Bivalirudin: a pharmacoeconomic profile of its use in patients with acute coronary syndromes

Bivalirudin (Angiox?; Angiomax?), a direct thrombin inhibitor, is an intravenous anticoagulant. The efficacy of bivalirudin in the management of patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) or ST-segment elevation myocardial infarction (STEMI) planned for invasive interventions has been shown in large, pivotal, open-label trials. Bivalirudin provided similar ischaemic protection to heparin plus a glycoprotein (GP) IIb/IIIa inhibitor, but with a significant reduction in bleeding events, in patients with NSTE-ACS planned for urgent or early intervention and those with STEMI planned for primary percutaneous coronary intervention (PCI). Mortality rates were also significantly lower in patients with STEMI receiving bivalirudin than in those receiving heparin plus a GP IIb/IIIa inhibitor in the key trial of patients with STEMI. Based on this clinical data, modelled cost-utility analyses from the perspective of various UK NHS providers have predicted that bivalirudin would be highly likely to be cost effective with regard to the cost per QALY gained relative to a heparin plus GP IIb/IIIa inhibitor-based strategy over a lifetime horizon in these patient populations. In patients with NSTE-ACS planned for urgent or early invasive intervention, a bivalirudin-based strategy was considered to be cost effective in the UK, Scotland and Wales. In patients with STEMI planned for primary PCI, a bivalirudin-based strategy was dominant in the UK and Scotland. Parallel and sensitivity analyses demonstrated that base-case conclusions were robust over a range of plausible changes in parameter estimates and assumptions, including changes made to more closely reflect current local clinical practice. In addition, budgetary impact analyses in several countries suggested that the implementation of a bivalirudin-based strategy, instead of a heparin plus GP IIb/IIIa inhibitor-based strategy, would be cost saving from a hospital perspective in patients with NSTE-ACS undergoing urgent or early PCI, as well as in patients with STEMI undergoing primary PCI. Likewise, prospective and retrospective treatment cost studies in the US indicated that treatment with bivalirudin was less costly than treatment with heparin plus a GP IIb/IIIa inhibitor in these indications. In conclusion, available pharmacoeconomic data from several countries, despite some inherent limitations, support the use of strategies based on bivalirudin over those based on heparin plus a GP IIb/IIIa inhibitor in patients with NSTE-ACS planned for urgent or early invasive intervention or STEMI planned for primary PCI. These pharmacoeconomic advantages primarily reflect that, relative to heparin plus a GP IIb/IIIa inhibitor, bivalirudin is associated with lower rates of bleeding over the short term, and is associated with lower rates of early mortality that are subsequently maintained over the longer term in patients with STEMI.     

Ticagrelor: a review of its use in the management of acute coronary syndromes

Ticagrelor (Brilique?; Brilinta?), a cyclopentyl-triazolo-pyrimidine antiplatelet agent, is the first oral antagonist of the P2Y(12) receptor to offer reversible receptor binding. It is indicated in the EU for the prevention of atherothrombotic events in adults with acute coronary syndromes (ACS) [unstable angina pectoris, ST-segment elevation myocardial infarction [STEMI] or non-STEMI), including those managed medically or with percutaneous coronary intervention or coronary artery bypass grafting (CABG). Ticagrelor provides selective and reversible inhibition of adenosine diphosphate-induced platelet aggregation, with a faster onset and offset of action than that of clopidogrel, and is effective in the treatment of patients with ACS, with or without ST-segment elevation. In the large, randomized, double-blind, multicentre PLATO trial conducted in this patient population, ticagrelor was more effective than clopidogrel in terms of preventing ischaemic events over 12 months, providing a significantly lower risk of the primary composite endpoint of myocardial infarction, stroke or death from vascular causes, and was associated with an overall mortality benefit. The risk of major bleeding with ticagrelor, including bleeds related to CABG, did not differ from that seen with clopidogrel in this study, although ticagrelor was associated with more non-CABG-related major bleeds and fatal intracranial bleeding, albeit the latter bleeding events were rare. Further long-term and comparative efficacy and tolerability data are required to definitively position ticagrelor with respect to other antiplatelet agents, including prasugrel. However, the clinical data currently available indicate that ticagrelor is a promising option for the treatment of patients with ACS and may be of particular use in those at high risk of ischaemic events or unresponsive to clopidogrel.     

