Delayed-onset eptifibatide-induced thrombocytopenia.

PURPOSE: We present a unique case of delayed-onset, profound eptifibatide-induced thrombocytopenia that occurred 5 days after initiation of the drug. SUMMARY: Eptifibatide is a platelet glycoprotein IIb/IIIa receptor inhibitor with indications for use in patients with acute coronary syndromes. Eptifibatide-induced thrombocytopenia is uncommon but well studied and typically occurs within 24 hours of initiation of the drug. In the case described here, a 62-year-old male with a past history of coronary artery disease (including percutaneous coronary intervention within the past 12 months) was started on eptifibatide at a dosage of 2 µg/kg per minute for management of significant thrombus burden prior to a planned cardiac revascularization procedure; heparin for anticoagulation was also initiated. About 5 days after initiation of eptifibatide, the patient developed severe thrombocytopenia, with the platelet count dropping precipitously from 249 × 103/µL on admission to less than 1 × 103/µL. After eptifibatide and heparin therapy were discontinued and the patient was switched to argatroban, the platelet count recovered to 38 × 103/µL over the next 2 days. An eptifibatide platelet antibody assay was positive for IgG-mediated reactions consistent with eptifibatide-induced thrombocytopenia. Scoring of this case with the Naranjo scale yielded a score of 4, suggesting a possible adverse reaction to eptifibatide. CONCLUSION: This is the first published case report of profound eptifibatide-induced thrombocytopenia occurring more than 24 hours after eptifibatide initiation and serves to bring awareness that a delayed reaction can occur.

Cryo-EM structures of full-length integrin αIIbß3 in native lipids.

Platelet integrin αIIbß3 is maintained in a bent inactive state (low affinity to physiologic ligand), but can rapidly switch to a ligand-competent (high-affinity) state in response to intracellular signals ("inside-out" activation). Once bound, ligands drive proadhesive "outside-in" signaling. Anti-αIIbß3 drugs like eptifibatide can engage the inactive integrin directly, inhibiting thrombosis but inadvertently impairing αIIbß3 hemostatic functions. Bidirectional αIIbß3 signaling is mediated by reorganization of the associated αIIb and ß3 transmembrane α-helices, but the underlying changes remain poorly defined absent the structure of the full-length receptor. We now report the cryo-EM structures of full-length αIIbß3 in its apo and eptifibatide-bound states in native cell-membrane nanoparticles at near-atomic resolution. The apo form adopts the bent inactive state but with separated transmembrane α-helices, and a fully accessible ligand-binding site that challenges the model that this site is occluded by the plasma membrane. Bound eptifibatide triggers dramatic conformational changes that may account for impaired hemostasis. These results advance our understanding of integrin structure and function and may guide development of safer inhibitors.

Eptifibatide, an Older Therapeutic Peptide with New Indications: From Clinical Pharmacology to Everyday Clinical Practice.

Therapeutic peptides are oligomers or short polymers of amino acids used for various medical purposes. Peptide-based treatments have evolved considerably due to new technologies, stimulating new research interests. They have been shown to be beneficial in a variety of therapeutic applications, notably in the treatment of cardiovascular disorders such as acute coronary syndrome (ACS). ACS is characterized by coronary artery wall damage and consequent formation of an intraluminal thrombus obstructing one or more coronary arteries, leading to unstable angina, non-ST elevated myocardial infarction, and ST-elevated myocardial infarction. One of the promising peptide drugs in the treatment of these pathologies is eptifibatide, a synthetic heptapeptide derived from rattlesnake venom. Eptifibatide is a glycoprotein IIb/IIIa inhibitor that blocks different pathways in platelet activation and aggregation. In this narrative review, we summarized the current evidence on the mechanism of action, clinical pharmacology, and applications of eptifibatide in cardiology. Additionally, we illustrated its possible broader usage with new indications, including ischemic stroke, carotid stenting, intracranial aneurysm stenting, and septic shock. Further research is, however, required to fully evaluate the role of eptifibatide in these pathologies, independently and in comparison to other medications.

A Double-Blinded Randomized Controlled Trial Comparing Eptifibatide Bolus Only Versus Bolus Plus Infusion In Patients Undergoing Primary Percutaneous Coronary Intervention For ST-Elevation Myocardial Infarction.

