Abciximab: an updated review of its therapeutic use in patients with ischaemic heart disease undergoing percutaneous coronary revascularisation

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

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

Immunothrombosis and the Role of Platelets in Venous Thromboembolic Diseases

Venous thromboembolism (VTE) is the third leading cardiovascular cause of death and is conventionally treated with anticoagulants that directly antagonize coagulation. However, recent data have demonstrated that also platelets play a crucial role in VTE pathophysiology. In the current review, we outline how platelets are involved during all stages of experimental venous thrombosis. Platelets mediate initiation of the disease by attaching to the vessel wall upon which they mediate leukocyte recruitment. This process is referred to as immunothrombosis, and within this novel concept inflammatory cells such as leukocytes and platelets directly drive the progression of VTE. In addition to their involvement in immunothrombosis, activated platelets can directly drive venous thrombosis by supporting coagulation and secreting procoagulant factors. Furthermore, fibrinolysis and vessel resolution are (partly) mediated by platelets. Finally, we summarize how conventional antiplatelet therapy can prevent experimental venous thrombosis and impacts (recurrent) VTE in humans.

Clinical pharmacology of antiplatelet drugs

INTRODUCTION

Platelets play a key role in arterial thrombosis and antiplatelet therapy is pivotal in the treatment of cardiovascular disease. Current antiplatelet drugs target different pathways of platelet activation and show specific pharmacodynamic and pharmacokinetic characteristics, implicating clinically relevant drug-drug interactions.

AREAS COVERED

This article reviews the role of platelets in hemostasis and cardiovascular thrombosis, and discusses the key pharmacodynamics, drug-drug interactions and reversal strategies of clinically used antiplatelet drugs.

EXPERT OPINION

Antiplatelet therapies target distinct pathways of platelet activation: thromboxane A₂ synthesis, adenosine diphosphate-mediated signaling, integrin α_IIbβ₃ (GPIIb/IIIa), thrombin-mediated platelet activation via the PAR1 receptor and phosphodiesterases. Key clinical drug-drug interactions of antiplatelet agents involve acetylsalicylic acid - ibuprofen, clopidogrel - omeprazole, and morphine - oral P2Y₁₂ inhibitors, all of which lead to an attenuated antiplatelet effect. Platelet function and genetic testing and the use of scores (ARC-HBR, PRECISE-DAPT, ESC ischemic risk definition) may contribute to a more tailored antiplatelet therapy. High on-treatment platelet reactivity presents a key problem in the acute management of ST-elevation myocardial infarction (STEMI). A treatment strategy involving early initiation of an intravenous antiplatelet agent may be able to bridge the gap of insufficient platelet inhibition in high ischemic risk patients with STEMI.

Evaluate Short-Term Outcomes of abciximab in ST-Segment Elevation Myocardial Infarction Patients Undergoing Percutaneous Coronary Intervention: A Meta-Analysis of Randomized Clinical Trials

Objectives

This meta-analysis was to verify the short-time efficacy and safety of abciximab in patients with ST-segment elevation myocardial infarction (STEMI) undergoing percutaneous coronary intervention (PCI).

Background

Abciximab has long-term efficacy in patients with STEMI undergoing PCI, but the short-term efficacy is still controversial.

Methods

We conducted a systematic review and meta-analysis compared with or without abciximab in patients with STEMI undergoing PCI. The relevant randomized controlled trials were included by searching PubMed, EMBASE, Cochrane Library, and Web of Science databases and other sources. The relative risk (RR) and 95% confidence intervals (CI) of outcomes were calculated by the fixed-effects model.

Results

Ten randomized controlled trials with 5008 patients met inclusion criteria. There were no significant differences in risk of all-cause death at 30-day (RR 0.79, CI 0.55–1.12, P=0.18), major bleeding (1.37, 0.93–2.03, P=0.11), and transfusion (1.23, 0.94–1.61, P=0.13) between the two groups. However, there were significant differences in risk of all-cause death at 6 months (0.57, 0.36–0.90, P=0.02), recurrent myocardial infarction (0.55, 0.33–0.92, P=0.02), repeat revascularization (0.58, 0.43–0.78, P=0.0004), final TIMI flow <3 (0.77, 0.62–0.96, P=0.02), minor bleeding (1.29, 1.02–1.63, P=0.04), and thrombocytopenia (2.04, 1.40–2.97, P=0.0002).

Conclusions

The application of abciximab can lead to a lower risk of reinfarction, revascularization, and all-cause death at 6 months, but a higher risk of minor bleeding, and thrombocytopenia.

