Randomised trial of coronary intervention with antibody against platelet IIb/IIIa integrin for reduction of clinical restenosis: results at six months. The EPIC Investigators

The role of platelet glycoprotein IIb / IIIa inhibitors in current treatment of acute coronary syndrome

Current management of patients with acute coronary syndrome (ACS) includes a dual antiplatelet therapy with acetylsalicylic acid and a platelet P2Y12 receptor inhibitor. For patients without a high risk of bleeding, prasugrel and ticagrelor are preferred, since their effect is more pronounced, less dependent on metabolism of a specific patient, and occurs faster that the effect of clopidogrel. The prescription rate of platelet glycoprotein IIb/IIIa (GP IIb / IIIa) receptor inhibitors has considerably decreased. However, these drugs remain relevant in percutaneous coronary interventions in patients with a high risk of coronary thrombosis or a massive coronary thrombus, in thrombotic complications of the procedure, and in the "no-reflow" phenomenon. The intravenous route of GP IIb / IIIa inhibitor administration provides their effectiveness in patients with difficulties of drug intake or with impaired absorption of oral medications. This review presents clinical and pharmacological characteristics of various GP IIb / IIIa inhibitors and data of randomized clinical studies and registries of recent years that evaluated results of their use in patients with ACS.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet agents may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased. This is an update of a review first published in 2013.

OBJECTIVES

To evaluate the benefits and harms of antiplatelet agents in people with any form of CKD, including those with CKD not receiving renal replacement therapy, patients receiving any form of dialysis, and kidney transplant recipients.

SEARCH METHODS

We searched the Cochrane Kidney and Transplant Register of Studies up to 13 July 2021 through contact with the Information Specialist using search terms relevant to this review. Studies in the Register are identified through searches of CENTRAL, MEDLINE, and EMBASE, conference proceedings, the International Clinical Trials Register (ICTRP) Search Portal and ClinicalTrials.gov.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet agents versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Four authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data were pooled using the random-effects model. Confidence in the evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

MAIN RESULTS

We included 113 studies, enrolling 51,959 participants; 90 studies (40,597 CKD participants) compared an antiplatelet agent with placebo or no treatment, and 29 studies (11,805 CKD participants) directly compared one antiplatelet agent with another. Fifty-six new studies were added to this 2021 update. Seven studies originally excluded from the 2013 review were included, although they had a follow-up lower than two months. Random sequence generation and allocation concealment were at low risk of bias in 16 and 22 studies, respectively. Sixty-four studies reported low-risk methods for blinding of participants and investigators; outcome assessment was blinded in 41 studies. Forty-one studies were at low risk of attrition bias, 50 studies were at low risk of selective reporting bias, and 57 studies were at low risk of other potential sources of bias. Compared to placebo or no treatment, antiplatelet agents probably reduces myocardial infarction (18 studies, 15,289 participants: RR 0.88, 95% CI 0.79 to 0.99, I² = 0%; moderate certainty). Antiplatelet agents has uncertain effects on fatal or nonfatal stroke (12 studies, 10.382 participants: RR 1.01, 95% CI 0.64 to 1.59, I² = 37%; very low certainty) and may have little or no effect on death from any cause (35 studies, 18,241 participants: RR 0.94, 95 % CI 0.84 to 1.06, I² = 14%; low certainty). Antiplatelet therapy probably increases major bleeding in people with CKD and those treated with haemodialysis (HD) (29 studies, 16,194 participants: RR 1.35, 95% CI 1.10 to 1.65, I² = 12%; moderate certainty). In addition, antiplatelet therapy may increase minor bleeding in people with CKD and those treated with HD (21 studies, 13,218 participants: RR 1.55, 95% CI 1.27 to 1.90, I² = 58%; low certainty). Antiplatelet treatment may reduce early dialysis vascular access thrombosis (8 studies, 1525 participants) RR 0.52, 95% CI 0.38 to 0.70; low certainty). Antiplatelet agents may reduce doubling of serum creatinine in CKD (3 studies, 217 participants: RR 0.39, 95% CI 0.17 to 0.86, I² = 8%; low certainty). The treatment effects of antiplatelet agents on stroke, cardiovascular death, kidney failure, kidney transplant graft loss, transplant rejection, creatinine clearance, proteinuria, dialysis access failure, loss of primary unassisted patency, failure to attain suitability for dialysis, need of intervention and cardiovascular hospitalisation were uncertain. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, including prasugrel, ticagrelor, different doses of clopidogrel, abciximab, defibrotide, sarpogrelate and beraprost.

AUTHORS' CONCLUSIONS

Antiplatelet agents probably reduced myocardial infarction and increased major bleeding, but do not appear to reduce all-cause and cardiovascular death among people with CKD and those treated with dialysis. The treatment effects of antiplatelet agents compared with each other are uncertain.

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.

Influence of integrins on thrombus formation: a road leading to the unravelling of DVT

Integrins are a group of transmembrane glycoprotein receptors that are responsible for platelet activation through bidirectional signalling. These receptors have left their footprints in various cellular events and have intrigued many groups of scientists that have led to some significant discoveries. A lot of the recent understanding of haemostasis has been possible due to the integrins filling the gaps in between several cellular mechanism. Apart from this, other important functions carried out by integrins are growth and maturation of cardiomyocytes, mechano-transduction, and interaction with actin cytoskeleton. The signalling cascade for integrin activation involves certain intracellular interacting proteins, which initiates the step-by-step activation procedure through 'inside-out' signalling. The signalling cascade gets activated through 'outside-in' signalling with the involvement of agonists such as ADP, Fibronectin, Vitronectin, and so on. This is a crucial step for the downstream processes of platelet spreading, followed by aggregation, clot progression and finally thrombus formation. Researchers throughout the world have shown direct relation of integrins with CVD and cardiac remodelling. The present review aims to summarize the information available so far on the involvement of integrins in thrombosis and its relationship to DVT. This information could be a bedrock of hidden answers to several questions on pathogenesis of deep vein thrombosis.