BACKGROUNDS: The use of eptifibatide combined with heparin during percutaneous coronary intervention (PCI) in patients presenting with ST-elevation myocardial infarction (STEMI) is recommended to be followed by continuous infusion. Recently, there are some suggestions that using bolus only may be sufficient and cost-effective but randomized trials are lacking. AIMS: The goal of this study was to evaluate these two approaches in a double-blinded randomized control trial. METHODS: The primary PCI patients who received bolus eptifibatide were randomized to 75 mg IV eptifibatide infusion or placebo blindly. The patients were followed up for the primary outcome of vascular or bleeding complications and secondary outcome of ischemic complications. RESULTS: 330 patients (165 from each group) completed the study. The mean age was 57.67 ± 11.53 years and 77.3 % were male. Major bleeding was seen in 1 patient in each group. Hematoma occurred in 8.5 %. The relative risk of hematoma and ecchymosis in bolus plus infusion group to bolus only group were 0.988 (95 % CI: 0.486-2.006) and 1.032 (95 % CI: 0.729-1.459). Multivariate analysis confirmed no significant differences in the bleeding event. Furthermore, there was no significant difference in in-hospital death or any ischemic events. (Cath lab death: 1.4 % in bolus only vs zero % in the control group, p = 0.217, stent thrombosis was seen in one patient in each group). CONCLUSION: There were no differences in the risk of access site ecchymosis, hematoma or major bleeding. Ischemic events and stent thrombosis rates were also similar. Our study suggests that using eptifibatide bolus only during PCI of patients with STEMI is safe and can be cost-saving.

Fibrin-glycoprotein VI interaction increases platelet procoagulant activity and impacts clot structure.

BACKGROUND: The glycoprotein VI (GPVI) signaling pathway was previously reported to direct procoagulant platelet activity through collagen binding. However, the impact of GPVI-fibrin interaction on procoagulant platelet development and how it modulates the clot structure are unknown. OBJECTIVES: To determine the effect of GPVI-fibrin interaction on the platelet phenotype and its impact on the clot structure. METHODS: Procoagulant platelets in platelet-rich plasma clots were determined by scanning electron microscopy (wild-type and GPVI-deficient murine samples) and confocal microscopy. Procoagulant platelet number, clot density, clot porosity, and clot retraction were determined in platelet-rich plasma or whole blood clots of healthy volunteers in the presence of tyrosine kinase inhibitors (PRT-060318, ibrutinib, and dasatinib) and eptifibatide. RESULTS: GPVI-deficient clots showed a higher nonprocoagulant vs procoagulant platelet ratio than wild-type clots. The fiber density and the procoagulant platelet number decreased in the presence of Affimer proteins, inhibiting GPVI-fibrin(ogen) interaction and the tyrosine kinase inhibitors. The effect of GPVI signaling inhibitors on the procoagulant platelet number was exacerbated by eptifibatide. The tyrosine kinase inhibitors led to an increase in clot porosity; however, no differences were observed in the final clot weight, following clot retraction with the tyrosine kinase inhibitors, except for ibrutinib. In the presence of eptifibatide, clot retraction was impaired. CONCLUSION: Our findings showed that GPVI-fibrin interaction significantly contributes to the development of procoagulant platelets and that inhibition of GPVI signaling increases clot porosity. Clot contractibility was impaired by the integrin αIIbß3 and Btk pathway inhibition. Thus, inhibition of GPVI-fibrin interactions can alleviate structural characteristics that contribute to a prothrombotic clot phenotype, having potential important implications for novel antithrombotic interventions.

Changes in anticoagulant and antiplatelet drug supply at US hospitals before and during the COVID-19 pandemic (2018-2021).

PURPOSE: Antithrombotic agents have a role in coronavirus disease 2019 (COVID-19) treatment, but the pandemic disrupted medication supply. This study examined changes in the volume of oral and parenteral anticoagulant and antiplatelet medications at US hospitals during the pandemic. METHODS: IQVIA National Sales Perspective (NSP) data was used to determine the monthly volume of anticoagulants and antiplatelets purchased at US hospitals between January 2018 and February 2021. Mean monthly medication volumes, reported as extended units (EUs), and year-over-year changes in medication volume were determined. A single-group interrupted time series analysis was used to evaluate changes in the rate of growth of monthly medication volumes before (January 2019-February 2020) and during (March 2020-February 2021) the COVID-19 pandemic. RESULTS: Overall, there was a 43.4% decline in the total volume of anticoagulants and antiplatelets at US hospitals in March 2020, driven by a decrease in heparin volume. Mean monthly volumes decreased significantly (P < 0.05) for parenteral anticoagulants (-106,691,340 EU [95% CI, -200,033,910 to -13,348,780]), oral anticoagulants (-354,800 EU [95% CI, -612,180 to -97,420]), and parenteral antiplatelets (-391,880 EU [95% CI, -535,420 to -248,330]). During the pandemic, the monthly volume of oral anticoagulants, parenteral anticoagulants, and parenteral antiplatelets grew significantly more than in the prepandemic period. This growth was primarily seen in volumes of apixaban, argatroban, enoxaparin, heparin, eptifibatide, and tirofiban. Apixaban and heparin volumes continued a prepandemic uptrend, while argatroban and eptifibatide volumes reversed trend. CONCLUSION: Rapid changes in anticoagulant and antiplatelet volume at US hospitals during the COVID-19 pandemic highlight the need for institutional protocols to manage fluctuating medication volume demands.