Glycoprotein IIb/IIIa inhibitors for the neurointerventionalist

Antiplatelet therapies are commonly used in neurointerventional procedures. However, specific guidelines for their use in these settings is lacking and it can often be difficult to balance the potential risks and benefits of these medications. Considering the continued growth and adoption of neurointerventional procedures, it is crucial to understand the properties of these agents in order to use them safely. Large-scale clinical trials are still needed to clarify many of these aspects for this emerging field. However, the existing literature already provides insight into which antiplatelet drugs are of benefit to the neurointerventionalist as well as their associated risks of ischemic and hemorrhagic complications. Hence, this review focuses on the applications of GPIIb/IIIA inhibitors to neurointerventional procedures.

Bilateral subconjunctival hemorrhage secondary to abciximab use: case report

CONTEXT

There are no reports on cases of subconjunctival hemorrhage due to use of glycoprotein IIb/IIIa inhibitors. In this report, we present the case of a patient with bilateral subconjunctival hemorrhage after receiving abciximab.

CASE REPORT

A 40-year-old male patient underwent coronary angiography after acute anterior myocardial infarction and a coronary stent was placed. Abciximab was added to the therapy because of stent thrombosis. Bilateral subconjunctival hemorrhage was observed after the administration of the abciximab treatment. We treated our patient by stopping abciximab and administering artificial tears.

CONCLUSİON

For the first time in the literature, we presented the case of a patient with bilateral subconjunctival hemorrhage after receiving abciximab, which was managed conservatively.

A regulatory role for the co-chaperone FKBP51s in PD-L1 expression in glioma

Background

FKBP51 is a co-chaperone with isomerase activity, abundantly expressed in glioma. We previously identified a spliced isoform (FKBP51s) and highlighted a role for this protein in the upregulation of Programmed Death Ligand 1 (PD-L1) expression in melanoma. Because gliomas can express PD-L1 causing a defective host anti-tumoral immunity, we investigated whether FKBP51s was expressed in glioma and played a role in PD-L1 regulation in this tumour.

Methods

We used D54 and U251 glioblastoma cell lines that constitutively expressed PD-L1. FKBP51s was measured by immunoblot, flow cytometry and microscopy. In patient tumours, IHC and qPCR were used to measure protein and mRNA levels respectively. FKBP51s depletion was achieved by siRNAs, and its enzymatic function was inhibited using selective inhibitors (SAFit). We investigated protein maturation using N-glycosidase and cell fractionation approaches.

Results

FKBP51s was expressed at high levels in glioma cells. Glycosylated-PD-L1 was increased and reduced by FKBP51s overexpression or silencing, respectively. Naïve PD-L1 was found in the endoplasmic reticulum (ER) of glioma cells complexed with FKBP51s, whereas the glycosylated form was measured in the Golgi apparatus. SAFit reduced PD-L1 levels (constitutively expressed and ionizing radiation-induced). SAFit reduced cell death of PBMC co-cultured with glioma.

Conclusions

Here we addressed the mechanism of post-translational regulation of PD-L1 protein in glioma. FKBP51s upregulated PD-L1 expression on the plasma membrane by catalysing the protein folding required for subsequent glycosylation. Inhibition of FKBP51s isomerase activity by SAFit decreased PD-L1 levels. These findings suggest that FKBP51s is a potential target of immunomodulatory strategies for glioblastoma treatment.

Antiplatelet and anti-proliferative action of disintegrin from Echis multisquamatis snake venom

Aim

To purify the platelet aggregation inhibitor from Echis multisquamatis snake venom (PAIEM) and characterize its effect on platelet aggregation and HeLa cell proliferation.

Methods

Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) were used for PAIEM identification. Platelet aggregation in the presence of PAIEM was studied on aggregometer Solar-AP2110. The changes of shape and granularity of platelets in the presence of PAIEM were studied on flow cytometer COULTER EPICS XL, and degranulation of platelets was estimated using spectrofluorimetry. Indirect enzyme-linked immunosorbent assay was used for the determination of target of PAIEM on platelet surface. An assay based on 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide was used to evaluate the effect of PAIEM on the proliferation of HeLa cells in cell culture.

Results

The molecular weight of the protein purified from Echis multisquamatis venom was 14.9 kDa. Half-maximal inhibitory concentration (IC₅₀) of PAIEM needed to inhibit adenosine diphosphate (ADP)-induced platelet aggregation was 7 μM. PAIEM did not affect thrombin- or ADP-induced platelet activation, but it did prevent binding of the anti-IIb antibody to glycoprotein IIb/IIIa (GPIIbIIIa)-receptor of adhered platelets and inhibited the viability of HeLa cells by 54%.

