Effects of platelet glycoprotein IIb/IIIa blockade with tirofiban on adverse cardiac events in patients with unstable angina or acute myocardial infarction undergoing coronary angioplasty. The RESTORE Investigators. Randomized Efficacy Study of Tirofiban for Outcomes and REstenosis

A 10-year retrospective study of antibacterial-induced thrombocytopenia in a women and children hospital using China Hospital Pharmacovigilance System and Visual Basic for Applications

AIMS

We aimed to investigate antibacterial-induced thrombocytopenia using the China Hospital Pharmacovigilance System (CHPS) in conjunction with Visual Basic for Applications (VBA).

METHODS

Between September 2011 and December 2022, a 2-phase workflow was employed to identify antibacterial-induced thrombocytopenia, including preliminary screening in phase (I) conducted by CHPS algorithms and causality assessment by trained pharmacists in phase (II) using VBA. The incidence of thrombocytopenia in each antibacterial was calculated, and comparisons were performed between paediatric and adult patients.

RESULTS

CHPS algorithms identified 4080 cases from 485 238 admissions (including 223 735 admissions receiving at least 1 antibacterial treatment). After ruling out cases with chemotherapy and abnormal platelet count at admission, 3832 cases were available. Using VBA, pharmacists identified 1039 cases (1246 antibacterial treatments, 28 agents) as potential thrombocytopenia instances (κ = 0.89), with an incidence of 0.46%. All antibacterial treatments correlated temporally with thrombocytopenia. Carbapenems (meropenem 1.77%), glycopeptides (vancomycin 1.55%) and lincosamides (clindamycin 0.44%) were prominent causal groups. The highest incidences of thrombocytopenia in the cephalosporins and penicillins groups were ceftazidime (2.04%) and piperacillin/tazobactam (1.24%), respectively. Among all antibacterial treatments, clindamycin showed the shortest time to onset (TTO), and erythromycin showed the longest TTO. Paediatric patients exhibited a longer TTO (61 vs. 29 h), extended time to nadir (83 vs. 37 h), lower platelet nadir count values (110 vs. 92 × 109/L), and a higher severe case proportion (12.37 vs. 3.86%) when compared with adults.

CONCLUSION

Different antibacterial agents exhibit varying incidences of thrombocytopenia, with notable disparities between adults and children in the characteristics of thrombocytopenia.

Prehospital crushed versus integral prasugrel loading dose in STEMI patients with a large myocardial area

BACKGROUND

The effect of administering a crushed prasugrel loading dose is uncertain in patients presenting with a large myocardial infarction and ST-segment elevation myocardial infarction (STEMI).

AIMS

The aim of this study was to investigate if patients with a large myocardial infarction may benefit from prehospital administration of a crushed prasugrel loading dose.

METHODS

Patients from the CompareCrush trial with an available ambulance electrocardiography (ECG) were included in the study. An independent core laboratory confirmed a prehospital large myocardial area. We compared pre- and postprocedural angiographic markers, including Thrombolysis in Myocardial Infarction (TIMI) 3 flow in the infarct-related artery, high thrombus burden, and myocardial blush grade 3, in STEMI patients with and without a prehospital large myocardial area.

RESULTS

Ambulance ECG was available for 532 patients, of whom 331 patients were identified with a prehospital large myocardial area at risk. Crushed prasugrel significantly improved postprocedural TIMI 3 flow rates in STEMI patients with a prehospital large myocardial area at risk (92% vs 79%, odds ratio [OR] 3.00, 95% confidence interval [CI]: 1.50-6.00) but not in STEMI patients without a prehospital large myocardial area at risk (91% vs 95%, OR 0.47, 95% CI: 0.14-1.57; pinteraction=0.009).

CONCLUSIONS

Administration of crushed prasugrel may improve postprocedural TIMI 3 flow in STEMI patients with signs of a large myocardial area at risk on the ambulance ECG. The practice of crushing tablets of prasugrel loading dose might, therefore, represent a safe, fast and cost-effective strategy to improve myocardial reperfusion in this high-risk STEMI subgroup undergoing primary percutaneous coronary intervention.

Tirofiban-induced thrombocytopenia

Tirofiban is a small non-peptide ligand-mimetic Glycoprotein (GP) IIb/IIIa inhibitor which can reversibly bind to the arginine-glycine-aspartic acid (RGD) recognition site of GP IIb/IIIa to prevent platelet aggregation. It reduces the incidence of thrombotic cardiovascular events in patients with non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Although generally considered safe, tirofiban has been reported to be associated with thrombocytopenia in several case reports and clinical trials. The pathogenesis for this adverse reaction is not entirely understood, is thought to be due to immune-mediated reaction. This side effect caused by tirofiban is especially concerning given how frequently it is used in the practice of contemporary cardiovascular care. The present review provides an overview of the pathophysiology, clinical presentation, management, and risk factors associated with tirofiban-induced thrombocytopenia.

Adverse Drug Effect Profiles of Gp2b/3a Inhibitors: A Comparative Review of the Last Two Decades

ST-Elevation Myocardial Infarction and non-ST Elevation Myocardial Infarction belong to the acute coronary syndrome group of diseases. These conditions are characterized by the complete or partial blockage of one or several coronary arteries, resulting in myocardial injury or necrosis. Various medications are used in their treatment, with the most recent addition being Glycoprotein IIb/IIIa inhibitors. They work by hindering the activity of glycoprotein IIb/IIIa receptors, which, in turn, prevents the clumping of platelets. Some of the GpIIb/IIIa inhibitors available in this category include abciximab, tirofiban, eptifibatide, roxifiban, and orbofiban. With this comprehensive literature review, we aimed to explore the potential adverse effects of these medications and compare the three in terms of their side effects profile. We searched through PubMed and Google Scholar and pinpointed 13 articles aligned with our inclusion criteria: six articles utilized eptifibatide, four were related to abciximab, and three used tirofiban. In 85% of the cases, a severe drop in platelet count, reaching as low as 1000/μL, was reported. Additionally, several other side effects were noted: one case documented multiple bruising spots appearing around the patient's body, two cases reported diffuse alveolar hemorrhage, and one case described a cardiac tamponade resulting from hemorrhagic pericarditis. Our study highlights the crucial significance of keeping a watchful eye on and comprehending the potential drawbacks linked to these medications in cardiovascular treatment. The necessity of researching these medications and their side effects is also evident, as this will significantly enhance the quality of treatment provided.

