Immediate and intermediate results of intracoronary stand-alone bolus administration of eptifibatide during coronary intervention (ICE) study

An Updated Review on Glycoprotein IIb/IIIa Inhibitors as Antiplatelet Agents: Basic and Clinical Perspectives

The glycoprotein (GP) IIb/IIIa receptor is found integrin present in platelet aggregations. GP IIb/IIIa antagonists interfere with platelet cross-linking and platelet-derived thrombus formation through the competition with fibrinogen and von Willebrand factor. Currently, three parenteral GP IIb/IIIa competitors (tirofiban, eptifibatide, and abciximab) are approved for clinical use in patients affected by percutaneous coronary interventions (PCI) in the location of acute coronary syndrome (ACS). GP IIb/IIIa antagonists have their mechanism of action in platelet aggregation prevention, distal thromboembolism, and thrombus formation, whereas the initial platelet binding to damage vascular areas is preserved. This work is aimed to provide a comprehensive review of the significance of GP IIb/IIIa inhibitors as a sort of antiplatelet agent. Their mechanism of action is based on factors that affect their efficacy. On the other hand, drugs that inhibit GP IIb/IIIa already approved by the FDA were reviewed in detail. Results from major clinical trials and regulatory practices and guidelines to deal with GP IIb/IIIa inhibitors were deeply investigated. The cardiovascular pathology and neuro-interventional surgical application of GP IIb/IIIa inhibitors as a class of antiplatelet agents were developed in detail. The therapeutic risk/benefit balance of currently available GP IIb/IIa receptor antagonists is not yet well elucidated in patients with ACS who are not clinically evaluated regularly for early cardiovascular revascularization. On the other hand, in patients who have benefited from PCI, the antiplatelet therapy intensification by the addition of a GP IIb/IIIa receptor antagonist (intravenously) may be an appropriate therapeutic strategy in reducing the occurrence of risks of thrombotic complications related to the intervention. Development of GP IIb/IIIa inhibitors with oral administration has the potential to include short-term antiplatelet benefits compared with intravenous GP IIb/IIIa inhibitors for long-term secondary preventive therapy in cardiovascular disease. But studies showed that long-term oral administration of GP IIb/IIIa receptor inhibitors has been ineffective in preventing ischemic events. Paradoxically, they have been linked to a high risk of side effects by producing prothrombotic and pro-inflammatory events.

The effect of intracoronary versus intralesional injection of eptifibatide on myocardial perfusion outcomes during primary percutaneous coronary intervention in acute ST-segment elevation myocardial infarction; A randomized clinical trial study

BACKGROUND

Previous studies have proved that intracoronary injection of eptifibatide is safe and more effective in infarct size reduction and clinical outcomes than intravenously injection in the patients with acute myocardial infarction (AMI). This study aimed to compare the effect of localized and intracoronary injection of eptifibatide on myocardial perfusion improvement and its outcomes.

METHODS

We conducted a randomized clinical trial study of 60 patients presented with thrombotic AMI. The patients underwent percutaneous coronary intervention (PCI), and were randomly divided into two equal number groups. The first group received two bolus doses of 180 μg/kg eptifibatide through guiding catheter. The second group received the same bolus doses through export aspiration catheter into the coronary lesion directly. Thrombolysis in myocardial infarction (TIMI) flow, myocardial blush grade (MBG), and no-reflow phenomenon were primary end points. Secondary end points were pre- and postprocedure cardiac arrhythmia, in-hospital mortality, adverse effects, reinfection, pre-discharge ventricular systolic function, and re-hospitalization and mortality after 6 month of follow up.

RESULTS

The mean ages of group I and group II were 58.3 ± 1.8 and 57.0 ±2.0 years, respectively, and most of patient were men (90% in group I and 80% in group II). Postprocedural TIMI flow grade 3 was achieved in 60.0% and 76.7% of the intracoronary and intralesional groups, respectively (P = 0.307). Postprocedural MBG grade 3 was achieved in 53.3% and 70.0% in intracoronary and intralesional groups, respectively (P = 0.479). There was no significant difference between the groups in no-reflow assessment. Moreover, no significant difference was seen between the two groups in secondary end-point analysis.

CONCLUSION

Both methods of intracoronary and intralesional eptifibatide administration during primary PCI in patients with acute ST-elevation myocardial infarction (STEMI) were safe and similar in myocardial perfusion outcomes.

Eptifibatide Bolus Dose During Elective Percutaneous Coronary Intervention

Background

Eptifibatide is a platelet glycoprotein IIb/IIIa receptor antagonist used for the prevention of cardiac ischemic complications of percutaneous coronary intervention (PCI). Eptifibatide has been used with bolus dose only or bolus plus infusion in patients undergoing PCI which have shown less complications, but the risk of bleeding has been increased. We aimed to compare the outcome and bleeding rate of bolus dose alone or plus infusion in elective PCI.

Methods

In this quasi-experimental study, we compared the outcome of elective PCI following single bolus dose intracoronary (41 patients) or bolus plus intravenous infusion (19 patients) of eptifibatide. In-hospital and follow-up major adverse cardiac events (MACEs) and bleeding rate were recorded and evaluated between groups.

Results

Both groups were comparable regarding baseline findings. Bolus only compared to bolus plus infusion group had lower in-hospital (19.5% vs. 31.6%) and follow-up MACE (15.4% vs. 17.6%), lower bleeding in-hospital (14.6% vs. 21.1%) and follow-up (2.4% vs. 5.3%) as well as lower mortality rate in hospital (4.9% vs. 15.8%), but higher follow-up mortality (10.3% vs. 0), but the difference was not significant.