Conclusion

As a member of the disintegrin family, PAIEM inhibited platelet aggregation and cell proliferation possibly by blocking integrin-mediated interactions. However, it did not impair cellular signaling causing any changes in platelet shape and granularity and did not affect ADP-induced platelet degranulation. This disintegrin was shown to be a potent inhibitor of integrin-mediated cellular interactions including platelet aggregation or cancer cell proliferation.

Diagnosis, Treatment, and Long-Term Management of Kawasaki Disease: A Scientific Statement for Health Professionals From the American Heart Association

BACKGROUND

Kawasaki disease is an acute vasculitis of childhood that leads to coronary artery aneurysms in ≈25% of untreated cases. It has been reported worldwide and is the leading cause of acquired heart disease in children in developed countries.

METHODS AND RESULTS

To revise the previous American Heart Association guidelines, a multidisciplinary writing group of experts was convened to review and appraise available evidence and practice-based opinion, as well as to provide updated recommendations for diagnosis, treatment of the acute illness, and long-term management. Although the cause remains unknown, discussion sections highlight new insights into the epidemiology, genetics, pathogenesis, pathology, natural history, and long-term outcomes. Prompt diagnosis is essential, and an updated algorithm defines supplemental information to be used to assist the diagnosis when classic clinical criteria are incomplete. Although intravenous immune globulin is the mainstay of initial treatment, the role for additional primary therapy in selected patients is discussed. Approximately 10% to 20% of patients do not respond to initial intravenous immune globulin, and recommendations for additional therapies are provided. Careful initial management of evolving coronary artery abnormalities is essential, necessitating an increased frequency of assessments and escalation of thromboprophylaxis. Risk stratification for long-term management is based primarily on maximal coronary artery luminal dimensions, normalized as Z scores, and is calibrated to both past and current involvement. Patients with aneurysms require life-long and uninterrupted cardiology follow-up.

CONCLUSIONS

These recommendations provide updated and best evidence-based guidance to healthcare providers who diagnose and manage Kawasaki disease, but clinical decision making should be individualized to specific patient circumstances.

The P2Y1 receptor antagonist MRS2500 prevents carotid artery thrombosis in cynomolgus monkeys

Adenosine diphosphate directly induces platelet aggregation via the G-protein coupled P2Y1 and P2Y12 receptors. P2Y12, but not P2Y1, receptor antagonists are available in the clinic. The relevance of the P2Y1 receptor as an antiplatelet target has been studied in rodents, but not in higher species. We therefore examined effects of the pharmacological blockade of the P2Y1 receptor with its selective antagonist MRS2500 in monkey models of electrolytic-mediated arterial thrombosis (ECAT) and kidney bleeding time (KBT). Abciximab, a GPIIb-IIIa antagonist, and cangrelor, a P2Y12 antagonist, were utilized to validate these monkey models. Compounds were given IV at 15-60 min before thrombosis initiation in anesthetized monkeys. Scanning electron microscopy showed the luminal surface of thrombotic artery covered with platelet aggregates and fibrin network. Administration of abciximab at 0.25 and 0.7 mg/kg IV significantly reduced thrombus weight by 71 ± 1 and 100 ± 0 %, and increased KBT by 10.0 ± 0.1- and 10.1 ± 0-fold, respectively (n = 3/dose). Likewise, cangrelor at 0.6 and 2 mg/kg/h IV significantly reduced thrombus weight significantly by 72 ± 9 % and 100 ± 0 % and increased KBT by 2.1 ± 0.1- and 9.8 ± 0.2-fold, respectively (n = 3/dose). MRS2500 [mg/kg + mg/kg/h IV] at 0.09 + 0.14 and 0.45 + 0.68 significantly reduced thrombus weight by 57 ± 1 % and 88 ± 1 % and increased KBT by 2.1 ± 0.3- and 4.9 ± 0.6-fold, respectively (n = 4/dose). In summary, MRS2500 prevented occlusive arterial thrombosis at a dose that moderately prolonged KBT, indicating a role of P2Y1 receptors in arterial thrombosis and hemostasis in monkeys. Thus P2Y1 receptor antagonism provides a suitable target for drug discovery.

Immunomodulatory pathways regulate expression of a spliced FKBP51 isoform in lymphocytes of melanoma patients

FKBP51 (gene FKBP5) is an immunophilin capable of immunosuppression expressed in melanoma and lymphocytes. We found increased levels of a spliced FKBP5 variant in the PBMCs of 124 patients with melanoma. This variant encodes for an unknown isoform (FKBP51s). We hypothesized that FKBP51s resulted from tumour interaction with immune cells, through PDL-1/PD-1. To address this issue, we performed melanoma/PBMC cocultures. Furthermore, the immunohistochemistry of 76 melanoma specimens served to investigate whether FKBP51s stained tumour infiltrating lymphocytes. Our results showed that PBMCs expressed FKBP51s when cocultured with melanoma. Tumour PDL-1 knockdown or anti-PD-1 reduced FKBP51s expression in cocultured PBMCs. IHC showed a strong FKBP51s signal in tumour infiltrating lymphocytes, and lymphocytes of the invasion front of the tumour, along with melanoma PDL-1 expression. When overexpressed in melanoma, FKBP51s facilitated PDL-1 expression on the cell surface. In conclusion, our study shows that FKBP51s marks the PBMCs of patients with melanoma and is exploited by the tumour to immunomodulate through PDL-1.