Bivalirudin during percutaneous coronary intervention in acute coronary syndromes

Introduction: Anticoagulant therapy is critical to prevent ischemic recurrences and complications in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI). Unfractionated heparin (UFH), an injectable anticoagulant has several limitations: lack of predictability of its biological efficacy, platelets activation, heparin-induced thrombopenia and bleedings. Bivalirudin, a synthetic direct thrombin inhibitor has biological properties that promised better clinical outcome in ACS patients undergoing PCI.

Areas covered: The present review aimed to summarize two decades of randomized clinical trials that compared bivalirudin to UFH in ACS patients treated with PCI. Early trials highlighted a reduction of bleedings with bivalirudin compared to UFH in combination with glycoprotein inhibitors (GPI). Recent studies questioned this reduction given that GPI are less and less used during PCI. Further, trials raised concerns about the risk of stent thrombosis in patients treated with bivalirudin. In light of this data, bivalirudin has been downgraded in international guidelines and appears as a second line anticoagulant agent after UFH.

Expert opinion: The highly questioned reduction of bleedings under bivalirudin and the potential risk of stent thrombosis are unwarranted. Based on clinical trials, UFH has no equivalent in terms of anticoagulation in ACS patients undergoing PCI.     

Bivalirudin: an anticoagulant for acute coronary syndromes and coronary interventions

Heparin is a commonly used anticoagulant in patients with coronary artery disease but its use does not always result in low rates of ischaemic and bleeding events, so the search for new anticoagulants continues. Thrombin plays a key role in both thrombosis and haemostasis and direct thrombin inhibitors modelled on the hirudin molecule found in the saliva of the medicinal leech, Hirudo medicinalis, have recently been developed. To date, the only direct thrombin inhibitor shown to reduce both the ischaemic and the bleeding complications associated with percutaneous coronary intervention (PCI) is bivalirudin, which is approved for this indication in the US and New Zealand. This agent is currently being studied in patients undergoing PCI with or without glycoprotein IIb/IIIa inhibitors and stenting. Bivalirudin has been shown to significantly reduce the risk of reinfarction in patients with acute myocardial infarction (MI) treated with streptokinase, but its use for this indication is not approved in the US. It may also prove to be beneficial in patients with acute MI treated with other fibrinolytic regimens or with primary or facilitated PCI. Bivalirudin is suitable for use as an alternative to heparin in the majority of patients undergoing PCI and in patients receiving streptokinase for acute MI.     

Bivalirudin: an anticoagulant for acute coronary syndromes and coronary interventions

Heparin is a commonly used anticoagulant in patients with coronary artery disease but its use does not always result in low rates of ischaemic and bleeding events, so the search for new anticoagulants continues. Thrombin plays a key role in both thrombosis and haemostasis and direct thrombin inhibitors modelled on the hirudin molecule found in the saliva of the medicinal leech, Hirudo medicinalis, have recently been developed. To date, the only direct thrombin inhibitor shown to reduce both the ischaemic and the bleeding complications associated with percutaneous coronary intervention (PCI) is bivalirudin, which is approved for this indication in the US and New Zealand. This agent is currently being studied in patients undergoing PCI with or without glycoprotein IIb/IIIa inhibitors and stenting. Bivalirudin has been shown to significantly reduce the risk of reinfarction in patients with acute myocardial infarction (MI) treated with streptokinase, but its use for this indication is not approved in the US. It may also prove to be beneficial in patients with acute MI treated with other fibrinolytic regimens or with primary or facilitated PCI. Bivalirudin is suitable for use as an alternative to heparin in the majority of patients undergoing PCI and in patients receiving streptokinase for acute MI.     

