Platelet glycoprotein IIb/IIIa inhibitor use during percutaneous coronary intervention: IIb or Not IIb,what is the question?

Over the past decade, numerous placebo-controlled randomized clinical trials have documented robust clinical benefits of intravenous platelet glycoprotein (GP) IIb/IIIa inhibitors in patients undergoing percutaneous coronary intervention (PCI). This evidence has led to U.S. Food and Drug Administration approval and indication for use of two GP IIb/IIIa inhibitors at the time of PCI, namely, the chimeric monoclonal antibody fragment abciximab (ReoPro, Centocor, Inc. and Eli Lilly & Company) and the cyclic heptapeptide small molecule eptifibatide (Integrilin, COR Therapeutics and Key Pharmaceuticals). Currently, another small molecule GP IIb/IIIa inhibitor, tirofiban (Aggrastat, Merck & Company), which (similar to eptifibatide) is approved for the medical therapy of patients with non-ST segment elevation acute coronary syndromes (ACS), has not received indication for use in the PCI setting. Although the clinical benefits of both abciximab and eptifibatide administered at the time of PCI have been proven in randomized clinical trials, only abciximab has demonstrated a late survival advantage in patients following PCI. Evidence in support of the presence, magnitude and possible mechanisms for abciximab survival advantage is herein reviewed.     

Safety of glycoprotein IIb/IIIa inhibitors in urgent or emergency coronary artery bypass graft surgery

Approximately 2% to 4% of patients undergo urgent or emergency coronary artery bypass grafting (CABG) for complications of percutaneous coronary intervention (PCI) after treatment with glycoprotein (GP) IIb/IIIa inhibitors. The pharmacokinetic and pharmacodynamic properties of GP IIb/IIIa inhibitors play a large role in determining the safety of their use in the setting of urgent or emergency CABG procedures. Emergency or urgent CABG after treatment with the GP IIb/IIIa inhibitor, abciximab, may be associated with increased risk of hemorrhage and the requirement of platelet transfusions if surgery is performed within 12 h of abciximab discontinuation. Eptifibatide is associated with a similar risk compared with placebo, even when surgery is performed within 2 h of eptifibatide cessation. Limited data for tirofiban show that bleeding is not increased when compared with acetylsalicylic acid or heparin. Eptifibatide and tirofiban appear to have favourable safety profiles compared with abciximab in the setting of emergency or urgent CABG after failed PCI.     

Combination Enoxaparin and Abciximab During Percutaneous Coronary Intervention: A New Standard of Care?

Evidence from randomized trials supports the administration of platelet glycoprotein (GP) IIb/IIIa blockade both to patients undergoing percutaneous coronary intervention (PCI) and those presenting with non-ST elevation acute coronary syndromes (ACSs). Similarly, the low molecular weight heparin (LMWH), enoxaparin, has demonstrated superior efficacy when compared with unfractionated heparin (UFH) in the treatment of patients with non-ST elevation ACS. Algorithms for seamless integration of pharmacotherpy through the course of hospitalization for patients who present with ACS and who require PCI will likely combine therapy with enoxaparin and platelet GP IIb/IIIa blockade (abciximab). Our preliminary experience with combination enoxaparin and abciximab as adjunctive pharmacotherapy for PCI suggests that this strategy is safe and effective and may offer advantages over a conventional strategy, which employs UFH.     

GP IIb/IIIa inhibitors during primary percutaneous coronary intervention for STEMI: New trial and registry data

Primary percutaneous coronary intervention (PCI) with adjunctive glycoprotein (GP) IIb/IIIa receptor inhibitor therapy administered in the cardiac catheterization laboratory is the optimal reperfusion strategy for patients with ST-elevation myocardial infarction. Most available data regarding these agents are from trials comparing abciximab to placebo alone. Noninferiority trials comparing small-molecule GP IIb/IIIa receptor inhibitors, such as tirofiban and eptifibatide with abciximab, have used markers for myocardial reperfusion as primary end points but are underpowered to detect significant differences in hard clinical outcomes. Such a trial would need to enroll a very large number of patients and thus make it practically impossible to perform. Registry data reveal that most patients undergoing primary PCI are treated with small-molecule GP IIb/IIIa receptor inhibitors in clinical practice, and no observed difference is observed in safety and efficacy when compared with patients treated with abciximab therapy.     