Anti-Platelet Peptides Targeting αIIbß3 Outside-In Signaling Pathway.

Platelets and their progenitors express high levels of integrin αIIbß3, which plays a key role in platelet functions, hemostasis, and arterial thrombosis. Because of their quick and high efficacy, the three anti-αIIbß3 drugs, abciximab, eptifibatide, and tirofiban, are regarded as potent anti-thrombotics and clinically approved by US Food and Drug Administration. However, because they interfere with the inside-out signaling of αIIbß3, which is required for stable platelet adhesion and aggregation, the application of abciximab, eptifibatide, and tirofiban is restricted to patients undergoing percutaneous coronary intervention. On the other hand, the outside-in signaling of αIIbß3 in platelets appears to be responsible for thrombus stabilization, and selective interference with the propagation of outside-in signals might signify a new therapeutic strategy to preferentially inhibit platelet-rich arterial thrombosis with less bleeding issues caused by way of compromised major hemostasis. The purpose of this review is to describe the bidirectional signal transduction of integrin αIIbß3 in platelets with a focus on outside-in signaling, more efficient and safer anti-αIIbß3 peptides, and the potential drug targets for future anti-platelet research.

Single-antiplatelet regimen in ruptured cerebral blood blister and dissecting aneurysms treated with flow-diverter stent reconstruction.

BACKGROUND: Flow diversion treatment of ruptured cerebral aneurysms remains challenging due to the need for double-antiplatelet therapy. We report our experience with flow-diverter stent (FDS) reconstruction with single-antiplatelet therapy of ruptured cerebral blood blister and dissecting aneurysms. METHODS: In this case series we performed a retrospective analysis of all patients with ruptured cerebral aneurysms who were treated with a phosphoryl-bonded FDS between 2019 and 2022 in a single center. Periprocedurally, all patients received weight-adapted eptifibatide IV and heparin IV. After 6-24 hours, eptifibatide was switched to oral prasugrel as monotherapy. We analyzed the rate of bleeding complications, thromboembolic events, occlusion rate and clinical outcome. RESULTS: Nine patients with subarachnoid hemorrhage were treated, eight within 24 hours of symptom onset. Seven patients were treated with one FDS and two patients received two FDS in a telescopic fashion. Two aneurysms were additionally coil embolized. Fatal re-rupture occurred in one case; eight patients survived and had no adverse events associated with the FDS. Six patients showed complete occlusion of the aneurysm after 3 months (n=2) and 1 year (n=4), respectively. Two patients showed subtotal occlusion of the aneurysm at the last follow-up after 3 months and 6 months, respectively. Favorable clinical outcome was achieved in five patients. CONCLUSIONS: Peri-interventional single-antiplatelet therapy with eptifibatide followed by prasugrel was sufficient to prevent thromboembolic events and reduce re-bleeding using an anti-thrombogenic FDS. FDS with single-antiplatelet therapy might be a viable option for ruptured blood blister and dissecting cerebral aneurysms.

Studying the efficacy of antiplatelet drugs on atherosclerosis by optofluidic imaging on a chip.

Vascular stenosis caused by atherosclerosis instigates activation and aggregation of platelets, eventually resulting in thrombus formation. Although antiplatelet drugs are commonly used to inhibit platelet activation and aggregation, they unfortunately cannot prevent recurrent thrombotic events in patients with atherosclerosis. This is partially due to the limited understanding of the efficacy of antiplatelet drugs in the complex hemodynamic environment of vascular stenosis. Conventional methods for evaluating the efficacy of antiplatelet drugs under stenosis either fail to simulate the hemodynamic environment of vascular stenosis characterized by high shear stress and recirculatory flow or lack spatial resolution in their analytical techniques to statistically identify and characterize platelet aggregates. Here we propose and experimentally demonstrate a method comprising an in vitro 3D stenosis microfluidic chip and an optical time-stretch quantitative phase imaging system for studying the efficacy of antiplatelet drugs under stenosis. Our method simulates the atherogenic flow environment of vascular stenosis while enabling high-resolution and statistical analysis of platelet aggregates. Using our method, we distinguished the efficacy of three antiplatelet drugs, acetylsalicylic acid (ASA), cangrelor, and eptifibatide, for inhibiting platelet aggregation induced by stenosis. Specifically, ASA failed to inhibit stenosis-induced platelet aggregation, while eptifibatide and cangrelor showed high and moderate efficacy, respectively. Furthermore, we demonstrated that the drugs tested also differed in their efficacy for inhibiting platelet aggregation synergistically induced by stenosis and agonists (e.g., adenosine diphosphate, and collagen). Taken together, our method is an effective tool for investigating the efficacy of antiplatelet drugs under vascular stenosis, which could assist the development of optimal pharmacologic strategies for patients with atherosclerosis.