Bivalirudin: a review of its use in patients undergoing percutaneous coronary intervention

Bivalirudin (Angiox, Angiomax) is a synthetic 20-amino acid peptide analogue of hirudin. It is a direct thrombin inhibitor that binds specifically and reversibly to both fibrin-bound and unbound thrombin. Intravenous bivalirudin is approved in Europe for use as an anticoagulant in patients undergoing percutaneous coronary intervention (PCI). In the US, bivalirudin is approved in patients with unstable angina pectoris undergoing percutaneous transluminal coronary angioplasty (PTCA) and has recently been approved for use with provisional glycoprotein (GP) IIb/IIIa inhibition in patients undergoing PCI. Bivalirudin plus provisional GP IIb/IIIa inhibition is effective in patients undergoing PCI. The large, well controlled REPLACE-2 (Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events) study showed that bivalirudin plus provisional GP IIb/IIIa inhibition was noninferior to heparin plus planned GP IIb/IIIa inhibition and that bivalirudin was associated with a reduced risk of bleeding complications. In patients with heparin-induced thrombocytopenia (HIT), bivalirudin was effective against ischaemic events and there was a low incidence of bleeding complications. Bivalirudin should be considered as an alternative to heparin plus planned GP IIb/IIIa inhibition in any patient undergoing urgent or elective PCI, especially in any patient with a high risk of bleeding complications.     

Eptifibatide: a pharmacoeconomic review of its use in percutaneous coronary intervention and acute coronary syndromes

Eptifibatide (Integrilin) is a selective inhibitor of platelet glycoprotein (GP) IIb/IIIa receptors used as adjunctive therapy for patients undergoing percutaneous coronary intervention (PCI) and for patients with acute coronary syndromes (ACS), particularly those requiring PCI. Most economic analyses of eptifibatide have incorporated clinical and healthcare resource use data from either the ESPRIT (Enhanced Suppression of the Platelet IIb/IIIa Receptor with Integrilin Therapy) study in low- to moderate-risk patients undergoing selective PCI with stent implantation or the PURSUIT (Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy) trial in patients with ACS. Eptifibatide achieved statistically significant reductions in combined endpoints of death and ischaemic complications in both of these large multicentre clinical trials, in which patients were randomised to receive intravenous eptifibatide or placebo as adjunctive therapy to heparin and aspirin (plus a thienopyridine in ESPRIT). In US economic analyses using ESPRIT trial data, approximately 40% and 70% of the acquisition cost of eptifibatide was offset by reduced medical resource consumption during the initial hospitalisation period and over a 1-year period, respectively. Eptifibatide was associated with a favourable cost-effectiveness ratio of $US1407 (year 2000 costs) per life-year gained (LYG) in a retrospective US cost-effectiveness analysis that incorporated data from the ESPRIT trial and modelled life expectancy using a large cardiovascular database.Several cost-effectiveness analyses used prospectively collected data from the PURSUIT trial and modelled survival projections using similar methods. These analyses, conducted in the US, Canada and Western Europe, also showed favourable results ($US3761-$US18 774 per LYG; various years of costing). Cost-utility ratios reported in US analyses varied somewhat, but remained <$US20 000 per quality-adjusted life-year gained (1996 values) when clinical efficacy data were derived from the US cohort of PURSUIT. CONCLUSION: Significant clinical benefits have been demonstrated with eptifibatide as adjunctive therapy in patients undergoing selective PCI with stent implantation in the ESPRIT trial and in patients with ACS in the PURSUIT trial. Pharmacoeconomic analyses using data from either ESPRIT or PURSUIT have demonstrated favourable cost-effectiveness ratios for both indications in various countries. ESPRIT-based results from the limited number of available economic analyses are particularly favourable. The cost-effectiveness of eptifibatide in ACS (i.e. PURSUIT-based results) may be further improved by targeting the drug for patients in whom catheterisation and PCI are planned, although further analyses are required to confirm this.     

Bivalirudin: in patients with acute coronary syndromes : planned for urgent or early intervention

