(Circulation. 2002;106:2284.)
© 2002 American Heart Association, Inc.
Current Perspective |
From the Division of Cardiovascular Medicine, Mayo Clinic, Rochester, Minn (P.B.B.); and the Division of Cardiology, University of North Carolina, Chapel Hill (S.S.).
Correspondence to Peter B. Berger, MD, Division of Cardiovascular Diseases-West 16, Mayo Clinic, 200 First St S.W., Rochester, MN 55905. E-mail berger.peter{at}mayo.edu
| Introduction |
|---|
|
|
|---|
Although dual antiplatelet therapy with clopidogrel and aspirin is often considered to be of benefit only in patients treated with stents, an interesting finding in PCI-CURE was that pretreatment and continued therapy with clopidogrel appeared to be as beneficial among the 19% of patients who did not receive a coronary stent as among the 81% of patients who did.2 There had not previously been evidence of benefit from thienopyridines use among patients undergoing PCI without stent placement, although it seems logical that there might be.3
| Applicability to US Practice |
|---|
|
|
|---|
In view of these issues, what findings from the PCI-CURE analysis can be used to help guide patient treatment? The study attempts to address 2 issues that physicians must deal with in every patient undergoing PCI in their practice: when a thienopyridine should be started and how long it should be continued after the procedure.
| Pretreatment With a Clopidogrel |
|---|
|
|
|---|
A critically important potential confounder of the PCI-CURE results is that there were important differences between the 2 groups of patients not at study entry, but at the time the PCI procedure was performed; in fact, the differences were apparent within several hours of randomization (Figure). Because the event curves for clopidogrel and placebo-treated patients in the CURE trial separated within hours and continued to separate throughout the study, a significantly greater proportion of patients had suffered an adverse event in the placebo arm even before the PCI procedure was performed (MI or refractory ischemia before PCI: 15.3% placebo versus 12.1% clopidogrel, P=0.008). This adds bias to the analysis in favor of dual antiplatelet therapy. However, it is unlikely that this difference accounted entirely for the relatively large difference in events observed in the following 30 days between the 2 groups of patients.
|
Yet another source of bias in the PCI-CURE substudy derives from the fact that 25% of patients assigned to placebo received open-label clopidogrel before their PCI procedure, so that if pretreatment with clopidogrel is beneficial, this study design would serve to underestimate the true benefits of clopidogrel therapy. All these reasons make it difficult to be definitive about any conclusions regarding the actual benefit of pretreatment with clopidogrel one might reach from the study.
| Duration of Therapy With Clopidogrel |
|---|
|
|
|---|
| Remaining Unanswered Questions |
|---|
|
|
|---|
Therefore, a reasonable approach to minimizing bleeding risks or treatment delays, an approach we suggest might be to withhold clopidogrel pretreatment before diagnostic angiography in patients at increased risk of requiring CABG, particularly if angiography will be performed after minimal delay. Such patients would include those with known multivessel disease shown by prior angiograms (particularly if they were not to be amenable to PCI but were amenable to surgery), those with known borderline left main disease, and those with diabetes mellitus or with chronic renal failure; these are patient groups in whom PCI appears to be associated with a much higher risk than CABG. Also, patients with old vein grafts and those with peripheral and cerebrovascular disease are much more likely to require CABG than patients without any of these characteristics. Note that the list of patients more likely to require CABG is similar to the list of patients most likely to benefit from long-term treatment with clopidogrel after a successful PCI procedure.
As it is likely that only a small percentage of ACS patients actually require an emergent surgical revascularization, another strategy for minimizing bleeding would be to delay surgery for at least 5 days in patients already receiving clopidogrel. However, as a large proportion of such patients would have to remain hospitalized awaiting surgery, the additional cost of such a strategy may be prohibitive at many institutions.
Use With GPIIb/IIIa Antagonists
Perhaps the most important questions facing the interventional cardiologist regarding clopidogrel pretreatment, which are unanswered by the PCI-CURE trial, are whether pretreatment with clopidogrel remains beneficial if a platelet GPIIb/IIIa inhibitor is administered, or visa versa, and whether the benefit of aspirin plus clopidogrel plus a GPIIb/IIIa antagonist is additive without an unacceptable bleeding risk. The results of the Evaluation of Platelet IIb/IIIa Inhibitor for STENTing (EPISTENT) Trial analysis suggested that pretreatment was no longer beneficial in reducing adverse events at 30 days when the IIb/IIIa inhibitor abciximab was used; however, the duration of pretreatment with the slower-onset ticlopidine was unknown and likely short.6 On the other hand, the results of the do Tirofiban (Aggrastat) And ReoPro Give similar Efficacy outcomes Trial (TARGET) suggested that event rates were lower among patients pretreated with clopidogrel even when all patients received a GPIIb/IIIa antagonist.7 However, both the EPISTENT and TARGET trials were not designed to answer the question about the benefit of pretreatment with a thienopyridine among patients receiving a GPIIb/IIIa inhibitor, and therefore the optimal use of a GPIIb/IIIa antagonist when a patient has already received clopidogrel, or of clopidogrel in a patient already receiving a GPIIb/IIIa antagonist, remains unclear.
