Balancing the Risks of Restenosis and Stent Thrombosis in Bare-Metal Versus Drug-Eluting Stents

Cost-effectiveness of CYP2C19-guided antiplatelet therapy in patients with acute coronary syndrome and percutaneous coronary intervention informed by real-world data

Current guidelines recommend dual antiplatelet therapy (DAPT) consisting of aspirin and a P2Y12 inhibitors following percutaneous coronary intervention (PCI). CYP2C19 genotype can guide DAPT selection, prescribing ticagrelor or prasugrel for loss-of-function (LOF) allele carriers (genotype-guided escalation). Cost-effectiveness analyses (CEA) are traditionally grounded in clinical trial data. We conduct a CEA using real-world data using a 1-year decision-analytic model comparing primary strategies: universal empiric clopidogrel (base case), universal ticagrelor, and genotype-guided escalation. We also explore secondary strategies commonly implemented in practice, wherein all patients are prescribed ticagrelor for 30 days post PCI. After 30 days, all patients are switched to clopidogrel irrespective of genotype (nonguided de-escalation) or to clopidogrel only if patients do not harbor an LOF allele (genotype-guided de-escalation). Compared with universal clopidogrel, both universal ticagrelor and genotype-guided escalation were superior with improvement in quality-adjusted life years (QALY's). Only genotype-guided escalation was cost-effective ($42,365/QALY) and demonstrated the highest probability of being cost-effective across conventional willingness-to-pay thresholds. In the secondary analysis, compared with the nonguided de-escalation strategy, although genotype-guided de-escalation and universal ticagrelor were more effective, with ICER of $188,680/QALY and $678,215/QALY, respectively, they were not cost-effective. CYP2C19 genotype-guided antiplatelet prescribing is cost-effective compared with either universal clopidogrel or universal ticagrelor using real-world implementation data. The secondary analysis suggests genotype-guided and nonguided de-escalation may be viable strategies, needing further evaluation.

Cost and Mortality Implications of Lower Event Rates After Implantation of an Ultrathin-Strut Coronary Stent Compared With a Thin-Strut Stent Over Four Years

BACKGROUND

The recent BIOFLOW V trial (ClinicalTrials.gov: NCT02389946) showed that revascularization with an ultrathin strut, bioresorbable polymer sirolimus-eluting stent (BP SES) was associated with lower rates of clinically driven target lesion revascularization (TLR) and target vessel-related myocardial infarction (TVMI) at 24-month follow-up than that with a thin strut, durable polymer everolimus-eluting stent (DP EES). We simulated the impact on cost and mortality.

METHODS AND RESULTS

We projected the impact of the lower adverse event rates from a U.S. health system perspective over a 48-month horizon with a Markov model using event data from the BIOFLOW V trial and estimates for costs and excess mortality due to adverse events from published sources. All cost estimates were CPI-adjusted to 2018 US$ and future cost discounted by 3%. We estimated that use of BP SES compared to DP EES was associated with cumulative net reductions in medical cost of $2429 per patient over 48 months. Peri-procedural TVMI contributed $124 (5%), TLR in patients without TVMI $810 (33%) and spontaneous TVMI $1496 (62%) of cost. Use of BP SES compared to DP EES was associated with 2603 fewer deaths in one million patients over four years, corresponding to a relative risk reduction of 6%.

CONCLUSIONS

Lower adverse event rates associated with revascularization using BP SES translate into reductions in direct medical cost and mortality. Most of the cost reduction is attributed to reduction in spontaneous TVMI. Given the high volume of coronary procedures, such results are an important consideration for patients, clinicians and payers.

Weighing the potential late benefits versus early hazard associated with bioresorbable vascular scaffolds in percutaneous coronary interventions: a Markov decision analytic model

OBJECTIVE

Use of poly-L-lactic acid-based bioresorbable scaffolds (BRS) has been associated with increased risk of device thrombosis during the first 3 years after implantation as compared to metallic everolimus-eluting stents (EES). The long-term performance of BRS relative to EES remains unknown.

METHODS

We used a Markov decision analysis model to evaluate the effectiveness of BRS vs. EES over a lifetime horizon. In addition to one-way sensitivity analyses of key variables, we evaluated the impact of optimal implantation technique and limiting procedures to larger vessels (>2.6 mm in diameter) on model results.

RESULTS

Assuming no risk of target lesion revascularization for BRS after 3 years, we found a small increment in quality-adjusted life expectancy (QALE) of 0.02 with the use of BRS relative to EES, with benefit being observed after 21.8 years. Optimal implantation technique and limiting to larger vessels resulted in larger gains in QALE (0.08 and 0.06, respectively) with BRS and shorter times to equipoise (6.7 and 8.3 years, respectively). Model results were highly sensitive to variations in the relative risk of stent thrombosis (BRS vs. EES).

CONCLUSIONS

Based on currently available data, it would take approximately 21.8 years for the presumed late benefits of current BRS relative to EES to overcome the early hazard associated with their use under favorable assumptions. Optimal implantation technique and limiting procedures to larger vessels improved BRS performance and reduced time to equipoise. Eliminating the higher BRS thrombosis risk is necessary in developing future generations of BRS as an acceptable alternative to EES.

Cost-effectiveness analysis of short-duration dual antiplatelet therapy with newer drug-eluting stent platforms versus longer-duration dual antiplatelet therapy with a second-generation drug-eluting stent in elective percutaneous coronary intervention

BACKGROUND

The cost-effectiveness of newer drug-eluting stents (DES) such as biodegradable-polymer or polymer-free stents with shorter dual antiplatelet therapy (DAPT) duration is unknown. We evaluated the cost-effectiveness of treatment with newer DES that may allow for shorter DAPT duration.

PATIENTS AND METHODS

We performed a cost-effectiveness analysis of treatment with newer DES platforms followed by 1 or 3 months of DAPT compared with standard second-generation DES followed by 6 or 12 months of DAPT in patients with stable coronary disease. A Markov model simulated distinct health states over a lifetime. Probabilistic sensitivity analysis and one-way sensitivity analyses were performed. A high-risk bleeding scenario was also evaluated.

RESULTS

Among patients with typical bleeding risk, second-generation DES and 6 months of DAPT was less expensive and resulted in marginally higher quality-adjusted life years compared with other strategies. A newer DES platform and 3 months of DAPT was preferred when the risk of fatal bleeding was two times greater than baseline, or when bleeding increased long-term mortality by a factor of 1.5. In a probabilistic sensitivity analysis, second-generation DES and 6 months of DAPT was preferred in 58% of iterations, whereas in a high-risk bleeding patient scenario, a newer DES and 3 months of DAPT was preferred in 52% of iterations.

CONCLUSION

A DES that allows 3 months of DAPT without increasing stent-related events is likely to be cost-effective among patients at elevated risk of bleeding, but not in patients with average bleeding risk.

