Economic impact of GPIIB/IIIA blockade after high-risk angioplasty: results from the RESTORE trial. Randomized Efficacy Study of Tirofiban for Outcomes and Restenosis

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

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

Conducting economic evaluations alongside multinational clinical trials: toward a research consensus

Demand for economic evaluations in multinational clinical trials is increasing, but there is little consensus about how such studies should be conducted and reported. At a workshop in Durham, North Carolina, we sought to identify areas of agreement about how the primary findings of economic evaluations in multinational clinical trials should be generated and presented. In this paper, we propose a framework for classifying multinational economic evaluations according to (a) the sources of an analyst's estimates of resource use and clinical effectiveness and (b) the analyst's method of estimating costs. We review existing studies in the cardiology literature in the context of the proposed framework. We then describe important methodological and practical considerations in conducting multinational economic evaluations and summarize the advantages and disadvantages of each approach. Finally, we describe opportunities for future research. Delineation of the various approaches to multinational economic evaluation may assist researchers, peer reviewers, journal editors, and decision makers in evaluating the strengths and limitations of particular studies.

Economic evaluation of bivalirudin with provisional glycoprotein IIB/IIIA inhibition versus heparin with routine glycoprotein IIB/IIIA inhibition for percutaneous coronary intervention: results from the REPLACE-2 trial

OBJECTIVES

The purpose of this study was to compare the cost of percutaneous coronary intervention (PCI) using bivalirudin with provisional platelet glycoprotein (GP) IIb/IIIa inhibition with that of heparin + routine GP IIb/IIIa inhibition.

BACKGROUND

Although GP IIb/IIIa inhibition has been shown to reduce ischemic complications in a broad range of patients undergoing PCI, many patients currently do not receive such therapy because of concerns about bleeding complications or cost. Recently, bivalirudin with provisional GP IIb/IIIa inhibition has been validated as an alternative to heparin + routine GP IIb/IIIa inhibition for patients undergoing PCI. However, the cost-effectiveness of this novel strategy is unknown.

METHODS

In the Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events (REPLACE)-2 trial, 4,651 U.S. patients undergoing non-emergent PCI were randomized to receive bivalirudin with provisional GP IIb/IIIa (n = 2,319) versus heparin + routine GP IIb/IIIa (n = 2,332). Resource utilization data were collected prospectively through 30-day follow-up on all U.S. patients. Medical care costs were estimated using standard methods including bottom-up accounting (for procedural costs), the Medicare fee schedule (for physician services), hospital billing data (for 2,821 of 4,862 admissions), and regression-based approaches for the remaining hospitalizations.

RESULTS

Among the bivalirudin group, 7.7% required provisional GP IIb/IIIa. Thirty-day ischemic outcomes including death or myocardial infarction were similar for the bivalirudin and GP IIb/IIIa groups, but bivalirudin resulted in lower rates of major bleeding (2.8% vs. 4.5%, p = 0.002) and minor bleeding (15.1% vs. 28.1%, p < 0.001). Compared with routine GP IIb/IIIa, in-hospital and 30-day costs were reduced by $405 (95% confidence interval [CI] $37 to $773) and $374 (95% CI $61 to $688) per patient with bivalirudin (p < 0.001 for both). Regression modeling demonstrated that, in addition to the costs of the anticoagulants themselves, hospital savings were due primarily to reductions in major bleeding (cost savings = $107/patient), minor bleeding ($52/patient), and thrombocytopenia ($47/patient).

CONCLUSIONS

Compared with heparin + routine GP IIb/IIIa inhibition, bivalirudin + provisional GP IIb/IIIa inhibition resulted in similar acute ischemic events and cost savings of $375 to $400/patient depending on the analytic perspective.

Glycoprotein IIb/IIIa receptor antagonists: a comparative review of their use in percutaneous coronary intervention

Antiplatelet therapy is critical during percutaneous coronary intervention (PCI) as it reduces the incidence of abrupt closure and distal thrombi embolization, which are significant acute peri-procedural complications likely responsible for the clinical adverse outcomes with PCI, namely death, myocardial infarction or urgent target vessel revascularization. Glycoprotein (GP) IIb/IIIa receptor antagonists, potent antiplatelet agents, have been specifically tested during PCI. There are currently three commercially available GP IIb/IIIa receptor antagonists and results from more than ten randomized clinical PCI trials have established their clinical efficacy and tolerability during coronary intervention. There remain questions regarding variability in efficacy among individual clinical trials and among population subsets, potential clinical differences among the available agents, and their optimal use. This article will critically review the body of evidence for clinical efficacy and tolerability of each individual tested compound, highlight potential differences among agents, and raise important issues involving their use in clinical practice.