Integrin-Targeting Peptides for the Design of Functional Cell-Responsive Biomaterials

Integrins are a family of cell surface receptors crucial to fundamental cellular functions such as adhesion, signaling, and viability, deeply involved in a variety of diseases, including the initiation and progression of cancer, of coronary, inflammatory, or autoimmune diseases. The natural ligands of integrins are glycoproteins expressed on the cell surface or proteins of the extracellular matrix. For this reason, short peptides or peptidomimetic sequences that reproduce the integrin-binding motives have attracted much attention as potential drugs. When challenged in clinical trials, these peptides/peptidomimetics let to contrasting and disappointing results. In the search for alternative utilizations, the integrin peptide ligands have been conjugated onto nanoparticles, materials, or drugs and drug carrier systems, for specific recognition or delivery of drugs to cells overexpressing the targeted integrins. Recent research in peptidic integrin ligands is exploring new opportunities, in particular for the design of nanostructured, micro-fabricated, cell-responsive, stimuli-responsive, smart materials.

Comparing efficacy of receiving different dosages of eptifibatide in bleeding after percutaneous coronary intervention in patients with myocardial infarction

BACKGROUND

Acute coronary syndrome (ACS) is a common condition that needs appropriate treatment like percutaneous coronary intervention (PCI). Glycoprotein IIb/IIIa inhibitors (GPI) like eptifibatide prevent procedural ischemic complications after PCI. Eptifibatide has increased the risk of bleeding complications, although it is effective in reducing mortality and morbidity. Eptifibatide is routinely used in bolus and infusion forms and the aim of this study is to evaluate the efficacy of bolus-only dose and bolus + infusion strategy for administrating eptifibatide in bleeding complications and consequences after PCI.

METHODS

This randomized clinical trial was conducted on subjects who experienced PCI after incidence of myocardial infarction (MI). Patients were randomly divided into two groups who received bolus-only dose (n = 51) or bolus + infusion form of eptifibatide (n = 50). Then, PCI blood pressure, mean time duration of hemostasis after arterial sheath removal, laboratory data, need for blood transfusion, and presence of bleeding complications were evaluated. After 6 months, patients were followed for needs for additional coronary interventions.

RESULTS

The mean age of participants was 61.68 ± 1.50 years. The prevalence of men was 70.29%. There was no significant difference in mean of systolic blood pressure (SBP) and diastolic blood pressure (DBP) during hospitalization (P > 0.050). The mean time duration of hemostasis was 8.13 ± 0.45 minutes in the bolus-only group and 16.46 ± 0.71 minutes in the bolus + infusion group (P < 0.001). There was no significant difference in the hemoglobin (Hb) level, platelet count, white blood cell (WBC), blood urea nitrogen (BUN), and creatinine level (P > 0.050).

CONCLUSION

The results of this study suggested that bolus-only dose of eptifibatide before PCI could be able to decrease significantly bleeding complication and other clinical and cardiovascular outcomes.

Platelet integrin αIIbβ3: signal transduction, regulation, and its therapeutic targeting

Integrins are a family of transmembrane glycoprotein signaling receptors that can transmit bioinformation bidirectionally across the plasma membrane. Integrin αIIbβ3 is expressed at a high level in platelets and their progenitors, where it plays a central role in platelet functions, hemostasis, and arterial thrombosis. Integrin αIIbβ3 also participates in cancer progression, such as tumor cell proliferation and metastasis. In resting platelets, integrin αIIbβ3 adopts an inactive conformation. Upon agonist stimulation, the transduction of inside-out signals leads integrin αIIbβ3 to switch from a low- to high-affinity state for fibrinogen and other ligands. Ligand binding causes integrin clustering and subsequently promotes outside-in signaling, which initiates and amplifies a range of cellular events to drive essential platelet functions such as spreading, aggregation, clot retraction, and thrombus consolidation. Regulation of the bidirectional signaling of integrin αIIbβ3 requires the involvement of numerous interacting proteins, which associate with the cytoplasmic tails of αIIbβ3 in particular. Integrin αIIbβ3 and its signaling pathways are considered promising targets for antithrombotic therapy. This review describes the bidirectional signal transduction of integrin αIIbβ3 in platelets, as well as the proteins responsible for its regulation and therapeutic agents that target integrin αIIbβ3 and its signaling pathways.

Biomaterials for revascularization and immunomodulation after spinal cord injury

Spinal cord injury (SCI) causes immediate damage to the nervous tissue accompanied by loss of motor and sensory function. The limited self-repair competence of injured nervous tissue underscores the need for reparative interventions to recover function after SCI. The vasculature of the spinal cord plays a crucial role in SCI and repair. Ruptured and sheared blood vessels in the injury epicenter and blood vessels with a breached blood-spinal cord barrier (BSCB) in the surrounding tissue cause bleeding and inflammation, which contribute to the overall tissue damage. The insufficient formation of new functional vasculature in and near the injury impedes endogenous tissue repair and limits the prospect of repair approaches. Limiting the loss of blood vessels, stabilizing the BSCB, and promoting the formation of new blood vessels are therapeutic targets for spinal cord repair. Inflammation is an integral part of injury-mediated vascular damage, which has deleterious and reparative consequences. Inflammation and the formation of new blood vessels are intricately interwoven. Biomaterials can be effectively used for promoting and guiding blood vessel formation or modulating the inflammatory response after SCI, thereby governing the extent of damage and the success of reparative interventions. This review deals with the vasculature after SCI, the reciprocal interactions between inflammation and blood vessel formation, and the potential of biomaterials to support revascularization and immunomodulation in damaged spinal cord nervous tissue.