Successful Treatment of Myocardial Infarction in an Infant With Kawasaki Disease

Although early treatment with intravenous immunoglobulin reduces the risk of coronary artery aneurysms, in refractory cases of Kawasaki disease, myocardial infarction can result from thrombosis of coronary artery aneurysms. Early recognition of myocardial infarction from Kawasaki disease myocarditis can reduce morbidity and mortality. This report describes successful treatment of myocardial infarction from coronary thrombosis in an infant with Kawasaki disease using intravenous tissue plasminogen activator and abciximab.

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.

PAR-1 antagonists: current state of evidence

Vorapaxar (SCH 530348) and atopaxar (E5555) are oral protease-activated receptor-1 (PAR-1) antagonists with high bioavailability. They inhibits thrombin induced platelet aggregation by competitively inhibiting PAR-1. We systematically evaluated the evidence for the efficacy and safety of all PAR-1 antagonists as well as for the individual drugs vorapaxar and atopaxar in different databases-PubMed, EMBASE, Scopus, and Cochrane register of Controlled Clinical Trials (CENTRAL).We selected randomized controlled trials of PAR-1 antagonists that reported on cardiovascular mortality as a clinical outcome. The random-effects Mantel-Haenszel model was used to evaluate the effect of PAR-1 antagonists on cardiovascular mortality. Seven trials were selected (N = 42,355) for analysis. PAR-1 antagonists as a class, as well as individually, were associated with a non-significant numerically lower risk of cardiovascular mortality than that seen with agents used in the control group; RR, 0.93; 95% CI, 0.83-1.04; P = 0.20). No heterogeneity was noted. However, PAR-1 antagonists also appeared to increase the risk of bleeding significantly. PAR-1 antagonists appear to be associated with some reduction in the risk of cardiovascular mortality; however the significantly higher bleeding risk noted with PAR-1 antagonists appear to mandate a very careful selection of patients that may benefit without a substantially increased risk of bleeds.

Comparison of abciximab versus eptifibatide during percutaneous coronary intervention in ST-segment elevation myocardial infarction (from the HORIZONS-AMI trial)

There are limited safety and effectiveness data comparing glycoprotein IIb/IIIa inhibitors in the setting of primary percutaneous coronary intervention. In this substudy of the Harmonizing Outcomes With Revascularization and Stents in Acute Myocardial Infarction (HORIZONS-AMI) trial, the clinical and bleeding outcomes of eptifibatide versus abciximab were evaluated in patients with ST-segment elevation myocardial infarction who underwent percutaneous coronary intervention. Three-year clinical outcomes of patients in the heparin plus glycoprotein IIb/IIIa inhibitor arm were compared according to treatment with abciximab (n = 907) versus eptifibatide (n = 803). Adjudicated end points included major adverse cardiovascular events (MACEs; mortality, reinfarction, ischemia-driven target vessel revascularization, or stroke), major bleeding, and net adverse clinical events (MACEs or major bleeding). Propensity score matching was used to identify 1,342 matched cases (671 each in the abciximab and eptifibatide groups). Multivariate analysis was performed in the entire cohort and the propensity-matched groups. At 3-year follow-up, eptifibatide and abciximab resulted in nonsignificantly different rates of MACEs (18.3% vs 19.6%, hazard ratio [HR] 0.93, 95% confidence interval [CI] 0.74 to 1.16, p = 0.51), major bleeding (10.7% vs 11.9%, HR 0.90, 95% CI 0.67 to 1.19, p = 0.44), and net adverse clinical events (24.5% vs 25.5%, HR 0.96, 95% CI 0.79 to 1.17, p = 0.69). Similarly, at 3 years by multivariate analysis, there was no statistically significant difference between abciximab and eptifibatide for net adverse clinical events (HR 0.89, 95% CI 0.73 to 1.09, p = 0.27), MACEs (HR 0.96, 95% CI 0.77 to 1.20, p = 0.73), and major bleeding (HR 1.05, 95% CI 0.78 to 1.41, p = 0.75). The propensity-matched groups also had similar outcomes. In conclusion, abciximab and eptifibatide have comparable bleeding risks and clinical efficacy in primary percutaneous coronary intervention.