| Ongoing Trials |
|---|
|
|
|---|
In the Intracoronary Stenting and Antithrombotic Regimen-Rapid Early Action for Coronary Treatment (ISAR-REACT) study, patients who had symptoms of coronary artery disease and scheduled to undergo coronary angiography and who are extremely unlikely to require CABG within days of angiography will receive a loading dose of 600 mg clopidogrel at least 2 hours before the procedure; those with insulin-dependent diabetes mellitus and those with a positive biomarker are excluded. Patients receiving this large dose of clopidogrel before their procedure will then be randomized to receive either abciximab and reduced dose heparin or standard dose heparin and placebo. The primary end point of the study is the composite rate of death, MI, and urgent target vessel revascularization within 30 days; secondary end points include the incidence of major and minor bleeding complications, as well as indices of restenosis after 6 months.
| Conclusion |
|---|
|
|
|---|
| References |
|---|
|
|
|---|
2. Mehta S, Yusuf S, Peters R, et al. Effects of pretreatment with clopidogrel and aspirin followed by long-term therapy in patients undergoing percutaneous coronary intervention: the PCI-CURE study. Lancet.;. 2001; 358: 527533.[CrossRef][Medline] [Order article via Infotrieve]
3. Berger PB, Dzavik V, Penn IM, et al. Does ticlopidine reduce reocclusion and other adverse events after successful balloon angioplasty of occluded coronary arteries? Results from the Total Occlusion Study of Canada. Am Heart J. 2001; 142: 776781.[CrossRef][Medline] [Order article via Infotrieve]
4. Mehta SR, Yusuf S. The Clopidogrel in Unstable angina to prevent Recurrent Events (CURE) trial programe: rationale, design and baseline characteristics including a meta-analysis of the effects of thienopyridines in vascular disease. Eur Heart J. 2000; 21: 20332041.
5. Steinhubl SR, Lauer MS, Mukherjee DP, et al. The duration of pretreatment with ticlopidine prior to stenting is associated with the risk of procedure-related non-Q-wave myocardial infarctions. J Am Coll Cardiol. 1998; 32: 13661370.
6. Steinhubl SR, Ellis SG, Wolski K, et al. Ticlopidine pretreatment before coronary stenting is associated with sustained decrease in adverse cardiac events: data from the Evaluation of Platelet IIb/IIIa Inhibitor for STENTing (EPISTENT) Trial. Circulation. 2001; 103: 14031409.
7. Topol EJ, Moliterno DJ, Herrmann HC, et al. Comparison of two platelet glycoprotein IIb/IIIa inhibitors, tirofiban and abciximab, for the prevention of ischemic events with percutaneous coronary revascularization. N Engl J Med. 2001; 344: 18881894.
8. Gaspoz J-M, Coxson PG, Goldman PA, et al. Cost effectiveness of aspirin, clopidogrel, or both for secondary prevention of coronary heart disease. N Engl J Med. 2002; 346: 18001806.
9. Schuhlen H, Kastrati A, Pache J, et al. Sustained benefit over four years from an initial combined antiplatelet regimen after coronary stent placement in the ISAR trial. Intracoronary Stenting and Antithrombotic Regimen. Am J Cardiol. 2001; 87: 397400.[CrossRef][Medline] [Order article via Infotrieve]
10. Berger PB, Bell MR, Grill DE, et al. Safety and efficacy of ticlopidine for only two weeks after successful intracoronary stent placement. Circulation. 1999; 99: 248253.
11. Topol EJ, Mark DB, Lincoff AM, et al. Outcomes at 1 year and economic implications of platelet glycoprotein IIb/IIIa blockade in patients undergoing coronary stenting: results from a multicentre randomised trial. Lancet. 1999; 354: 20192024.[CrossRef][Medline] [Order article via Infotrieve]
12. OShea JC, Buller CE, Cantor WJ, et al. Long-term efficacy of platelet glycoprotein IIb/IIIa integrin blockade with eptifibatide in coronary stent intervention. JAMA. 2002; 287: 618621.
13. Cannon C, Weintraub W, Demopoulos L, et al. Comparison of early invasive and conservative strategies in patients with unstable coronary syndromes treated with the glycoprotein IIb/IIIa inhibitor tirofiban. N Engl J Med. 2001; 344: 18791887.