Costs and cost effectiveness of low molecular weight heparins and platelet glycoprotein IIb/IIIa inhibitors: in the management of acute coronary syndromes

The most well established antithrombotic treatment for acute coronary syndromes (ACS) is unfractionated heparin (UFH) plus aspirin, but such treatment may not prevent arterial thrombotic events. Low molecular weight heparins (LMWHs) and platelet glycoprotein (GP) IIb/IIIa inhibitors offer alternative or adjunctive treatments. However, before these alternatives with higher acquisition costs are accepted in today's healthcare systems, their cost effectiveness must be proven. This paper reviews international pharmacoeconomic studies on the use of LMWHs and GP IIb/IIIa inhibitors in patients with ACS in an attempt to determine whether these therapies are cost effective. Most of the studies on LMWHs have been cost-minimisation analyses and have focused on enoxaparin sodium, because this is the only LMWH proven to be superior to UFH. Several analyses show that, compared with UFH plus aspirin, enoxaparin sodium provides cost savings both during hospitalisation (30 days) and 1-year follow-up. These cost savings are mainly attributable to fewer cardiac interventions, shorter hospital stays and lower administrative costs. Indeed, the clinical and economic advantages of enoxaparin sodium have led to its recommendation in recent guidelines as the antithrombotic agent of choice for coronary artery disease. Most of the economic analyses of GP IIb/IIIa inhibitors have been cost-effectiveness analyses. Such analyses indicate that the high acquisition costs of these drugs may be at least partially offset by reductions in other costs if a noninvasive approach to risk stratification is used. Furthermore, use of GP IIb/IIIa inhibitors appears to give favourable cost-effectiveness ratios compared with other accepted therapies, such as fibrin-specific thrombolytic therapy, in the cardiovascular field, particularly in high-risk patients and those undergoing percutaneous coronary intervention. However, more comprehensive economic data on the GP IIb/IIIa inhibitors are needed.

A practical cost analysis of bivalirudin

Despite advances in percutaneous coronary intervention (PCI) techniques and adjunctive therapies, the risks of ischemic and bleeding complications with PCI remain significant. These complications are associated with significant morbidity and mortality, as well as substantially higher costs. Bivalirudin is the only antithrombotic agent that has been shown to reduce both ischemic and hemorrhagic complications associated with PCI. Cost models drawn from the results of three clinical trials of bivalirudin have estimated its potential impact on total medical costs. In addition, the number needed to treat to avoid a bleeding complication has been calculated based on patients shown to have a heightened risk of bleeding in the Bivalirudin Angioplasty Trial. In all models assessed, the use of bivalirudin offset most of its own cost through reductions in bleeding and ischemic complications.

A comparison of total hospital costs for percutaneous coronary intervention patients receiving abciximab versus tirofiban

The purpose of this study was to examine the total hospital costs associated with the receipt of abciximab versus tirofiban for percutaneous coronary intervention (PCI) patients. Hospital billing data for patients with a primary procedure of PCI was examined for the period of July 1998 to June 1999 from HCIA-Sach's Clinical Pathways Database. Data were analyzed for all patient discharges whose records indicated use of abciximab or tirofiban with a PCI. Results are reported for 3,967 patients. Multivariate analysis was used to control for a wide range of factors (GP IIb/IIIa selection, patient demographics, stent use, insurance type, health conditions, admission information, and hospital characteristics) that may influence the cost of hospitalization. A two-stage sample selection model was used to estimate total costs. The first stage of the analysis utilizes a probit regression to determine the factors associated with the likelihood of receiving abciximab versus tirofiban. The second stage of the analysis examines the factors associated with total hospital costs, while controlling for unobserved factors that may be correlated with the patient's likelihood of receiving abciximab. The mean unadjusted cost per hospitalization, including drug costs, was $10,762 (abciximab $10,813 and tirofiban $10,567). After controlling for high-risk indications and selection bias with the two-stage sample selection model, results indicate there was no significant difference in costs associated with the receipt of abciximab versus tirofiban. However, the results also indicate that the two-stage sample selection model may not be needed (lambda was not statistically significant) hence, the cost equation was reestimated using ordinary least-squares methodology (OLS). In the OLS analysis, receipt of abciximab versus tirofiban was associated with a significant reduction in costs ($470 reduction; P = 0.05). This study uses real-world data to examine the total hospital costs for PCI patients who receive abciximab versus tirofiban. Results of the two-stage sample selection model indicate there is no difference in total hospital costs (including drug costs) between abciximab- and tirofiban-treated patients. If the results of the OLS model are considered, a slight decrease in total hospital costs is observed in abciximab recipients. Cost-containment strategies that focus on component costs may not lead to intended overall cost savings.