A Review of Clinical Trials with Eptifibatide in Cardiology

Glycoprotein (GP) IIb/IIIa receptor antagonists inhibit the binding of ligands to activated platelet GP IIb/IIIa receptors and, therefore, prevent the formation of platelet thrombi. Additional antithrombin therapy should be given in connection with GP IIb/IIIa administration. Eptifibatide is a small heptapeptide, which is highly selective and rapidly dissociates from its receptor after cessation of therapy. In clinical trials (IMPACT‐II and ESPRIT) concomitant administration of eptifibatide to patients undergoing percutaneous coronary intervention (PCI) reduced thrombotic complications. In the PURSUIT trial, in patients with non‐ST‐elevation acute coronary syndromes, eptifibatide, compared to placebo, significantly reduced the primary endpoint of death and nonfatal myocardial infarction at 30 days. In patients with STEMI eptifibatide has been studied as an adjunct to fibrinolysis and primary PCI; it improved epicardial flow and tissue reperfusion. Current studies are evaluating eptifibatide as upstream therapy in high‐risk patients with NSTE‐ACS, in the EARLY‐ACS and in comparison with abciximab in patients with primary PCI in the EVA‐AMI trial.     

Timing of glycoprotein IIb/IIIa inhibitor use and outcomes among patients with non-ST-segment elevation myocardial infarction undergoing percutaneous coronary intervention (results from CRUSADE)

Although glycoprotein (GP) IIb/IIIa inhibitors are recommended for patients with unstable angina and non-ST-segment elevation myocardial infarction who undergo percutaneous coronary intervention (PCI), the American College of Cardiology/American Heart Association guidelines do not specify optimal timing for their initiation. We compared patient characteristics and clinical outcomes in 30,830 patients with non-ST-segment elevation myocardial infarction included in the CRUSADE initiative (January 2001 to December 2004) who underwent PCI with upstream (>1 hour before PCI) or periprocedural use of GP IIb/IIIa inhibitors. GP IIb/IIIa inhibitors were administered upstream in 43% of patients versus periprocedurally in 57%. Time from arrival to PCI was longer for patients who received GP IIb/IIIa inhibitors upstream (median 25.6 hours) compared with periprocedurally (18.2 hours). Unadjusted incidence of in-hospital death or reinfarction was lower with upstream GP IIb/IIIa inhibitor use (3.8% vs 4.3%, p = 0.046), but after adjusting for patient and hospital characteristics, this difference was not statistically significant. Treatment with upstream GP IIb/IIIa inhibitors was associated with a lower incidence of unadjusted death or reinfarction in patients who underwent PCI <12 hours from hospital arrival. In conclusion, in this observational analysis, overall ischemic outcomes were similar between the 2 groups, but clinical trials are needed to solve the controversy over optional timing of GP IIb/IIIa inhibitor use.     

Update on Glycoprotein IIb/IIIa Blockade in Endovascular Interventions

Platelet aggregation plays a central role in the ischemic complications of percutaneous coronary interventions (PCI) and the acute coronary syndromes (ACS). Although aspirin and heparin have been effective at decreasing adverse events in these settings, the perceived need for more potent inhibition of platelet aggregation has led to targeting of the platelet surface membrane glycoprotein IIb/IIIa (GP IIb/IIIa) receptor. Several agents have been developed; four: abciximab, tirofiban, eptifibatide, and lamifiban have been tested in clinical trials. Overall, the positive findings of these studies have supported the hypothesis that enhanced platelet blockade leads to improved clinical outcomes in the settings of PCI and ACS. In this article, an overview of the various GP IIb/IIIa receptor inhibitors is presented. The clinical trials of these agents as adjunctive therapy for patients undergoing PCI and in treatment of acute myocardial infarction are reviewed. Practical considerations relating to clinical efficacy, drug safety, and economic issues are discussed.     