Concept and Clinical Application of Platelet Glycoprotein IIb/IIIa Inhibition with Abciximab (c7E3 Fab; ReoPro) for the Prevention of Acute Ischemic Syndromes

The platelet membrane glycoprotein (GP) IIb/IIIa integrin receptor is the final common pathway leading to platelet aggregation. Local aggregation commonly occurs following atherosclerotic plaque rupture or other injury to the vascular wall. When GP IIb/IIIa is activated, fibrinogen and von Willebrand factor bind to the receptor with high affinity, crosslinking platelets and locking them to the vessel surface and to each other. This process is central to arterial thrombus formation and consequent acute coronary syndromes, such as myocardial infarction (MI), unstable angina, and abrupt closure following revascularization procedures. Abciximab (c7E3 Fab; ReoPro) is a chimeric monoclonal antibody fragment developed specifically to inhibit GP IIb/IIIa receptor activity and thus prevent platelet aggregation and thrombosis. Abciximab has been evaluated in several clinical studies, the largest of which was the Evaluation of Abciximab for the Prevention of Ischemic Complications (EPIC) trial. This randomized, multicenter, placebo-controlled trial enrolled 2,099 patients at high risk for ischemic complications following coronary revascularization. The patients were randomized into three treatment groups: placebo, abciximab bolus (0.25 mg/kg), or abciximab bolus plus 12-h infusion (10 μg/min). Patients in the abciximab bolus plus infusion group had significant reductions, compared with placebo, in a composite end point of death, nonfatal MI, and urgent coronary intervention within 30 days. These positive, short-term findings were maintained at 6 months of follow-up. Bleeding complications and transfusions were significantly increased in abciximab patients, although there was no increase in bleeding-related death, stroke, or surgery. Retrospective secondary analyses suggested that many of the bleeding events observed in the EPIC trial may have been associated with concomitant high-dose heparin therapy, particularly in lighter weight patients. Subsequent clinical trials have shown that bleeding events can be reduced in patients treated with abciximab by using weight-adjusted heparin dosing without affecting the efficacy of the abciximab bolus plus infusion regimen. Examination of health economic data from the EPIC trial showed that abciximab bolus plus infusion is cost effective as well as clinically beneficial. These results confirm the importance of platelet GP IIb/IIIa receptor blockade in the treatment of acute thrombotic syndromes. Key Words: Platelet aggregation—GP IIb/IIIa receptor—Coronary revascularization— Ischemia.

Clopidogrel: An Antithrombotic Drug Acting on the ADP-dependent Activation Pathway of Human Platelets

The aim of the study was to determine the effect of clopidogrel on adenosine diphosphate (ADP)- induced platelet activation in human volunteers. Platelets from human volunteers before and after a 7-day treatment with clopidogrel (75 mg/kg), were tested for their sensi tivity to ADP by measuring ADP-induced aggregation, adenylyl cyclase downregulation, and [3H]-2-MeS-ADP binding. Platelet membrane glycoprotein (GP IIb-IIIa; GP Ib, GMP-140) expression was measured by flow cy tometry using fluorescent-labeled antibodies or fibrino gen. After oral administration to human volunteers (75 mg/day for 7 days), clopidogrel, a novel ADP-selective antiplatelet agent, inhibited ADP-induced aggregation of platelets ex vivo. This effect was irreversible in nature, and no activity could be detected in the plasma of treated subjects. Although clopidogrel did not modify ADP- induced shape change, it prevented the inhibitory effect of ADP (but not that of epinephrine) on the prostoglandin- E1(PGE1)-induced increase in platelet cAMP. The num ber of binding sites for [3H]-2-MeS-ADP, a stable ana logue of ADP that labels ADP binding sites linked to the inhibition of stimulated adenylyl cyclase, was reduced from 525 ± 62 sites/cell in the controls to 32 ± 5 sites/cell after treatment with clopidogrel (p < 0.001). This effect occurred with no consistent change in the binding affinity of [3H]-2-MeS-ADP, indicating that inhibition of platelet functions by clopidogrel was mainly due to a selective and irreversible reduction of ADP binding sites on plate lets. Flow cytometry experiments showed that clopi dogrel selectively inhibited ADP-inducing binding of fi brinogen to platelets. This effect occurred through a ma jor reduction of the ADP-induced activation of the GP IIb-IIIa complex. These findings therefore indicate that clopidogrel downregulates platelet responses via a selec tive and direct interaction with the ADP receptors, me diating the inhibition of stimulated adenylyl cyclase ac tivity in human platelets.

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.

Anti-inflammatory therapies for atherosclerosis

The view of atherosclerosis as an inflammatory disease has emerged from observations of immune activation and inflammatory signalling in human atherosclerotic lesions, from the definition of inflammatory biomarkers as independent risk factors for cardiovascular events, and from evidence of low-density lipoprotein-induced immune activation. Studies in animal models of hyperlipidaemia have also supported the beneficial effects of countering inflammation to delay atherosclerosis progression. Specific inflammatory pathways with relevance to human diseases have been identified, and inhibitors of these pathways are either already in use for the treatment of other diseases, or are under development and evaluation. These include 'classic' drugs (such as allopurinol, colchicine, and methotrexate), biologic therapies (for example tumour necrosis factor inhibitors and IL-1 neutralization), as well as targeting of lipid mediators (such as phospholipase inhibitors and antileukotrienes) or intracellular pathways (inhibition of NADPH oxidase, p38 mitogen-activated protein kinase, or phosphodiesterase). The evidence supporting the use of anti-inflammatory therapies for atherosclerosis is mainly based on either observational or small interventional studies evaluating surrogate markers of disease activity. Nevertheless, these data are crucial to understand the role of inflammation in atherosclerosis, and to design randomized controlled studies to evaluate the effect of specific anti-inflammatory strategies on cardiovascular outcomes.

Bivalirudin versus Unfractionated Heparin during Percutaneous Coronary Intervention in Patients at High Risk for Bleeding

Low/medium-bleeding-risk populations undergoing percutaneous coronary intervention (PCI) show significantly less bleeding with bivalirudin (BIV) than with unfractionated heparin (UFH), but this has not been established for high-risk patients. We performed a randomized double-blind prospective trial comparing efficacy and safety of BIV versus UFH combined with dual antiplatelet therapy during PCI among 100 high-risk patients with non-ST elevation myocardial infarction (NSTEMI) or angina pectoris. The baseline characteristics were similar in both treatment arms. A radial approach was used in 84% of patients with a higher rate in the BIV group (90 vs. 78%, p < 0.05). Study end points were: major and minor bleeding, port-of-entry complications, major adverse cardiac events (MACE) in-hospital, and at long-term follow-up. There was one case of major gastrointestinal bleeding in the BIV group and 7% minor bleeding complications in both categories. Rate of periprocedural myocardial infarction (PPMI) in the BIV group was twice that in the UFH group (20 vs. 10%, p < 0.16). In-hospital MACE rate was higher in BIV patients as well (12 vs. 2%, p = 0.1). By univariate analysis, the femoral approach was the predictor of PPMI and in-hospital MACE. In a multivariate model, the independent predictor of PPMI was previous MI (odds ratio, 7.7; p < 0.0158). PPMI was 49.7 times more likely with the femoral approach plus BIV than the nonfemoral approach plus UFH (p < 0.0021). At 41.5 ± 14 months' follow-up, end points did not significantly differ between the groups. In patients at high risk for bleeding undergoing PCI, BIV was not superior to UFH for bleeding complications, and early and late clinical outcomes.