Trends in Dual Antiplatelet Therapy Use for Neurointerventional Procedures for the Management of Intracranial Aneurysms

The use of periprocedural dual antiplatelet therapy (DAPT) has significantly evolved along with innovations in the endovascular management of intracranial aneurysms. Historically, aspirin and clopidogrel have been the most commonly employed regimen due to its safety and efficacy. However, recent studies highlight the importance of tailoring DAPT regimens to individual patient characteristics which may affect clopidogrel metabolism, such as genetic polymorphisms. In the present report, a systematic review of the literature was performed to determine optimal antiplatelet use with flow diverting stents, intracranial stents, intrasaccular devices, and stent-assisted coiling. Studies were analyzed for the number of aneurysms treated, DAPT regimen, and any thromboembolic complications. Based on inclusion criteria, 368 studies were selected, which revealed the increasing popularity of alternative DAPT regimens with the aforementioned devices. Thromboembolic or hemorrhagic complications associated with antiplatelet medications were similar across all medications. DAPT with ticagrelor, tirofiban, or prasugrel are effective and safe alternatives to clopidogrel and do not require enzymatic activation. Further clinical trials are needed to evaluate different antiplatelet regimens with various devices to establish highest-level evidence-based guidelines and recommendations.

Revealing concealed cardioprotection by platelet Mfsd2b-released S1P in human and murine myocardial infarction

Antiplatelet medication is standard of care in acute myocardial infarction (AMI). However, it may have obscured beneficial properties of the activated platelet secretome. We identify platelets as major source of a sphingosine-1-phosphate (S1P) burst during AMI, and find its magnitude to favorably associate with cardiovascular mortality and infarct size in STEMI patients over 12 months. Experimentally, administration of supernatant from activated platelets reduces infarct size in murine AMI, which is blunted in platelets deficient for S1P export (Mfsd2b) or production (Sphk1) and in mice deficient for cardiomyocyte S1P receptor 1 (S1P₁). Our study reveals an exploitable therapeutic window in antiplatelet therapy in AMI as the GPIIb/IIIa antagonist tirofiban preserves S1P release and cardioprotection, whereas the P2Y12 antagonist cangrelor does not. Here, we report that platelet-mediated intrinsic cardioprotection is an exciting therapeutic paradigm reaching beyond AMI, the benefits of which may need to be considered in all antiplatelet therapies.

Exploratory Use of Glycoprotein IIb/IIIa Inhibition in Prevention of Blalock-Taussig Shunt Thrombosis

OBJECTIVES

Morbidity and mortality related to modified Blalock-Taussig shunt (mBTTS) thrombosis remain a significant risk. Platelet inhibition following mBTTS may reduce this risk. However, oral antiplatelet agents have variable absorption following surgery. We determine risk factors for mBTTS thrombosis and hypothesize that IV glycoprotein IIb/IIIa inhibitor (tirofiban) as a bridge to oral aspirin reduces the rate of shunt thrombosis in the immediate postoperative period. End points within the 14-day follow-up period include mBTTS thrombosis, overall thrombosis, bleeding, length of stay, and mortality.

DESIGN

Retrospective, Institutional Review Board-approved cohort study.

SETTING

Single-center cardiac ICU.

PATIENTS

Patients under the age of 18 who had an mBTTS placed within the study period of January 2008 to December 2018 were included.

INTERVENTIONS

Patients were divided into two groups: standard of care (SOC) anticoagulation alone and SOC with tirofiban as a bridge to oral aspirin.

MEASUREMENTS AND MAIN RESULTS

Freedom from mBTTS thrombosis was estimated using the Kaplan-Meier method. A multivariable predictive model using the four most significant risk factors was developed using logistic regression. A total of 272 patients were included: 36 subjects in the SOC/tirofiban group and 236 in the SOC group. Shunt thrombosis occurred in 26 (11%) SOC group with zero in SOC/tirofiban group ( p = 0.03). The median time to thrombosis was 0 days (range, 0-12 d). The area under the curve for the predictive model (anticoagulation group, history of coagulopathy, intraoperative shunt clipping, and shunt size/weight ratio) is 0.790 ( p < 0.001). Prevalence of bleeding and mortality was not significantly different between the groups.

CONCLUSIONS

Highest risk for shunt thrombosis following mBTTS occurs within the first few days after surgical procedure. Tirofiban is a safe addition to SOC and may be an effective strategy to prevent early mBTTS thrombosis.

Antiplatelet Agents in Acute ST Elevation Myocardial Infarction

Platelet aggregation and thrombus formation represent the basic mechanism for clinical, electrocardiographic, and biomarker changes consistent with acute coronary syndrome. Various oral and intravenous formulations of platelet function inhibitors have been developed to help decrease platelet aggregation due to acute atherosclerotic plaque rupture. In this article, we review the various mechanisms, pharmacokinetics/pharmacodynamics, and the key clinical trials related to the platelet inhibitors that form the basis for current recommendations of their use in the ST elevation myocardial infarction guidelines by the American College of Cardiology/American Heart Association.

Pharmacosimulation of delays and interruptions during administration of tirofiban: a systematic comparison between EU and US dosage regimens

Tirofiban is a glycoproteine (GP) IIb/IIIa receptor antagonist, which inhibits platelet-platelet aggregation and is a potential adjunctive antithrombotic treatment in patients with acute coronary syndromes (ACS) or high-risk percutaneous coronary interventions (PCI). It is administered intravenously as a bolus followed by continuous infusion. However, the dosage recommendations in the United States (US) and European Union (EU) differ considerably. Furthermore, in routine clinical practice, deviations from the recommendations may occur. The objective of the present study was to investigate the impact of different alterations on tirofiban plasma concentrations in US and EU administration regimens and to give suggestions for delay management in clinical practice. We therefore mathematically simulated the effects of different bolus-infusion delays and infusion interruptions in different scenarios according to the renal function. Here, we provide a systematic assessment of concentration patterns of tirofiban in the US versus EU dosage regimens. We show that differences between the two regimens have important effects on plasma drug levels. Furthermore, we demonstrate that deviations from the proper administration mode affect the concentration of tirofiban. Additionally, we calculated the optimal dosage of a second bolus to rapidly restore the initial concentration without causing overdosage. In conclusion, differences in tirofiban dosing regimens between the U.S and EU and potential infusion interruptions have important effects on drug levels that may impact on degrees of platelet inhibition and thus antithrombotic effects. Thus, the findings of our modelling studies may help to explain differences in clinical outcomes observed in previous clinical trials on tirofiban.

Role of Integrins in Modulating Smooth Muscle Cell Plasticity and Vascular Remodeling: From Expression to Therapeutic Implications

Smooth muscle cells (SMCs), present in the media layer of blood vessels, are crucial in maintaining vascular homeostasis. Upon vascular injury, SMCs show a high degree of plasticity, undergo a change from a “contractile” to a “synthetic” phenotype, and play an essential role in the pathophysiology of diseases including atherosclerosis and restenosis. Integrins are cell surface receptors, which are involved in cell-to-cell binding and cell-to-extracellular-matrix interactions. By binding to extracellular matrix components, integrins trigger intracellular signaling and regulate several of the SMC function, including proliferation, migration, and phenotypic switching. Although pharmacological approaches, including antibodies and synthetic peptides, have been effectively utilized to target integrins to limit atherosclerosis and restenosis, none has been commercialized yet. A clear understanding of how integrins modulate SMC biology is essential to facilitate the development of integrin-based interventions to combat atherosclerosis and restenosis. Herein, we highlight the importance of integrins in modulating functional properties of SMCs and their implications for vascular pathology.

