi-Sankyo, Eisai, Novartis, Portola, Schering-Plough, and The Medicines Company. Van de Werf: Schering Plough, Roche. Advisory board and speakers fee from Schering Plough, Merck, Roche Armstrong: Sanofi-Aventis, BMS, Merck, Abbott, GlaxoSmithKline, Pfizer, Regado, Hoffman-La-Roche, Boehringer Ingelheim, Eli Lilly, Schering Plough, Scios, Portola, Uppsala Clinical Research Center, AstraZeneca Braunwald: Eli Lilly, Schering Plough, Daiichi Sankyo, Merck Califf: Schering Plough, Merck. Others at www.dcri.duke.edu/research/coi.jsp. Newby: Schering Plough, Merck. Others at www.dcri.duke.edu/research/coi.jsp. TY Wang: Research grants from Bristol-Myers Squibb/Sanofi Partnership, Schering-Plough, The Medicines Company, Heartscape, Canyon Pharmaceuticals, and Eli Lilly/Daiichi Sankyo Alliance. JA White: None. RP Giugliano: Research grant support, advisory board, and honoraria for lectures, Schering-Plough, Inc., and Merck & Co., Inc; research grant support from Daiichi-Sankyo; consultant/honoraria for lectures from Bristol Myers Squibb and Sanofi-Aventis. P Tricoci: Research grant from Merck & Co., Inc., Whitehouse Station, NJ, USA, through the Duke Clinical Research Institute; advisory board for Merck & Co. RA Harrington: Research funding and consulting with Schering-Plough, now Merck. A complete listing of Dr. Harrington’s relationships with industry is available at http://www.dcri.duke.edu/research/coi.jsp. G Montalescot: Research grants (to the institution) from Bristol Myers Squibb, Boston Scientific, Centocor, Cordis, Eli-Lilly, Fédération Française de Cardiologie, Fondation de France, Guerbet Medical, INSERM, ITC Edison, Medtronic, Pfizer, Sanofi-Aventis Group, Société Française de Cardiologie; consulting or lecture fees from Accumetrics, Astra-Zeneca, Bayer, Boehringer-Ingelheim, Bristol-Myers Squibb, Daichi-Sankyo, Eisai, Eli-Lilly, Menarini, MSD, Novartis, Portola, Sanofi-Aventis Group, Schering-Plough, and The Medicines Company. U Zeymer: I will email. F Van de Werf: Research grants from Schering-Plough (now Merck) and Roche; advisory board and speakers fee from Schering-Plough, Merck, and Roche. PW Armstrong: Consulting or other services that generate personal income from sanofi-aventis, Bristol-Myers Squibb Canada, Merck Frosst Canada Ltd, Abbott Laboratories, GlaxoSmithKline, Bristol-Myers Squibb/Pfizer, Regado Biosciences, and F. Hoffmann-La Roche Ltd; research grant or contract from Boehringer Ingelheim (Canada) Ltd, sanofi-aventis Canada, Eli Lilly, Schering-Plough Research Institute, Scios Inc/Ortho-Biotech, GlaxoSmithKline, Portola Pharmaceutical Inc, Uppsala Clinical Research Center and AstraZeneca, and Merck & Company Inc., that partially supports his university salary and/or research projects. EA Braunwald: Dr. Braunwald is Chairman of the TIMI Study Group at the Brigham and Women’s Hospital, which receives (or has received within the past 24 months) grant support for the TIMI Study Group from the following pharmaceutical companies (all > $10,000): Eli Lilly, Merck & Co., Inc., Schering-Plough Research Institute, Daiichi Sankyo. Dr. Braunwald has also participated occasionally (max 2–3/yr) in symposia/advisory board meetings/consultancies for the following companies for which he receives an honorarium (always < $10,000) and reimbursement of travel-related expenses: Daiichi Sankyo, Eli Lilly, Merck & Co., Inc., Schering-Plough. RM Califf: Research funding and consulting with Schering-Plough, now Merck (all consulting funds donated to not for profits). A complete listing of Dr. Califf’s relationships with industry is available at http://www.dcri.duke.edu/research/coi.jsp. LK Newby: Research grant from Schering Plough and Merck & Co., Inc. through the Duke Clinical Research Institute; consulting honoraria from Schering-Plough. A complete listing of Dr. Newby’s relationships with industry is available at www.dcri.duke.edu/research/coi.jsp.