Management of acquired bleeding problems in cancer patients

Cancer patients can have acquired bleeding problems for many reasons. In this review, an approach to the evaluation and management of the bleeding patient is discussed. Specific issues including coagulation defects, thrombocytopenia, platelet dysfunction, and bleeding complications of specific hematological malignancies due to anticoagulation, are discussed.

Clinical pharmacology of antithrombotic drugs in coronary artery disease

Coronary heart disease is the leading cause of death in the Western world. Antithrombotic therapy is the cornerstone of its successful treatment. Clinical trials have demonstrated that antithrombotic therapy reduces the risk for recurrent myocardial infarction and cardiovascular death. Antiplatelet drugs and anticoagulants interfere with haemostasis and thus bleeding is a major risk factor of these drugs. The benefit of antithrombotic therapy must therefore be carefully balanced with the risk of bleeding and other potential adverse reactions of these drugs. However, to date there is no firm evidence that dosage adaptation of aspirin or clopidogrel according to platelet aggregation testing translates directly into any clinical benefit. Resistance to antithrombotic drugs is a serious problem because these patients are at a higher risk of myocardial infarction, stroke and cardiovascular death. It has most recently been demonstrated that resistance to clopidogrel is at least in part caused by polymorphism of CYP2C19. Clinical trials have also demonstrated that optimal benefit in different settings depends unequivocally on the meticulous choice of the various drugs. Thus, profound knowledge of the clinical pharmacological profiles of the different antithrombotic drugs is indispensable for successful treatment.

Management of acquired bleeding problems in cancer patients

Cancer patients can have acquired bleeding problems for many reasons. In this review, an approach to the bleeding patient in the Emergency Department is discussed. Specific issue including coagulation defects, thrombocytopenia, platelet dysfunction, bleeding complications of specific hematological malignancies and due to anticoagulation, are discussed.

Protein therapeutics: a summary and pharmacological classification

Once a rarely used subset of medical treatments, protein therapeutics have increased dramatically in number and frequency of use since the introduction of the first recombinant protein therapeutic--human insulin--25 years ago. Protein therapeutics already have a significant role in almost every field of medicine, but this role is still only in its infancy. This article overviews some of the key characteristics of protein therapeutics, summarizes the more than 130 protein therapeutics used currently and suggests a new classification of these proteins according to their pharmacological action.

Clinical Outcomes Comparing Eptifibatide and Abciximab in ST Elevation Acute Myocardial Infarction Patients Undergoing Percutaneous Coronary Interventions

BACKGROUND

Randomized clinical trials comparing glycoprotein IIb-IIIa inhibitors have largely excluded patients with ST segment elevation myocardial infarction (STEMI).

METHODS

We conducted an open-label, sequential comparison of in-hospital and 6-month clinical outcomes in STEMI patients receiving eptifibatide or abciximab as adjunctive therapy during percutaneous coronary intervention (PCI). Registry data were collected and compared for STEMI patients undergoing PCI and receiving eptifibatide or abciximab over a 3.5-year period. Six-month follow-up, using telephone interviews, included major adverse cardiac events and functional status.

RESULTS

Baseline characteristics were similar for patients receiving eptifibatide (n = 294) or abciximab (n = 158). No significant differences in hospital clinical outcomes were observed for reinfarction (2 vs. 3% for eptifibatide and abciximab, respectively), repeat revascularization (3 vs. 4%), bleeding complications (8 vs. 12%), congestive heart failure (5 vs. 3%), cerebrovascular accidents (0 vs. 2%), renal failure (2 vs. 3%), and all-cause mortality at discharge (5 vs. 4%). No significant difference was seen between groups in all-cause mortality at 6 months (6.5 vs. 6.4%; hazard ratio 0.976; 95% confidence interval 0.43-2.23; log-rank, p = 0.95).

CONCLUSIONS

No significant differences were observed in clinical outcomes between STEMI patients receiving eptifibatide or abciximab in the setting of PCI. Considering the substantially lower cost of eptifibatide, these data suggest that eptifibatide can be substituted for abciximab to lower overall medication costs while maintaining beneficial safety and efficacy effects.

Anesthesia for Endovascular Neurosurgery

Endovascular neurosurgical procedures are complex, requiring significant planning, foresight, and coordination. The neuroanesthetist is an integral part of these procedures, organizing efforts of the technicians and nurses and responding to the needs of the neurointerventionalist. The purpose of this article is to review, in detail, the role of the neuroanesthetist in the endovascular operating room. An overview of all areas either partially or completely managed by the anesthetist is provided.