Bivalirudin is a 20-amino acid synthetic polypeptide that directly inhibits both fibrin-bound and soluble thrombin. In a randomized, open-label, phase III study (ACUITY) in 13,819 patients with acute coronary syndromes (unstable angina or non-ST-segment elevation myocardial infarction) in whom urgent or early intervention was planned, both bivalirudin plus a glycoprotein (GP) IIb/IIIa inhibitor and bivalirudin alone were noninferior to heparin plus a GP IIb/IIIa inhibitor for the primary endpoint of composite ischaemia (myocardial infarction, unplanned revascularization or death from any cause) at 30 days. The primary endpoint of major bleeding not related to coronary artery bypass graft surgery had occurred in significantly fewer recipients of bivalirudin alone than of heparin plus a GP IIb/IIIa inhibitor after 30 days. Bivalirudin plus a GP IIb/IIIa inhibitor was noninferior to the heparin regimen with regard to this bleeding event. Bivalirudin alone was also associated with a significantly lower incidence of the primary net clinical outcome endpoint (composite ischaemia or major bleeding) after 30 days. Bivalirudin plus a GP IIb/IIIa inhibitor was noninferior to the heparin regimen with regard to this endpoint. The findings of ACUITY at 1 year indicate that both bivalirudin plus a GP IIb/IIIa inhibitor and bivalirudin alone were as effective as heparin plus a GP IIb/IIIa inhibitor with regard to the long-term incidence of composite ischaemia and all-cause mortality.     

Enoxaparin: an update of its clinical use in the management of acute coronary syndromes

Enoxaparin (enoxaparin sodium) is a low molecular weight heparin (LMWH) indicated for use in the treatment of ischaemic complications of unstable angina and non-Q wave myocardial infarction (MI). Unfractionated heparin (UFH) has for many years represented the standard in anticoagulant therapy for patients with acute coronary syndromes; however, recent studies suggest that enoxaparin is also a viable option for anticoagulant therapy in these patients. The ESSENCE (Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q wave Coronary Events) and the TIMI 11B (Thrombolysis in Myocardial Infarction) studies reported that twice daily enoxaparin was significantly more effective than a continuous infusion of UFH in reducing the composite triple endpoint of death, MI, or recurrent angina or urgent revascularisation. Follow-up of both patient populations showed continued benefit associated with enoxaparin. Enoxaparin has been compared with tinzaparin in the treatment of unstable coronary artery disease using a nonblind study design. There was no difference between treatment groups in the therapeutic endpoints. Three nonblind studies have also compared the effects of enoxaparin and UFH in patients receiving thrombolytic therapy following acute MI. The HART II (Heparin and Aspirin Reperfusion Therapy), the ASSENT 3 (Assessment of the Safety and Efficacy of a New Thrombolytic Regimen) and the ENTIRE-TIMI 23 (Enoxaparin and Tenecteplase with or without glycoprotein IIb/IIIa Inhibitor as Reperfusion strategy in ST Elevation MI - Thrombolysis in Myocardial Infarction) studies have revealed that enoxaparin in combination with alteplase or tenecteplase is at least equivalent (HART II and ENTIRE-TIMI 23), and possibly superior (ASSENT 3) to UFH. Enoxaparin is administered as a twice-daily subcutaneous injection. In contrast, UFH is administered as an intravenous infusion which requires routine monitoring of the activated partial thromboplastin time to ensure adequate levels of anticoagulation are maintained. During the acute phase of the the ESSENCE and TIMI 11B studies, the incidence of major bleeding was similar in patients receiving enoxaparin to that in patients receiving UFH. In contrast, the rates of minor bleeding were higher in patients receiving enoxaparin than in those receiving UFH throughout these studies. Conclusions: Data from the ESSENCE, TIMI 11B and ASSENT 3 studies have prompted calls for those LMWHs which have been shown to be superior to UFH, to be considered as first choice treatment for anticoagulation in unstable coronary syndromes. To date, these suggestions are not reflected in current guidelines which consider UFH and LMWHs equally. Irrespective, the clinical data reported in this review support the use of enoxaparin in the treatment of acute coronary syndromes. These data suggest that enoxaparin shows certain clinical and practical advantages over standard treatment with UFH and represents an important development in the treatment of acute coronary syndromes.     

Clopidogrel: a pharmacoeconomic review of its use in patients with non-ST elevation acute coronary syndromes