Cost-effectiveness analysis of biodegradable polymer versus durable polymer drug-eluting stents incorporating real-world evidence

AIM

Compared with second-generation durable polymer drug-eluting stents (DP-DES), the cost-effectiveness of biodegradable polymer drug-eluting stents (BP-DES) remains unclear in the real-world setting. We assessed the cost-effectiveness of BP-DES in patients with coronary artery disease undergoing percutaneous coronary intervention (PCI).

METHODS

We developed a decision-analytic model to compare the cost-effectiveness of BP-DES to DP-DES over 1 year and 5 years from healthcare payer perspective. Relative treatment effects during the first year post-PCI were obtained from a real-world population analysis while clinical event risks in the subsequent 4 years were derived from a meta-analysis of published studies.

RESULTS

At 1 year, based on the clinical data analysis of 497 propensity-score matched pairs of patients, BP-DES were associated with an incremental cost-effectiveness ratio (ICER) of USD20 503 per quality-adjusted life-year (QALY) gained. At 5 years, BP-DES yielded an ICER of USD4062 per QALY gained. At the willingness-to-pay threshold of USD50 400 (one gross domestic product per capita in Singapore in 2015), BP-DES were cost-effective. Sensitivity analysis showed that the cost of stents had a significant impact on the cost-effectiveness of BP-DES. Threshold analysis demonstrated that if the cost difference between BP-DES and DP-DES exceeded USD493, BP-DES would not be cost-effective in patients with 1 year of follow-up.

CONCLUSIONS

Biodegradable polymer drug-eluting stents were cost-effective compared with DP-DES in patients with coronary artery disease at 1 year and 5 years after PCI. It is worth noting that the cost of stents had a significant impact on the findings.

Preliminary Validation of a Dynamic Electrochemical Biodegradation Test Bench in Pseudo-Physiological Conditions

There is a growing interest in the development of next generation stent materials. In vitro tests that accurately predict in vivo conditions, are needed for a full evaluation of a material's corrosion in vivo. In this manuscript a novel approach for the design of a dynamic electrochemical test bench is evaluated in hopes to later characterize and model biodegradable metallic stent materials. This dynamic test bench design allows for real-time corrosion testing with easy variation of temperature, shear stress, and simulated body fluids (SBF), with minimal complications of test sample fabrication. Preliminary tests have shown Tafel generation stable. Further testing of the stability of the test bench were conducted with the incorporation SBF, shear stress, and temperature. Shear stress was applied through variation in fluid velocities at 0 m/s, 0.127 m/s, 0.245 m/s, 0.372 m/s, 0.489 m/s at 37°C. Incorporation of the different SBFs showed no significant difference in corrosion readings; however, variances were observed higher in DMEM and PBS, than in Hanks, respectively. This dynamic test bench showed to be relatively stable under temperature and SBF modification; however, further optimization is needed to decrease variances seen throughout fluid velocity analysis.

Computing Methods for Composite Clinical Endpoints in Unprotected Left Main Coronary Artery Revascularization: A Post Hoc Analysis of the DELTA Registry

OBJECTIVES

The study sought to investigate the impact of different computing methods for composite endpoints other than time-to-event (TTE) statistics in a large, multicenter registry of unprotected left main coronary artery (ULMCA) disease.

BACKGROUND

TTE statistics for composite outcome measures used in ULMCA studies consider only the first event, and all the contributory outcomes are handled as if of equal importance.

METHODS

The TTE, Andersen-Gill, win ratio (WR), competing risk, and weighted composite endpoint (WCE) computing methods were applied to ULMCA patients revascularized by percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) at 14 international centers.

RESULTS

At a median follow-up of 1,295 days (interquartile range: 928 to 1,713 days), all analyses showed no difference in combinations of death, myocardial infarction, and cerebrovascular accident between PCI and CABG. When target vessel revascularization was incorporated in the composite endpoint, the TTE (p = 0.03), Andersen-Gill (p = 0.04), WR (p = 0.025), and competing risk (p < 0.001) computing methods showed CABG to be significantly superior to PCI in the analysis of 1,204 propensity-matched patients, whereas incorporating the clinical relevance of the component endpoints using WCE resulted in marked attenuation of the treatment effect of CABG, with loss of significance for the difference between revascularization strategies (p = 0.10).

CONCLUSIONS

In a large study of ULMCA revascularization, incorporating the clinical relevance of the individual outcomes resulted in sensibly different findings as compared with the conventional TTE approach. In particular, using the WCE computing method, PCI and CABG were no longer significantly different with respect to the composite of death, myocardial infarction, cerebrovascular accident, or target vessel revascularization at a median of 3 years.

Cost-Effectiveness of Different Durations of Dual-Antiplatelet Use After Percutaneous Coronary Intervention

BACKGROUND

There is uncertainty regarding the optimal duration of dual-antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI). Our goal was to evaluate the cost-effectiveness of different durations of DAPT.

METHODS

We created a probabilistic patient-level Markov microsimulation model to assess the discounted lifetime costs and quality-adjusted life years (QALYs) of short duration (3-6 months: short-duration group) vs standard therapy (12 months: standard-duration group) vs prolonged therapy (30-36 months: long-duration group) in patients undergoing PCI.

RESULTS

The majority of patients in the model underwent PCI for stable angina (47.1%) with second-generation drug-eluting stents (62%) and were receiving clopidogrel (83.6%). Short-duration DAPT was the most effective strategy (7.163 ± 1.098 QALYs) compared with standard-duration DAPT (7.161 ± 1.097 QALYs) and long-duration DAPT (7.156 ± 1.097 QALYs). However, the magnitude of these differences was very small. Similarly, the average discounted lifetime cost was CAN$24,859 ± $6533 for short duration, $25,045 ± $6533 for standard duration, and $25,046 ± $6548 for long duration. Thus, in the base-case analysis, short duration was dominant, being more effective and less expensive. However, there was a moderate degree of uncertainty, because short duration was the preferred option in only ∼ 55% of simulations at a willingness to pay threshold of $50,000.

CONCLUSIONS

Based on a stable angina cohort receiving clopidogrel with second-generation stents, a short duration of DAPT was marginally better. However, the differences are minimal, and decisions about duration of therapy should be driven by clinical data, patient risk of adverse events, including bleeding, and cardiovascular events.

Cost-effectiveness of percutaneous coronary intervention with cobalt-chromium everolimus eluting stents versus bare metal stents: Results from a patient level meta-analysis of randomized trials

BACKGROUND

Second-generation drug eluting stents (DES) may reduce costs and improve clinical outcomes compared to first-generation DES with improved cost-effectiveness when compared to bare metal stents (BMS). We aimed to conduct an economic evaluation of a cobalt-chromium everolimus eluting stent (Co-Cr EES) compared with BMS in percutaneous coronary intervention (PCI).

OBJECTIVE

To conduct a cost-effectiveness analysis (CEA) of a cobalt-chromium everolimus eluting stent (Co-Cr EES) versus BMS in PCI.