Eptifibatide-induced acute profound thrombocytopenia: A case report.

RATIONALE: Eptifibatide is an antiplatelet agent used in the medical management of acute coronary syndrome. Although multiple studies did not reveal a significant association between eptifibatide and the development of thrombocytopenia, recent case reports brought attention to this relatively rare side effect. PATIENT CONCERNS: We report a 61 years old male with acute coronary syndrome who underwent primary coronary intervention. DIAGNOSIS AND INTERVENTION: The patient developed acute profound thrombocytopenia following eptifibatide administration. Following prompt offending drug discontinuation, the platelet counts recovered, without clinical sequelae or the need for platelet transfusion. Dual antiplatelet therapy with aspirin and clopidogrel was resumed after platelet count normalization. OUTCOMES: The patient had a normal platelet count and no bleeding events on follow-up after three months upon discharge. CONCLUSION: Eptifibatide, a glycoprotein IIa/IIIb inhibitor used in the management of acute coronary syndrome, can induce acute, profound thrombocytopenia that can have significant morbidity in patients. This case highlights this relatively rare side effect and the importance of monitoring blood counts and observing for any signs of bleeding or thrombosis that might occur in such patients.

Anticoagulants as Potential SARS-CoV-2 Mpro Inhibitors for COVID-19 Patients: In Vitro, Molecular Docking, Molecular Dynamics, DFT, and SAR Studies.

In this article, 34 anticoagulant drugs were screened in silico against the main protease (Mpro) of SARS-CoV-2 using molecular docking tools. Idraparinux, fondaparinux, eptifibatide, heparin, and ticagrelor demonstrated the highest binding affinities towards SARS-CoV-2 Mpro. A molecular dynamics study at 200 ns was also carried out for the most promising anticoagulants to provide insights into the dynamic and thermodynamic properties of promising compounds. Moreover, a quantum mechanical study was also conducted which helped us to attest to some of the molecular docking and dynamics findings. A biological evaluation (in vitro) of the most promising compounds was also performed by carrying out the MTT cytotoxicity assay and the crystal violet assay in order to assess inhibitory concentration 50 (IC50). It is worth noting that ticagrelor displayed the highest intrinsic potential for the inhibition of SARS-CoV-2 with an IC50 value of 5.60 µM and a safety index of 25.33. In addition, fondaparinux sodium and dabigatran showed promising inhibitory activities with IC50 values of 8.60 and 9.40 µM, respectively, and demonstrated safety indexes of 17.60 and 15.10, respectively. Moreover, the inhibitory potential of the SARS-CoV-2 Mpro enzyme was investigated by utilizing the SARS-CoV-2 Mpro assay and using tipranavir as a reference standard. Interestingly, promising SARS-CoV-2 Mpro inhibitory potential was attained for fondaparinux sodium with an IC50 value of 2.36 µM, surpassing the reference tipranavir (IC50 = 7.38 µM) by more than three-fold. Furthermore, highly eligible SARS-CoV-2 Mpro inhibitory potential was attained for dabigatran with an IC50 value of 10.59 µM. Finally, an SAR was discussed, counting on the findings of both in vitro and in silico approaches.

Intracranial stenting as a bail-out option for posthemorrhagic cerebral vasospasm: a single-center experience with long-term follow-up.

