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

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

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

Analysis of the Financial Impact of Using Cangrelor on the Safety and Efficacy Outcomes in Patients Undergoing Percutaneous Coronary Intervention in Whom Oral Therapy with P2Y12 Inhibitors is Not Feasible or Desirable, in Spain

PURPOSE

Cangrelor is an intravenous, direct-acting, reversible P2Y12 inhibitor indicated for the reduction of thrombotic cardiovascular events in patients with coronary artery disease (CAD) undergoing percutaneous coronary intervention (PCI) in whom oral P2Y12 inhibitors are not feasible or desirable. The objective was to assess the financial impact of introducing cangrelor into the hospital formulary in Spain.

PATIENTS AND METHODS

A budget impact model was developed to calculate the cost difference between two scenarios (without and with cangrelor) to treat CAD patients undergoing PCI in whom oral P2Y12 inhibitors are not feasible or desirable, over 3 years. Intravenous P2Y12 inhibitor (cangrelor), oral P2Y12 inhibitors (clopidogrel, prasugrel, and ticagrelor), and glycoprotein IIb-IIIa inhibitors (GPIs) for bail-out use were considered. Epidemiological, efficacy (thrombotic events including cardiac death), safety (bleeding events), and costs (€, 2019) data were based on Spanish registries, clinical trials, and meta-analyses. One-way sensitivity analysis established the effect of uncertainty on results.

RESULTS

For years 1, 2, and 3, the target population to receive cangrelor was 607, 1,822, and 3,340 patients, and cangrelor uptake was 23.70%, 58.30%, and 51.30%, respectively. The 3-year budget impact was 1,021,717€ varying from 50,245€ in year 1 to 599,272€ in year 3. The results were sensitive to the number of patients treated with GPIs in Spanish hospitals.

CONCLUSION

Based on our results, the financial effort needed to introduce the use of cangrelor in patients undergoing PCI in whom antiplatelet therapy with oral P2Y12 inhibitors is not feasible or desirable barely exceeds one million € over three years, in Spain.

Snake venom components in medicine: From the symbolic rod of Asclepius to tangible medical research and application

Both mythologically and logically, snakes have always fascinated man. Snakes have attracted both awe and fear not only because of the elegant movement of their limbless bodies, but also because of the potency of their deadly venoms. Practically, in 2017, the world health organization (WHO) listed snake envenomation as a high priority neglected disease, as snakes inflict up to 2.7 million poisonous bites, around 100.000 casualties, and about three times as many invalidities on man. The venoms of poisonous snakes are a cocktail of potent compounds which specifically and avidly target numerous essential molecules with high efficacy. The individual effects of all venom toxins integrate into lethal dysfunctions of almost any organ system. It is this efficacy and specificity of each venom component, which after analysis of its structure and activity may serve as a potential lead structure for chemical imitation. Such toxin mimetics may help in influencing a specific body function pharmaceutically for the sake of man's health. In this review article, we will give some examples of snake venom components which have spurred the development of novel pharmaceutical compounds. Moreover, we will provide examples where such snake toxin-derived mimetics are in clinical use, trials, or consideration for further pharmaceutical exploitation, especially in the fields of hemostasis, thrombosis, coagulation, and metastasis. Thus, it becomes clear why a snake captured its symbolic place at the Asclepius rod with good reason still nowadays.