Strategies to inhibit tumor associated integrin receptors: rationale for dual and multi-antagonists

The integrins are a family of 24 heterodimeric transmembrane cell surface receptors. Involvement in cell attachment to the extracellular matrix, motility, and proliferation identifies integrins as therapeutic targets in cancer and associated conditions: thrombosis, angiogenesis, and osteoporosis. The most reported strategy for drug development is synthesis of an agent that is highly selective for a single integrin receptor. However, the ability of cancer cells to change their integrin repertoire in response to drug treatment renders this approach vulnerable to the development of resistance and paradoxical promotion of tumor growth. Here, we review progress toward development of antagonists targeting two or more members of the Arg-Gly-Asp (RGD) binding integrins, notably αvβ3, αvβ5, αvβ6, αvβ8, α5β1, and αIIbβ3, as anticancer therapeutics.

Platelet glycoprotein IIb/IIIa blockers during percutaneous coronary intervention and as the initial medical treatment of non-ST segment elevation acute coronary syndromes

BACKGROUND

During percutaneous coronary intervention (PCI), and in non-ST segment elevation acute coronary syndromes (NSTEACS), the risk of acute vessel occlusion by thrombosis is high. Glycoprotein IIb/IIIa blockers strongly inhibit platelet aggregation and may prevent mortality and myocardial infarction. This is an update of a Cochrane review first published in 2001, and previously updated in 2007 and 2010.

OBJECTIVES

To assess the efficacy and safety effects of glycoprotein IIb/IIIa blockers when administered during PCI, and as initial medical treatment in patients with NSTEACS.

SEARCH METHODS

We updated the searches of the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 12, 2012), MEDLINE (OVID, 1946 to January Week 1 2013) and EMBASE (OVID, 1947 to Week 1 2013) on 11 January 2013.

SELECTION CRITERIA

Randomised controlled trials comparing intravenous IIb/IIIa blockers with placebo or usual care.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion, assessed trial quality and extracted data. We collected major bleeding as adverse effect information from the trials. We used odds ratios (OR) and 95% confidence intervals (CI) for effect measures.

MAIN RESULTS

Sixty trials involving 66,689 patients were included. During PCI (48 trials with 33,513 participants) glycoprotein IIb/IIIa blockers decreased all-cause mortality at 30 days (OR 0.79, 95% CI 0.64 to 0.97) but not at six months (OR 0.90, 95% CI 0.77 to 1.05). All-cause death or myocardial infarction was decreased both at 30 days (OR 0.66, 95% CI 0.60 to 0.72) and at six months (OR 0.75, 95% CI 0.64 to 0.86), although severe bleeding was increased (OR 1.39, 95% CI 1.21 to 1.61; absolute risk increase (ARI) 8.0 per 1000). The efficacy results were homogeneous for every endpoint according to the clinical condition of the patients, but were less marked for patients pre-treated with clopidogrel, especially in patients without acute coronary syndromes.As initial medical treatment of NSTEACS (12 trials with 33,176 participants), IIb/IIIa blockers did not decrease mortality at 30 days (OR 0.90, 95% CI 0.79 to 1.02) or at six months (OR 1.00, 95% CI 0.87 to 1.15), but slightly decreased death or myocardial infarction at 30 days (OR 0.91, 95% CI 0.85 to 0.98) and at six months (OR 0.88, 95% CI 0.81 to 0.96), although severe bleeding was increased (OR 1.29, 95% CI 1.14 to 1.45; ARI 1.4 per 1000).

AUTHORS' CONCLUSIONS

When administered during PCI, intravenous glycoprotein IIb/IIIa blockers reduce the risk of all-cause death at 30 days but not at six months, and reduce the risk of death or myocardial infarction at 30 days and at six months, at a price of an increase in the risk of severe bleeding. The efficacy effects are homogeneous but are less marked in patients pre-treated with clopidogrel where they seem to be effective only in patients with acute coronary syndromes. When administered as initial medical treatment in patients with NSTEACS, these agents do not reduce mortality although they slightly reduce the risk of death or myocardial infarction.

Platelet glycoprotein IIb/IIIa blockers during percutaneous coronary intervention and as the initial medical treatment of non-ST segment elevation acute coronary syndromes

BACKGROUND

During percutaneous coronary intervention (PCI), and in non-ST segment elevation acute coronary syndromes (NSTEACS), the risk of acute vessel occlusion by thrombosis is high. Glycoprotein IIb/IIIa blockers strongly inhibit platelet aggregation and may prevent mortality and myocardial infarction. This is an update of a Cochrane review first published in 2001, and previously updated in 2007 and 2010.

OBJECTIVES

To assess the efficacy and safety effects of glycoprotein IIb/IIIa blockers when administered during PCI, and as initial medical treatment in patients with NSTEACS.

SEARCH METHODS

We updated the searches of the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 12, 2012), MEDLINE (OVID, 1946 to January Week 1 2013) and EMBASE (OVID, 1947 to Week 1 2013) on 11 January 2013.

SELECTION CRITERIA

Randomised controlled trials comparing intravenous IIb/IIIa blockers with placebo or usual care.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion, assessed trial quality and extracted data. We collected major bleeding as adverse effect information from the trials. We used odds ratios (OR) and 95% confidence intervals (CI) for effect measures.