METHODS

A Markov state transition model with a 2-year time horizon was applied from a US Medicare setting with patients undergoing PCI with Co-Cr EES or BMS. Baseline characteristics, treatment effects, and safety measures were taken from a patient level meta-analysis of 5 RCTs (n = 4,896). The base-case analysis evaluated stent-related outcomes; a secondary analysis considered the broader set of outcomes reported in the meta-analysis.

RESULTS

The base-case and secondary analyses reported an additional 0.018 and 0.013 quality-adjusted life years (QALYs) and cost savings of $236 and $288, respectively with Co-Cr EES versus BMS. Results were robust to sensitivity analyses and were most sensitive to the price of clopidogrel. In the probabilistic sensitivity analysis, Co-Cr EES was associated with a greater than 99% chance of being cost saving or cost effective (at a cost per QALY threshold of $50,000) versus BMS.

CONCLUSIONS

Using data from a recent patient level meta-analysis and contemporary cost data, this analysis found that PCI with Co-Cr EES is more effective and less costly than PCI with BMS. © 2016 The Authors. Catheterization and Cardiovascular Interventions Published by Wiley Periodicals, Inc.

Contemporary Context of Drug-Eluting Stents in Brazil: A Cost Utility Study

BACKGROUND

Although drug-eluting stents (DES) have been widely incorporated into clinical practice in developed countries, several countries restrict their use mainly because of their high cost and unfavorable incremental cost-effectiveness ratios (ICER).

OBJECTIVE

To evaluate the cost-effectiveness of DES in comparison with bare-metal stents (BMS) for treatment of coronary artery disease (CAD).

DESIGN

Markov model.

DATA SOURCES

Published literature, government database, and CAD patient cohort.

TARGET POPULATION

Single-vessel CAD patients.

TIME HORIZON

One year and lifetime.

PERSPECTIVE

Brazilian Public Health System (SUS).

INTERVENTION

Six strategies composed of percutaneous intervention with a BMS or 1 of 5 DES (paclitaxel, sirolimus, everolimus, zotarolimus, and zotarolimus resolute).

OUTCOME MEASURES

Cost for target vessel revascularization avoided and cost for quality-adjusted life year gained.

BASE CASE ANALYSIS

In the short-term analysis, sirolimus was the most effective and least costly among DES (ICER of I$20,642 per target vessel revascularization avoided), with all others DES dominated by sirolimus. Lifetime cumulative costs ranged from I$18,765 to I$21,400. In the base case analysis, zotarolimus resolute had the most favorable ICER among the DES (ICER I$62,761), with sirolimus, paclitaxel, and zotarolimus being absolute dominated and everolimus extended dominated by zotarolimus resolute, although all the results were above the willingness-to-pay threshold of 3 times the gross domestic product per capita (I$35,307).

SENSITIVITY ANALYSIS

In deterministic sensitivity analysis, results were sensitive to cost of DES, number of stents used per patient, baseline probability, and duration of stent thrombosis risk. The probabilistic sensitivity analysis demonstrated a probability of 81% for BMS being the strategy of choice, with 9% for everolimus and 9% zotarolimus resolute, at the willingness-to-pay threshold.

CONCLUSION

DES is not a good value for money in SUS perspective, despite its benefit in reducing target vessel revascularization. Since the cost-effectiveness of DES is mainly driven by the stents' cost difference, they should cost less than twice the BMS price to become a cost-effective alternative.

Chinese Herbal Medicines Might Improve the Long-Term Clinical Outcomes in Patients with Acute Coronary Syndrome after Percutaneous Coronary Intervention: Results of a Decision-Analytic Markov Model

Aims. The priority of Chinese herbal medicines (CHMs) plus conventional treatment over conventional treatment alone for acute coronary syndrome (ACS) after percutaneous coronary intervention (PCI) was documented in the 5C trial (chictr.org number: ChiCTR-TRC-07000021). The study was designed to evaluate the 10-year effectiveness of CHMs plus conventional treatment versus conventional treatment alone with decision-analytic model for ACS after PCI. Methods and Results. We constructed a decision-analytic Markov model to compare additional CHMs for 6 months plus conventional treatment versus conventional treatment alone for ACS patients after PCI. Sources of data came from 5C trial and published reports. Outcomes were expressed in terms of quality-adjusted life years (QALYs). Sensitivity analyses were performed to test the robustness of the model. The model predicted that over the 10-year horizon the survival probability was 77.49% in patients with CHMs plus conventional treatment versus 77.29% in patients with conventional treatment alone. In combination with conventional treatment, 6-month CHMs might be associated with a gained 0.20% survival probability and 0.111 accumulated QALYs, respectively. Conclusions. The model suggested that treatment with CHMs, as an adjunctive therapy, in combination with conventional treatment for 6 months might improve the long-term clinical outcome in ACS patients after PCI.

A Decision Analysis of Percutaneous Left Atrial Appendage Occlusion Relative to Novel and Traditional Oral Anticoagulation for Stroke Prevention in Patients with New-Onset Atrial Fibrillation

Background. Percutaneous left atrial appendage occlusion (LAAO) is a nonpharmacologic approach for stroke prevention in nonvalvular atrial fibrillation (NVAF). No direct comparisons to novel oral anticoagulants (OACs) exists, limiting decision making on the optimal strategy for stroke prevention in NVAF patients. Addressing this gap in knowledge is timely given the recent debate by the US Food and Drug Administration regarding the effectiveness of LAAO. Objective. To assess the cost-effectiveness of LAAO and novel OACs relative to warfarin in patients with new-onset NVAF without contraindications to OAC. Design. A cost-utility analysis using a patient-level Markov micro-simulation decision analytic model was undertaken to determine the lifetime costs, quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratio (ICER) of LAAO and all novel OACs relative to warfarin. Effectiveness and utility data were obtained from the published literature and cost from the Ontario Drug Benefits Formulary and Case Costing Initiative. Results. Warfarin had the lowest discounted QALY (5.13 QALYs), followed by dabigatran (5.18 QALYs), rivaroxaban and LAAO (5.21 QALYs), and apixaban (5.25 QALYs). The average discounted lifetime costs were $15 776 for warfarin, $18 280 for rivaroxaban, $19 156 for apixaban, $20 794 for dabigatran, and $21 789 for LAAO. Apixaban dominated dabigatran and LAAO and demonstrated extended dominance over rivaroxaban. The ICER for apixaban relative to warfarin was $28 167/QALY. Apixaban was preferred in 40.2% of simulations at a willingness-to-pay threshold of $50 000/QALY. Limitations. Assumptions regarding clinical and methodological differences between published studies of each therapy were minimized. Conclusions. Apixaban is the most cost-effective therapy for stroke prevention in patients with new-onset NVAF without contraindications to OAC. Uncertainty around this conclusion exists, highlighting the need for further research.