Clinical and economic studies of eptifibatide in coronary stenting

Platelet adhesion and aggregation at the site of coronary stenting can have catastrophic clinical and economic consequences. Therefore, effective platelet inhibition is vital during and after percutaneous coronary intervention. Eptifibatide is an intravenous antiplatelet agent that blocks the final common pathway of platelet aggregation and thrombus formation by binding to glycoprotein IIb/IIIa receptors on the surface of platelets. In clinical studies, eptifibatide was associated with a significant reduction of mortality, myocardial infarction, or target vessel revascularization in patients with acute coronary syndrome undergoing percutaneous coronary intervention. However, recent trials conducted in the era of dual antiplatelet therapy and newer anticoagulants failed to demonstrate similar results. The previously seen favorable benefit of eptifibatide was mainly offset by the increased risk of bleeding. Current American College of Cardiology/American Heart Association guidelines recommend its use as an adjunct in high-risk patients who are undergoing percutaneous coronary intervention with traditional anticoagulants (heparin or enoxaparin), who are not otherwise at high risk of bleeding. In patients receiving bivalirudin (a newer safer anticoagulant), routine use of eptifibatide is discouraged except in select situations (eg, angiographic complications). Although older pharmacoeconomic studies favor eptifibatide, in the current era of P2Y12 inhibitors and newer safer anticoagulants, the increased costs associated with bleeding make the routine use of eptifibatide an economically nonviable option. The cost-effectiveness of eptifibatide with the use of strategies that decrease the bleeding risk (eg, transradial access) is unknown. This review provides an overview of key clinical and economic studies of eptifibatide well into the current era of potent antiplatelet agents, novel safer anticoagulants, and contemporary percutaneous coronary intervention.

Cost-effectiveness of adjunctive eptifibatide in patients undergoing coronary stenting in Germany

OBJECTIVE

To determine the cost-effectiveness of adding eptifibatide to the standard treatment for selected high-risk patients undergoing coronary stenting in Germany. Furthermore, to investigate the impact of several extrapolation methods on the results.

METHODS

A Markov model was developed to reflect the clinical events in this specific patient population, including target vessel revascularization, myocardial infarction, and death. To extrapolate clinical data beyond 1 year, a linear, an exponential, and a Weibull survival curves were estimated. Patient characteristics and transition probabilities were derived from a high-risk subgroup of the ESPRIT trial; patient-level utility data came from a published Dutch study. Costs were calculated from a hospital and from a third-party payer perspective.

RESULTS

For both perspectives, the additional treatment with eptifibatide is the considered dominant alternative. The incremental net benefit of its use exceeds €10,000 for both perspectives. Results proved stable in probabilistic sensitivity analysis as well as under the different extrapolation scenarios.

CONCLUSIONS

Eptifibatide is likely to be dominant strategy with 77.7 and 96.7% of the simulations leading to QALYs gained and generating cost savings from both the hospital and the third-party payer perspective. Eptifibatide offsets its additional treatment costs by avoiding costly repeat procedures and leads to positive QALY gains by preventing cardiovascular events lending themselves to transient or permanent lower quality of life. The method used to extrapolate the short-term risks did not impact on results, mainly due to similar clinical risk profiles between the two treatment groups in the long term.

Structure and function of snake venom proteins affecting platelet plug formation

Many snake venom proteins have been isolated that affect platelet plug formation by interacting either with platelet integrins, membrane glycoprotein Ib (GPIb), or plasma von Willebrand factor (VWF). Among them, disintegrins purified from various snake venoms are strong inhibitors of platelet aggregation. Botrocetin and bitiscetin derived from Bothrops jararaca and Bitis arietans venom, respectively, induce VWF-dependent platelet agglutination in vitro. Several GPIb-binding proteins have also been isolated from snake venoms. In this review, we focus on the structure and function of those snake venom proteins that influence platelet plug formation. These proteins are potentially useful as reagents for the sub-diagnosis of platelet disorder or von Willebrand disease, as well as for clinical and basic research of thrombosis and hemostasis.

Cost effectiveness of fondaparinux in non-ST-elevation acute coronary syndrome

BACKGROUND

Fondaparinux has been shown to reduce the risk of major bleeding and 30-day mortality compared with enoxaparin, in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS). However, its cost effectiveness is not well known.

OBJECTIVE

To evaluate the effectiveness and economic attractiveness of fondaparinux relative to enoxaparin in patients with NSTE-ACS treated with triple antiplatelet therapy and early (non-urgent) invasive strategy.