Current strategies with eptifibatide and other antiplatelet agents in percutaneous coronary intervention and acute coronary syndromes

Antiplatelet and anticoagulation therapies are essential for the prevention of thromboembolic-induced myocardial ischaemia in non-ST-elevation acute coronary syndromes and the ischaemic complications of percutaneous coronary intervention. Although heparin, direct thrombin inhibitors and oral platelet activation inhibitors provide substantial benefit, only glycoprotein (GP) IIb/IIIa inhibitors block the final common pathway leading to platelet aggregation, and the American College of Cardiology/American Heart Association guidelines recommend GP IIb/IIIa inhibitors as an integral component of care in these patients. Abciximab, eptifibatide and tirofiban all act through the GP IIb/IIIa receptor; however, variations in clinical outcomes among patients receiving these agents may be related to their structural and pharmacological differences, as well as to patient demographics. Data indicate that eptifibatide, at the current recommended dosing schedule, achieves the highest level of consistent platelet inhibition compared with current doses of abciximab and tirofiban.

Percutaneous coronary intervention for revascularization of the diabetic patient

The field of interventional cardiology has progressed rapidly in recent years with the advent of new technology and expanding role of adjunctive pharmacology. This article provides an overview of both current and historical approaches to treating coronary artery disease in the diabetic patient.

Antiplatelet therapy: current strategies and future trends

Pharmacological management of thrombotic complications is strongly influenced by antiplatelet treatment strategies. Recent clinical trials have clearly indicated that current antiplatelet strategies may not inhibit recurrent thrombotic events in selected patients and improvement is necessary. Recently, there has been a gradual modification in the guidelines for clopidogrel dosing. In addition, newly developed P2Y12 receptor inhibitors and thrombin inhibitors are undergoing Phase II and III clinical trials. Moreover, research related to novel agents that interfere with other steps in coagulation and platelet adhesion, and platelet thromboxane and thrombin receptor blockers, show promise. An important future step will probably be the development of personalized therapy based on defining the individual patient’s propensity for thrombosis through investigation of platelet–thrombin–fibrin interactions. Such an approach will enhance the targeting of specific therapy based on the pathophysiology of the individual patient.

Early elevation of interleukin-1beta and interleukin-6 levels after bare or drug-eluting stent implantation in patients with stable angina

INTRODUCTION

Drug-eluting stent (DES) implantation represents an important innovation in the treatment of coronary artery disease. However, inflammatory-related complications, including subacute thrombosis and in-stent restenosis, are still important limitations to percutaneous coronary intervention (PCI). The aim of this study was to compare early local release of interleukin 1beta (IL-1beta) and IL-6 proinflammatory cytokines after elective placement of either bare metal stents or DES.

MATERIALS AND METHODS

IL-1beta and IL-6 levels were assayed in plasma obtained from the coronary sinus both before and 20 min after stent implantation in 59 patients with stable angina, who were randomly assigned to receive bare, paclitaxel-, or sirolimus-eluting stents during elective PCI.

RESULTS

We found that IL-1beta and IL-6 levels were significantly increased in the coronary sinus of patients receiving either bare, paclitaxel- or sirolimus-eluting stents 20 min after stent implantation as compared with basal concentrations. The variation in the level of both cytokines was comparable among the three study groups.

CONCLUSIONS

A local release of proinflammatory cytokines occurs shortly after coronary stent placement, including DES, which is possibly related to plaque rupture and/or endothelium traumatism following the stenting procedure. This suggests that precocious anti-inflammatory treatment could be of benefit to further improve the PCI clinical outcome.

Venous Thromboembolism in the ICU and Reversal of Bleeding on Anticoagulants

Venous thromboembolic disease is a very common complication in the ICU. This article reviews incidence, prevention, and therapy related to venous thromboembolism, including both deep venous thrombosis and pulmonary embolism. Special diagnostic and treatment considerations in the ICU setting are highlighted. The increased use of antithrombotic agents has led to an increased number of patients who experience bleeding complications on anticoagulant therapy. This review also addresses the methods of reversing various anticoagulants.

Diagnosis, treatment, and long-term management of Kawasaki disease: a statement for health professionals from the Committee on Rheumatic Fever, Endocarditis and Kawasaki Disease, Council on Cardiovascular Disease in the Young, American Heart Association

BACKGROUND

Kawasaki disease is an acute self-limited vasculitis of childhood that is characterized by fever, bilateral nonexudative conjunctivitis, erythema of the lips and oral mucosa, changes in the extremities, rash, and cervical lymphadenopathy. Coronary artery aneurysms or ectasia develop in approximately 15% to 25% of untreated children and may lead to ischemic heart disease or sudden death.