MAIN RESULTS

Sixty trials involving 66,689 patients were included. During PCI (48 trials with 33,513 participants) glycoprotein IIb/IIIa blockers decreased all-cause mortality at 30 days (OR 0.79, 95% CI 0.64 to 0.97) but not at six months (OR 0.90, 95% CI 0.77 to 1.05). All-cause death or myocardial infarction was decreased both at 30 days (OR 0.66, 95% CI 0.60 to 0.72) and at six months (OR 0.75, 95% CI 0.64 to 0.86), although severe bleeding was increased (OR 1.39, 95% CI 1.21 to 1.61; absolute risk increase (ARI) 8.0 per 1000). The efficacy results were homogeneous for every endpoint according to the clinical condition of the patients, but were less marked for patients pre-treated with clopidogrel, especially in patients without acute coronary syndromes.As initial medical treatment of NSTEACS (12 trials with 33,176 participants), IIb/IIIa blockers did not decrease mortality at 30 days (OR 0.90, 95% CI 0.79 to 1.02) or at six months (OR 1.00, 95% CI 0.87 to 1.15), but slightly decreased death or myocardial infarction at 30 days (OR 0.91, 95% CI 0.85 to 0.98) and at six months (OR 0.88, 95% CI 0.81 to 0.96), although severe bleeding was increased (OR 1.29, 95% CI 1.14 to 1.45; ARI 1.4 per 1000).

AUTHORS' CONCLUSIONS

When administered during PCI, intravenous glycoprotein IIb/IIIa blockers reduce the risk of all-cause death at 30 days but not at six months, and reduce the risk of death or myocardial infarction at 30 days and at six months, at a price of an increase in the risk of severe bleeding. The efficacy effects are homogeneous but are less marked in patients pre-treated with clopidogrel where they seem to be effective only in patients with acute coronary syndromes. When administered as initial medical treatment in patients with NSTEACS, these agents do not reduce mortality although they slightly reduce the risk of death or myocardial infarction.

Role of Parenteral Agents in Percutaneous Coronary Intervention for Stable Patients

Numerous agents are available for anticoagulation during percutaneous coronary intervention (PCI), and various antiplatelet agents are also used. With all of the medications available, an assessment must be made regarding the ischemic risk and risk of bleeding for an individual patient during elective PCI when selecting the optimal medical strategy to support PCI. Whether new antiplatelet medications will enhance or reduce complications when paired with various newer anticoagulant agents requires further investigation. This article summarizes existing data examining the benefits and limitations of the various anticoagulant and antiplatelet medications, and summarizes guidelines for their use.

Antiplatelet agents for chronic kidney disease

BACKGROUND

Antiplatelet agents are widely used to prevent cardiovascular events. The risks and benefits of antiplatelet treatment may be different in people with chronic kidney disease (CKD) for whom occlusive atherosclerotic events are less prevalent, and bleeding hazards might be increased.

OBJECTIVES

To summarise the effects of antiplatelet treatment (antiplatelet agent versus control or other antiplatelet agent) for the prevention of cardiovascular and adverse kidney outcomes in individuals with CKD.

SEARCH METHODS

In January 2011 we searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE and the Cochrane Renal Group's Specialised Register without language restriction.

SELECTION CRITERIA

We selected randomised controlled trials of any antiplatelet treatment versus placebo or no treatment, or direct head-to-head antiplatelet agent studies in people with CKD. Studies were included if they enrolled participants with CKD, or included people in broader at-risk populations in which data for subgroups with CKD could be disaggregated.

DATA COLLECTION AND ANALYSIS

Two authors independently extracted data from primary study reports and any available supplementary information for study population, interventions, outcomes, and risks of bias. Risk ratios (RR) and 95% confidence intervals (CI) were calculated from numbers of events and numbers of participants at risk which were extracted from each included study. The reported RRs were extracted where crude event rates were not provided. Data was pooled using the random-effects model.

MAIN RESULTS

We included 50 studies, enrolling 27,139 participants; 44 studies (21,460 participants) compared an antiplatelet agent with placebo or no treatment, and six studies (5679 participants) directly compared one antiplatelet agent with another. Compared to placebo or no treatment, antiplatelet agents reduced the risk of myocardial infarction (17 studies; RR 0.87, 95% CI 0.76 to 0.99), but not all-cause mortality (30 studies; RR 0.93, 95% CI 0.81 to 1.06), cardiovascular mortality (19 studies; RR 0.89, 95% CI 0.70 to 1.12) or stroke (11 studies; RR 1.00, 95% CI 0.58 to 1.72). Antiplatelet agents increased the risk of major (27 studies; RR 1.33, 95% CI 1.10 to 1.65) and minor bleeding (18 studies; RR 1.49, 95% CI 1.12 to 1.97). In terms of dialysis access outcomes, antiplatelet agents reduced access thrombosis or patency failure but had no effect on suitability for dialysis. Meta-regression analysis indicated no differences in the relative benefit or harms of treatment (risk of all-cause mortality, myocardial infarction, or major bleeding) by type of antiplatelet agent or stage of CKD. Limited data were available for direct head-to-head comparisons of antiplatelet drugs, treatment in kidney transplant recipients, primary prevention, or risk of ESKD.

AUTHORS' CONCLUSIONS

Antiplatelet agents reduce myocardial infarction but increase major bleeding. Risks may outweigh harms among people with low annual risks of cardiovascular events, including those with early stages of CKD who do not have clinically-evident occlusive cardiovascular disease.

Appropriate anti-thrombotic/anti-thrombin therapy for thrombotic lesions

Managing coronary thrombus is a challenging task and requires adequate knowledge of the various antithrombotic agents available. In this article, we will briefly analyze the risk-benefit profile of antithrombotic agents, with critical analysis of the scientific evidence available to support their use. Since thrombus consists of platelets and coagulation cofactors, an effective antithrombotic strategy involves using one anticoagulant with two or more antiplatelet agents. Unfractionated heparin traditionally has been the most commonly used anticoagulant but is fast being replaced by relatively newer agents like LMWH, direct thrombin inhibitors, and Factor Xa inhibitors.

In recent years, the antiplatelet landscape has changed significantly with the availability of more potent and rapidly acting agents, like prasugrel and ticagrelor. These agents have demonstrated a sizeable reduction in ischemic outcomes in patients with ACS, who are treated invasively or otherwise, with some concern for an increased bleeding risk. Glycoprotein IIb/IIIa inhibitors have an established role in high risk NSTE ACS patients pretreated with dual antiplatelets, but its role in STEMI patients, treated with invasive approach and dual antiplatelets, has not been supported consistently across the studies. Additionally, in recent years, its place as a directly injected therapy into coronaries has been looked into with mixed results. In conclusion, a well-tailored antithrombotic strategy requires taking into account each patient’s individual risk factors and clinical presentation, with an effort to strike balance between not only preventing ischemic outcomes but also reducing bleeding complications.