The combination of enoxaparin, glycoprotein IIb/IIIa inhibitors and an early invasive approach among acute coronary syndrome patients

OBJECTIVES: This study was designed to assess the feasibility and safety of enoxaparin in combination with glycoprotein (GP) IIb/IIIa inhibitors during percutaneous coronary intervention (PCI) as part of an early invasive strategy in patients presenting with acute coronary syndromes (ACS). BACKGROUND: Trials in patients with ACS have evaluated the utility of enoxaparin, adjuvant GP IIb/IIIa inhibitors with PCI, and an early invasive approach. Information about the combination of all three of these approaches, however, is limited. METHODS: Forty-nine patients with ACS underwent cardiac catheterization, of whom 23 underwent PCI with enoxaparin and GP IIb/IIIa inhibitors. RESULTS: The primary endpoint of the study, a composite of death, myocardial infarction or urgent revascularization at 30 days, occurred in 8% of patients undergoing PCI. There were no deaths. One patient received a blood transfusion. No other adverse events occurred. These event rates were comparable to those from the pooled EPILOG/EPISTENT database, in which intravenous unfractionated heparin was used in conjunction with GP IIb/IIIa receptor blockade. The mean anti-Xa level in patients undergoing PCI was 0.74 0.48 U/ml. The majority of patients who underwent PCI within eight hours of their last dose of enoxaparin had therapeutic anti-Xa levels. CONCLUSION: In patients with ACS, enoxaparin in combination with GP IIb/IIIa inhibitors and an early invasive approach resulted in comparable clinical complication and bleeding rates versus historical references utilizing unfractionated heparin.     

Profound thrombocytopenia associated with tirofiban: case report and review of literature

Platelet glycoprotein (GP)IIb/IIIa inhibitors prevent fibrinogen binding and platelet aggregation. Inhibition of platelet activity at the injured coronary plaque is a target for novel therapeutic strategies. They decrease ischemic complications associated with non-ST-segment elevation acute coronary syndromes and percutaneous coronary intervention. Thrombocytopenia is a serious complication well described with the use of the prototype GP IIb/IIIa inhibitor abciximab. Its association with other agents of this class has been underemphasized. It is important to monitor platelet counts closely after initiation of GP IIb/IIIa inhibitor therapy, not only for abciximab, but also for small molecule inhibitors such as eptifibatide and tirofiban. Monitoring of platelet counts at 2 to 6 hours and 24 hours will detect most cases of acute thrombocytopenia. Adverse events may be prevented by prompt discontinuation of GP IIb/IIIa inhibitor therapy. The authors present a case of profound thrombocytopenia after the administration of tirofiban in the treatment of a patient with an acute coronary syndrome.     

Bleeding risk of platelet glycoprotein IIb/IIIa receptor antagonists in broad-based practice (results from the Society for Cardiac Angiography and Interventions Registry)

Randomized trials of platelet glycoprotein (GP) IIb/IIIa receptor inhibitors in patients who have undergone percutaneous coronary intervention (PCI) have shown a modest increase in bleeding risk associated with GP IIb/IIIa inhibitor use. Because clinical trials often enroll highly selected patient populations and are performed in high-volume experienced centers, these results may not apply to a nonclinical trial population, thus altering the risk-benefit ratio of the drugs. Given the widespread use of these agents, we sought to determine bleeding risks in a broad-based population of patients who underwent PCI. We performed a retrospective cohort study of GP IIb/IIIa inhibitors and bleeding in 18,821 procedures from June 1, 1996 to December 31, 1998 using the Society for Cardiac Angiography and Interventions Registry. The primary outcome was bleeding events, defined as clinically significant hematoma formation or hemorrhage. Bleeding risk was 1.9% in the 2,525 patients who received GP IIb/IIIa inhibitors compared with 1.0% in the 16,296 who did not (unadjusted odds ratio [OR] 1.87, 95% confidence interval [CI] 1.35 to 2.59, p <0.001). After adjustment for multiple clinical and procedural variables, the effect was attenuated, with at most a twofold bleeding risk associated with GP IIb/IIIa inhibitor use (adjusted OR 1.39, 95% CI 0.96 to 2.03, p = 0.083). The small increase in absolute risk of bleeding from GP IIb/IIIa inhibitor use in this study is similar to the risk observed in clinical trials. Assuming these agents are as effective as shown in these trials, the risk-benefit ratio of GP IIb/IIIa inhibitors in broad-based PCI practice should be favorable.     