Conclusions

We observed no significant difference regarding bleeding or MACE between intracoronary bolus infusion and bolus plus intravenous infusion of eptifibatide. It seems intracoronary bolus infusion of eptifibatide due to use of lower doses is a better choice in elective PCI to prevent post-PCI MACE.

Platelet activation and aggregation promote lung inflammation and influenza virus pathogenesis

RATIONALE

The hallmark of severe influenza virus infection is excessive inflammation of the lungs. Platelets are activated during influenza, but their role in influenza virus pathogenesis and inflammatory responses is unknown.

OBJECTIVES

To determine the role of platelets during influenza A virus infections and propose new therapeutics against influenza.

METHODS

We used targeted gene deletion approaches and pharmacologic interventions to investigate the role of platelets during influenza virus infection in mice.

MEASUREMENTS AND MAIN RESULTS

Lungs of infected mice were massively infiltrated by aggregates of activated platelets. Platelet activation promoted influenza A virus pathogenesis. Activating protease-activated receptor 4, a platelet receptor for thrombin that is crucial for platelet activation, exacerbated influenza-induced acute lung injury and death. In contrast, deficiency in the major platelet receptor glycoprotein IIIa protected mice from death caused by influenza viruses, and treating the mice with a specific glycoprotein IIb/IIIa antagonist, eptifibatide, had the same effect. Interestingly, mice treated with other antiplatelet compounds (antagonists of protease-activated receptor 4, MRS 2179, and clopidogrel) were also protected from severe lung injury and lethal infections induced by several influenza strains.

CONCLUSIONS

The intricate relationship between hemostasis and inflammation has major consequences in influenza virus pathogenesis, and antiplatelet drugs might be explored to develop new antiinflammatory treatment against influenza virus infections.

Proceedings from the scientific symposium: Sex differences in cardiovascular disease and implications for therapies

A consortium of investigator-thought leaders was convened at the Heart Institute at Cedars-Sinai Medical Center and produced the following summary points: POINT 1: Important sex differences exist in cardiovascular disease (CVD) that affect disease initiation, diagnosis, and treatment.

IMPLICATION

Research that acknowledges these differences is needed to optimize outcomes in women and men. POINT 2: Atherosclerosis is qualitatively and quantitatively different in women and men; women demonstrate more plaque erosion and more diffuse plaque with less focal artery lumen intrusion.

IMPLICATION

Evaluation of CVD strategies that include devices should be used to explore differing anatomical shapes and surfaces as well as differing drug coating and eluting strategies. POINT 3: Bone marrow progenitor cells (PCs) engraft differently based on the sex of the donor cell and the sex of the recipient.

IMPLICATION

PC therapeutic studies need to consider the sex of cells of the source and the recipient. POINT 4: Women have a greater risk of venous but not arterial thrombosis compared with men, as well as more bleeding complications related to anticoagulant treatment. Several genes coding for proteins involved in hemostasis are regulated by sex hormones.

IMPLICATIONS

Research should be aimed at evaluation of sex-based differences in response to anticoagulation based on genotype. POINT 5: Women and men can have differences in pharmacological response.

IMPLICATION

Sex-specific pharmacogenomic studies should be included in pharmacological development. POINT 6: CVD progression results from an imbalance of cell injury and repair in part due to insufficient PC repair, which is affected by sex differences, where females have higher circulating levels of PCs with greater rates of tissue repair.

IMPLICATION

CVD regenerative strategies should be directed at learning to deliver cells that shift the recipient balance from injury toward repair. CVD repair strategies should ideally be tested first in females to have the best chance of success for proof-of-concept.

Intracoronary Eptifibatide Bolus Administration During Percutaneous Coronary Revascularization for Acute Coronary Syndromes With Evaluation of Platelet Glycoprotein IIb/IIIa Receptor Occupancy and Platelet Function

Background— Eptifibatide reduces major adverse cardiac events in patients with acute coronary syndromes undergoing percutaneous coronary intervention (PCI). Intracoronary bolus administration of eptifibatide may result in higher levels of platelet glycoprotein IIb/IIIa receptor occupancy in the local coronary bed, disaggregate thrombus in the epicardial artery and microvasculature, and thereby improve coronary flow.

Methods and Results— Patients undergoing PCI for an acute coronary syndrome were randomized to either intracoronary or intravenous bolus administration of eptifibatide. The primary end point was the local glycoprotein IIb/IIIa receptor occupancy measured in the coronary sinus. There were no angiographic, electrophysiological, or other adverse findings attributable to intracoronary eptifibatide. Platelet glycoprotein IIb/IIIa receptor occupancy was significantly greater with intracoronary versus intravenous administration: first bolus, 94±9% versus 51±15% ( P <0.001); and second bolus, 99±2% versus 91±4% ( P =0.001), respectively. Microvascular perfusion was significantly improved as measured by the corrected thrombolysis in myocardial infarction frame count (cTFC) with intracoronary versus intravenous administration: pre-PCI, 36 (median) (25th and 75th percentiles, 16 and 64) versus 31 (25th and 75th percentiles, 23 and 45; P =0.8); and post-PCI, 18 (25th and 75th percentiles, 10 and 22) versus 25 (25th and 75th percentiles, 22 and 35; P =0.007), respectively. The only multivariate predictor associated with a post-PCI cTFC rank score was the first bolus glycoprotein IIb/IIIa receptor occupancy ( P <0.001).

Conclusions— Intracoronary bolus administration of eptifibatide during PCI in patients with acute coronary syndromes results in higher local platelet glycoprotein IIb/IIIa receptor occupancy, which is associated with improved microvascular perfusion demonstrated by an improved cTFC.