BACKGROUND: Cerebral vasospasm (CVS) is a leading cause of morbidity and mortality in patients after aneurysmal subarachnoid hemorrhage (aSAH). Endovascular treatment, including intraarterial infusion of drugs with vasodilation effects, and balloon- and stentriever angioplasty, are helpful but may achieve only short-term effects. There is a clinical need for long-lasting treatment of refractory recurrent vasospasm. We report our experience in stent implantation as a treatment for recurrent severe post-SAH vasospasm. METHODS: A retrospective analysis of our institutional database of 883 patients with SAH, managed between January 2010 and December 2021, was performed. Six patients were identified as having received intracranial stenting in the context of post-SAH cerebral vasospasm. All patients were initially treated with intra-arterial infusion of nimodipine and/or milrinone. Self-expanding intracranial stents were implanted during endovascular aneurysm treatment to enable access despite impaired perfusion (Group 1) or as a bail-out strategy after failed intraarterial drug infusion or mechanical treatment (Group 2). All stented patients received dual antiplatelet therapy (DAPT) for 6 months. RESULTS: Nine vessels in six patients with severe post-SAH vasospasm were stented. The stents were deployed in 16 vessel segments. All attempted implantations were technically successful. All patients demonstrated radiographic and clinical improvement of the vessel narrowing. No recurrent vasospasm or permanent vessel occlusion of the stented vessels was encountered. A thrombus formation in a Group 1 patient resolved under 4 mg eptifibatide IA infusion. During long-term angiographic follow-up, neither in-stent stenosis nor stent occlusion was found. CONCLUSIONS: Endovascular implantation of self-expanding stents is a potential ultima ratio strategy for patients with severe refractory post-SAH cerebral vasospasm. Stents with reduced thrombogenicity (avoiding DAPT) and bioabsorbable self-expanding stents might further advance this concept.

The Pharmacological Effects of Silver Nanoparticles Functionalized with Eptifibatide on Platelets and Endothelial Cells.

Purpose: In the search for new drug delivery platforms for cardiovascular diseases and coating of medical devices, we synthesized eptifibatide-functionalized silver nanoparticles (AgNPs-EPI) and examined the pharmacological activity of AgNPs-EPI on platelets and endothelial cells in vitro and ex vivo. Methods: Spherical AgNPs linked to eptifibatide were synthesized and characterized. Cytotoxicity was measured in microvascular endothelial cells (HMEC-1), platelets and red blood cells. Platelet mitochondrial respiration was measured using the Oxygraph-2k, a high-resolution modular respirometry system. The effect of AgNPs-EPI on the aggregation of washed platelets was measured by light aggregometry and the ex vivo occlusion time was determined using a reference laboratory method. The surface amount of platelet receptors such as P-selectin and GPIIb/IIIa was measured. The influence of AgNPS-EPI on blood coagulation science was assessed. Finally, the effect of AgNPs-EPI on endothelial cells was measured by the levels of 6-keto-PGF1alpha, tPa, cGMP and vWF. Results: We describe the synthesis of AgNPs using eptifibatide as the stabilizing ligand. The molecules of this drug are directly bonded to the surface of the nanoparticles. The synthesized AgNPs-EPI did not affect the viability of platelets, endothelial cells and erythrocytes. Preincubation of platelets with AgNPs-EPI protected by mitochondrial oxidative phosphorylation capacity. AgNPs-EPI inhibited aggregation-induced P-selectin expression and GPIIb/IIIa conformational changes in platelets. AgNPs-EPI caused prolongation of the occlusion time in the presence of collagen/ADP and collagen/adrenaline. AgNPs-EPI regulated levels of 6-keto-PGF1alpha, tPa, vWf and cGMP produced in thrombin stimulated HMEC-1 cells. Conclusion: AgNPs-EPI show anti-aggregatory activity at concentrations lower than those required by the free drug acting via regulation of platelet aggregation, blood coagulation, and endothelial cell activity. Our results provide proof-of-principle evidence that AgNPs may be used as an effective delivery platform for antiplatelet drugs.

Eptifibatida y vasodilatadores intracoronarios para prevenir la ausencia de reperfusión en el IAMCEST con diabetes y alta carga de trombos. Un ensayo aleatorizado / Intracoronary eptifibatide with vasodilators to prevent no-reflow in diabetic STEMI with high thrombus burden. A randomized trial