Review of Currently Available GP IIb/IIIa Inhibitors and Their Role in Peripheral Vascular Interventions

The glycoprotein IIb/IIIa (GP IIb/IIIa) antagonists are the most recent additions to the antiplatelet agents available to the interventional radiologist. The currently available GP IIb/IIIa antagonists are abciximab, eptifibatide, and tirofiban. These medications have demonstrated excellent safety and efficacy in the setting of coronary arterial interventions. The fundamental benefit of the GP IIb/IIIa antagonists lies in their unique mechanism of action: the ability to prevent platelet aggregation, thrombus formation, and distal thromboembolism while preserving initial platelet binding to damaged vascular surfaces. A paucity of data exists regarding the role of GP IIb/IIIa inhibitors in peripheral vascular interventions. The GP IIb/IIIa antagonists would theoretically provide excellent antiplatelet therapy in patients undergoing any of a variety of endovascular interventions during which thrombosis or thromboembolism may endanger distal perfusion in patients with peripheral vascular disease. The goal of this summary is to review the indications for use, pharmacology, and evidence for efficacy of the GP IIb/IIIa antagonists in hopes of translating these data for application in the peripheral arterial circulation. Further research is necessary to determine how these agents may be safely used in combination with other anticoagulants or with stents, efficacy compared with standard regimens, success at preventing distal thromboembolism, and cost effectiveness.

Meta-analysis of prospective randomized controlled trials comparing intracoronary versus intravenous abciximab in patients with ST-elevation myocardial infarction undergoing primary percutaneous coronary intervention

Abciximab is a glycoprotein IIb/IIIa receptor inhibitor that has been shown to improve outcomes in patients with ST-segment elevation myocardial infarction who undergo primary percutaneous coronary intervention (pPCI). An earlier study reported better efficacy with intracoronary (IC) compared to intravenous (IV) administration, but this finding has not been duplicated in other studies, thus leaving a great deal of uncertainty as to the most efficacious route of administration. To investigate if IC abciximab compared to IV administration decreases mortality and major adverse cardiac events in patients with ST-segment elevation myocardial infarction who undergo pPCI, a meta-analysis was performed consisting only of prospective randomized controlled trials. Subgroup analysis was performed to investigate the source of difference in efficacy between the 2 strategies. A meta-analysis of 4 trials including 1,148 subjects revealed that IC abciximab significantly reduced mortality compared to IV administration (1.5% vs 3.6%, odds ratio 0.44, 95% confidence interval 0.20 to 0.95, p = 0.04). Major adverse cardiac events were also reduced in a subgroup in which <30% of patients received aspiration thrombectomy (6.1% vs 16.2%, odds ratio 0.33, 95% confidence interval 0.18 to 0.61, p = 0.0004). In conclusion, the totality of the data available from relatively small but high-quality studies shows a significant mortality reduction associated using IC abciximab for pPCI compared to IV abciximab. IC abciximab in the setting of pPCI for ST-segment elevation myocardial infarction may be beneficial for patients with higher risk profiles.

Treatment with tirofiban for acute coronary syndrome (ACS): a systematic review and network analysis

OBJECTIVE

To assess the efficacy of tirofiban in comparison to usual care or other GPIIb/IIIa antagonists (eptifibatide and abciximab). Results were analysed by drug administration with planned percutaneous coronary intervention (PCI) or as medical management without planned PCI, and separately for STEMI or NSTE ACS patients.

RESEARCH DESIGN AND METHODS

A systematic review was performed of randomized controlled trials of tirofiban, abciximab, eptifibatide or usual care given to patients with acute coronary syndrome. Nine databases were searched up to March 2010. Pair-wise meta-analysis was used to combine all available direct comparisons; indirect comparisons and network analysis were performed when this was not possible. The primary outcome was MACE (major adverse cardiac event).

RESULTS

The search yielded 8, 119 records and 50 trials were included (total number of patients = 52,958). Compared to usual care, high and medium-dose tirofiban (25 and 10 µg/kg/min) administered with planned PCI reduced MACE at 30 days for patients with STEMI (RR 0.67, 95% CI 0.45, 0.99; RR 0.28, 95% CI 0.10, 0.80), but was not effective as a medical management. Medium-dose tirofiban (10 µg/kg/min) administered with planned PCI or low dose (0.4 µg/kg/min) as medical management reduced the risk of MACE for patients with NSTE ACS (RR 0.39, 95% CI 0.21, 0.75; RR 0.58, 95% CI 0.41, 0.83) in comparison to usual care, but at the expense of increased thrombocytopenia (RR 3.26, 95% CI 1.31, 8.13). Evidence from RCTs and network analysis indicated tirofiban and abciximab were equally effective and safe. Comparing tirofiban and eptifibatide treatment by indirect and network analysis produced inconclusive results.

CONCLUSIONS

Tirofiban was more effective than usual care for STEMI and NSTE ACS patients receiving planned PCI, and NSTE ACS patients receiving medical management. Tirofiban and abciximab were equally effective. Comparisons of tirofiban and eptifibatide were inconclusive.

Intracoronary versus intravenous abciximab administration in STEMI patients: overview of current status and open questions

OBJECTIVES

To perform a systematic review to provide rationale for intracoronary (IC) abciximab administration in patients with ST-segment elevation myocardial infarction (STEMI), to summarize recent studies comparing IC vs. intravenous (IV) abciximab administration in this setting and to define questions that need to be answered in future trials determining the optimal abciximab regimen.

METHODS

A search covering the period from January 1993 to June 2011 was conducted by two independent investigators using MEDLINE, CENTRAL and Google Scholar databases. Proceedings from the scientific sessions of ACC, AHA, ESC, TCT and EuroPCR were also considered.