Acute Stenting and Concomitant Tirofiban Administration for the Endovascular Treatment of Acute Ischemic Stroke Related to Intracranial Artery Dissections: A Single Center Experience and Systematic Review of the Literature

BACKGROUND

Intracranial artery dissection is an uncommon cause of acute ischemic stroke. Although acute stenting of the dissected arterial segment is a therapeutic option, the associated antiplatelet regimen remains a matter of debate.

OBJECTIVES

To evaluate the efficacy and safety of acute intracranial stenting together with concomitant intravenous administration of tirofiban and to perform a systematic review of the literature.

MATERIALS AND METHODS

A single-center, retrospective study of the clinical and radiological records of all patients treated at our center by intracranial stenting in the setting of acute ischemic stroke between January 2010 and December 2020. A systematic review of the literature was conducted according to the PRISMA-P guidelines for relevant publications from January 1976 to December 2020 on intracranial artery dissection treated by stent.

RESULTS

Seven patients with intracranial artery dissections underwent acute stenting with concomitant tirofiban during the study period. Mid-term follow-up showed parent artery patency in 6/7 cases (85.7%). The modified Rankin Score was ≤ 0-2 at 3 months in 5/7 cases (71.4%). The literature review identified 22 patients with intracranial artery dissection treated with acute stenting in association with different antithrombotic therapies. Complete revascularization was obtained in 86.3% of cases with a modified Rankin Score of ≤ 0-2 in 68% of patients at 3-month follow-up.

CONCLUSIONS

Acute intracranial stenting together with intravenous tirofiban administration could be a therapeutic option in patients with intracranial artery dissection and a small ischemic core.

Predictive value of the age, creatinine and ejection fraction score in patients undergoing primary percutaneous coronary intervention with bail-out tirofiban therapy

INTRODUCTION

In patients who have undergone interventional cardiac procedures, the risk of bleeding is higher than in patients who received conservative treatment due to multiple medications and comorbidities.

AIM

This study aimed to evaluate the usefulness of the age, creatinine and ejection fraction (ACEF) score for predicting bleeding events and to compare short- and long-term clinical outcomes according to the ACEF score in patients with ST-elevation myocardial infarction (STEMI) undergoing primary percutaneous coronary intervention (pPCI) with bail-out tirofiban therapy (BOTT).

MATERIAL AND METHODS

A total of 2,543 patients were included and divided into three groups according to the following ACEF score tertiles: T1 (ACEFlow ≤ 1.033), T2 (1.033 < ACEFmid ≤ 1.371), and T3 (ACEFhigh > 1.371). The main outcomes measured were the incidence rates of relevant bleeding events and mortality within 30 days and 3 years after the procedure.

RESULTS

A total of 73 (2.9%) patients had Bleeding Academic Research Consortium bleeding events of grades 3, 4 or 5 and 104 (4%) patients died in a 30-day period. The ACEF score was effective at predicting 30-day bleeding (area under the receiver operating characteristic curve (AUC): 0.658, 95% confidence interval (CI): 0.579-0.737; p < 0.001), 30-day mortality (AUC = 0.701, 95% CI: 0.649-0.753; p < 0.001) and 3-year mortality (AUC = 0.778, 95% CI: 0.748-0.807; p < 0.001) events. Considering the ACEF score tertiles, T3 patients presented greater 30-day bleeding (1.6%, 2.8% and 4.1%; odds ratio (OR) = 2.56, 95% CI: 1.37-4.80), 30-day mortality (1.7%, 3.5% and 7.1%; OR = 4.53, 95% CI: 2.51-8.18) and 3-year mortality (6.4%, 11% and 19.8%; hazard ratio = 3.56, 95% CI: 2.58-4.91) risks.

CONCLUSIONS

The ACEF score is a user-friendly tool with excellent predictive value for bleeding events and mortality in patients undergoing pPCI with BOTT.

Successful rescue treatment of right posterior inferior cerebellar artery (PICA) vascular stasis with tirofiban following endovascular coil implantation

This report describes a patient who developed intraprocedural vascular stasis immediately following elective endovascular coil emboliation. Urgent antiplatelet treatment with the GpIIb/IIIa agent tirofiban was used. It was infused intra-arterially during the procedure, followed by a fixed rate intravenous continuous infusion, and successfully restored normal circulation. There were no reports of further bleeding or haemodynamic compromise during the hospital stay. The patient’s condition returned to baseline and he was discharged the following day with no neurological deficits.

Thrombocytopenia induced by glycoprotein (GP) IIb-IIIa antagonists: about two cases

In this paper, we report two cases of induced thrombocytopenia after the infusion of glycoprotein (GP) IIb/IIIa receptors antagonists, following a coronary angioplasty. The first patient is a 65-year-old woman, admitted with acute coronary syndrome requiring percutaneous angioplasty with stenting. The patient was given tirofiban + unfractionated heparin (UFH). Ten hours later, the patient revealed very severe thrombocytopenia and went into hemorrhagic shock (hematemesis and hematoma at the injection site). The patient was transfused with nine units of red blood cells (RBCs), 24 platelets pellets and 4 units of fresh frozen plasma (FFP). The second patient is a 76-year-old woman. She was admitted to hospital for acute coronary syndrome necessitating percutaneous angioplasty with stenting and a glycoprotein IIb/IIIa receptor antagonists, tirofiban + unfractionated (UFH). Four hours later, the patient presented with gingivorrhagia associated thrombocytopenia. She received six platelet pellets transfusion with well clinical and biological improvement. These two observations raise the significance of a close monitoring of platelet count after the initiation of GP IIb/IIIa antagonists infusion, which are sometimes responsible for life-threatening adverse events.

The safety and efficacy of low-dosage tirofiban for stent-assisted coiling of ruptured intracranial aneurysms

Stent-assisted coiling (SAC) of acutely ruptured aneurysms with antiplatelet therapy has been controversial. Tirofiban has been used for the treatment of thromboembolism of ruptured aneurysms with a stent. However, there are few comparative studies of a reasonable dosage for the prophylactic use of tirofiban. This study evaluated the safety and efficacy of reducing the dosage of tirofiban for the ruptured aneurysms with SAC. Patients with ruptured intracranial aneurysms in our institution from January 2014 to June 2018 were retrospectively reviewed. Three hundred and nine patients were treated using SAC within 72 h of onset. Patients were divided into either a standard group (211 patients, 10 μg/kg intravenous bolus within 3 min, maintained with 0.15 μg/kg/min) or a half-dose group (98 patients, 5 μg/kg intravenous bolus within 3 min, maintained with 0.075 μg/kg/min) according to the dose of tirofiban received intraoperatively. Medical records including clinical and radiological details were reviewed. No significant differences in demographic information or aneurysm characteristics existed between the two groups. Thromboembolic complications were found in 15 patients (4.9%), including 11 patients (5.2%) in the standard group and four patients (4.1%) in the half-dose group, without significant difference (P = 0.782). Intracranial hemorrhage was found in 13 patients (4.2%), and all occurred in the standard group, which was significantly different (6.2% vs 0%, P = 0.011). Of these 13 patients, four were left disabled and five died. Except for three patients who had intraoperative aneurysm rupture, the incidence of postoperative early rebleeding (10 patients) was significantly different between the two groups (4.7% vs 0%, P = 0.034). The rate of initial complete occlusion in the half-dose group was significantly higher than that in the standard group (55.1% vs 39.8%). The rate of a good outcome (modified Rankin Scale 0-2) was not significantly different between the standard group and half-dose group (78.7% vs 87.8%, P > 0.05). Intravenous tirofiban for SAC of acutely ruptured intracranial aneurysms is feasible and safe. The half-dose tirofiban treatment was associated with a decrease in the prevalence of intracranial hemorrhage but no increase in thromboembolic events compared with those in standard-dose tirofiban treatment.