Balancing the risks of bleeding and stent thrombosis: a decision analytic model to compare durations of dual antiplatelet therapy after drug-eluting stents

BACKGROUND

After coronary stent placement, whether dual antiplatelet therapy (DAPT) duration should be extended to prevent late stent thrombosis (ST) or adverse cardiovascular events is uncertain.

METHODS

To define the reduction in ischemic events required to outweigh increased bleeding with longer-duration DAPT, we developed a decision-analytic Markov model comparing DAPT durations of 6, 12, and 30 months after DES. Separate models were developed for patients presenting with and without an acute coronary syndrome (ACS). We used sensitivity analyses to identify the incremental benefit of longer-duration DAPT on either ST or the composite of cardiac death, myocardial infarction, and ischemic stroke (major adverse cardiovascular and cerebrovascular events [MACCEs]) required to outweigh the increased risk of bleeding associated with longer DAPT. The outcome from each strategy was quantified in terms of quality-adjusted life years.

RESULTS

In the non-ACS population, in order for 30 months of DAPT to be preferred over 12 months of therapy, DAPT would have to result in a 78% reduction in the risk of ST (relative risk [RR] 0.22, 3.1 fewer events per 1000) and only a 5% reduction in MACCE (RR 0.95, 2.2 fewer events per 1000) as compared with aspirin alone. For the ACS population, DAPT would have to result in a 44% reduction in the risk of ST (RR 0.56, 3.4 fewer events per 1000) but only a 2% reduction in MACCE (RR 0.98, 2.3 fewer events per 1000) as compared with aspirin alone, for 30 months of DAPT to be preferred for 12 months.

CONCLUSIONS

Small absolute differences in the risk of ischemic events with longer DAPT would be sufficient to outweigh the known bleeding risks.

Medical therapy v. PCI in stable coronary artery disease: a cost-effectiveness analysis

BACKGROUND

Percutaneous coronary intervention (PCI) with either drug-eluting stents (DES) or bare metal stents (BMS) reduces angina and repeat procedures compared with optimal medical therapy alone. It remains unclear if these benefits are sufficient to offset their increased costs and small increase in adverse events.

OBJECTIVE

Cost utility analysis of initial medical therapy v. PCI with either BMS or DES.

DESIGN

. Markov cohort decision model. Data Sources. Propensity-matched observational data from Ontario, Canada, for baseline event rates. Effectiveness and utility data obtained from the published literature, with costs from the Ontario Case Costing Initiative.

TARGET POPULATION

Patients with stable coronary artery disease, confirmed after angiography, stratified by risk of restenosis based on diabetic status, lesion size, and lesion length. Time Horizon. Lifetime. Perspective. Ontario Ministry of Health and Long Term Care. Interventions. Optimal medical therapy, PCI with BMS or DES.

OUTCOME MEASURES

Lifetime costs, quality-adjusted life years (QALYs), and the incremental cost-effectiveness ratio (ICER).

RESULTS

of Base Case Analysis. In the overall population, medical therapy had the lowest lifetime costs at $22,952 v. $25,081 and $25,536 for BMS and DES, respectively. Medical therapy had a quality-adjusted life expectancy of 10.1 v. 10.26 QALYs for BMS, producing an ICER of $13,271/QALY. The DES strategy had a quality-adjusted life expectancy of only 10.20 QALYs and was dominated by the BMS strategy. This ranking was consistent in all groups stratified by restenosis risk, except diabetic patients with long lesions in small arteries, in whom DES was cost-effective compared with medical therapy (ICER of $18,826/QALY). Limitations. There is the possibility of residual unobserved confounding.

CONCLUSIONS

In patients with stable coronary artery disease, an initial BMS strategy is cost-effective.

Economic evaluation of percutaneous left atrial appendage occlusion, dabigatran, and warfarin for stroke prevention in patients with nonvalvular atrial fibrillation

BACKGROUND

Percutaneous left atrial appendage (LAA) occlusion and novel pharmacological therapies are now available to manage stroke risk in patients with nonvalvular atrial fibrillation; however, the cost-effectiveness of LAA occlusion compared with dabigatran and warfarin in patients with nonvalvular atrial fibrillation is unknown.

METHODS AND RESULTS

Cost-utility analysis using a patient-level Markov microsimulation decision analytic model with a lifetime horizon was undertaken to determine the lifetime costs, quality-adjusted life years, and incremental cost-effectiveness ratio of LAA occlusion in relation to dabigatran and warfarin in patients with nonvalvular atrial fibrillation at risk for stroke without contraindications to oral anticoagulation. The analysis was performed from the perspective of the Ontario Ministry of Health and Long Term Care, the third-party payer for insured health services in Ontario, Canada. Effectiveness and utility data were obtained from the published literature. Cost data were obtained from the Ontario Drug Benefits Formulary and the Ontario Case Costing Initiative. Warfarin therapy had the lowest discounted quality-adjusted life years at 4.55, followed by dabigatran at 4.64 and LAA occlusion at 4.68. The average discounted lifetime cost was $21 429 for a patient taking warfarin, $25 760 for a patient taking dabigatran, and $27 003 for LAA occlusion. Compared with warfarin, the incremental cost-effectiveness ratio for LAA occlusion was $41 565. Dabigatran was extendedly dominated.

CONCLUSIONS

Percutaneous LAA occlusion represents a novel therapy for stroke reduction that is cost-effective compared with warfarin for patients at risk who have nonvalvular atrial fibrillation.

Stent thrombosis and major clinical events at 3 years after zotarolimus-eluting or sirolimus-eluting coronary stent implantation: a randomised, multicentre, open-label, controlled trial

BACKGROUND

We sought to compare the long-term safety of two devices with different antiproliferative properties: the Endeavor zotarolimus-eluting stent (E-ZES; Medtronic, Inc) and the Cypher sirolimus-eluting stent (C-SES; Cordis, Johnson & Johnson) in a broad group of patients and lesions.

METHODS

Between May 21, 2007 and Dec 22, 2008, we recruited 8791 patients from 36 recruiting countries to participate in this open-label, multicentre, randomised, superiority trial. Eligible patients were those aged 18 years or older undergoing elective, unplanned, or emergency procedures in native coronary arteries. Patients were randomly assigned to either receive E-ZES and C-SES (ratio 1:1). Randomisation was stratified per centre with varying block sizes of four, six, or eight patients, and concealed with a central telephone-based or web-based allocation service. The primary outcome was definite or probable stent thrombosis at 3 years and was analysed by intention to treat. Patients and investigators were aware of treatment assignment. This trial is registered with ClinicalTrials.gov, number NCT00476957.

FINDINGS

PROTECT randomised 8791 patients, of whom 8709 provided consent to participate and were eligible: 4357 were allocated to the E-ZES group and 4352 patients to the C-SES group. At 3 years, rates of definite or probable stent thrombosis did not differ between groups (1·4% for E-ZES [predicted: 1·5%] vs 1·8% [predicted: 2·5%] for C-SES; hazard ratio [HR] 0·81, 95% CI 0·58-1·14, p=0·22). Dual antiplatelet therapy was used in 8402 (96%) patients at discharge, 7456 (88%) at 1 year, 3041 (37%) at 2 years, and 2364 (30%) at 3 years.