METHODS

The decision model compares two alternative strategies: subcutaneous (SC) enoxaparin (1 mg/kg 12 hourly) versus SC fondaparinux (2.5 mg/day) in NSTE-ACS patients pre-treated with triple antiplatelet therapy and early revascularization. Cost-effectiveness and cost-utility analyses were performed from a healthcare perspective, based on a Markov model with a time horizon of the patient lifespan. Univariate sensitivity analysis and probabilistic (Monte Carlo) microsimulation analysis were performed.

RESULTS

In the base-case analysis (65 years, Thrombolysis In Myocardial Infarction [TIMI] score 4), the use of fondaparinux was associated with a significant reduction in major bleeding, a slight reduction in adverse cardiac events, and minor improvements in survival and QALYs, together with a small reduction in costs. The dominance of fondaparinux over enoxaparin remained unchanged in the univariate sensitivity analyses. According to Monte Carlo simulation, fondaparinux was cost saving in 99.9% of cases.

CONCLUSION

Compared with enoxaparin, the use of fondaparinux in patients with NSTE-ACS managed with an early invasive strategy appears to be cost effective, even in patients with a low risk of bleeding.

Using triple antiplatelet therapy in patients with non-ST elevation acute coronary syndrome managed invasively: a cost-effectiveness analysis

OBJECTIVES

To assess the incremental cost-effectiveness ratio (ICER) of glycoprotein IIb/IIIa (GPIIb/IIIa) inhibitors in patients with non-ST elevation acute coronary syndrome (NSTE-ACS) pretreated with aspirin and clopidogrel undergoing an early invasive treatment strategy.

METHODS

Cost-effectiveness analysis and cost-utility analysis were performed from a health-care system perspective, based on a Markov model with a time horizon of the patient life span. The risk of death and ischemic events was assessed using the Thrombolysis in Myocardial Infarction (TIMI) risk score. We compared three strategies: 1) routine upstream use of a GPIIb/IIIa inhibitor to all patients before angiography, 2) deferred selective use of abciximab in the catheterization laboratory just before angioplasty, and 3) double antiplatelet therapy without GPIIb/IIIa inhibitors. Both univariate sensitivity analysis and second-order probabilistic microsimulation were performed.

RESULTS

In the base case (65 years old, TIMI score 3), strategy A was the most effective, with an ICER of 15,150 euros per quality-adjusted life-year gained. Strategy B was dominated by a combination of strategies A and C. The ICER was very sensitive to the age and baseline risk of the patient. According to the widely accepted cost-effectiveness thresholds, strategy A would be cost-effective only in patients with an intermediate to high TIMI score, especially within the younger age groups. The probability that strategy A was cost-effective under the base case was 91.2%.

CONCLUSIONS

The use of GPIIb/IIIa inhibitors upstream in high-risk NSTE-ACS patients (TIMI score > or = 3) pretreated with aspirin and clopidogrel is cost-effective, particularly in the younger age groups.

A longitudinal analysis of outcomes associated with abciximab and eptifibatide in a consecutive series of 3074 percutaneous coronary interventions

BACKGROUND

Although the efficacy of platelet glycoprotein IIb/IIIa inhibitors (GPIIb/IIIa) in reducing complication rates during percutaneous coronary intervention (PCI) is well established, comparative studies assessing currently approved agents as administered in current practice are limited. We studied the clinical and length of stay (LOS) outcomes of patients undergoing PCI who received either abciximab or eptifibatide.

METHODS

All patients undergoing elective, urgent, or emergency PCI at Mayo Clinic Rochester between November 17, 2000 and August 31, 2004 who received either abciximab or eptifibatide were included. Clinical, angiographic, and follow-up data were prospectively recorded in the Mayo Clinic PCI Registry; administrative data recorded LOS. We used logistic and Cox proportional hazard models to estimate the risk of adverse events and generalized linear modeling to predict LOS. Propensity score and standard risk adjustments were used to account for baseline differences.