Introducción y objetivos Estudiar el impacto de la inyección intracoronaria de eptifibatida más vasodilatadores a través de un catéter de aspiración de trombos frente a la aspiración de trombos aislada en la reducción del riesgo de ausencia de reperfusión (no-reflow) en infarto agudo de miocardio con elevación del ST (IAMCEST) con diabetes y elevada carga de trombos. Métodos Participaron 413 pacientes diabéticos con IAMCEST y elevada carga de trombos que se aleatorizaron a inyección intracoronaria (distal a la oclusión) de eptifibatida, nitroglicerina y verapamilo después de aspirar el trombo y previo al inflado del balón (n=206) frente a aspiración del trombo únicamente (n=207). El criterio de valoración principal fue el grado de blush miocárdico (GBM) y el Thrombolysis in Myocardial Infarction (TIMI) frame count corregido (cTFC). Los eventos cardiovasculares adversos mayores (MACE) se notificaron a los 6 meses. Resultados El grupo de eptifibatida intracoronaria y vasodilatadores fue superior a la tromboaspiración sola en lo que respecta a la MBG-3 (82,1% frente a 31,4%; p=0,001). El grupo de eptifibatida y vasodilatadores intracoronarios locales tuvo un cTFC más corto (18,16±6,54 frente a 29,64±5,53; p=0,001), y mejor flujo TIMI-3 (91,3% frente a 61,65%; p=0,001). La eptifibatida intracoronaria y los vasodilatadores mejoraron la fracción de eyección a los 6 meses (55,2±8,13 frente a 43±6,67; p=0,005). No hubo diferencia en las tasas de MACE a los 6 meses. Conclusiones Entre los pacientes diabéticos con IAMCEST y alta carga de trombos, la inyección intracoronaria distal de eptifibatida más vasodilatadores fue beneficiosa en prevenir la falta de reperfusión comparada con la tromboaspiración sola. Se recomiendan estudios más amplios para investigar el beneficio de esta estrategia en reducir el riesgo de eventos clínicos adversos (AU)

Introduction and objectives To study the impact of injecting intracoronary eptifibatide plus vasodilators via thrombus aspiration catheter vs thrombus aspiration alone in reducing the risk of no-reflow in acute ST-elevation myocardial infarction (STEMI) with diabetes and high thrombus burden. Methods The study involved 413 diabetic STEMI patients with high thrombus burden, randomized to intracoronary injection (distal to the occlusion) of eptifibatide, nitroglycerin and verapamil after thrombus aspiration and prior to balloon inflation (n=206) vs thrombus aspiration alone (n=207). The primary endpoint was post procedural myocardial blush grade and corrected Thrombolysis in Myocardial Infarction (TIMI) frame count (cTFC). Major adverse cardiovascular events were reported at 6 months. Results The intracoronary eptifibatide and vasodilators arm was superior to thrombus aspiration alone regarding myocardial blush grade-3 (82.1% vs 31.4%; P=.001). The local intracoronary eptifibatide and vasodilators arm had shorter cTFC (18.16±6.54 vs 29.64±5.53, P=.001), and better TIMI 3 flow (91.3% vs 61.65%; P=.001). Intracoronary eptifibatide and vasodilators improved ejection fraction at 6 months (55.2±8.13 vs 43±6.67; P=.005). There was no difference in the rates of major adverse cardiovascular events at 6 months. Conclusions Among diabetic patients with STEMI and high thrombus burden, intracoronary eptifibatide plus vasodilators injection was beneficial in preventing no-reflow compared with thrombus aspiration alone. Larger studies are encouraged to investigate the benefit of this strategy in reducing the risk of adverse clinical events (AU)

Unraveling the role of the homoarginine residue in antiplatelet drug eptifibatide in binding to the αIIbß3 integrin receptor.

Eptifibatide is an αIIbß3 inhibitor that is currently used in the clinic. More than 10 scientific communications indicate that eptifibatide has a Lys-Gly-Asp or Arg-Gly-Asp sequence, while it actually has a hArg-Gly-Asp sequence. We aimed to unravel the importance of the homoarginine residue in eptifibatide in platelet activation and aggregation. Arg- and Lys-eptifibatide were synthesized by solid-phase peptide synthesis and measured in light transmission aggregometry, flow cytometry and whole blood thrombus formation under flow. Interactions of eptifibatide and its variants with αIIbß3 integrin were studied using molecular dynamics simulations. Eptifibatide showed inhibition of collagen- and ADP-induced platelet aggregation, while Arg- and Lys-eptifibatide did not. Multiparameter assessment of thrombus formation showed suppressed platelet aggregate and fibrin formation upon eptifibatide treatment, in contrast to the other variants. Molecular dynamics simulations revealed that the hArg residue in eptifibatide is crucial to its activity, since the substitution of the hArg to Arg or Lys resulted in the inability to form double H-bonds with Asp224 in the αIIb chain of the αIIbß3 receptor. The hArg is pivotal for the interaction of eptifibatide for the αIIbß3 receptor and efficient inhibition of platelet aggregation.

Inhibition of Src but not Syk causes weak reversal of GPVI-mediated platelet aggregation measured by light transmission aggregometry.