INTERPRETATION

No evidence of superiority of E-ZES compared with C-SES in definite or probable stent thrombosis rates was noted at 3 years. Time analysis suggests a difference in definite or probable stent thrombosis between groups is emerging over time, and a longer follow-up is therefore needed given the clinical relevance of stent thrombosis.

FUNDING

Medtronic, Inc.

Decreased expression of vitamin D receptors in neointimal lesions following coronary artery angioplasty in atherosclerotic swine

Background

Inflammatory cytokines, such as TNF-α, play a key role in the pathogenesis of occlusive vascular diseases. Activation of vitamin D receptors (VDR) elicits both growth-inhibitory and anti-inflammatory effects. Here, we investigated the expression of TNF-α and VDR in post-angioplasty coronary artery neointimal lesions of hypercholesterolemic swine and examined the effect of vitamin D deficiency on the development of coronary restenosis. We also examined the effect of calcitriol on cell proliferation and effect of TNF-α on VDR activity and expression in porcine coronary artery smooth muscle cells (PCASMCs) in-vitro.

Methodology/Principal Findings

Expression of VDR and TNF-α and the effect of vitamin D deficiency in post-angioplasty coronary arteries were analyzed by immunohistochemistry and histomorphometry. Cell proliferation was examined by thymidine and BrdU incorporation assays in cultured PCASMCs. Effect of TNF-α-stimulation on the activity and expression of VDR was analyzed by luciferase assay, immunoblotting and immunocytochemistry. In-vivo, morphometric analysis of the tissues revealed typical lesions with significant neointimal proliferation. Histological evaluation showed expression of smooth muscle α-actin and significantly increased expression of TNF-α in neointimal lesions. Interestingly, there was significantly decreased expression of VDR in PCASMCs of neointimal region compared to normal media. Indeed, post-balloon angioplasty restenosis was significantly higher in vitamin D-deficient hypercholesterolemic swine compared to vitamin D-sufficient group. In-vitro, calcitriol inhibited both serum- and PDGF-BB-induced proliferation in PCASMCs and TNF-α-stimulation significantly decreased the expression and activity of VDR in PCASMCs.

Conclusions/Significance

These data suggest that significant downregulation of VDR in proliferating smooth muscle cells in neointimal lesions could be due to atherogenic cytokines, including TNF-α. Vitamin D deficiency potentiates the development of coronary restenosis. Calcitriol has anti-proliferative properties in PCASMCs and these actions are mediated through VDR. This could be a potential mechanism for uncontrolled growth of neointimal cells in injured arteries leading to restenosis.

Spot drug-eluting stenting for long coronary stenoses: long-term results of a randomized clinical study

BACKGROUND

Preliminary results of a randomized trial have suggested that total lesion coverage with drug-eluting stents (DES) is not necessary in the presence of diffuse disease of nonuniform severity. In the present study, we report long-term results of this trial.

METHODS

Consecutive, consenting patients with a long (>20 mm) coronary lesion of nonuniform severity and indication for percutaneous coronary intervention were randomized to full stent coverage of the atherosclerotic lesion with multiple, overlapping (full DES group, n = 90) or spot stenting of the hemodynamically significant parts of the lesion only (defined as diameter stenosis > 50%) (spot DES group, n = 89).

RESULTS

At a follow-up of 2-7 years, 30 patients with full DES (33.3%) and 12 patients (13.5%) with spot DES had a major adverse cardiac event (MACE) (P = 0.015). Cox proportional hazard model showed that the risk for MACE was almost 65% lower among patients who were subjected to spot DES compared to those who underwent full DES (HR = 0.35, 95% CI = 0.18-0.68, P = 0.002). This association remained significant even after controlling for age, sex, and lesion length, and the type of stent used (HR = 0.41, 95% CI = 0.20-0.81, P = 0.011).

CONCLUSIONS

In the presence of diffuse disease of nonuniform severity, selective stenting of only the significantly stenosed parts of the lesion confers better long-term results compared to total lesion coverage with DES.

Second- and third-generation drug-eluting coronary stents: progress and safety

Drug-eluting stents (DES) have revolutionized the treatment of coronary artery disease by reducing the rate of in-stent restenosis from 20-40% with bare-metal stent (BMS) to 6-8% with DES. However, with widespread use of DES, safety concerns have risen due to the observation of late stent thrombosis. With this in mind and better understanding of mechanism and pathophysiology of stent thrombosis, the technological platform, especially innovative anti-restenotic agents, polymeric coatings, and stent platforms, improved with newer DES. Two second-generation DES, the Endeavor zotarolimus-eluting stent (ZES) and the Xience-V everolimus-eluting stent (EES), have provided promising results in both randomized controlled trials (SPIRIT and ENDEAVOR) and registries (E-Five, COMPARE) compared with bare-metal stents (BMS) and first-generation DES. Newer third-generation stent technology, especially biodegradable polymers, polymer-free stents, and biodegradable stents on the basis of poly-L-lactide (PLLA) or magnesium, has been evaluated in preclinical and initial clinical trials. However, despite encouraging initial results, long-term data of large-scale randomized trials as well as registries comparing them to currently approved first- and second-generation DES are still lacking.

Correlation of angiographic late loss with neointimal coverage of drug-eluting stent struts on follow-up optical coherence tomography

Minimal data have been published on the correlation between angiographic late loss (LL) and incomplete neointimal coverage of struts after drug-eluting stent (DES) implantation. Therefore, we evaluated the relationship between angiographic LL and the percentage of uncovered struts on follow-up optical coherence tomography (OCT) images, in all cross-sections of the lesions. From the OCT registry database, 219 lesions without restenosis after DES implantation were divided into tertiles based on angiographic LL: tertile I (LL ≤ 0.26 mm), tertile II (0.26 < LL < 0.59 mm), and tertile III (≥0.59 mm). Lesions with the percentage of uncovered struts in the highest quartile (≥75th percentile; >6.0%) were defined as highly uncovered; in an independent analysis, lesions without any uncovered strut(s) were defined as completely covered. Higher percentages of uncovered struts were observed in tertile I than in both tertile II and III (10.3 ± 12.8% vs. 4.2 ± 7.4% vs. 2.4 ± 5.1%, respectively; P < 0.001 for I vs. II and I vs. III). Angiographic LL correlated significantly with the percentage of uncovered struts on OCT (r = -0.340, P < 0.001). The best cut-off values of angiographic LL to predict highly uncovered and completely covered lesions were 0.29 mm (area under curves [AUC] = 0.723, P < 0.001) and 0.61 mm (AUC = 0.692, P < 0.001), respectively. Angiographic LL inversely and significantly correlated with the percentage of uncovered struts on OCT after DES implantation.