RESULTS

A total of 2123 PCI patients received eptifibatide and 951 received abciximab. The adjusted odds ratio for in-hospital death and myocardial infarction (MI) with eptifibatide was 0.80 (95% CI 0.56-1.14, P = 0.21) versus abciximab. Adjusted hazard ratios for death and MI and for death, MI, or target vessel revascularization during a median follow-up of 24.6 months were 0.84 (95% CI 0.68-1.02, P = 0.08) and 0.95 (95% CI 0.81-1.11, P = 0.53), respectively. Adjusted postprocedural LOS was similar at 3.4 days.

CONCLUSION

This large observational study found no evidence of a clinical or LOS advantage to physician choice of either abciximab or eptifibatide during PCI in contemporary practice.

Beta-cardiotoxin: a new three-finger toxin from Ophiophagus hannah (king cobra) venom with beta-blocker activity

Snake venoms have provided a number of novel ligands with therapeutic potential. We have constructed a partial cDNA library from the mRNA of Ophiophagus hannah (king cobra) venom gland tissue and identified five new genes encoding proteins belonging to the three-finger toxin family of snake venom proteins. We have isolated and characterized one of these beta-sheet containing proteins with a mass of 7012.43 +/- 0.91 Da from the venom. The protein was nonlethal up to a dose of 10 mg/kg when injected intraperitoneally into Swiss albino mice. However, it induces labored breathing and death at a dose of 100 mg/kg. It does not show any hemolytic or anticoagulant activity. It caused a dose-dependent decrease of heart rate in vivo (anesthetized Sprague-Dawley rats) and also ex vivo (Langendorff isolated rat heart). This is in contrast to classical cardiotoxins from snake venom that increase the heart rate in animals. Radioligand displacement studies showed that this protein targets beta-adrenergic receptors with a binding affinity (Ki) of 5.3 and 2.3 microM toward beta1 and beta2 subtypes, respectively, to bring about its effect, and hence, it was named as beta-cardiotoxin. This is the first report of a natural exogenous beta-blocker.

Hemextin AB Complex, a Unique Anticoagulant Protein Complex from Hemachatus haemachatus (African Ringhals Cobra) Venom That Inhibits Clot Initiation and Factor VIIa Activity

During injury or trauma, blood coagulation is initiated by the interaction of factor VIIa (FVIIa) in the blood with freshly exposed tissue factor (TF) to form the TF.FVIIa complex. However, unwanted clot formation can lead to death and debilitation due to vascular occlusion, and hence, anticoagulants are important for the treatment of thromboembolic disorders. Here, we report the isolation and characterization of two synergistically acting anticoagulant proteins, hemextins A and B, from the venom of Hemachatus haemachatus (African Ringhals cobra). N-terminal sequences and CD spectra of the native proteins indicate that these proteins belong to the three-finger toxin family. Hemextin A (but not hemextin B) exhibits mild anticoagulant activity. However, hemextin B forms a complex (hemextin AB complex) with hemextin A and synergistically enhances its anticoagulant potency. Prothrombin time assay showed that these two proteins form a 1:1 complex. Complex formation was supported by size-exclusion chromatography. Using a "dissection approach," we determined that hemextin A and the hemextin AB complex prolong clotting by inhibiting TF.FVIIa activity. The site of anticoagulant effects was supported by their inhibitory effect on the reconstituted TF.FVIIa complex. Furthermore, we demonstrated their specificity of inhibition by studying their effects on 12 serine proteases; the hemextin AB complex potently inhibited the amidolytic activity of FVIIa in the presence and absence of soluble TF. Kinetic studies showed that the hemextin AB complex is a noncompetitive inhibitor of soluble TF.FVIIa amidolytic activity, with a Ki of 50 nm. Isothermal titration calorimetric studies showed that the hemextin AB complex binds directly to FVIIa with a binding constant of 1.62 x 10(5) m(-1). The hemextin AB complex is the first reported natural inhibitor of FVIIa that does not require a scaffold to mediate its inhibitory activity. Molecular interactions of the hemextin AB complex with FVIIa/TF.FVIIa will provide a new paradigm in the search for anticoagulants that inhibit the initiation of blood coagulation.