Background ACC/AHA/ESC Guidelines recommend For patients with NSTE ACS treated with early invasive strategy, either clopidogrel or GPI should be initiated upstream before angiography (Class I, level of evidence A) For patients with high-risk features, upstream initiation of both clopidogrel and GPI can be considered (Class IIa, level of evidence B) Current American College of Cardiology/American Heart Association (ACC/AHA) and European Society of Cardiology (ESC) clinical practice guidelines recommend that for patients with non–ST-segment elevation acute coronary syndrome (NSTE ACS) treated with an early invasive management strategy, antiplatelet therapy with either clopidogrel or a glycoprotein IIb/IIIa inhibitor should be initiated upstream before diagnostic angiography (Class I recommendation, level of evidence A).1, 2 Among patients with high-risk features, upstream initiation of both clopidogrel and glycoprotein IIb/IIIa inhibitor can be considered before coronary angiography (Class IIa recommendation, level of evidence B).

Clopidogrel and GPI ISAR-REACT 2 CREDO GPI (N=826) % of Patients RRR: 25% CREDO P=.03 P=NS GPI (N=826) No GPI (N=1289) % of Patients In CREDO, patients who received clopidogrel at least 6 hours before PCI had a 38.6% risk reduction compared with patients treated later; the event curves started to diverge 3 to 4 days after randomization.7 Interestingly, although glycoprotein IIb/IIIa inhibitor use rates were low in this population, a benefit of clopidogrel pre-treatment was suggested only in patients concomitantly receiving glycoprotein IIb/IIIa inhibitor (30% relative reduction, p=0.12). In ISAR-REACT 2, Kastrati et al showed that, among ACS patients who received a 600-mg load of clopidogrel at least 2 hours before PCI, peri-procedural glycoprotein IIb/IIIa inhibitor use resulted in a 25% risk reduction of the primary end point of death/MI/urgent target vessel revascularization at 30 days.8 These results did not vary with the duration of clopidogrel pre-treatment, but the possibility of a greater benefit from glycoprotein IIb/IIIa inhibitor therapy had this been started earlier, prior to coronary angiography and PCI, could not be assessed in this study. Clopidogrel Better Placebo Better 1-yr Death/MI/Stroke * *Death, MI, or uTVR Steinhubl S et al. JAMA 2002;288: 2411-20. Kastrati A et al. JAMA. 2006;295:1531-38. 4

Study Design High-risk NSTE ACS n = 10,500 Routine, early eptifibatide 2 of 3 high-risk criteria: 1. Age > 60 years 2. + CKMB or TnT/I 3. ST  or transient ST  (Or age 50-59, h/o CVD and + CKMB or TnT/I) High-risk NSTE ACS n = 10,500 Routine, early eptifibatide Placebo / delayed provisional eptifibatide pre-PCI Randomized within 12 hours of presentation with planned angiography 12 to 96 hours after randomization Primary Endpoint: 96-hr Death, MI, recurrent ischemia requiring urgent revascularization, or thrombotic bailout Secondary Endpoints: 30-d Death or MI, 120-hr Bleeding

EARLY-ACS Trial: Primary Endpoint 15 10.0% 10 Delayed provisional eptifibatide 9.3% Death, MI, RIUR or TBO (%) P = 0.23 5 Routine early eptifibatide 8 16 24 32 40 48 56 64 72 80 88 96 Time Since Randomization (Hours)

Secondary Endpoint: 30-day Death or MI 15 12.4% Delayed provisional eptifibatide 10 11.2% Death or MI (%) Routine early eptifibatide P = 0.079 5 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 Time Since Randomization (Days)