Long-term clinical outcomes with zotarolimus-eluting versus bare-metal coronary stents

OBJECTIVES

This study sought to evaluate the long-term safety of the zotarolimus-eluting stent (ZES) using a pooled analysis of pivotal trials.

BACKGROUND

Drug-eluting stents, compared with bare-metal stents (BMS), have reduced restenosis; however, individual trials of these stents have not had sufficient power to ascertain long-term safety.

METHODS

We combined patient level data from 6 prospective randomized single-arm multicenter trials involving 2,132 patients treated with ZES and 596 patients treated with a BMS control. The median follow-up was 4.1 years, with 5-year follow-up completed in 1,256 patients (97% of those eligible). The recommended minimum duration of dual antiplatelet therapy in these studies was 3 to 6 months regardless of stent type. An independent events committee adjudicated all events. The 2 treatment groups were compared after adjustment for between trial variation and for individual patient clinical and angiographic characteristics by propensity score.

RESULTS

The cumulative incidence of adverse events at 5 years for ZES and BMS were: death: 5.9% versus 7.6% (adjusted hazard ratio: 0.81, p = 0.34), cardiac death: 2.4 versus 3.7% (0.83, p = 0.57), myocardial infarction: 3.4 versus 4.8% (0.77, p = 0.37), target lesion revascularization: 7.0% vs. 16.5% (0.42, p < 0.001), stent thrombosis (definite or probable): 0.8 versus 1.7% (0.50, p = 0.21). After adjustment for variation in study and patient characteristics, there were no significant differences in stent thrombosis or the clinical safety event rates at 5 years between ZES and BMS.

CONCLUSIONS

Over 5 years, there was no increased risk of death, myocardial infarction, or stent thrombosis, and there was a benefit of prevention of repeat revascularization procedures in ZES compared with BMS.

Improved late clinical safety with zotarolimus-eluting stents compared with paclitaxel-eluting stents in patients with de novo coronary lesions: 3-year follow-up from the ENDEAVOR IV (Randomized Comparison of Zotarolimus- and Paclitaxel-Eluting Stents in Patients With Coronary Artery Disease) trial

OBJECTIVES

The increased frequency of very late (>1 year) stent thrombosis (VLST) has raised concerns with regard to the safety of sirolimus-eluting stents and paclitaxel-eluting stents (PES).

BACKGROUND

Experimental and preliminary clinical findings with the zotarolimus-eluting stent (ZES) have suggested a favorable safety profile.

METHODS

The ENDEAVOR IV (Randomized Comparison of Zotarolimus- and Paclitaxel-Eluting Stents in Patients With Coronary Artery Disease) trial is a single-blind randomized ZES versus PES clinical trial in 1,548 patients with de novo native coronary lesions; the primary end point-9-month target vessel failure-was previously reported, annual clinical follow-up is planned for 5 years, and this report describes the 3-year outcomes.

RESULTS

The ZES compared with PES reduced target vessel failure (12.3% vs. 15.9%, hazard ratio [HR]: 0.76, 95% confidence interval [CI]: 0.58 to 1.00, p = 0.049), myocardial infarctions (MI) (2.1% vs. 4.9%, HR: 0.44, 95% CI: 0.25 to 0.80, p = 0.005), and cardiac death plus MI (3.6% vs. 7.1%, HR: 0.52, 95% CI 0.32 to 0.82, p = 0.004). Although the overall 3-year rate of Academic Research Consortium definite/probable stent thrombosis did not differ significantly (1.1% vs. 1.7%, HR: 0.67, 95% CI 0.28 to 1.64, p = 0.380), VLST (between 1 and 3 years) was significantly reduced in ZES patients (1 event vs. 11 events; 0.1% vs. 1.6%, HR: 0.09, 95% CI: 0.01 to 0.71, p = 0.004). Ischemia-driven target lesion revascularization at 3 years was similar with ZES versus PES (6.5% vs. 6.1%, HR: 1.10, 95% CI: 0.73 to 1.65, p = 0.662).

CONCLUSIONS

Three-year follow-up results from the ENDEAVOR IV trial indicate similar antirestenosis efficacy but improved clinical safety associated with ZES compared with PES, due to significantly fewer peri-procedural and remote MIs associated with fewer VLST events. (A Randomized, Controlled Trial of the Medtronic Endeavor Drug [ABT-578] Eluting Coronary Stent System Versus the Taxus Paclitaxel-Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions; NCT00217269).

Impact of drug-eluting stents and diabetes mellitus in patients with coronary bifurcation lesions: a survey from the Italian Society of Invasive Cardiology

BACKGROUND

We investigated the long-term impact of different stent types and diabetes mellitus (DM) in patients undergoing percutaneous coronary intervention (PCI) of bifurcation lesions, based on a large multicenter survey endorsed by the Italian Society of Invasive Cardiology.

METHODS AND RESULTS

Relative benefits of drug eluting stent (DES) over bare metal stent (BMS) in patients with (n=1049) and without (n=3020) DM were analyzed with extensive multivariable adjustment. At 3 years, stenting with DES was associated with lower adjusted risk of major adverse cardiac events (MACE, adjusted hazard ratio [HR] 0.27, 95% confidence interval [CI] 0.15 to 0.49, P<0.001), cardiac death, and target lesion revascularization in DM patients but failed to demonstrate any significant benefit in patients without DM.

CONCLUSIONS

In a large observational registry with admitted potential for selection bias and residual confounding, DES in DM patients with coronary bifurcation lesions were associated with improved outcomes in terms of MACE, cardiac death, and repeat revascularization at long-term follow up. These figures were not replicated in non-DM subjects.

A retrospective analysis of consecutive patients undergoing nonurgent percutaneous coronary intervention comparing bare metal stents with drug-eluting stents using the National Institute for Clinical Excellence criteria

OBJECTIVE

In the National Institute for Clinical Excellence (NICE) guidelines, lesions with a reference vessel diameter of less than 3.0 mm or lesions with a length of greater than 15 mm are considered carrying a high risk of restenosis. In contrast, lesions with a reference vessel diameter of at least 3.0 mm or a lesion length of 15 mm or less are considered at low risk of restenosis. We performed a retrospective analysis of consecutive patients undergoing nonurgent percutaneous coronary intervention (PCI) comparing bare metal stent (BMS) with drug-eluting stent (DES) using the NICE guidelines.

METHODS AND RESULTS

Between 2003 and 2007, a total of 3883 patients underwent a nonurgent PCI for a de-novo coronary lesion; 2050 patients were considered to be at low risk and 1833 patients were considered at high risk of restenosis according to the NICE criteria. In the low-risk group, the 1-year composite of cardiac death, myocardial infarction, and target vessel revascularization was 10.5% in the BMS group and 11.1% in the DES group (P=0.85). Target lesion revascularization (TLR) was 5.3% by PCI and 1.6% by coronary artery bypass grafting (CABG) in the BMS group and 4.0 and 3.0% in the DES group (P=0.59 and P=0.24). In the high-risk group, the composite of cardiac death, myocardial infarction, and target vessel revascularization was 12.1 and 11.0% in the BMS and DES groups (P=0.48). TLR was 6.7% by PCI and 1.3% by CABG in the BMS group and 3.9 and 2.8% in the DES group (P=0.01; P=0.02). Definite stent thrombosis (ST) was 0.8% in the BMS-treated patients and 1.7% in the DES-treated patients (P=0.09).