Antiplatelet Strategies: Evaluating Their Current Role in the Setting of Acute Coronary Syndromes

Numerous clinical trials have established the value of antiplatelet therapies for acute coronary syndromes (ACS). Aspirin (ASA), thienopyridines (i.e., clopidogrel and ticlopidine) and GP IIb/IIIa antagonists comprise the major classes of antiplatelet therapies demonstrated to be of benefit in the treatment of ACS and for the prevention of thrombotic complications of percutaneous coronary intervention (PCI). Clopidogrel is beneficial when administered before and after PCI, and is more effective when combined with either ASA or GP IIb/IIIa inhibitors in preventing post‐PCI complications, coronary subacute stent thrombosis, and thrombotic events in general. It is currently unclear whether a higher loading dose of clopidogrel (600 mg) is better than the standard loading dose (300 mg), how long therapy should continue, and which maintenance dose is optimal. The role of the GP IIb/IIIa antagonists in ACS is less clear due to conflicting data from several studies with different patient populations. Currently, it appears that the use of GP IIb/IIIa antagonists might be most beneficial in high‐risk ACS patients scheduled to undergo PCI, who demonstrate non‐ST‐segment elevation myocardial infarction and elevated troponin levels. Copyright © 2008 Wiley Periodicals, Inc.     

Meta-analysis of randomized trials of glycoprotein IIb/IIIa inhibitors in high-risk acute coronary syndromes patients undergoing invasive strategy

It is still unknown whether upstream administration of glycoprotein (Gp) IIb/IIIa inhibitors, aiming at cooling the culprit lesion before angioplasty, is superior to its selective downstream administration in high-risk patients with acute coronary syndromes (ACSs) undergoing coronary angioplasty. Therefore, the aim of the present study was to perform a meta-analysis of randomized trials comparing upstream to downstream administration of Gp IIb/IIIa inhibitors in high-risk patients with ACS undergoing early invasive strategy. We obtained results from all randomized trials on this issue. The literature was scanned by formal searches of electronic databases from January 1990 to March 2010. The following key words were used: "randomized trial," "myocardial infarction," "ACS," "coronary angioplasty," "upstream," "downstream," "Gp IIb/IIIa inhibitors," "abciximab," "tirofiban," and "eptifibatide." Primary and secondary clinical end points were mortality and myocardial infarction at 30 days, respectively. Major bleeding complications were assessed as a safety end point. Seven randomized trials were included in the meta-analysis, involving 19,929 patients (9,981 or 50.0% in the upstream Gp IIb/IIIa inhibitors group and 9,948 or 50% in the downstream Gp IIb/IIIa inhibitors group). Upstream Gp IIb/IIIa inhibitors did not decrease 30-day mortality (2.0% vs 2.0%, p = 0.84) or recurrence of myocardial infarction (7.0% vs 7.6%, p = 0.11) but were associated with higher risk of major bleeding complications (1.8% vs 1.3%, p = 0.0002). In conclusion, this meta-analysis shows that in high-risk patients with ACS undergoing an early invasive strategy, upstream administration of Gp IIb/IIIa inhibitors does not improve clinical outcome compared to a downstream selective administration, and it is associated with an increased risk of major bleeding complications. Therefore, a strategy of upstream Gp IIb/IIIa inhibitors cannot be recommended.     

Safety and efficacy of low-dose intravenous enoxaparin and GP IIb/IIIa inhibitor therapy during PCI

The use of intravenous enoxaparin, a glyco-protein (GP) IIb/IIIa inhibitor, during percutaneous coronary intervention (PCI) has been shown to be safe and to possibly reduce in-hospital and 30-day major adverse cardiac events(MACE). NICE-4, a recent PCI observational study, evaluated a reduced dose of intravenous (IV) enoxaparin (0.75 mg/kg) with abciximab. However, prior PCI studies evaluating IV enoxaparin have not used percutaneous closure devices. The purpose of this study was to observe the safety and efficacy of a lower dose of IV enoxaparin (0.5 mg/kg) in conjunction with any GP IIb/IIIa inhibitor. The Angio-Seal femoral closure device was also employed as part of the treatment strategy. We administered 0.5 mg/kg IV enoxaparin and a GP IIIb/IIIa inhibitor to 75 eligible PCI patients. None received anticoagulation 24 hours prior to PCI; all received pre-procedural aspirin, post-procedural deployment of the Angio-Seal and clopidogrel therapy, and were discharged home within 36 hours. TIMI minor bleeding was 1.3%; there were no TIMI major bleeding events or major adverse cardiac events during in-hospital stay or at 30-day follow-up. Our small observational study shows that IV enoxaparin is safe and efficacious during PCI when given at a dose 33% lower than previously reported in conjunction with any GP IIb/IIIa inhibitor and Angio-Seal. However, large, randomized PCI trials are needed to confirm the clinical efficacy, safety and cost-effectiveness of lower doses of enoxaparin with GPIIb/IIIa inhibitors and vascular closure devices.     