Secondary Endpoint: Bleeding Routine Early Eptifibatide (n=4686) Delayed Provisional Eptifibatide (n=4643) OR (95% CI) P Bleeding (all patients, %) TIMI major 2.6 1.8 1.42 (1.07-1.89) 0.015 GUSTO moderate or severe 7.6 5.1 1.52 (1.28-1.80) <0.001 PRBC transfusion 8.6 6.7 1.31 (1.12-1.53) 0.001

Clopidogrel Use in EARLY-ACS Clopidogrel use and timing were determined by treating physician Randomization in the EARLY-ACS Trial was stratified by declared intent for upstream clopidogrel use In this analysis, we examined whether upstream clopidogrel pre-treatment influenced the benefit or safety of routine, upstream eptifibatide use prior to angiography. For the primary analysis, upstream clopidogrel use was defined according to the intended use declared at randomization; this information was obtained from the electronic records of the interactive voice response system used for randomization. In a sensitivity analysis, we then defined upstream clopidogrel use by actual treatment before angiography. Actual treatment was determined from the case report form and included patients already on clopidogrel at the time of study randomization as well as those for whom the date and time of first clopidogrel administration occurred prior to the time of coronary angiography. Of the 9406 evaluable patients enrolled in the EARLY ACS trial, 9166 patients (97.4%) underwent coronary angiography during the index hospitalization at a median of 21.4 (16.8, 32.7) hours following randomization. An intention to use upstream clopidogrel was declared in 6895 patients (75.2%) at the time of randomization; for 2271 (24.8%), the investigator declared an intent not to use upstream clopidogrel. Overall, 7068 patients actually received upstream clopidogrel (5592 pre-randomization, 1476 post-randomization). A total of 1223 patients had clopidogrel initiated after angiography, and 841 patients never received clopidogrel

Final Study Population No upstream Clopidogrel EARLY-ACS Patients N = 9,406 No cardiac catheterization (n=240) Final Study Population N =9,166 (97%) Median time to angiography 21 hrs (IQR 17 - 33) A total of 9492 patients were randomized within 12 hours of hospital admission to receive either early administration of double bolus and infusion of eptifibatide or early placebo with delayed, provisional administration of eptifibatide after angiography but before the patient underwent PCI at the treating physician’s discretion. Of these, 9406 were evaluable for the primary and key secondary end points (see main manuscript for details9), and 240 patients did not proceed to catheterization, leaving 9166 patients eligible for this analysis. Upstream Clopidogrel N = 6895 (75%) No upstream Clopidogrel N = 2271 (25%)

No upstream Clopidogrel Baseline Characteristics Upstream Clopidogrel N = 6895 (75%) No upstream Clopidogrel N = 2271 (25%) P-value Median age (yrs) 67.1 68.2 <0.001 Women (%) 31 34 0.001 Region North America 21 60 Western Europe 48 18 Eastern Europe 11 9 Middle East/Africa/Asia 20 13 Diabetes (%) 29 32 0.006 Hypertension (%) 70 74 Prior MI 27 28 0.04 Prior PCI 25 24 0.38 Prior CABG 16 Periph arterial disease 10 0.34 Of the 9406 evaluable patients enrolled in the EARLY ACS trial, 9166 patients (97.4%) underwent coronary angiography during the index hospitalization at a median of 21.4 (16.8, 32.7) hours following randomization. An intention to use upstream clopidogrel was declared in 6895 patients (75.2%) at the time of randomization; for 2271 (24.8%), the investigator declared an intent not to use upstream clopidogrel. Overall, 7068 patients actually received upstream clopidogrel (5592 pre-randomization, 1476 post-randomization). A total of 1223 patients had clopidogrel initiated after angiography, and 841 patients never received clopidogrel Upstream clopidogrel use is often constrained by the potential for multivessel disease on angiography requiring surgical revascularization, yet paradoxically, the proportion of patients with prior CABG (thus, lower risk of subsequent surgical revascularization) was lower in the clopidogrel-treated group.