How not to discover a drug - integrins

INTRODUCTION

Integrins are a family of 24 cell adhesion receptors that play a role in the biggest unmet needs in medicine - cardiovascular disease, immunology and cancer. Their discovery promised huge potential for the pharmaceutical industry. Areas covered. Over 35-years since their discovery, there is little to show for the hundreds of billions of dollars of investment in anti-integrin drug discovery programmes. In this review the author discusses the reasons for the failure of this promising class of drugs and the future for this class of drugs. Expert opinion. Within 10-years, there was a plethora of potent, specific anti-integrin molecules and since their discovery, many of these agents have entered clinical trials. The success in discovering these agents was due to recently discovered monoclonal antibody technology. The integrin-recognition domain Arg-Gly-Asp (RGD) provided the basis for discovering small molecule inhibitors to integrins - both cyclic peptides and peptidomimetics. Most agents failed in the Phase III clinical trials and those agents that did make it to the market were plagued with issues of toxicity and limited efficacy and were soon replaced with non-integrin targeting agents. Their failure was due to a combination of poor pharmacokinetics and pharmacodynamics, complicated by the complex pathophysiology of integrins.

New Antithrombotic Drugs in Acute Coronary Syndrome

In recent years, much progress has been made in the field of antithrombotic drugs in acute coronary syndrome (ACS) treatment, as reflected by the introduction of the more potent P2Y12-inhibitors prasugrel and ticagrelor, and novel forms of concomitant anticoagulation, such as fondaparinux and bivalirudin. However, despite substantial improvements in contemporary ACS treatment, there remains residual ischemic risk in this group and hence the need for even more effective antithrombotic drugs, while balancing antithrombotic efficacy against bleeding risk. This review discusses recently introduced and currently developed antiplatelet and anticoagulant drugs in ACS treatment.

Platelet Inhibition With IV Glycoprotein IIb/IIIa Inhibitor to Prevent Thrombosis in Pediatric Patients Undergoing Aortopulmonary Shunting

OBJECTIVES

Shunt thrombosis, a potential complication of aortopulmonary shunting, is associated with high mortality. Commonly used oral antiplatelet drugs such as aspirin demonstrate variable absorption and inconsistent antiplatelet effect in critically ill patients early after surgery. IV glycoprotein IIb/IIIa inhibitors are antiplatelet agents with rapid and reproducible effect that may be beneficial as a bridge to oral therapy.

DESIGN

Retrospective review of pediatric patients undergoing treatment with IV tirofiban. Discarded blood samples were used to determine pharmacokinetic parameters.

SETTING

Pediatric cardiac ICU at a single institution.

PATIENTS

Fifty-two pediatric patients (< 18 yr) undergoing surgical aortopulmonary shunt procedure who received tirofiban infusion as a bridge to oral aspirin.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Primary outcome measures were shunt thrombosis and bleeding events, whereas secondary outcomes included measurement of platelet inhibition by thromboelastography with platelet mapping and pharmacokinetic analysis (performed in a subset of 15 patients). Shunt thrombosis occurred in two of 52 patients (3.9%) after prophylaxis treatment with tirofiban; both thrombosis events occurred after discontinuation of the drug. One patient (1.9%) experienced bleeding complication during the infusion. A tirofiban bolus of 10 µg/kg and infusion of 0.15 µg/kg/min resulted in significantly increased platelet inhibition via adenosine diphosphate pathway (median 66% [43-96] pre-tirofiban compared with 97% [92-99%] at 2 hr; p < 0.05). Half-life of tirofiban in plasma was 142 ± 1.5 minutes, and the average steady-state concentration was 112 ± 62 ng/mL. Age and serum creatinine were significant covariates associated with systemic clearance. Dosing simulations were generated based upon one compartment model.

CONCLUSIONS

IV glycoprotein IIb/IIIa inhibitor as a bridge to oral antiplatelet therapy is safe in pediatric patients after aortopulmonary shunting. Dosing considerations should include both age and renal function. Randomized trials are warranted to establish efficacy compared with current anticoagulation practices.

Life after abciximab; what's next for intracoronary thrombus?

A case is described in which the short-acting glycoprotein IIb/IIIa receptor antagonist tirofiban was used in combination with heparin, aspirin and prasugrel to successfully treat extensive intracoronary thrombus in a delayed presentation STEMI, illustrating the utility of this approach.

From Snake Venom's Disintegrins and C-Type Lectins to Anti-Platelet Drugs

Snake venoms are attractive natural sources for drug discovery and development, with a number of substances either in clinical use or in research and development. These drugs were developed based on RGD-containing snake venom disintegrins, which efficiently antagonize fibrinogen activation of αIIbβ3 integrin (glycoprotein GP IIb/IIIa). Typical examples of anti-platelet drugs found in clinics are Integrilin (Eptifibatide), a heptapeptide derived from Barbourin, a protein found in the venom of the American Southeastern pygmy rattlesnake and Aggrastat (Tirofiban), a small molecule based on the structure of Echistatin, and a protein found in the venom of the saw-scaled viper. Using a similar drug discovery approach, linear and cyclic peptides containing the sequence K(R)TS derived from VP12, a C-type lectin protein found in the venom of Israeli viper venom, were used as a template to synthesize Vipegitide, a novel peptidomimetic antagonist of α2β1 integrin, with anti-platelet activity. This review focus on drug discovery of these anti-platelet agents, their indications for clinical use in acute coronary syndromes and percutaneous coronary intervention based on several clinical trials, as well as their adverse effects.