Trends in outcome and costs of coronary intervention in the 1990s

Our objective was to examine trends in outcome and cost of percutaneous coronary intervention (PCI) between 1990 and 1999. PCI has become the most common form of myocardial revascularization in recent years, rivaling the more established coronary artery bypass surgery. There has been increasing interest in improving outcome of PCI while also seeking to minimize cost. A total of 21,755 patients undergoing PCI were evaluated. Clinical data were gathered from the Emory Cardiovascular Database and financial data from the UB92 formulation of the hospital bill. Charges were reduced to cost using departmental cost-to-charge ratios. Costs were inflated to 1999 dollars using medical care inflation rates. Mortality varied without a significant trend from 0.63% to 0.44% (p = 0.64). The Q-wave myocardial infarction rate decreased from 0.68% to 0.40% (p = 0.0003). Emergent coronary surgery decreased from 3.50% to 1.25% (p <0.0001). Mean hospital inflation-adjusted cost decreased from $10,478 to $8,367 (p <0.0001). Length of stay after the procedure decreased from 2.8 to 1.8 days (p <0.0001). Outcome of PCI continues to improve, with a decrease in coronary surgery and Q-wave myocardial infarction but with no significant change in mortality. This was accomplished while also decreasing costs and length of stay. Whether these favorable trends will continue remains to be seen.

Risk stratification in non-ST segment elevation acute coronary syndromes with special focus on recent guidelines

Patients with unstable angina or non-ST segment elevation (non-Q-wave) myocardial infarction are a heterogeneous group with respect to their risk of developing clinically significant adverse events such as subsequent myocardial infarction and death. Recent guidelines promote risk stratification of these patients, targeting high-risk patients for maximal antithrombotic and antiischemic therapy and low-risk patients for early discharge. We reviewed current and future modalities for risk stratification of patients and the predictive value of these methods in context with available pharmacologic agents. Unfortunately, most of the data identifying a particular pharmacologic regimen as beneficial in high-risk patients are retrospectively derived from large trials. Until prospective studies that use markers to guide therapy are available, clinicians should be familiar with the use of these risk markers and their application to the role of a given management strategy, including pharmacologic therapy.

Impact of abciximab versus tirofiban on hospital length of stay for PCI patients

The purpose of this retrospective study was to examine in a naturalistic setting the effect of abciximab versus tirofiban on hospital length of stay for patients undergoing percutaneous coronary intervention (PCI). Retrospective data were obtained from HCIASach's Clinical Pathways Database on 5,560 PCI patients who were administered either abciximab or tirofiban. Multivariate analysis was used to control for a wide range of factors (GPIIb/IIIa selection, patient demographics, insurance provider, health conditions, admission information, and hospital characteristics) that may influence hospital length of stay. Estimation was conducted via a two-stage sample selection model. After controlling for high-risk indications and sources of selection bias, results indicate that receipt of abciximab was associated with significantly shorter lengths of hospital stays compared to tirofiban (1.01 fewer days; p < 0.001). In a subgroup analysis of patients having an acute myocardial infarction (AMI; n = 2,593), receipt of abciximab was also found to be associated with significantly shorter hospital stays compared to tirofiban (0.60 fewer days; p < 0.001). Results of this study indicate that patients who are administered abciximab versus tirofiban have significantly shorter hospital stays. This reduction in length of stay may imply potential cost offsets for PCI patients who receive abciximab.

Glycoprotein IIb/IIIa receptor therapy in percutaneous coronary intervention and non-ST-segment elevation acute coronary syndromes. Estimating the economic implications

In addition to efficacy and safety, cost is an important determinant of the use of glycoprotein IIb/IIIa (GPIIb/IIIa) therapy in patients with acute coronary syndromes (ACS) or undergoing percutaneous coronary intervention (PCI). In PCI, the average procurement cost of GPIIb/IIIa therapy ranges from $US400 to $US1500 (1999 values) per patient treated, depending on agent, dose and duration of infusion. Prospective economic substudies with abciximab and tirofiban have demonstrated subsequent cost savings that partially offset the procurement costs of the agents. The drug procurement costs per death or myocardial infarction (MI) prevented in PCI appear to vary from $US10,500 to $US37,000, depending on the agent. Abciximab has been proven to provide a survival benefit in the setting of PCI, including coronary stenting. Analyses of abciximab use yield cost-effectiveness ratios of $US2875 to $US14,765 per life-year or quality-adjusted life-year saved, which compares favourably with most widely accepted therapies. In non-ST-segment elevation ACS, drug procurement costs range from $US700 to $US1700 per patient treated, also depending on agent, dose and duration of infusion. Evidence of cost offsets from changes in subsequent resource utilisation are limited and seem contingent upon a conservative risk-stratification approach. Drug procurement costs have been calculated as $US32,000 to $US82,000 per death or MI prevented in the ACS trials. Cost-effectiveness ratios of $US16,000 per life-year saved for the US and Western European cohorts in the Platelet Glycoprotein IIb/IIIa in Unstable Angina: Receptor Suppression Using Integrilin Therapy (PURSUIT) trial are favourable. If these analyses prove correct, the cost effectiveness of GPIIb/IIIa receptor therapy for patients with non-ST-segment elevation ACS will also compare favourably with other widely accepted therapies in industrialised countries. More clinical and economic data are necessary to allow better selection of specific patients who will receive the most benefit from GPIIb/IIIa therapy in healthcare systems with limited resources.