Angiographic and clinical outcomes of bivalirudin versus heparin in patients with acute coronary syndrome undergoing percutaneous coronary intervention

BACKGROUND: Heparin with adjunctive glycoprotein IIb/IIIa platelet receptor (GP IIb/IIIa) inhibitors has demonstrated its effectiveness in patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). Bivalirudin, a direct thrombin inhibitor, has recently been shown to be an effective alternative for patients undergoing elective PCI. OBJECTIVES: To assess the angiographic and clinical outcomes of adjunctive pharmacological strategies in a high-risk population presenting with ACS. METHODS: Of 891 consecutive PCI patients with ACS, 304 received bivalirudin (60.5% male, 68+/-11 years) and were compared with 283 who received heparin (58.7% male, 66+/-12 years). A 30-day major adverse cardiac event was defined as the occurrence of cardiac death, nonfatal myocardial infarction, urgent revascularization or major hemorrhage. RESULTS: Adjunctive GP IIb/IIIa inhibitors were used in 14.1% of the bivalirudin group and in 72.4% of the heparin group (P<0.010). The occurrence of Thrombolysis In Myocardial Infarction (TIMI) flow less than grade 3 was lower and the achievement of angiographic success was higher in the bivalirudin group than in the heparin group (5.2% versus 8.2%, 94.7% versus 89.7%, P=0.039 and P<0.010, respectively). There was no difference between groups in the incidence of bleeding events (bivalirudin 2.0% versus heparin 3.5%, P not significant) and in 30-day major adverse cardiac events (bivalirudin 8.3% versus heparin 5.7%, P=0.223). CONCLUSIONS: In the high-risk cohort undergoing PCI, bivalirudin with provisional GP IIb/IIIa inhibitors achieved better angiographic results. Although not powered to show a difference, and while acknowledging that a selection bias could have affected the data, the present study showed that bivalirudin may be as clinically effective and safe as heparin with adjunctive GP IIb/IIIa inhibitors.     

A propensity analysis of the impact of platelet glycoprotein IIb/IIIa inhibitor therapy on in-hospital outcomes after percutaneous coronary intervention

It is unknown whether the benefits of parenteral platelet glycoprotein (GP) IIb/IIIa inhibitors as an adjunct to percutaneous coronary intervention (PCI) demonstrated in randomized clinical trials extend to patients treated outside the setting of clinical trials. A contemporary registry of 10,847 consecutive PCI procedures was analyzed to determine the effect of GP IIb/IIIa inhibitor treatment on in-hospital major adverse coronary events ([MACEs] composite of death, urgent coronary artery bypass surgery, periprocedural myocardial infarction, abrupt closure, and stent thrombosis). In this registry, GP IIb/IIIa inhibitors were administered to 20.1% of patients. These patients were younger, more often men, and less often hypertensive than untreated patients. GP IIb/IIIa inhibitor-treated patients were more likely to present with acute myocardial infarction or unstable angina. Stents were placed in 79% of patients treated with GP IIb/IIIa inhibitors. MACEs occurred in 7.8% of GP IIb/IIIa inhibitor-treated patients compared with 3.8% of untreated patients (p <0.001). After multivariable adjustment for the propensity of GP IIb/IIIa inhibitor treatment as well as other possible confounders and interactions known to influence MACEs, GP IIb/IIIa inhibitor treatment was associated with a 57% increase in the risk of a MACE (odds ratio 1.57, 95% confidence interval 1.22 to 2.03; p = 0.0004). In a data set consisting of patients with a high degree of acuity predominantly treated with stent placement, GP IIb/IIIa inhibitor treatment is associated with an increase in thrombotic complications of PCI.     

Long-term results following switch from abciximab to eptifibatide during percutaneous coronary intervention

Background:

The usage of platelet glycoprotein (GP) IIb/IIIa receptor inhibitors improves the outcome during high‐risk percutaneous coronary interventions (PCI). The aim of this study was to evaluate the long‐term effects after a planned switch from abciximab to eptifibatide during PCI.