Comparison of In-Hospital Bleeding and Cardiovascular Events with High-Dose Bolus Tirofiban and Shortened Infusion to Short-Duration Eptifibatide as Adjunctive Therapy for Percutaneous Coronary Intervention

Potent platelet inhibition is one of the most important medical interventions to prevent ischemic complications during and after percutaneous coronary intervention (PCI). Practice has evolved with the introduction of potent oral P2Y₁₂ inhibitors that provide quick, effective platelet inhibition, and the need for routine glycoprotein IIb/IIIa inhibitors (GPIs) has decreased. Additionally, a shorter duration of GPI infusion has been shown to be safe with adequate oral antiplatelet loading, but clinical outcome data are limited to eptifibatide. This single-center, retrospective cohort study analyzed in-hospital outcomes for patients who received adjunctive GPI therapy for PCI before and after an institution-wide switch to high-dose bolus tirofiban with shortened infusion from short-duration eptifibatide. The primary end point was a composite in-hospital outcome of major and minor bleeding and cardiovascular events (death, myocardial infarction, coronary artery bypass grafting, ischemic stroke, and target vessel revascularization). Secondary end points included bleeding and cardiovascular event types. A total of 357 and 446 patients received eptifibatide and tirofiban, respectively, from February 1, 2014 through September 30, 2017. Thirty five eptifibatide and 46 tirofiban patients experienced an in-hospital composite event (9.8% vs 10.3%, p = 0.81). There was no difference found between in-hospital bleeding (6.4% vs 5.4%, p = 0.52) or cardiovascular events (5.6% vs 6.5%, p = 0.60) with the use of eptifibatide or tirofiban, respectively. Multivariable analysis showed that patients with transradial access or an indication of unstable angina were less likely to experience an in-hospital composite event (OR 0.30 and 0.19, respectively, p <0.001 for both). In conclusion, the use of high-dose bolus tirofiban with shortened infusion versus short-duration eptifibatide was not associated with an increase of in-hospital bleeding or cardiovascular events.

Safety and efficacy of Tirofiban in STEMI-patients

BACKGROUND

Tirofiban is recommended as bail out therapy in patients with ST-elevation myocardial infarction (STEMI). However, evidence regarding safety and efficacy of tirofiban is unclear. Tirofiban has been shown to improve ST-resolution, to decrease infarct size (IS) and to reduce incidence of major adverse cardiac and cerebrovascular events (MACCE). However, bleeding is enhanced in tirofiban treated patients. In this study, we aim to investigate efficacy and safety of Tirofiban in STEMI-patients.

METHODS

610 STEMI patients were analyzed. MACCE (death, myocardial infarction [MI], stroke) and TIMI bleeding events were registered during hospital course and 12 month follow-up.

RESULTS

Tirofiban patients were slightly younger (tirofiban 63 ± 13 years vs. control 65 ± 14 years; p = 0.04). They had higher peak-high-sensitive troponin T [Hs-TnT] (tirofiban 6561 ± 11,065 vs. control 4594 ± 11,200, p-value = 0.047) and peak-creatine kinase [CK] (tirofiban 2742 ± 5097 vs. control 1416 ± 2160, p-value < 0.0001). Percutaneous coronary intervention (PCI) was more complex in tirofiban treated patients as radiation time (tirofiban 18 ± 15 vs. control 14 ± 13; p-value = 0.02) and use of contrast agent (tirofiban 240 ± 106 vs. control 209 ± 99; p-value = 0.01) was higher in tirofiban patients. However, there were no differences in MACCE (HR 0.877, 95% CI 0.62-1.25, p = 0.47) and bleeding (major: HR 1.494, 95% CI 0.65-3.44, p = 0.34; minor: HR 1.294, 95% CI 0.67-2.52, p = 0.45).

CONCLUSION

MACCE and bleeding events were similar. However, PCI was more complex and infarcts larger in tirofiban treated patients.

Preliminary Study of Tirofiban Infusion in Coil Embolization of Ruptured Intracranial Aneurysms

BACKGROUND

There have been some reports on the use of intra-arterial tirofiban in ruptured intracranial aneurysms, but few studies have reported on the use of 24 h of intravenous tirofiban infusion in patients with subarachnoid hemorrhage.

OBJECTIVE

To present our experience with intravenous tirofiban infusion, in the form of a monotherapy as well as in addition to intra-arterial tirofiban, as a prophylactic, and as a rescue management for thrombus in patients who have undergone embolization with coils for ruptured intracranial aneurysms.

METHODS

Between December 2008 and January 2015, we retrospectively reviewed 249 ruptured intracranial aneurysms that were treated with coiling at our institutions. A total of 28 patients harboring 28 ruptured and 3 unruptured intracranial aneurysms underwent intravenous tirofiban infusion during or after coil embolization of an aneurysm. Intra-arterial infusion of tirofiban via a microcatheter was also performed in 26 patients.

RESULTS

Thromboembolic formation during the procedure was detected in 25 cases. Intra-arterial tirofiban dissolved the thromboembolus under angiographic control after 10 or more minutes in 19 (76%) of 25 patients. Two intracranial hemorrhagic complications (increase in the extent of hematoma) occurred during the follow-up period. Two cases of other complications occurred: hematuria and perioral bleeding.

CONCLUSION

Intravenous tirofiban, as a monotherapy or in addition to intra-arterial tirofiban for thrombotic complications, seems to be useful as a treatment for acute aneurysm. However, alternatives to tirofiban should be considered if an associated hematoma is discovered before a patient receives a tirofiban infusion.

[Long-lasting thrombocytopenia induced by glycoprotein IIb/IIIa inhibitor]

INTRODUCTION

Glycoprotein IIb/IIIa inhibitors (anti-GPIIbIIIa) prevent platelet binding to fibrinogen. Transient sometimes-severe thrombocytopenia is a well-known side effect.

OBSERVATION

A 71-year-old patient presented severe thrombocytopenia after the administration of tirofiban (anti-GPIIbIIIa). Corticosteroid treatment was initiated at day 10 because of persistence of severe thrombocytopenia with poor platelet transfusion efficacy. Corticosteroid treatment led to platelet recovery evoking an immune mediated mechanism for thrombocytopenia.

CONCLUSION

Anti-GPIIbIIIa are associated with a risk of dramatic thrombocytopenia. The underlying mechanism is poorly understood. The management of these usually transient thrombocytopenias is based on platelet transfusion. As report here, in some cases persistent thrombocytopenia can respond to corticosteroids.

Optimal Antiplatelet Therapy in ST-Segment Elevation Myocardial Infarction

Cardiovascular disease is the leading cause of death worldwide. Case-fatality rates for myocardial infarction (MI) in the United States have decreased over the past decades, in large part due to advances in the treatment of acute MI and secondary preventive therapy after MI. Antiplatelet therapy remains the cornerstone of treatment of MI. This article reviews the current state of antiplatelet therapy in ST-segment elevation MI.

A randomized trial assessing the impact of three different glycoprotein IIb/IIIa antagonists on glycoprotein IIb/IIIa platelet receptor inhibition and clinical endpoints in patients with acute coronary syndromes

AIMS

To compare three glycoprotein IIb/IIIa receptor antagonists (GPIs) in terms of platelet inhibition and major adverse cardiac events (MACEs), and assess the rate of bleeding and MACEs between GPIs and coadministered P2Y12 agents.

METHODS

Eighty-three acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) with planned GPI use were randomized to receive high-dose bolus tirofiban, double-bolus eptifibatide, or abciximab followed by a 12-hour infusion. Glycoprotein IIb/IIIa platelet receptor inhibition was measured at baseline and at 10 minutes, 1 hour, and 24 hours postbolus dose. Major adverse cardiac events and bleeding complications at 30 days were documented. The incidence of MACEs and bleeding in patients receiving ticagrelor or prasugrel were compared to those given clopidogrel.