METHODS AND RESULTS

A multidisciplinary committee of experts was convened to revise the American Heart Association recommendations for diagnosis, treatment, and long-term management of Kawasaki disease. The writing group proposes a new algorithm to aid clinicians in deciding which children with fever for > or =5 days and < or =4 classic criteria should undergo echocardiography, receive intravenous gamma globulin (IVIG) treatment, or both for Kawasaki disease. The writing group reviews the available data regarding the initial treatment for children with acute Kawasaki disease, as well for those who have persistent or recrudescent fever despite initial therapy with IVIG, including IVIG retreatment and treatment with corticosteroids, tumor necrosis factor-alpha antagonists, and abciximab. Long-term management of patients with Kawasaki disease is tailored to the degree of coronary involvement; recommendations regarding antiplatelet and anticoagulant therapy, physical activity, follow-up assessment, and the appropriate diagnostic procedures to evaluate cardiac disease are classified according to risk strata.

CONCLUSIONS

Recommendations for the initial evaluation, treatment in the acute phase, and long-term management of patients with Kawasaki disease are intended to assist physicians in understanding the range of acceptable approaches for caring for patients with Kawasaki disease. The ultimate decisions for case management must be made by physicians in light of the particular conditions presented by individual patients.

Is primary angioplasty more effective than prehospital fibrinolysis in diabetics with acute myocardial infarction? Data from the CAPTIM randomized clinical trial

AIMS

The CAPTIM study randomized patients managed within 6 h of acute ST-segment elevation myocardial infarction to primary angioplasty or prehospital fibrinolysis (rt-PA), with immediate transfer to a centre with interventional facilities. It found a similar incidence of the primary endpoint of death, recurrent MI, or stroke at 30 days with both strategies. We report here the outcome in the diabetic subgroup.

METHODS AND RESULTS

The relationship of diabetic status (diabetics, n=103, non-diabetics, n=731) and treatment strategy with the occurrence of the primary endpoint and of death was analysed. Compared with non-diabetics, diabetics had a higher baseline risk profile, a higher rate of the primary endpoint (14.6 vs. 5.6%; P=0.002), and a high rate of mortality (8.7 vs. 3.1%; P=0.01) at 30 days. The incidence of the primary endpoint tended to be higher in diabetics randomized to prehospital fibrinolysis compared with those randomized to primary angioplasty [21.7 vs. 8.8% (10/46 vs. 5/57); RR: 2.47 (0.91-6.74); P=0.09]. This difference was driven by the higher mortality in the fibrinolysis group [13.0 vs. 5.3% (6/46 vs. 3/57); RR: 2.47 (0.7-9.4); P=0.29]. For non-diabetics, no such trend was observed. Compared with non-diabetics, diabetics had a much higher rate of rescue angioplasty (41.4 vs. 23.5%; P=0.01) and a higher mortality after rescue angioplasty [17.4 vs. 0% (4/23 vs. 0/90); P=0.001].

CONCLUSION

These results suggest that diabetic patients presenting within 6 h of an acute myocardial infarction may derive particular benefit from a strategy of primary angioplasty. However, the small number of diabetic patients in this subgroup analysis does not allow a final conclusion and a specifically designed study is warranted.

Glycoprotein IIb/IIIa Inhibitors in Patients with End-Stage Renal Disease

OBJECTIVE:

To determine whether glycoprotein IIb/IIIa inhibitors (GPIs) are effective and safe as adjunctive therapy for percutaneous coronary intervention (PCI) in patients with end-stage renal disease (ESRD).

DATA SOURCES:

MEDLINE (1966–June 2004), EMBASE (1980–June 2004), and International Pharmaceutical Abstracts (1970–June 2004) were searched, in addition to a manual bibliographic search.

DATA SYNTHESIS:

Even though GPIs have an established role as adjunctive therapy in PCI, little is known about their use in patients with ESRD. We found 3 reports describing experience with abciximab in this population. Based on the limited information from registries and a retrospective chart review, it is difficult to draw definitive conclusions about the utility of GPIs in ESRD. The decision to use abciximab in this population must be made on an individual case basis.

CONCLUSIONS:

Studies are needed to evaluate the benefit versus risk of GPI therapy in ESRD.

Antibodies as therapeutic agents: vive la renaissance!