Hypothesis:

A switch from the general use of abciximab to eptifibatide as a GP IIb/IIIa in connection with PCI would not have any negative effects on long‐term clinical outcomes.

Methods:

To reduce costs, a general switch from abciximab to eptifibatide was instituted in 2004 in 2 university hospitals in Sweden. All patients treated 6 months before and 6 months after the switch were followed for 30 months. During the study period, 1038 patients underwent PCI and received a GP IIb/IIIa receptor inhibitor, 481 (46%) before the switch (Group A) and 557 (54%) after the switch (Group B). The 2 groups had similar baseline characteristics. The primary endpoint was the composite of death, myocardial infarction, stroke, or new coronary revascularization (percutaneous or surgical); secondary endpoints were the individual components of this composite. A separate analysis was performed on patients treated for ST‐segment elevation myocardial infarction, non–ST‐segment elevation myocardial infarction/unstable angina, and diabetes, respectively. Data were collected from the Swedish Coronary Angiography and Angioplasty Registry.

Results:

There were no differences between the groups in the primary endpoint (29.7% in Group A vs 29.3% in Group B; P = 0.48) or in any of the secondary endpoints.

Conclusions:

A switch from the general usage of abciximab to eptifibatide as a GP IIb/IIIa receptor inhibitor in connection with PCI did not seem to have any negative effects on long‐term clinical outcomes. Copyright © 2008 Wiley Periodicals, Inc. The authors have no funding, financial relationships, or conflicts of interest to disclose.     

Drip and Ship: A New Strategy for the Treatment of Acute Coronary Syndromes

Glycoprotein (GP) IIb/IIIa inhibitors block the final common pathway of platelet aggregation by preventing fibrinogen from binding to the GP IIb/IIIa platelet receptor. In patients with unstable angina (UA) or a non–Q wave myocardial infarction (NQWMI), including those with UA refractory to medical therapy, these agents decrease the risk of death, myocardial infarction (MI), and recurrent ischemia. Most patients with acute coronary syndromes are managed in hospitals without on-site angioplasty capabilities and often require transfer for an interventional procedure. We propose that GP IIb/IIIa inhibitors can be safely initiated at the referring hospital. We studied 20 patients with UA/NQWMI in whom therapy with a GP IIb/IIIa inhibitor, in addition to standard medical therapy, was initiated prior to transfer for an urgent percutaneous coronary intervention (PCI) (drip and ship). The primary end point was a composite of death, MI, and recurrent ischemia at 30 days. Twelve patients were treated with abciximab, 5 patients were treated with tirofiban, and 3 patients initially treated with tirofiban were converted to abciximab. Procedural success occurred in 33 out of 36 (92%) lesions and 18 out of 20 (90%) patients. At 30 days, 4 out of 20 (20%) patients had recurrent ischemia. The PTCA sites were widely patent in the 3 patients who underwent repeat angiography. The fourth patient had an unsuccessful PCI and was referred for coronary artery bypass surgery. There were no MIs or deaths. Patients who require transfer for an urgent PCI can be managed safely and efficaciously by initiating a GP IIb/IIIa inhibitor, in addition to standard medical therapy, prior to transfer.     

Rationale and design of the ETN-STEP (Early administration of Tirofiban in mid to high risk patients with non-ST elevation acute coronary syndrome referred for percutaneous coronary intervention) project: A multi-center, randomized, controlled clinic trial in Chinese patients

As a member of Glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitors, Tirofiban had been shown to improve myocardial reperfusion and clinical outcomes in patients undergoing percutaneous coronary intervention (PCI), but the optimal timing of administration of Tirofiban remains unclear. In order to compare the effects of upstream versus downstream administration of Tirofiban in Chinese patients with mid to high risk, non-ST elevation acute coronary syndrome (ACS) referred for PCI, a multicenter, randomized, controlled, prospective study will be conducted. A total of 500 mid to high risk, non-ST-segment elevation myocardial infarction (NSTEMI) ACS patients will be recruited for this study. Patients will be randomized to Tirofiban upstream administration group (initiated 12 h before PCI) and Tirofiban downstream administration group (initiated at cath-lab after angiography). Thrombolysis in myocardial infarction (TIMI) flow grades, TIMI myocardial perfusion grades (TMPG), and Corrected TIMI frame counting (CTFC) before and after PCI, as well as clinical outcomes during the hospital stay, and within 30 days after PCI will be compared between the two groups. This study will provide evidence on the optimal timing for initiating administration of Tirofiban in mid to high NSTEMI ACS subjects undergoing PCI.     