RESULTS

There were no statistically significant differences in platelet inhibition between GPIs at 10 minutes (P=.085) and 1 hour (P=.337). At 24 hours, abciximab achieved statistically significantly higher median [interquartile range] platelet inhibition (75 [65-88]%) compared to tirofiban (28 [3-56]%; P<.0001) and eptifibatide (44 [31-63]%; P=.007). There were no differences in bleeding or MACEs depending on GPI or P2Y12 inhibitor administered.

CONCLUSIONS

Glycoprotein receptor inhibitors achieve similar levels of platelet inhibition at 10 minutes and 1 hour; however, abciximab maintains this benefit 24 hours after bolus dose. We did not witness an increased rate of bleeding in patients given new potent P2Y12 inhibitors and a GPI in the modern era.

Antithrombotic Therapy to Reduce Ischemic Events in Acute Coronary Syndromes Patients Undergoing Percutaneous Coronary Intervention

Antithrombotic therapy is essential in the prevention of periprocedural death and myocardial infarction during and after percutaneous coronary intervention. In the pathogenesis of acute coronary syndromes (ACS), both platelets and the coagulation cascade play an important role. Therefore, periprocedural antithrombotic therapy is even more important in ACS than in elective PCI. The most used agents are aspirin, platelet P2Y12 blockers, platelet glycoprotein IIb/IIIa blockers, and parenteral anticoagulants. The P2Y12 blockers must be continued at least 12 months. High-risk patients should be treated with glycoprotein IIb/IIIa receptor antagonists, especially those undergoing primary angioplasty for ST-elevation acute coronary syndrome.

"Mind the gap" acute coronary syndrome in women: A contemporary review of current clinical evidence

The incidence and prevalence of coronary artery disease in women has exceeded that in men over the past four decades, and although a significant decline in mortality has occurred in the past two decades, there is a growing body of evidence suggesting that there are gender differences between the clinical manifestations and course of coronary artery disease, as well as differences in treatment and treatment response. This review article considers the current literature regarding the gender-specific manifestation of acute coronary syndromes. Through the review of basic science articles, subsets of trial data, and meta-analyses, the gender-specific differences in within acute coronary syndromes are considered in terms of diagnostic dilemmas, pathophysiology, and treatment options (including pharmacological, percutaneous and surgical methods). Finally, acute coronary syndromes and their management in the special circumstance of pregnancy are also reviewed.

Profound Thrombocytopenia Associated with Tirofiban

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.

The role of Glycoprotein IIb/IIIa inhibitors in acute coronary syndromes and the interference with anemia

The role played by glycoprotein (GP) IIb/IIIa inhibitors (GPI) has continuously evolved until the most recent Guidelines whereby they were stepped down from class I to class II recommendation for treating acute coronary syndromes (ACS). GPI compete with a wider use of ADP inhibitors and novel anticoagulant drugs although GPI use has greatly narrowed. However, GPI may still have a role. Several criteria were proposed to define post-PCI anemia which is strictly related to bleeding and transfusion. In ACS, it should be important to define anemia in comparative terms versus baseline levels: ≥ 15% of red blood cell decrease should be a practical cut-off value. If one wishes to concentrate on hemoglobin (Hb), a≥2g/dl Hb decrease from baseline should be considered. It is important to recognize post-PCI anemia in the setting of ACS. There are sub-populations exposed to short-term hemorrhagic and/or long-term ischemic risks. Ischemic and hemorrhagic risks need to be carefully evaluated along with thrombocytopenia and its prognostic significance in order to put all these blood and rheological parameters into a clinically oriented perspective on which therapeutical decisions should be based. Definition of high risk procedures (complexity, angiographic characteristics and patient's risk profile, regardless whether STEMI or NSTEMI) may help selecting GPI. There are positive elements in GPI use: efficacy, rapid onset and reversibility of action, absence of pharmacogenomic variability, pharmacoeconomic considerations and the possibility of intracoronary administration. All these elements should be evaluated when selecting these agents for therapeutics.

Preoperative Platelet Inhibition With Eptifibatide During Coronary Artery Bypass Grafting With Cardiopulmonary Bypass

Platelet glycoprotein IIb-IIIa antagonists reduce cardiac events in acute coronary syndromes (ACSs), but their use is limited during coronary artery bypass grafting (CABG) because of bleeding concerns. Patients with ACS, however, are at increased risk for cardiac events after CABG. The use of short-acting glycoprotein IIbIIIa inhibitor eptifibatide in patients with ACS undergoing CABG was investigated. Fifteen patients with ACS and undergoing CABG with cardiopulmonary bypass were enrolled. One withdrew before surgery. Patients received heparin and eptifibatide preoperatively. Eptifibatide concentration and receptor occupancy (RO) at termination of infusion were similar in the two groups. Immediately before surgery, eptifibatide levels in the 2-hour group were twice that in the 4-hour group, and platelet RO was higher. Cessation of eptifibatide 4 hours before surgery results in less bleeding and transfusions than 2 hours before surgery. The optimal balance between bleeding and platelet inhibition is approximately 60% platelet RO. Further investigation of upstream therapy should target this threshold.

Platelets and Cardiovascular Disease

Platelets play an important, but often under-recognized role in cardiovascular disease. For example, the normal response of the platelet can be altered, either by increased pro-aggregatory stimuli or by diminished anti-aggregatory substances to produce conditions of increased platelet activation/aggregation and occur in active cardiovascular disease states both on a chronic (e.g. stable angina pectoris) and acute basis (e.g. acute myocardial infarction). In addition, platelet hyperaggregability is also associated with the risk factors for coronary artery disease (e.g. smoking, hypertension, and hypercholesterolaemia). Finally, the utility of an increasing range of anti-platelet therapies in the management of the above disease states further emphasizes the pivotal role platelets play in the pathogenesis of cardiovascular disease. This paper provides a comprehensive overview of the normal physiologic role of platelets in maintain homeostasis, the pathophysiologic processes that contribute to platelet dysfunction in cardiovascular disease and the associated role and benefits of anti-platelet therapies.

Comparison between the Outcomes of Intracoronary and Intravenous Administration of Eptifibatide during Primary Percutaneous Coronary Intervention in Patients with Acute ST-Elevation Myocardial Infarction

AIM

To compare the outcomes of intracoronary (IC) and intravenous (IV) administration of eptifibatide during primary percutaneous coronary intervention (PPCI) in patients with ST-elevation myocardial infarction (STEMI).

METHODS

In this prospective double-blind randomized clinical trial, 76 patients with STEMI selected for PPCI were randomly assigned in two groups to receive either IC or IV bolus of eptifibatide. The primary end point was coronary perfusion assessment by thrombolysis in myocardial infarction (TIMI) flow grade (TFG), TIMI perfusion grade (TPG), and corrected TIMI frame count (cTFC). Secondary end points were left ventricular ejection fraction (LVEF) restoration, ST-segment elevation resolution, and in-hospital major cardiovascular adverse events (MACEs) (including recurrent MI, need for target vessel revascularization (TVR), stroke, and death resulting from any cause) until discharge.