Until recently, the concept of antibodies as in vivo therapeutics was still considered to be an exceedingly ambitious goal. However, in 2003, the situation has been completely transformed, with 14 FDA-approved monclonal antibodies (mAbs), 70 in late stage clinical (Phase II+) trials and > 1000 in preclinical development. The driving force behind this reversal in fortune has been advances in antibody engineering and the emergence of novel discovery techniques which overcame stability and immunogenicity issues that had blighted previous clinical trials of murine antibodies. For indications as diverse as inflammation, cancer and infectious disease, it is clear that unique properties of antibodies make them safe, effective and versatile therapeutics. These drugs can be used to neutralise pathogens, toxins and endogenous mediators of pathology. As cell targeting reagents, antibodies can be used to modulate cytoplasmic cascades or to 'tag' specific cells for complement- or effector-mediated lysis. Antibodies can also be modified to deliver toxic or modulatory payloads (small molecules, radionuclides and enzymes) and engineered to bind multiple epitopes (bispecifics) or even to have novel catalytic activity (abzymes). The modular structure of immunoglobulins and the availability of antibody fragment libraries also make it possible to produce variable-domain therapeutics (Fab, single-chain and domain antibodies). Although exhibiting less favourable kinetics in vivo, these fragments are simple to express and have an increased tissue penetration, making them especially useful as neutralising agents or in the delivery of payload. The number of approved antibodies is expected to increase arithmetically in the near term, as the platform is adopted as a valid alternative to small molecule discovery. This review provides an introduction to the antibody discovery process and discusses the past, present and future applications of therapeutic antibodies, with reference to several FDA-approved precedents.

The Effect of Tirofiban and Clopidogrel Pretreatment on Outcome of Old Saphenous Vein Graft Stenting in Patients with Acute Coronary Syndromes

In spite of developments in interventional cardiology, the success rate of saphenous vein graft stenting is still low in patients with acute coronary syndromes. In this study, we aimed at finding out the effect of pretreatment with Tirofiban, a glycoprotein IIb/IIIa inhibitor, and clopidogrel, an adenosine diphosphate antagonist, on the outcome of saphenous vein graft stenting in patients with acute coronary syndrome. A total of 47 patients, who had lesions in saphenous vein grafts and acute coronary syndrome, could be randomized to treated group (n = 24), who received Tirofiban and clopidogrel for 48 hours before the intervention, and untreated group (n = 23), who did not receive Tirofiban and clopidogrel. In the untreated group, the intervention was performed just after the coronary angiography. All patients underwent stenting as the standard intervention. The groups were compared by Mann-Whitney's U-test or Chi-Square test. The level of statistical significance was set at 0.05. There were no significant differences regarding age, gender, and atherosclerotic risk factors between the two groups. In treated group, precutaneous coronary intervention was successful in all patients and no-reflow phenomenon occurred in only one patient. The rate of no-reflow or slow-flow phenomenon was significantly lower in treated group (one patient vs 9 patients, p = 0.004). One patient in untreated group experienced ventricular fibrillation, which was converted to sinus rhythm after defibrillation. During short-term follow-up, there were no acute myocardial infarction, coronary bypass surgery or death in both groups. There was no major bleeding. Minor bleeding was more frequent in treated group, but it did not achieve statistical significance (3 vs 1; p = 0.322). In conclusion, pretreatment with tirofiban and clopidogrel before percutaneous coronary intervention might result in better immediate outcomes in old saphenous vein grafts without any significant increase in bleeding complications.

Diagnosis, treatment, and long-term management of Kawasaki disease: a statement for health professionals from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, American Heart Association

BACKGROUND

Kawasaki disease is an acute self-limited vasculitis of childhood that is characterized by fever, bilateral nonexudative conjunctivitis, erythema of the lips and oral mucosa, changes in the extremities, rash, and cervical lymphadenopathy. Coronary artery aneurysms or ectasia develop in approximately 15% to 25% of untreated children and may lead to ischemic heart disease or sudden death.

METHODS AND RESULTS

A multidisciplinary committee of experts was convened to revise the American Heart Association recommendations for diagnosis, treatment, and long-term management of Kawasaki disease. The writing group proposes a new algorithm to aid clinicians in deciding which children with fever for > or =5 days and < or =4 classic criteria should undergo echocardiography [correction], receive intravenous gamma globulin (IVIG) treatment, or both for Kawasaki disease. The writing group reviews the available data regarding the initial treatment for children with acute Kawasaki disease, as well for those who have persistent or recrudescent fever despite initial therapy with IVIG, including IVIG retreatment and treatment with corticosteroids, tumor necrosis factor-alpha antagonists, and abciximab. Long-term management of patients with Kawasaki disease is tailored to the degree of coronary involvement; recommendations regarding antiplatelet and anticoagulant therapy, physical activity, follow-up assessment, and the appropriate diagnostic procedures to evaluate cardiac disease are classified according to risk strata.

CONCLUSIONS

Recommendations for the initial evaluation, treatment in the acute phase, and long-term management of patients with Kawasaki disease are intended to assist physicians in understanding the range of acceptable approaches for caring for patients with Kawasaki disease. The ultimate decisions for case management must be made by physicians in light of the particular conditions presented by individual patients.