Economic assessment of platelet glycoprotein IIb/IIIa receptor blockade with abciximab and low-dose heparin during percutaneous coronary revascularization: results from the EPILOG randomized trial. Evaluation in PTCA to Improve Long-term Outcome with abciximab GP IIb/IIIa blockade

BACKGROUND

In the EPILOG trial (Evaluation in PTCA to Improve Long-term Outcome with abciximab GP IIb/IIIa blockade), abciximab administered with weight-adjusted heparin diminished the risk of ischemic complications within 30 days by 56% among patients undergoing percutaneous coronary revascularization, without increased bleeding complications.

METHODS AND RESULTS

A prospective economic assessment was performed in the 2792 patients enrolled in EPILOG. Patients were randomized to receive placebo with standard-dose weight-adjusted heparin, abciximab with low-dose weight-adjusted heparin, or abciximab with standard-dose weight-adjusted heparin during percutaneous coronary intervention. Hospital billing data for the baseline hospitalization were collected for 2581 patients (92.4% of total) and imputed for the remainder, with physician fees estimated from the Medicare Fee Schedule. For the baseline hospitalization, medical costs (hospitalization and physician fees) averaged $9632 for the placebo arm compared with $8758 (P:=0.005) and $9092 (P:=0.176) for the abciximab with low-dose and standard-dose heparin arms, respectively. Inclusive of average drug cost ($1454 to $1457), the net incremental baseline cost of these 2 abciximab strategies was $583 with low-dose weight-adjusted heparin and $914 with standard-dose weight-adjusted heparin. During 6-month follow-up, average hospital costs were not significantly different in the 3 treatment groups; cumulative net incremental costs were $1236 and $1268 in the abciximab with low-dose and standard-dose heparin groups, respectively.

CONCLUSIONS

Treatment with abciximab and low-dose, weight-adjusted heparin during percutaneous coronary revascularization reduces ischemic events and associated costs, thereby offsetting some of the cost of the drug. The suppression of bleeding complications associated with this agent by heparin dose reduction optimizes the economic attractiveness of this treatment strategy.

Medical costs of intravascular ultrasound optimization of stent deployment. Results of the multicenter randomized 'REStenosis after Intravascular ultrasound STenting' (RESIST) study

OBJECTIVE: Intravascular ultrasound (IVUS) can be used to optimize the deployment of stents. The aim of this study was to assess the acute and long-term medical costs of the use of IVUS through the results of the 'REStenosis after Intravascular ultrasound STenting' (RESIST) study. METHODS: One hundred and fifty-five patients were randomized to routine stent deployment with (n = 79) versus without (n = 76) IVUS guidance, with clinical follow-up over 18 months. The medical costs (hospitalization plus procedural costs) were calculated using a cost accounting system at the time of stent implantation and for all repeat lesion revascularizations. (At the time of writing the exchange rate was 1 Euro = 1 US dollar.) RESULTS: Because of the cost of IVUS catheters and the need for more balloons, acute procedural costs were 18% higher in the group with IVUS guidance (2934 +/- 670 Euros vs 2481 +/- 911 Euros). Clinical events (death, myocardial infarction, unstable angina or lesion revascularization) occurred in 28/76 (37%) in the group without IVUS, versus 20/79 (25%) (OR = 1.7; 95%CI = [0.82; 3.63]) in the group with IVUS. There was a higher number of revascularization procedures in the control group (31 in the control group vs 20 in the IVUS group). The cumulative medical costs at 18 months were only slightly higher in the IVUS group (4535 +/- 2020 Euros vs 4679 +/- 1471 Euros in the IVUS group), as the higher acute costs in the group with IVUS guidance were partially offset by the lower cost for revascularization procedures. Sensitivity analysis using variations of the unit costs as well as variations in the number of revascularization procedures and length of hospital stay showed that the overcost remained in a range between 1% and 7.6%. CONCLUSIONS: Over 18 months of followup, despite higher acute costs, IVUS optimization of stent deployment did not considerably increase the medical costs.