RESULTS

Assessment revealed significantly better TFG (95% CI: 1.01-10.26, OR=3.224, P=0.042), more TFG 3 (65.79% vs. 86.11% in IV and IC groups, respectively), better TPG (P=0.024), more achieved TPG 3 and TPG 2＋3 (TPG 3: 44.74% vs. 72.22% and TPG 2＋3: 78.95% vs. 94.44% in the IV and IC groups, respectively) with better cTFC in the IC group (37.33±15.84 vs. 32.53± 20.71 in the IV and IC groups, respectively; P=0.034). LVEF was better restored in the IC group (6.21±8.61% vs. 14.72±5.34% in the IV and IC groups, respectively; P＜0.001) and the ST-segment elevation resolution was better achieved in the IC administration (95% CI: -22.55 to -6.23, P=0.001). There were no recurrent MI, stroke, or need for TVR among patients during the in-hospital stay.

CONCLUSIONS

IC administration of eptifibatide during PPCI in patients with STEMI in comparison with IV administration of eptifibatide is associated with significantly better coronary reperfusion and improved clinical outcomes (IRCT2012090510751N1).

Cost Effectiveness of Antiplatelet and Antithrombotic Therapy in the Setting of Acute Coronary Syndrome: Current Perspective and Literature Review

Acute coronary syndromes (ACS) are associated with high rates of morbidity and mortality. The advances of antiplatelet and anticoagulation therapy over several years time have resulted in improved in cardiac outcomes, but with increased health care costs. Multiple cost-effectiveness studies have been performed to evaluate the use of available antiplatelet agents and anticoagulation in the setting of both ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation acute coronary syndrome (NSTE-ACS). Early on, the use of glycoprotein IIb/IIIa receptor inhibitors (GPIs) proved to be economically attractive in the management of ACS; however, the introduction of P2Y12 receptor antagonists limited their use to a bail out agents in complex interventions. Generic clopidogrel is probably still an economically attractive P2Y12 receptor antagonist choice, especially in low-risk ACS, while both ticagrelor and prasugrel present an economically attractive alternative option, especially in high-risk ACS and patients at risk for stent thrombosis. While enoxaparin presents an economically dominant alternative to heparin in NSTE-ACS, its role in STEMI in the contemporary era is unclear. During percutaneous coronary intervention (PCI), bivalirudin monotherapy was shown to be an economically dominant alternative to the combination of heparin and GPI in ACS. However, new studies may suggest that using heparin monotherapy may offer an attractive alternative. The comparative and cost effectiveness of different combinations of antiplatelet and antithrombotic therapy will be the focus of future expected clinical and economic assessments.

Safety and efficacy of a new prophylactic tirofiban protocol without oral intraoperative antiplatelet therapy for endovascular treatment of ruptured intracranial aneurysms

BACKGROUND

Coil embolization of intracranial aneurysms is being increasingly used; however, thromboembolic events have become a major periprocedural complication.

OBJECTIVE

To determine the safety and efficacy of prophylactic tirofiban in patients with ruptured intracranial aneurysms.

METHODS

Tirofiban was administered as an intravenous bolus (8.0 μg/kg over 3 min) followed by a maintenance infusion (0.10 μg/kg/min) before stent deployment or after completion of single coiling. Dual oral antiplatelet therapy (loading doses) was overlapped with half the tirofiban dose 2 h before cessation of the tirofiban infusion. Cases of intracranial hemorrhage or thromboembolism were recorded.

RESULTS

Tirofiban was prophylactically used in 221 patients, including 175 (79.19%) who underwent stent-assisted coiling and 46 (20.81%) who underwent single coiling, all in the setting of aneurysmal subarachnoid hemorrhage. Six (2.71%) cases of intracranial hemorrhage occurred, including four (1.81%) tirofiban-related cases and two (0.90%) antiplatelet therapy-related cases. There were two (0.90%) cases of fatal hemorrhage, one related to tirofiban and the other related to dual antiplatelet therapy. Thromboembolic events occurred in seven (3.17%) patients (6 stent-assisted embolization, 1 single coiling), of which one (0.45%) event occurred during stenting and six (2.72%) occurred during intravenous tirofiban maintenance. No thromboembolic events related to dual antiplatelet therapy were found.

CONCLUSIONS

Tirofiban bolus over 3 min followed by maintenance infusion appears to be a safe and efficient prophylactic protocol for the endovascular treatment of ruptured intracranial aneurysms and may be an alternative to intraoperative oral antiplatelet therapy, especially in the case of stent-assisted embolization.

Routine early versus deferred provisional tirofiban treatment in patients with acute coronary syndrome undergoing percutaneous coronary intervention

The present study examined the optimal timing of tirofiban administration in moderate- or high-risk non-ST segment elevated acute coronary syndrome (NSTE-ACS) patients undergoing percutaneous coronary intervention (PCI). Eligible patients were randomized into two groups. Tirofiban was administered routinely at ≥ 4 h before angiography (routine early group; n = 141 patients) or provisionally only for bailout after angiography (deferred provisional group; n = 145 patients). The parameters analysed were: creatine kinase MB isoenzyme (CK-MB), thrombolysis in myocardial infarction (TIMI) flow, thrombotic complications during PCI, efficacy end-points (death, myocardial infarction or target vessel revascularization) at 7, 30 and 180 days and safety end-points (bleeding or thrombocytopenia). In the deferred provisional group, 48 patients (33.1%) required bailout tirofiban. Tirofiban was administered 5.8 h earlier in the routine early compared with the deferred provisional group. The routine early group showed a lower percentage increase in CK-MB (in U/L) 12-24 h after PCI compared with the deferred provisional group (0 (-4.0, 3.0) vs 0.4 (-3.0, 5.0), respectively; P = 0.045), as well as higher pre-PCI TIMI 3 (i.e. normal) flow (78.7% vs 64.8%, respectively; P = 0.042) and a lower incidence of thrombotic events (5.0% vs 33.1%, respectively; P < 0.0001). There were no significant differences in efficacy and safety end-points. In patients with moderate- or high-risk NSTE-ACS, early tirofiban combined with dual antiplatelet therapy was associated with better patency before PCI, attenuated minor myocardial damage and a lower prevalence of thrombotic complications during PCI, but had no significant benefit on the post-PCI TIMI 3 flow or short-term prognosis.

The effects of tirofiban infusion on clinical and angiographic outcomes of patients with STEMI undergoing primary PCI

Objective:

The present study was designed to determine the effects of tirofiban (Tiro) infusion on angiographic measures, ST-segment resolution, and clinical outcomes in patients with STEMI undergoing PCI. Glycoprotein (GP) IIb/IIIa inhibitors are beneficial in ST-segment elevation myocardial infarction (STEMI) patients undergoing percutaneous coronary intervention (PCI), while the most effective timing of administration is still under investigation.