Clopidogrel (Plavix) is a selective inhibitor of adenosine diphosphate-induced platelet aggregation. In patients with acute coronary syndromes (ACS) [unstable angina or non-ST-segment elevation myocardial infarction], clopidogrel plus aspirin (acetylsalicylic acid) for up to 1 year significantly reduced the risk of cardiovascular events relative to placebo plus aspirin in the well designed clinical trial CURE (Clopidogrel in Unstable angina to prevent Recurrent Events) and its substudy in patients undergoing percutaneous coronary intervention (PCI) [PCI-CURE]. In pharmacoeconomic evaluations based on data from these trials conducted in a number of countries that used a variety of models, methods and/or type of costs, clopidogrel plus aspirin was consistently predicted to be cost effective relative to aspirin alone in the management of patients with ACS, including those undergoing PCI. Clopidogrel plus aspirin in patients with ACS reduced the incremental cost per cardiovascular event prevented and/or life-year gained (LYG) relative to aspirin alone in analyses using within-trial data (including longer-term analyses incorporating life-expectancy estimates) from the CURE or PCI-CURE studies. In Markov models of cost effectiveness with a lifetime horizon from a healthcare payer perspective based on the CURE trial, relative to aspirin alone, clopidogrel plus aspirin for 1 year was predicted to have incremental costs per LYG of 8132Euro in Spain (2003 values) and 1365Euro in Sweden (2000 values). In similar Swedish analyses from a healthcare payer perspective, clopidogrel plus aspirin for 1 year was predicted to have incremental costs per LYG of 10,993Euro (2004 values) relative to aspirin alone based on data from the PCI-CURE substudy. Broadly similar results have also been reported in modelled analyses from other countries. Cost-utility analyses based on the CURE trial suggest that, relative to lifelong aspirin alone, clopidogrel plus aspirin for 1 year followed by aspirin alone is associated with incremental costs per QALY gained that are below the traditional threshold of cost utility in Spain, the UK and the US. In patients with ACS, including those undergoing PCI, the addition of clopidogrel to standard therapy with aspirin is clinically effective in preventing cardiovascular events. Available pharmacoeconomic data from several countries, despite some inherent limitations, support the use of clopidogrel plus aspirin for up to 1 year as a cost-effective treatment relative to aspirin alone in this patient population.     

Azacitidine: a review of its use in the management of myelodysplastic syndromes/acute myeloid leukaemia

Azacitidine (Vidaza?) is a pyrimidine nucleoside analogue of cytidine. This article reviews the clinical efficacy and tolerability of azacitidine in the treatment of patients with myelodysplastic syndromes (MDS)/acute myeloid leukaemia (AML), as well as summarizing its pharmacological properties. The randomized, multicentre Cancer and Leukemia Group B 9221 trial compared the efficacy of subcutaneous azacitidine with that of supportive care alone in patients with MDS fulfilling French-American-British (FAB) classification criteria. The overall response rate, the complete response rate and the complete plus partial response rate were significantly higher in patients receiving azacitidine than in those receiving supportive care alone. The randomized, open-label, multicentre AZA-001 trial compared the efficacy of subcutaneous azacitidine with that of conventional care in adults with higher-risk (i.e. International Prognostic Scoring System intermediate-2-risk or high-risk classification) MDS/AML. Prior to randomization, investigators preselected patients to the conventional care strategy considered most appropriate (i.e. best supportive care, low-dose cytarabine or intensive chemotherapy). The median duration of overall survival was significantly prolonged by 9.4 months in patients with higher-risk MDS receiving azacitidine versus those receiving conventional care. The survival benefit seen with azacitidine versus conventional care was maintained across various patient subgroups (e.g. in patients aged ≥75 years, in those who did not achieve complete remission and in patients with WHO-defined AML). The efficacy of subcutaneous or intravenous azacitidine was also shown in a noncomparative trial in Japanese patients with MDS fulfilling FAB classification criteria, and registry programmes in various countries support the efficacy of azacitidine in patients with MDS. Azacitidine was generally well tolerated in patients with MDS, including in the elderly. Across trials, peripheral cytopenias were the most commonly occurring adverse event in azacitidine recipients, with gastrointestinal adverse events (e.g. nausea, vomiting and diarrhoea) and injection-site reactions among the most commonly occurring non-haematological adverse events. In conclusion, azacitidine is an important agent for use in the treatment of patients with MDS/AML.     