Patterns of upstream antiplatelet therapy use before primary percutaneous coronary intervention for acute ST-elevation myocardial infarction (from the CRUSADE National Quality Improvement Initiative)

We sought to determine the usage patterns and impact of upstream glycoprotein IIb/IIIa inhibitor and clopidogrel in patients with ST-segment elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (PCI). We studied trends in the use of upstream glycoprotein IIb/IIIa inhibitors and clopidogrel in 3,895 patients with STEMI undergoing primary PCI at 124 hospitals in the United States participating in the CRUSADE initiative from March 2005 to December 2006. Administration of these agents >15 minutes before PCI was considered pre-PCI use, and administration < or =15 minutes before, during, and after PCI was considered peri-PCI use. A total of 3,566 patients (91.6%) received glycoprotein IIb/IIIa inhibitors within 24 hours of presentation, of whom 1,225 (34.4%) received this medication before PCI. Similarly, 3,785 patients (97.2%) received clopidogrel within 24 hours of presentation, of whom 1,029 (27.2%) received this medication before PCI. From 2005 to 2006, pre-PCI glycoprotein IIb/IIIa inhibitor use decreased from 43.4% to 33.5%, whereas pre-PCI clopidogrel use increased from 21.2% to 31.5%. Clinical characteristics, risk of adverse outcomes, and bleeding events were similar in the pre- versus peri-PCI glycoprotein IIb/IIIa inhibitor and clopidogrel cohorts, respectively. In conclusion, most patients with STEMI undergoing primary PCI receive glycoprotein IIb/IIIa inhibitors and clopidogrel, but only (1/3) are treated upstream with these agents and this upstream use does not have a significant impact on outcomes. These results indicate that further studies are needed to determine the optimal dosing and timing of antiplatelet therapies for patients undergoing primary PCI.     

Randomized comparison of upstream tirofiban versus downstream high bolus dose tirofiban or abciximab on tissue-level perfusion and troponin release in high-risk acute coronary syndromes treated with percutaneous coronary interventions: the EVEREST trial.

OBJECTIVES: We aimed to compare the effects of upstream tirofiban versus downstream high-dose bolus (HDB) tirofiban and abciximab on tissue level perfusion and troponin I release in high-risk non-ST-segment elevation acute coronary syndrome (ACS) patients treated with percutaneous coronary intervention (PCI). BACKGROUND: Optimal timing and dosage of glycoprotein IIb/IIIa inhibitors for ACS remain to be explored. METHODS: We randomized 93 high-risk ACS patients undergoing PCI to receive upstream (in the coronary care unit) tirofiban, downstream (just prior to PCI) HDB tirofiban, and downstream abciximab. We evaluated the effects of the three drug regimens on tissue-level perfusion using the corrected Thrombolysis In Myocardial Infarction (TIMI) frame count, the TIMI myocardial perfusion grade (TMPG), and intracoronary myocardial contrast echocardiography (MCE) before and immediately after PCI and after cardiac troponin I (cTnI). RESULTS: The TMPG 0/1 perfusion was significantly less frequent with upstream tirofiban compared with HDB tirofiban and abciximab both before (28.1% vs. 66.7% vs. 71%, respectively; p = 0.0009) and after PCI (6.2% vs. 20% vs. 35.5%, respectively; p = 0.015). Upstream tirofiban was also associated with a significantly higher MCE score index (0.88 +/- 0.18 vs. 0.77 +/- 0.32 vs. 0.71 +/- 0.30, respectively; p < 0.05). Post-procedural cTnI elevation was significantly less frequent among patients in the upstream tirofiban group compared with the HDB tirofiban and abciximab groups (9.4% vs. 30% vs. 38.7%, respectively; p = 0.018). The cTnI levels after PCI were significantly lower with upstream tirofiban compared with HDB tirofiban (3.8 +/- 4.1 vs. 7.2 +/- 12; p = 0.015) and abciximab (3.8 +/- 4.1 vs. 9 +/- 13.8; p = 0.0002) CONCLUSIONS: Among high-risk non-ST-segment-elevation ACS patients treated with an early invasive strategy, upstream tirofiban is associated with improved tissue-level perfusion and attenuated myocardial damage.