14. Wallentin L, Lagerqvist B, Husted S, et al. Outcome at 1 year after an invasive compared to a non-invasive strategy in unstable coronary-artery disease: the FRISC II invasive randomised trial. Lancet. 2000; 356: 916.[CrossRef][Medline] [Order article via Infotrieve]
15. Yende S, Wunderink RG. Effect of clopidogrel on bleeding after coronary artery bypass surgery. Crit Care Med. 2001; 29: 22712275.[CrossRef][Medline] [Order article via Infotrieve]
16. Hongo RH, Ley J, Dick SE, et al. The effect of clopidogrel in combination with aspirin when given before coronary artery bypass grafting. J Am Coll Cardiol. 2002; 40: 231237.
This article has been cited by other articles:
![]() |
M. S. Sabatine, C. P. Cannon, C. M. Gibson, J. L. Lopez-Sendon, G. Montalescot, P. Theroux, B. S. Lewis, S. A. Murphy, C. H. McCabe, E. Braunwald, et al. Effect of Clopidogrel Pretreatment Before Percutaneous Coronary Intervention in Patients With ST-Elevation Myocardial Infarction Treated With Fibrinolytics: The PCI-CLARITY Study JAMA, September 14, 2005; 294(10): 1224 - 1232. [Abstract] [Full Text] [PDF] |
||||
![]() |
S J Walsh, M S Spence, D Crossman, and A A J Adgey Clopidogrel in non-ST segment elevation acute coronary syndromes: an overview of the submission by the British Cardiac Society and the Royal College of Physicians of London to the National Institute for Clinical Excellence, and beyond Heart, September 1, 2005; 91(9): 1135 - 1140. [Abstract] [Full Text] [PDF] |
||||
![]() |
Authors/Task Force Members, S. Silber, P. Albertsson, F. F. Aviles, P. G. Camici, A. Colombo, C. Hamm, E. Jorgensen, J. Marco, J.-E. Nordrehaug, et al. Guidelines for Percutaneous Coronary Interventions: The Task Force for Percutaneous Coronary Interventions of the European Society of Cardiology Eur. Heart J., April 2, 2005; 26(8): 804 - 847. [Full Text] [PDF] |
||||
![]() |
J. M. Brophy and L. Joseph Medical Decision Making with Incomplete Evidence--Choosing a Platelet Glycoprotein IIbIIIa Receptor Inhibitor for Percutaneous Coronary Interventions Med Decis Making, March 1, 2005; 25(2): 222 - 228. [Abstract] [PDF] |
||||
![]() |
L. Chen, A. W. Bracey, R. Radovancevic, J. R. Cooper Jr, C. D. Collard, W. K. Vaughn, and N. A. Nussmeier Clopidogrel and bleeding in patients undergoing elective coronary artery bypass grafting J. Thorac. Cardiovasc. Surg., September 1, 2004; 128(3): 425 - 431. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Kastrati, J. Mehilli, H. Schuhlen, J. Dirschinger, F. Dotzer, J. M. ten Berg, F.-J. Neumann, H. Bollwein, C. Volmer, M. Gawaz, et al. A Clinical Trial of Abciximab in Elective Percutaneous Coronary Intervention after Pretreatment with Clopidogrel N. Engl. J. Med., January 15, 2004; 350(3): 232 - 238. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. S. Forrester Toward understanding the evolution of plaque rupture: Correlating vascular pathology with clinical outcomes J. Am. Coll. Cardiol., November 5, 2003; 42(9): 1566 - 1568. [Full Text] [PDF] |
||||
![]() |
D. J. Kereiakes Adjunctive Pharmacotherapy before Percutaneous Coronary Intervention in Non-ST-Elevation Acute Coronary Syndromes: The Role of Modulating Inflammation Circulation, October 21, 2003; 108(90161): III-22 - 27. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. N. Levine, M. J. Kern, P. B. Berger, D. L. Brown, L. W. Klein, D. J. Kereiakes, T. A. Sanborn, A. K. Jacobs, and for the American Heart Association Diagnostic and Management of Patients Undergoing Percutaneous Coronary Revascularization Ann Intern Med, July 15, 2003; 139(2): 123 - 136. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. R. Steinhubl, P. B. Berger, J. T. Mann III, E. T. A. Fry, A. DeLago, C. Wilmer, E. J. Topol, and for the CREDO Investigators Early and Sustained Dual Oral Antiplatelet Therapy Following Percutaneous Coronary Intervention: A Randomized Controlled Trial JAMA, November 20, 2002; 288(19): 2411 - 2420. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|
Circulation Home | Subscriptions | Archives | Feedback | Authors | Help | AHA Journals Home | Search Copyright © 2002 American Heart Association, Inc. All rights reserved. Unauthorized use prohibited. |