Bivalirudin: a review

Bivalirudin (Angiomax®) is a thrombin-inhibiting oligopeptide that was developed via rational drug design as a hirudin analogue (‘hirulog’). Similar to hirudin, it is a bivalent thrombin inhibitor, as its 20-amino acid structure combines a carboxy-terminal region that recognises thrombin’s fibrin(ogen)-binding site, and an amino-terminal tetrapeptide that inhibits the active site of thrombin, connected by a tetraglycine spacer. It has certain pharmacological advantages over hirudin, including enzymic metabolism (less dependence on renal clearance) and low immunogenicity (reduced potential for anaphylaxis). Bivalirudin is approved for use in percutaneous transluminal coronary angioplasty (PTCA), and is undergoing active investigation for anticoagulation during cardiac surgery, both ‘off-pump’ and with cardiopulmonary bypass (‘on-pump’). Anecdotal ‘off-label’ experience for the treatment of heparin-induced thrombocytopenia shows promise.     

Bivalirudin: a review

Bivalirudin (Angiomax) is a thrombin-inhibiting oligopeptide that was developed via rational drug design as a hirudin analogue ('hirulog'). Similar to hirudin, it is a bivalent thrombin inhibitor, as its 20-amino acid structure combines a carboxy-terminal region that recognises thrombin's fibrin(ogen)-binding site, and an amino-terminal tetrapeptide that inhibits the active site of thrombin, connected by a tetraglycine spacer. It has certain pharmacological advantages over hirudin, including enzymic metabolism (less dependence on renal clearance) and low immunogenicity (reduced potential for anaphylaxis). Bivalirudin is approved for use in percutaneous transluminal coronary angioplasty (PTCA), and is undergoing active investigation for anticoagulation during cardiac surgery, both 'off-pump' and with cardiopulmonary bypass ('on-pump'). Anecdotal 'off-label' experience for the treatment of heparin-induced thrombocytopenia shows promise.     

Eptifibatide: a review of its use in patients with acute coronary syndromes and/or undergoing percutaneous coronary intervention

Eptifibatide, a cyclic peptide, is a highly specific, intravenously administered glycoprotein (GP) IIb/IIIa receptor antagonist. By preventing fibrinogen binding to the GP IIb/IIIa receptor, eptifibatide inhibits platelet aggregation and prevents thrombus formation. Clinically, the drug is used as an adjunct to heparin and aspirin. The PURSUIT trial, conducted in >10,000 patients with unstable angina or non-Q-wave myocardial infarction (MI), showed that eptifibatide (180 microg/kg bolus then 2 microg/kg/min infusion for < or =72 hours) reduces the 30-day risk of death or nonfatal MI, with this benefit apparent at 96 hours. The absolute reduction in this end-point of 1.5% persisted at 6 months. The drug is effective in patients undergoing percutaneous coronary intervention (PCI), and, as shown in the North American subgroup, in patients in whom medical management is appropriate. Eptifibatide is also beneficial in patients undergoing PCI, whether or not they have unstable angina or non-Q-wave MI. In a dosage of 135 microg/kg then 0.5 microg/kg/min for 24 hours, eptifibatide reduced the 30-day risk of a combined end-point (death, nonfatal MI and urgent or emergency coronary interventions) by 2.5% (absolute reduction) in patients undergoing PCI in the IMPACT-II trial, when measured by per-protocol (patients treated), but not intent-to-treat, analysis. The drug also decreased the incidence of abrupt vessel closure and ischaemic cardiovascular complications in the first 24 hours (the period of greatest risk). Bleeding episodes are the most common adverse event associated with eptifibatide therapy. Although the incidence of major bleeding is increased with eptifibatide, most bleeding episodes are minor and occur at the vascular access site. The drug is not associated with an excess of intracranial bleeds, stroke or thrombocytopenia, does not appear to increase bleeding risk in patients undergoing coronary artery bypass graft (CABG), and does not cause antibody formation. Limited data suggest that eptifibatide may improve coronary flow when combined with alteplase in patients with acute Q-wave MI, but the possibility of increased bleeding with eptifibatide plus thrombolytics should be borne in mind. CONCLUSIONS: Intravenous eptifibatide, when combined with aspirin and heparin, reduces the 30-day risk of ischaemic events in patients with unstable angina and non-Q-wave MI and decreases ischaemic cardiovascular complications at the time of greatest risk in patients undergoing PCI. With its acceptable tolerability profile eptifibatide is a suitable option as a short term adjunct in these clinical settings. Whether eptifibatide in combination with fibrolysis may improve outcome in patients with acute Q-wave MI has yet to be determined.     