CONCLUSION

In patients with lesions carrying a low risk of restenosis, no differences were observed between BMS and DES in composite end points, TLR, or ST at 1-year follow-up. In patients with lesions carrying a high risk of restenosis, patients treated with BMS had a significantly higher rate of TLR by PCI, but a significantly lower rate of TLR by CABG compared with patients treated with DES. A nonsignificant lower rate of definite ST was observed in the BMS group compared with the DES group.

Late safety, efficacy, and cost-effectiveness of a zotarolimus-eluting stent compared with a paclitaxel-eluting stent in patients with de novo coronary lesions: 2-year follow-up from the ENDEAVOR IV trial (Randomized, Controlled Trial of the Medtronic Endeavor Drug [ABT-578] Eluting Coronary Stent System Versus the Taxus Paclitaxel-Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions)

OBJECTIVES

The aim of this study was to assess, after 2 years of follow-up, the safety, efficacy, and cost-effectiveness of a zotarolimus-eluting stent (ZES) compared with a paclitaxel-eluting stent (PES) in patients with native coronary lesions.

BACKGROUND

Early drug-eluting stents were associated with a small but significant incidence of very late stent thrombosis (VLST), occurring >1 year after the index procedure. The ZES has shown encouraging results in clinical trials.

METHODS

The ENDEAVOR IV trial (Randomized, Controlled Trial of the Medtronic Endeavor Drug [ABT-578] Eluting Coronary Stent System Versus the Taxus Paclitaxel-Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions), a randomized (1:1), single-blind, controlled trial (n = 1,548) compared ZES versus PES in patients with single de novo coronary lesions. Two-year follow-up was obtained in 96.0% of ZES and 95.4% of PES patients. The primary end point was target vessel failure (TVF), and safety end points included Academic Research Consortium-defined stent thrombosis. Economic end points analyzed included quality-adjusted survival, medical costs, and relative cost-effectiveness of ZES and PES.

RESULTS

The TVF at 2 years was similar in ZES and PES patients (11.1% vs. 13.1%, p = 0.232). There were fewer myocardial infarctions (MIs) in ZES patients (p = 0.022), due to fewer periprocedural non-Q-wave MIs and fewer late MIs between 1 and 2 years. Late MIs were associated with increased VLST (PES: 6 vs. ZES: 1; p = 0.069). Target lesion revascularization was similar comparing ZES with PES (5.9% vs. 4.6%; p = 0.295), especially in patients without planned angiographic follow-up (5.2% vs. 4.9%; p = 0.896). The cost-effectiveness of ZES and PES was similar.

CONCLUSIONS

After 2 years of follow-up, ZES demonstrated efficacy and cost-effectiveness comparable to PES, with fewer MIs and a trend toward less VLST. (The ENDEAVOR IV Clinical Trial: A Trial of a Coronary Stent System in Coronary Artery Lesions; NCT00217269).

Long-term clinical and economic analysis of the Endeavor zotarolimus-eluting stent versus the cypher sirolimus-eluting stent: 3-year results from the ENDEAVOR III trial (Randomized Controlled Trial of the Medtronic Endeavor Drug [ABT-578] Eluting Coronary Stent System Versus the Cypher Sirolimus-Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions)

OBJECTIVES

The aim of this study was to evaluate clinical and economic outcomes for subjects receiving zotarolimus-eluting (ZES) (n = 323) versus sirolimus-eluting stents (SES) (n = 113) in the ENDEAVOR III (Randomized Controlled Trial of the Medtronic Endeavor Drug [ABT-578] Eluting Coronary Stent System Versus the Cypher Sirolimus-Eluting Coronary Stent System in De Novo Native Coronary Artery Lesions) clinical trial.

BACKGROUND

Although previous clinical trials have evaluated long-term clinical outcome for drug-eluting stents, none considered their economic implications.

METHODS

We analyzed case report form information with quality-of-life adjustment and Medicare cost weights applied from secondary sources; compared differences in clinical outcomes, quality-adjusted survival, medical resource use, and medical costs; and evaluated cost-effectiveness through 3-year follow-up.

RESULTS

The use of ZES versus SES reduced the 3-year rates/100 subjects of death or myocardial infarction (3.9 vs. 10.8; difference, -6.9; 95% confidence interval [CI]: -13.0 to 0.8; p = 0.028), with no difference in target vessel revascularization rates (17.9 vs. 12.2; difference, 5.7; 95% CI: -3.7 to 15.1; p = 0.23) but greater use of coronary artery bypass graft (CABG) surgery (3.5 vs. 0.0; difference 3.5; 95% CI: 1.3 to 5.7; p = 0.002). After discounting at 3% per annum, total medical costs for ZES versus SES were similar ($23,353 vs. $21,657; difference, $1,696; 95% CI: -$1,089 to $4,482, p = 0.23), and the 3-year cost-effectiveness ratio was $57,002/quality-adjusted life year.

CONCLUSIONS

Despite a reduction in death or myocardial infarction and no difference in total revascularizations, medical costs were not decreased due to increased CABG repeat revascularization procedures for subjects receiving ZES versus SES. If future trials observe similar differences, improved safety with no difference in medical costs, the use of ZES versus SES will be a clinically and economically attractive treatment strategy. (The Medtronic Endeavor III Drug Eluting Coronary Stent System Clinical Trial [ENDEAVOR III]; NCT00217256).

Clinical and angiographic outcomes in diabetics from the ENDEAVOR IV trial: randomized comparison of zotarolimus- and paclitaxel-eluting stents in patients with coronary artery disease

OBJECTIVES

The aim of this study was to examine outcomes related to the use of the Endeavor zotarolimus-eluting stent (ZES) (Medtronic CardioVascular, Santa Rosa, California) compared with the TAXUS paclitaxel-eluting stent (PES) (Boston Scientific Corp., Natick, Massachusetts) in the 477 patients with diabetes mellitus (DM) enrolled in the randomized ENDEAVOR IV (Randomized Comparison of Zotarolimus- and Paclitaxel-Eluting Stents in Patients with Coronary Artery Disease) trial.

BACKGROUND

Percutaneous coronary intervention (PCI) in diabetic patients is associated with increased rates of restenosis-related end points compared with PCI in nondiabetic patients. Although ZES has been associated with similar clinical efficacy compared with PES in the overall trial population of the ENDEAVOR IV trial, whether these results are maintained in the higher-risk restenosis subgroup of patients with DM has not been determined.

METHODS

Clinical and angiographic outcomes were compared according to randomized treatment assignment to either ZES or PES.