Src tyrosine kinases and spleen tyrosine kinase (Syk) have recently been shown to contribute to sustained platelet aggregation on collagen under arterial shear. In the present study, we have investigated whether Src and Syk are required for aggregation under minimal shear following activation of glycoprotein VI (GPVI) and have extended this to C-type lectin-like receptor-2 (CLEC-2) which signals through the same pathway. Aggregation was induced by the GPVI ligand collagen-related peptide (CRP) and the CLEC-2 ligand rhodocytin and monitored by light transmission aggregometry (LTA). Aggregation and tyrosine phosphorylation by both receptors were sustained for up to 50 min. The addition of inhibitors of Src, Syk or Bruton's tyrosine kinase (Btk) at 150 sec, by which time aggregation was maximal, induced rapid loss of tyrosine phosphorylation of their downstream proteins, but only Src kinase inhibition caused a weak (~10%) reversal in light transmission. A similar effect was observed when the inhibitors were combined with apyrase and indomethacin or glycoprotein IIb-IIIa (GPIIb-IIIa) antagonist, eptifibatide. On the other hand, activation of GPIIb-IIIa by GPVI in a diluted platelet suspension, as measured by binding of fluorescein isothiocyanate-labeled antibody specific for the activated GPIIb-IIIa (FITC-PAC1), was reversed on the addition of Src and Syk inhibitors showing that integrin activation is rapidly reversible in the absence of outside-in signals. The results demonstrate that Src but not Syk and Btk contribute to sustained aggregation as monitored by LTA, possibly as a result of inhibition of outside-in signaling from GPIIb-IIIa to the cytoskeleton through a Syk-independent pathway. This is in contrast to the role of Syk in supporting sustained aggregation on collagen under arterial shear.

Efficacy and safety of a bridging strategy that uses intravenous platelet glycoprotein receptor inhibitors for patients undergoing surgery after coronary stent implantation: a meta-analysis.

BACKGROUND: Current guidelines indicate we can consider a bridging strategy that uses intravenous, reversible glycoprotein inhibitors for patients that required surgery following recent stent implantation. However, no strong clinical evidence exists that demonstrates the efficacy and safety of this treatment. Therefore, in this study, the efficacy and safety of a bridging strategy that uses intravenous platelet glycoprotein receptor inhibitors will be evaluated. METHODS: A meta-analysis was performed on preoperative bridging studies in patients undergoing coronary stent surgery. The primary outcome was the success rate of no major adverse cardiovascular events (MACE). The secondary outcomes were the success rate of no reoperations to stop bleeding. RESULTS: A total of 10 studies that included 382 patients were used in this meta-analysis. For the primary endpoint, the success rate was 97.7% (95% CI 94.4-98.0%) for glycoprotein IIb/IIIa inhibitors, 98.8% (95% CI 96.0-100%) for tirofiban (6 studies) and 95.8% (95% CI 90.4-99.4%) for eptifibatide (4 studies). For secondary endpoints, the success rate was 98.0% (95% CI 94.8-99.9%) for glycoprotein IIb/IIIa inhibitors, 99.7% (95% CI 97.1-100%) for tirofiban (5 studies), and 95.3% (95% CI 88.5-99.4%) for eptifibatide (4 studies). CONCLUSION: The results of this study showed that the use of intravenous platelet glycoprotein IIb/IIIa inhibitors as a bridging strategy might be safe and effective for patients undergoing coronary stent implantation that require surgery soon after.

Safety and Efficacy of Periprocedural Bridging With Cangrelor Versus Eptifibatide.

ABSTRACT: Patients with percutaneous coronary interventions undergoing procedures often require interruptions in their dual antiplatelet therapy. Periprocedural bridging is considered for patients at high thrombotic risk using intravenous cangrelor, a reversible P2Y12 inhibitor with a short half-life, or eptifibatide, a glycoprotein IIb/IIIa inhibitor, with a slightly longer half-life but less costly alternative. This study aims to assess the safety and efficacy of cangrelor compared with eptifibatide when used in a periprocedural setting. The primary outcome of this retrospective cohort study was the incidence of bleeding events defined by the global use of strategies to open occluded coronary arteries criteria, and the secondary outcomes include the transfusion requirements, inpatient major cardiac adverse events, and cost savings per patient. A total of 75 patients were included who were bridged to procedures (cangrelor, n = 50; eptifibatide, n = 25). There were no significant differences in overall bleeding events defined by global use of strategies to open occluded coronary arteries criteria: mild bleeding [8% (n= 4) vs. 8% (n= 2); P = 0.68], moderate bleeding [28% (n = 14) vs. 48% (n = 12); P = 0.07), and severe bleeding [8% (n = 4) vs. 8% (n = 2); P = 0.25] between cangrelor and eptifibatide. The composite inpatient major cardiac adverse events were also similar between cangrelor and eptifibatide [10% (n = 10) vs. 8% (n = 8); P = 0.78]. The average cost savings per each cangrelor patient on the equivalent duration of eptifibatide was calculated out to be $5824 per patient. Cangrelor and eptifibatide were similar in terms of safety and efficacy when used as a bridge in patients with recent coronary stents, but considerable cost savings could be made if cangrelor was substituted for by eptifibatide in select patients. Further studies are needed to determine its applicability specifically in patients at high thrombotic and hemorrhagic risk.