RESULTS

IC administration allows one to obtain a much higher concentration of abciximab than IV injection at the culprit lesion. Therefore it is hypothesized that IC abciximab administration provides more efficient GP IIb/IIIa receptor inhibition and more pronounced additional dose-dependent antiplatelet, antithrombotic, and anti-inflammatory effects when compared to the IV route. Numerous observational and randomized studies comparing IC vs. IV abciximab in STEMI patients indicated improvement in different surrogate end points (infarct size, obstruction of coronary microcirculation, ST segment resolution, inflammatory mediators and markers of platelet activation) related to IC administration. The evidence supporting clinical benefits associated with IC injection of abciximab comes from one randomized and several non-randomized trials as most of the studies were underpowered to assess clinical outcomes. No difference in bleeding complications was observed between IC and IV regimens. Issues that need to be addressed in future studies include: the use of IC abciximab in combination with thrombectomy, the role of selective delivery systems, and the necessity of a prolonged IV infusion of abciximab after IC bolus administration.

CONCLUSIONS

An accumulating body of evidence suggests the superiority of IC over IV abciximab administration in STEMI patients. However, further trials are warranted to establish the optimal strategy of abciximab treatment in this setting.

Use of antiplatelet inhibitors in peripheral vascular interventions

In the past decade, a tremendous amount of information has been gathered about platelet function and its impact on percutaneous vascular interventions. Strategies for prevention of platelet aggregation have moved beyond aspirin administration. Powerful oral antiplatelet agents such as ticlopidine (Ticlid) and clopidogrel (Plavix) have been developed to prevent platelet aggregation and thrombosis. The discovery of the glycoprotein IIb/IIIa receptor, which is responsible for platelet aggregation, has led to the development of receptor antagonists. These drugs include abciximab (ReoPro), eptifibatide (Integrilin), and tirofiban (Aggrastat). Several large studies have demonstrated that these drugs can improve outcomes in coronary interventions. Because most of the data regarding antiplatelet agents in percutaneous interventions comes from studies of coronary interventions, knowledge of these studies is necessary before using the antiplatelet drugs in peripheral vascular interventions. This article reviews the use of these agents in percutaneous coronary artery interventions and discusses their potential use in peripheral interventions.

The Optimal Route of Administration of the Glycoprotein IIb/IIIa Receptor Antagonist Abciximab During Percutaneous Coronary Intervention; Intravenous Versus Intracoronary

The use of the glycoprotein (GP) IIb/IIIa receptor antagonist Abciximab has over the years become an important part of the anticoagulant regimen in patients with acute coronary syndrome undergoing percutaneous coronary intervention. Abciximab is a potent inhibitor of platelet aggregation and thrombus formation, but other mechanisms, such as suppression of the inflammatory pathways, have also been proposed to contribute to the benefits of Abciximab.

The optimal route of administration, i.e. intravenous versus intracoronary, of the first dose has been questioned, but only tested in small, non-randomised and retrospective studies or studies with short follow-up. No definite conclusion can be made based on these studies.

In this review we present the current knowledge published about the intracoronary administration of Abciximab including the mechanisms behind the potential beneficial effects, and the safety. The emphasis will be on clinical trials rather than on studies on the pharmacological mechanisms, as the latter have been reviewed thoroughly elsewhere.

Our conclusion from this present review is that randomized trials of intracoronary versus intravenous bolus of Abciximab are needed.

Delivery of TFPI-2 using ultrasound with a microbubble agent (SonoVue) inhibits intimal hyperplasia after balloon injury in a rabbit carotid artery model

Here we report a new, simple and efficient method by using ultrasound and a microbubble agent (SonoVue) for delivering a gene to balloon-injured carotid arteries for restenosis prophylaxis. The tissue factor pathway inhibitor-2 (TFPI-2) has been shown to inhibit the postinjury intimae hyperplasia in atherosclerotic vessels. New Zealand white rabbits were divided into 4 groups with 14 in each, a treatment control for balloon injury, a gene vehicle control, a gene delivery of TFPI-2 without using ultrasound and a gene delivery of TFPI-2 using ultrasound. After four weeks, the injured artery neointimal proliferation was significantly lower in the TFPI-2 group with ultrasound than the control groups (p < 0.01) according to the measurement of the mean luminal diameters by B-mode ultrasonography. The ratio of intimal/media area and the stenosis rate in the gene delivery facilitated by ultrasound were significantly lower than those of the nonultrasound gene delivering method (p < 0.01).

Platelet glycoprotein IIb/IIIa blockers during percutaneous coronary intervention and as the initial medical treatment of non-ST segment elevation acute coronary syndromes

BACKGROUND

During percutaneous coronary intervention (PCI), and in non-ST segment elevation acute coronary syndromes (NSTEACS), the risk of acute vessel occlusion by thrombosis is high. IIb/IIIa blockers strongly inhibit platelet aggregation and may prevent mortality and myocardial infarction (MI). This is an update of a Cochrane review first published in 2001, and previously updated in 2007.

OBJECTIVES

To assess the effects and safety of IIb/IIIa blockers when administered during PCI, and as initial medical treatment in patients with NSTEACS.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) on The Cochrane Library (Issue 3, 2009), MEDLINE (1966 to October 2009), and EMBASE (1980 to October 2009).

SELECTION CRITERIA

Randomised controlled trials comparing intravenous IIb/IIIa blockers with placebo or usual care.

DATA COLLECTION AND ANALYSIS

Two authors independently selected studies for inclusion, assessed trial quality and extracted data. We collected major bleeding as adverse effect information from the trials. Odds ratios (OR) and 95% confidence intervals (CI) were used for effect measures.

MAIN RESULTS

Forty-eight trials involving 62,417 patients were included. During PCI, IIb/IIIa blockers decreased mortality at 30 days (OR 0.76, 95% CI 0.62 to 0.95) and at six months (OR 0.84, 95% CI 0.71 to 1.00). Death or MI was decreased both at 30 days (OR 0.65, 95% CI 0.60 to 0.72), and at 6 months (OR 0.70, 95% CI 0.61 to 0.81), although severe bleeding was increased (OR 1.38, 95% CI 1.20 to 1.59; absolute risk increase (ARI) 8.0 per 1000). The efficacy results were homogeneous for every endpoint according to the clinical condition of the patients, but were less marked for patients pre-treated with clopidogrel, especially in patients without ACS.As initial medical treatment of NSTEACS, IIb/IIIa blockers did not decrease mortality at 30 days (OR 0.91, 95% CI 0.80 to 1.03) or at six months (OR 1.00, 95% CI 0.87 to 1.15), but slightly decreased death or MI at 30 days (OR 0.92, 95% CI 0.86 to 0.99) and at six months (OR 0.88, 95% CI 0.81 to 0.96), although severe bleeding was increased (OR 1.27, 95% CI 1.12 to 1.43; ARI 1.4 per 1000).