No upstream Clopidogrel Presentation Upstream Clopidogrel N = 6895 (75%) No upstream Clopidogrel N = 2271 (25%) P-value TIMI Risk Score <0.001 0-2 17 14 3-4 48 49 >4 35 37 Killip Class 0.07 I 90 88 II 8 10 III 2 IV 0.3 0.4 Baseline CrCl (mL/min) 75 72 0.01 Baseline Hemoglobin (g/L) 14.1 0.91 Hours and symptom onset

Efficacy 96h Death/MI/ RIUR/TBO 30-day Death/MI

Efficacy (adjusted) Death/MI/RIUR/TBO at 96 hours Death/MI at 30 days Adjusted OR (95% CI) Death/MI/RIUR/TBO at 96 hours Upstream Clopidogrel 0.93 (0.79 – 1.10) No Clopidogrel 0.94 (0.72 – 1.22) p for interaction = 0.99 Death/MI at 30 days After adjustment for clinical characteristics, early eptifibatide, compared with a delayed provisional strategy, was not significantly associated with lower risk of death/MI/RIUR/TBO at 96 hours in either patients intended for upstream clopidogrel use (adjusted OR 0.93 [95% CI 0.79-1.10]) or patients without intended upstream clopidogrel use (adjusted OR 0.94 [95% CI 0.72-1.22]). The clopidogrel stratum by randomized treatment interaction term was not significant (p=0.99). There was a significant reduction in death or MI at 30 days in patients randomized to early eptifibatide compared with delayed provisional eptifibatide in the upstream clopidogrel stratum (adjusted OR 0.85 [95% CI 0.73-0.99]) but no difference in risk among patients without intended upstream clopidogrel use (adjusted OR 1.02 [95% CI 0.80-1.30]). As shown in Figure 2, event curves diverged early in the intended upstream clopidogrel group and remained separate out to 30 days. However, the intended clopidogrel strata by randomized treatment interaction term was not significant (p=0.23). Upstream Clopidogrel 0.85 (0.73 – 0.99) No Clopidogrel 1.02 (0.80 – 1.30) p for interaction = 0.23 1 2 3 Early eptifibatide better Provisional eptifibatide better

Death or MI at 30 days Upstream Clopidogrel No Upstream Clopidogrel Delayed Provisional Delayed Provisional Early Routine Early Routine Upstream Clopidogrel No Upstream Clopidogrel days days

Bleeding (adjusted) TIMI Major Bleeding GUSTO Mod/Severe Bleeding Adjusted OR (95% CI) TIMI Major Bleeding Upstream Clopidogrel 1.54 (1.07 – 2.24) No Clopidogrel 1.13 (0.69 – 1.84) p for interaction = 0.31 GUSTO Mod/Severe Bleeding Upstream Clopidogrel 1.72 (1.37 – 2.16) No Clopidogrel 1.29 (0.96 – 1.74) p for interaction = 0.13 Compared with delayed provisional use at PCI, early eptifibatide use was not associated with a higher rate of overall in-hospital GUSTO severe bleeding either when intended upstream clopidogrel use was declared (adjusted OR 1.01 [95% CI 0.58-1.77]), or when no intended upstream clopidogrel was declared (adjusted OR 1.02 [95% CI 0.44-2.36 ]); p for interaction=0.99 (Figure 1). However, in-hospital transfusion use was significantly increased in both strata (adjusted OR 1.38, [95% CI 1.04-1.83] for intended upstream clopidogrel, and adjusted OR 1.23 [95% CI 1.01-1.51] for no intended upstream clopidogrel; p for interaction=0.52, Table 3). For the combined end point of in-hospital GUSTO severe bleeding or transfusion, early eptifibatide use was associated with increased risk in both intended clopidogrel and no intended clopidogrel groups (adjusted ORs 1.41 [95% CI 1.07-1.87] and 1.26 [95% CI 1.03-1.54], respectively, Table 3 and Figure 1). Transfusion Upstream Clopidogrel 1.38 (1.04 – 1.83) No Clopidogrel 1.23 (1.01 – 1.51) p for interaction = 0.52 1 2 3 Early eptifibatide better Provisional eptifibatide better