Methods:

A total of 1242 patients (83.0% males, mean (standard deviation; SD) age: 54.7 (10.9) years) with STEMI who underwent primary PCI were included in this retrospective non-randomized study in four groups, composed of no tirofiban infusion [Tiro (-); n=248], tirofiban infusion before PCI (pre-Tiro; n=720), tirofiban infusion during PCI (peri-Tiro; n=50), and tirofiban infusion after PCI (post-Tiro; n=224). In all Tiro (+) patients, bolus administration of Tiro (10 pg/kg) was followed by infusion (0.15 pg/kg/min) for a mean (SD) duration of 22.4±6.8 hours.

Results:

The pre-PCI Tiro group was associated with the highest percentage of patients with TIMI 3 flow (99.4%; p<0.001), the lowest corrected TIMI frame count [21(18-23.4); p<0.001], the highest percentage of patients with >75% ST-segment resolution (78.1%; p<0.001), and the lowest rate of in-hospital sudden cardiac death and in-hospital all-cause mortality (3.2%, p<0.05, 3.3%, p=0.01). Major bleeding was reported in 18 (1.8%) patients who received tirofiban.

Conclusion:

Use of standard-dose bolus tirofiban in addition to aspirin, high-dose clopidogrel, and unfractionated heparin prior to primary PCI significantly improves myocardial reperfusion, ST-segment resolution, in-hospital mortality rate, and in-hospital sudden cardiac death in patients with STEMI with no increased risk of major bleeding.

The Safety and Efficacy of 12 Versus 24 Hours of Tirofiban Infusion in Patients Undergoing Primary Percutaneous Coronary Intervention

Aim:

We aimed to investigate the 6-month efficacy and safety of postprocedural 12-hour tirofiban administration versus 24-hour tirofiban administration in patients with ST-segment elevated myocardial infarction (STEMI) who underwent primary percutaneous coronary intervention (PCI).

Methods:

This retrospective study enrolled 349 patients with STEMI who underwent primary PCI. Following the administration of bolus tirofiban after primary PCI, those receiving a 12-hour tirofiban infusion as the maintenance dose were classified as group 1 (n = 123) while those receiving a 24-hour infusion were classified as group 2 (n = 226). In-hospital and 6-month major adverse cardiac events were recorded.

Results:

There were no statistically significant differences between the 2 groups regarding in-hospital efficacy (in-hospital death: 4.4% vs 5.7%, P = .600 and stent thrombosis 1.8% vs 1.6%, P = .921) and in-hospital safety (2.6% vs 1.6% for major bleeding and 5.3% vs 4.1% for minor bleeding, P = .562). During the 6-month follow-up period, the incidence of the recurrent revascularization (16.1% vs 15.5%, odds ratio [OR] = 1.05 [0.47-3.67]), the repeated nonfatal acute coronary syndrome and/or stent thrombosis (27% vs 24.4%, P = .598, OR = 1.02 [0.42-2.48]), and the cardiovascular deaths (6.6% vs 6.5%, P = .943, OR = 1.03 [0.43-2.43]) were comparable between group 1 and group 2.

Conclusion:

Our study revealed that 12-hour tirofiban administration versus 24-hour tirofiban administration in STEMI who underwent primary PCI was similar with respect to in-hospital efficacy and safety and major adverse cardiac events during 6-month follow-up.

Eptifibatide-induced acute profound thrombocytopenia: a case report

BACKGROUND

The interactions among cells or among cells and components of the extracellular matrix, is a crucial pathophysiological process involving some molecules collectively known as adhesion molecules (CAMs). Glycoprotein IIb / IIIa receptors are only restricted to blood platelets and they bind fibrinogen and adhesion proteins such as fibronectin, vitronectin, von Willebrand factor to form cross bridges between adjacent platelets. IIb/IIIa receptor antagonists are an object of intense research activity for target therapy worldwide during the last decades. Three GPIIb/IIIa inhibitors, abciximab, tirofiban, and eptifibatide, have been approved for clinical use. Profound thrombocytopenia is an uncommon but clinically important complication of glycoprotein IIb/IIIa inhibitors.

CASE PRESENTATION

This case report discusses a forty-four-year-old male patient with acute coronary syndrome who underwent percutaneous coronary intervention and developed profound thrombocytopenia within 4 hours of first administration of eptifibatide.

CONCLUSION

This report adds another case of eptifibatide-induced thrombocytopenia to the medical literature and endorses the importance of platelet count monitoring after initiating therapy with this agent.

Platelet activation in myocardial ischemic syndromes

Platelets play a central role in the pathogenesis of atherosclerosis and thrombosis. Platelet adhesion and aggregate formation are critical events that occur in unstable coronary syndromes. Platelet activation precedes the formation of homotypic and heterotypic aggregates. In the last 10 years, researchers have described the presence of activated platelets in the systemic circulation in various cardiovascular disease states, particularly acute coronary syndromes. This review describes the evidence for platelet activation in acute myocardial ischemic syndromes, describes the pathophysiology responsible for its occurrence, and discusses how platelet activation and reactivity may affect the use of concomitant drug therapies and patient prognosis.

Tirofiban in acute coronary syndromes

Acute coronary syndromes represent a major health problem in terms of incidence and mortality. Intracoronary platelet-rich thrombi may develop in response to plaque rupture, and are involved in the pathogenesis of all acute coronary syndromes. The glycoprotein IIb/IIIa receptor, a platelet surface integrin, plays a key role in platelet aggregation once it has been activated by specific ligands. The development of glycoprotein IIb/IIIa inhibitors has revolutionized the management of acute coronary syndromes. Tirofiban is one of three parenteral glycoprotein IIb/IIIa inhibitors in clinical use, and many trials have demonstrated its clinical efficacy and low rate of adverse effects in patients with non-ST-segment elevation acute coronary syndrome. This article reviews the data concerning its use in the clinical settings of acute coronary syndromes and percutaneous coronary angioplasty, and discusses its benefits in different treatment strategies and in association with other drugs. In particular, the role of early, upstream tirofiban coupled with early aggressive revascularization in the management of high-risk non-ST-segment elevation acute coronary syndromes is emphasized.

Development of glycoprotein IIb–IIIa antagonists: translation of pharmacodynamic effects into clinical benefit

This article will review the development of glycoprotein IIb-IIIa antagonists, with particular emphasis on the characteristics and pharmacodynamic studies of each agent that is available for clinical use. Abciximab is a Fab fragment of the 7E3 antibody that has high affinity and a slow rate of dissociation from glycoprotein IIb-IIIa. In contrast, the small molecules eptifibatide and tirofiban, have a much more rapid rate of dissociation, with an off time of 10 to 15 s. Accordingly, the circulating pool of abciximab is predominantly associated with platelets, whereas maintenance of a consistent concentration of tirofiban and eptifibatide in the blood is critical in order to achieve and sustain their inhibitory effects. The affinity of abciximab and tirofiban for glycoprotein IIb-IIIa are substantially greater than that of eptifibatide, necessitating maintenance of greater molar concentrations of eptifibatide in blood in order to achieve effective inhibition of the binding of fibrinogen to the activated conformer of glycoprotein IIb-IIIa.