AUTHORS' CONCLUSIONS

When administered during PCI, intravenous IIb/IIIa blockers reduce the risk of death and of death or MI at 30 days and at six months, at a price of an increase in the risk of severe bleeding. The efficacy effects are homogeneous but are less marked in patients pre-treated with clopidogrel where they seem to be effective only in patients with ACS. When administered as initial medical treatment in patients with NSTEACS, these agents do not reduce mortality although they slightly reduce the risk of death or MI.

Antithrombotic strategies in patients undergoing percutaneous coronary intervention for acute coronary syndrome

In patients undergoing percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS), both periprocedural acute myocardial infarction and bleeding complications have been shown to be associated with early and late mortality. Current standard antithrombotic therapy after coronary stent implantation consists of lifelong aspirin and clopidogrel for a variable period depending in part on the stent type. Despite its well-established efficacy in reducing cardiac-related death, myocardial infarction, and stroke, dual antiplatelet therapy with aspirin and clopidogrel is not without shortcomings. While clopidogrel may be of little beneficial effect if administered immediately prior to PCI and may even increase major bleeding risk if coronary artery bypass grafting is anticipated, early discontinuation of the drug may result in insufficient antiplatelet coverage with thrombotic complications. Optimal and rapid inhibition of platelet activity to suppress ischemic and thrombotic events while minimizing bleeding complications is an important therapeutic goal in the management of patients undergoing percutaneous coronary intervention. In this article we present an overview of the literature on clinical trials evaluating the different aspects of antithrombotic therapy in patients undergoing PCI and discuss the emerging role of these agents in the contemporary era of early invasive coronary intervention. Clinical trial acronyms and their full names are provided in Table 1.

Drug delivery by red blood cells: vascular carriers designed by mother nature

IMPORTANCE OF THE FIELD

Vascular delivery of several classes of therapeutic agents may benefit from carriage by red blood cells (RBC), for example, drugs that require delivery into phagocytic cells and those that must act within the vascular lumen. The fact that several protocols of infusion of RBC-encapsulated drugs are now being explored in patients illustrates a high biomedical importance for the field. AREAS COVERED BY THIS REVIEW: Two strategies for RBC drug delivery are discussed: encapsulation into isolated RBC ex vivo followed by infusion in compatible recipients and coupling therapeutics to the surface of RBC. Studies of pharmacokinetics and effects in animal models and in human studies of diverse therapeutic enzymes, antibiotics and other drugs encapsulated in RBC are described and critically analyzed. Coupling to RBC surface of compounds regulating immune response and complement, affinity ligands, polyethylene glycol alleviating immune response to donor RBC and fibrinolytic plasminogen activators are described. Also described is a new, translation-prone approach for RBC drug delivery by injection of therapeutics conjugated with fragments of antibodies providing safe anchoring of cargoes to circulating RBC, without need for ex vivo modification and infusion of RBC.

WHAT THE READER WILL GAIN

Readers will gain historical perspective, current status, challenges and perspectives of medical applications of RBC for drug delivery.

TAKE HOME MESSAGE

RBC represent naturally designed carriers for intravascular drug delivery, characterized by unique longevity in the bloodstream, biocompatibility and safe physiological mechanisms for metabolism. New approaches for encapsulating drugs into RBC and coupling to RBC surface provide promising avenues for safe and widely useful improvement of drug delivery in the vascular system.

Integrin targeted drug and gene delivery

IMPORTANCE OF THE FIELD

Recently, there has been substantial progress in the development of integrin targeted pharmaceuticals and drug delivery systems. Integrin is an important member in the cell adhesion molecule family, which is involved in regulation of complex biological conditions, from keeping normal physiological activities to causing cellular dysfunction in diseased cells. Hence, it is timely to summarize the recent developments in integrin targeted drug and gene delivery systems to understand better their advantages and limitations.

AREAS COVERED IN THIS REVIEW

In this review, advances in the discovery and clinical trials of these integrin antagonists against different integrin subunits are summarized and discussed. Besides using integrin inhibitor as a single therapeutic agent, integrin antagonists that were conjugated to cytotoxic drugs by synthetic chemistry or coupled to biomacromolecules by either DNA recombination technology or fusion protein technology for integrin targeted therapy have been explored. Furthermore, nanoparticles with integrin targeting ligands for both drug and gene delivery, typically for antiangiogenesis and anticancer therapy, are highlighted and evaluated.

WHAT THE READER WILL GAIN

This review sheds light on the future development of integrin targeted drug and/or gene delivery systems.

TAKE HOME MESSAGE

Although thus far there are still limitations, integrin targeted delivery systems have already shown their potential as important pharmaceuticals in the near future.

Adhesion molecules: potential therapeutic and diagnostic implications

The role of cell adhesion molecules (CAMs) and extracellular matrix (ECM) proteins in various pathological processes, including angiogenesis, thrombosis, inflammation, apoptosis, cell migration, and proliferation is well documented. These processes can lead to both acute and chronic disease states such as ocular diseases, metastasis, unstable angina, myocardial infarction, stroke, osteoporosis, a wide range of inflammatory diseases, vascular remodeling, and neurodegenerative disorders. A key success in this field was identification of the role of platelet glycoprotein (GP)IIb/IIIa in the prevention and diagnosis of various thromboembolic disorders. The use of soluble adhesion molecules as potential diagnostic markers for acute and chronic leukocyte, platelet, and endothelial cell insult is becoming increasingly common. The development of various therapeutic and diagnostic candidates based on the key role of CAMs, with special emphasis on integrins in various diseases, as well as the structure-function aspects of cell adhesion and signaling of the different CAMs and ECM are highlighted.