Limitations Confounding inherent to subgroup comparison Attenuated by stratified randomization strategy Large regional differences in clopidogrel treatment patterns Results are hypothesis generating 30-day death/MI risk reduction with early eptifibatide use was statistically significant, but interaction term not significant The primary limitation of this analysis is confounding inherent to any subgroup comparison, but in the EARLY ACS study, this limitation is attenuated by the randomization scheme used that stratified by declared intention of upstream clopidogrel use such that clopidogrel stratum is a pre-specified subgroup. Actual upstream use followed very closely to the pre-randomization declared intent; thus, the frequency of upstream clopidogrel use did not differ significantly. Regional differences were apparent in clopidogrel treatment patterns. Because of the high degree of confounding between clopidogrel use and geographic region, it was not possible to adjust for region in the multivariable models. Second, patients randomized into clinical trials represent a unique cohort of patients whose clinical characteristics, treatment, and outcomes may not always reflect actual clinical practice (e.g., shorter delays to angiography). However, with regard to time to angiography, the EARLY ACS cohort was remarkably similar to both the CRUSADE and GRACE registry observations of practice, and EARLY ACS patients were selected to reflect high-risk populations including patients of older age and with 84% troponin positivity.9, 26, 27 Third, use of clopidogrel more than 24 hours prior to randomization was not captured in the EARLY ACS case report form; thus, we were unable to assess the influence of long-term prior use with outcomes. Finally, the trial was not powered to examine outcomes within individual subgroups. The reduction in 30-day death/MI risk with early eptifibatide use was statistically significant both among patients with a declared intent for upstream clopidogrel use as well as among patients actually pre-treated with clopidogrel. However, the interaction term between upstream clopidogrel use and randomized treatment assignment was not significant; thus, these results are hypothesis generating and need to be confirmed in future randomized studies.

Conclusions Among NSTE ACS patients undergoing angiography, routine pre-procedure eptifibatide use did not improve short-term ischemic outcomes but may be associated with a reduction in 30-day death/MI among patients pre-treated with clopidogrel Eptifibatide use increased bleeding risk; this risk was slightly accentuated by the addition of clopidogrel 11% got no load, 72% 300 load, 17% 600 mg load, median time from clopidogrel to cath was 20 hours Discordance between intent and actual use Among intent, 3% did not receive Among no intent, 18% actually received. While elevated platelet reactivity is maintained for an extended period of time post ACS, it may be reasonable to postulate that the robustness of acute platelet activation defines, in part, the magnitude of the long-term reactivity. As glycoprotein IIb/IIIa inhibitors have rapid onset and result in a high level of platelet inhibition,23 early combined use of a glycoprotein IIb/IIIa inhibitor with clopidogrel may substantially lower both acute and sustained levels of platelet reactivity (more than either agent alone), and synergistically reduce long-term risks of cardiovascular events. In contrast, more potent and consistent oral platelet inhibition with agents such as prasugrel would not be expected to and did not show any significant interaction with glycoprotein IIb/IIIa inhibitor use.24

Implications Future investigation is needed to identify subgroups of patients with high likelihood of benefit from more intensive platelet inhibition without a significant excess in bleeding risk It might be reasonable to consider early eptifibatide and clopidogrel pre-treatment in these high-risk NSTE ACS patients intended for angiography The addition of clopidogrel did not accentuate bleeding risks associated with early eptifibatide use. These findings lend support to the concept of enhanced value for additive antiplatelet therapies, and future investigations are needed to identify those patients who may benefit from more intensive platelet inhibition without a significant excess in bleeding risk.