Eptifibatide: a review of its use in patients with acute coronary syndromes and/or undergoing percutaneous coronary intervention

Eptifibatide (Integrilin) is a highly specific, reversible, intravenously administered glycoprotein (GP) IIb/IIIa receptor antagonist that acts at the final common step of the platelet aggregation pathway. Data from large clinical trials indicate that intravenous eptifibatide as adjunctive therapy to standard care is effective in patients with non-ST-segment elevation (NSTE) acute coronary syndromes (ACS) and/or undergoing percutaneous coronary intervention (PCI). In the ESPRIT (Enhanced Suppression of the Platelet glycoprotein IIb/IIIa Receptor with Integrilin Therapy) trial in patients undergoing PCI with stenting, eptifibatide, compared with placebo, achieved significant reductions in death and ischaemic complications and was better than a strategy of reserving treatment for the bailout situation. In the large PURSUIT (Platelet IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin Therapy) trial in patients with NSTE ACS, eptifibatide was associated with a significant reduction in the incidence of death or myocardial infarction (MI) compared with placebo. Eptifibatide is well tolerated in these trials. Ongoing trials are currently investigating the efficacy and tolerability of regimens that include this agent in other indications, including ST-segment elevation MI (STEMI).     

MicroRNAs as circulating biomarkers in acute coronary syndromes: A review

Coronary artery disease (CAD) and its complications remain the most common cause of death worldwide. Cardiac troponins (cTn) are standard biomarkers used today for diagnosis and risk stratification of myocardial infarction (MI). Increasing efforts are made to develop additional, new biomarkers for more effective and safe rule-in and rule-out of MI patients at the emergency department. During the past decade, microRNAs (miRNAs) have emerged as new, potential diagnostic biomarkers in several diseases, including MI. In this review, we aimed to summarize some of the prominent studies in the field, and discuss the potential value of miRNAs in the diagnosis of MI.     

Major bleeding: management and risk reduction in acute coronary syndromes

Background: Guidelines for the management of high-risk non ST-segment elevation acute coronary syndrome (NSTE ACS) recommend antithrombotic and antiplatelet therapy combined with an early invasive strategy. While this strategy reduces ischemic complications, it places patients at risk for bleeding complications. Objective: We sought to provide a narrative review of the risk factors for bleeding, risks associated with bleeding and strategies to prevent bleeding complications. Methods: A comprehensive literature review was performed to identify relevant evidence. Results/conclusions: Bleeding complications in NSTE ACS are associated with adverse events and higher mortality. Prevention of bleeding complications can be achieved through judicious dosing of medications, the use of antithrombotic agents associated with a lower bleeding risk and use of the radial artery approach in patients requiring coronary intervention. Future work should focus on delineating the mechanisms underlying the bleeding–mortality relationship and developing a better understanding of the tradeoff between efficacy and safety.     

Enoxaparin: a pharmacoeconomic review of its use in the prevention and treatment of venous thromboembolism and in acute coronary syndromes

The pharmacoeconomics of the low molecular weight heparin (LMWH) enoxaparin in the prophylaxis and treatment of venous thromboembolism have mostly been investigated in cost-effectiveness studies that estimated direct costs associated with treatment, using decision analyses and clinical outcome data from randomised controlled trials. These studies have shown enoxaparin to be cost effective compared with unfractionated heparin (UFH) and warfarin in short-term thromboprophylaxis for hospital inpatients undergoing orthopaedic surgery and in thromboprophylaxis following trauma. Outpatient treatment of acute proximal deep vein thrombosis with enoxaparin has also been shown to be cost effective compared with inpatient treatment using UFH. In general surgery, however, it remains to be determined whether enoxaparin is a cost-effective alternative to UFH. The cost effectiveness of enoxaparin compared with UFH in the treatment of unstable angina and non-Q-wave myocardial infarction has also been investigated in several countries using clinical outcomes data from the Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q-wave Coronary Events (ESSENCE) randomised trial. ESSENCE demonstrated that enoxaparin was superior to UFH in terms of tolerability and efficacy, and cost saving at both 30-day and 1-year follow-ups. An increasing number of studies indicate enoxaparin to be of economic benefit when used for prevention and treatment of venous thromboembolism and treatment of acute coronary symdromes.