Combined Approach to Eptifibatide and Thrombectomy in Acute Ischemic Stroke Because of Large Vessel Occlusion: A Matched-Control Analysis.

BACKGROUND: In patients undergoing mechanical thrombectomy (MT), adjunctive antithrombotic might improve angiographic reperfusion, reduce the risk of distal emboli and reocclusion but possibly expose patients to a higher intracranial hemorrhage risk. This study evaluated the safety and efficacy of combined MT plus eptifibatide for acute ischemic stroke. METHODS: This was a propensity-matched analysis of data from 2 prospective trials in Chinese populations: the ANGEL-ACT trial (Endovascular Treatment Key Technique and Emergency Workflow Improvement of Acute Ischemic Stroke) in 111 hospitals between November 2017 and March 2019, and the EPOCH trial (Eptifibatide in Endovascular Treatment of Acute Ischemic Stroke) in 15 hospitals between April 2019 and March 2020. The primary efficacy outcome was good outcome (modified Rankin Scale score 0-2) at 3 months. Secondary efficacy outcomes included the distribution of 3-month modified Rankin Scale scores and poor outcome (modified Rankin Scale score 5-6) and successful recanalization. The safety outcomes included any intracranial hemorrhage, symptomatic intracranial hemorrhage, and 3-month mortality. Mixed-effects logistic regression models were used to account for within-hospital clustering in adjusted analyses. RESULTS: Eighty-one combination arm EPOCH subjects were matched with 81 ANGEL-ACT noneptifibatide patients. Compared with the no eptifibatide group, the eptifibatide group had significantly higher rates of successful recanalization (91.3% versus 81.5%; P=0.043) and 3-month good outcomes (53.1% versus 33.3%; P=0.016). No significant difference was found in the remaining outcome measures between the 2 groups. All outcome measures of propensity score matching were consistent with mixed-effects logistic regression models in the total population. CONCLUSIONS: This matched-control study demonstrated that MT combined with eptifibatide did not raise major safety concerns and showed a trend of better efficacy outcomes compared with MT alone. Overall, eptifibatide shows potential as a periprocedural adjunctive antithrombotic therapy when combined with MT. Further randomized controlled trials of MT plus eptifibatide should be prioritized. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03844594 (EPOCH), NCT03370939 (ANGEL-ACT).

Intracoronary eptifibatide with vasodilators to prevent no-reflow in diabetic STEMI with high thrombus burden. A randomized trial.

INTRODUCTION AND OBJECTIVES: To study the impact of injecting intracoronary eptifibatide plus vasodilators via thrombus aspiration catheter vs thrombus aspiration alone in reducing the risk of no-reflow in acute ST-elevation myocardial infarction (STEMI) with diabetes and high thrombus burden. METHODS: The study involved 413 diabetic STEMI patients with high thrombus burden, randomized to intracoronary injection (distal to the occlusion) of eptifibatide, nitroglycerin and verapamil after thrombus aspiration and prior to balloon inflation (n=206) vs thrombus aspiration alone (n=207). The primary endpoint was post procedural myocardial blush grade and corrected Thrombolysis in Myocardial Infarction (TIMI) frame count (cTFC). Major adverse cardiovascular events were reported at 6 months. RESULTS: The intracoronary eptifibatide and vasodilators arm was superior to thrombus aspiration alone regarding myocardial blush grade-3 (82.1% vs 31.4%; P=.001). The local intracoronary eptifibatide and vasodilators arm had shorter cTFC (18.16±6.54 vs 29.64±5.53, P=.001), and better TIMI 3 flow (91.3% vs 61.65%; P=.001). Intracoronary eptifibatide and vasodilators improved ejection fraction at 6 months (55.2±8.13 vs 43±6.67; P=.005). There was no difference in the rates of major adverse cardiovascular events at 6 months. CONCLUSIONS: Among diabetic patients with STEMI and high thrombus burden, intracoronary eptifibatide plus vasodilators injection was beneficial in preventing no-reflow compared with thrombus aspiration alone. Larger studies are encouraged to investigate the benefit of this strategy in reducing the risk of adverse clinical events.