RESULTS

Baseline characteristics were similar among ZES (n = 241) and PES (n = 236) diabetic patients, with slightly longer lesion lengths in PES-treated patients (12.9 mm vs. 14.0 mm, p = 0.041). Among the 86 DM patients assigned to routine angiographic follow-up (18% of the overall DM cohort), in-stent percent diameter stenosis at 8 months was greater among ZES-treated patients (32.9 vs. 21.1, p = 0.023), with a trend toward higher in-stent late loss. One-year clinical outcomes were similar among DM patients treated with either ZES or PES (target vessel failure: 8.6% vs. 10.8%, p = 0.53; target lesion revascularization: 6.9% vs. 5.8%, p = 0.70; target vessel revascularization: 8.6% vs. 9.4%, p = 0.87). There were no significant interactions between DM status and stent type with respect to the outcomes measured, and the relative efficacy/safety of ZES and PES were similar among insulin- and noninsulin-requiring subgroups.

CONCLUSIONS

One-year clinical outcomes were similar among DM patients treated with ZES and PES in the ENDEAVOR IV trial. These findings parallel the overall trial results, which demonstrated similar efficacy and safety of ZES and PES for single de novo coronary lesions.

Cost effectiveness of enoxaparin in acute ST-segment elevation myocardial infarction: the ExTRACT-TIMI 25 (Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment-Thrombolysis In Myocardial Infarction 25) study

OBJECTIVES

We used a U.S. model of health care costs to examine the cost effectiveness of enoxaparin compared with unfractionated heparin (UFH) as adjunctive therapy for fibrinolysis in patients with ST-segment elevation myocardial infarction (STEMI).

BACKGROUND

The ExTRACT-TIMI 25 (Enoxaparin and Thrombolysis Reperfusion for Acute Myocardial Infarction Treatment-Thrombolysis In Myocardial Infarction 25) study, a large, randomized, multinational trial, demonstrated a reduction in death or nonfatal myocardial infarction when enoxaparin was used instead of UFH as adjunctive therapy for fibrinolysis in patients with STEMI.

METHODS

We used patient-level clinical outcomes and resource use from the ExTRACT-TIMI 25 trial and estimates of life expectancy gains as a result of the prevention of the clinical events on the basis of the Framingham Heart Study.

RESULTS

Index hospitalization costs trended lower by $126 in the enoxaparin group (95% confidence interval [CI]: -$295 to $49). Thirty-day costs trended higher by $102 for enoxaparin (95% CI: $108 to $314). Patients receiving enoxaparin gained an average of 0.12 life-years relative to patients given UFH. Estimated total lifetime costs were $1,207 higher in the enoxaparin group (95% CI: $491 to $1,923). The incremental cost-effectiveness ratio of enoxaparin compared with UFH was $5,700 per life-year gained, with 99.9% of bootstrap-derived estimates <$50,000 per life-year gained. Using a probabilistic sensitivity analysis, there is a 90% probability that enoxaparin is cost effective for lifetime, provided that the willingness-to-pay value exceeds $50,000.

CONCLUSIONS

Based on a U.S. model of health care economics, the strategy of using enoxaparin instead of UFH as adjunctive therapy for fibrinolysis in patients with STEMI is cost effective according to commonly used benchmarks.

Comparison of long versus short ("spot") drug-eluting stenting for long coronary stenoses

We compared spot drug-eluting stenting (DES) to full stent coverage for treatment of long coronary stenoses. Consecutive, consenting patients with a long (>20 mm) coronary lesion of nonuniform severity and indication for percutaneous coronary intervention were randomized to full stent coverage of the atherosclerotic lesion with multiple, overlapping stenting (full DES group, n = 90) or spot stenting of hemodynamically significant parts of the lesion only (defined as diameter stenosis >50%; spot DES group, n = 89). At 1-year follow-up, 14 patients with full DES (15.6%) and 5 patients (5.6%) with spot DES had a major adverse cardiac event (MACE; p = 0.031). At 3 years, MACEs occurred in 18 patients with full DES (20%) and 7 patients (7.8%) with spot DES (p = 0.019). Cox proportional hazard model showed that the risk for MACEs was almost 60% lower in patients with spot DES compared to those with full DES (hazard ratio 0.41, 95% confidence interval 0.17 to 0.98, p = 0.044). This association remained even after controlling for age, gender, lesion length, and type of stent used (hazard ratio 0.42, 95% confidence interval 0.17 to 1.00, p = 0.05). In conclusion, total lesion coverage with DES is not necessary in the presence of diffuse disease of nonuniform severity. Selective stenting of only the significantly stenosed parts of the lesion is an appropriate therapeutic alternative in this setting, offering a favorable clinical outcome.

Safety and efficacy of drug-eluting and bare metal stents: comprehensive meta-analysis of randomized trials and observational studies

BACKGROUND

The safety and efficacy of drug-eluting stents (DES) among more generalized "real-world" patients than those enrolled in pivotal randomized controlled trials (RCTs) are controversial. We sought to perform a meta-analysis of DES studies to estimate the relative impact of DES versus bare metal stents (BMS) on safety and efficacy end points, particularly for non-Food and Drug Administration-labeled indications.

METHODS AND RESULTS

Comparative DES versus BMS studies published or presented through February 2008 with > or =100 total patients and reporting mortality data with cumulative follow-up of > or =1 year were identified. Data were abstracted from studies comparing DES with BMS; original source data were used when available. Data from 9470 patients in 22 RCTs and from 182 901 patients in 34 observational studies were included. RCT and observational data were analyzed separately. In RCTs, DES (compared with BMS) were associated with no detectable differences in overall mortality (hazard ratio [HR], 0.97; 95% confidence interval [CI], 0.81 to 1.15; P=0.72) or myocardial infarction (HR, 0.95; 95% CI, 0.79 to 1.13; P=0.54), with a significant 55% reduction in target vessel revascularization (HR, 0.45; 95% CI, 0.37 to 0.54; P<0.0001); point estimates were slightly lower in off-label compared with on-label analyses. In observational studies, DES were associated with significant reductions in mortality (HR, 0.78; 95% CI, 0.71 to 0.86), myocardial infarction (HR, 0.87; 95% CI, 0.78 to 0.97), and target vessel revascularization (HR, 0.54; 95% CI, 0.48 to 0.61) compared with BMS.

CONCLUSIONS

In RCTs, no significant differences were observed in the long-term rates of death or myocardial infarction after DES or BMS use for either off-label or on-label indications. In real-world nonrandomized observational studies with greater numbers of patients but the admitted potential for selection bias and residual confounding, DES use was associated with reduced death and myocardial infarction. Both RCTs and observational studies demonstrated marked and comparable reductions in target vessel revascularization with DES compared with BMS. These data in aggregate suggest that DES are safe and efficacious in both on-label and off-label use but highlight differences between RCT and observational data comparing DES and BMS.

Late stent thrombosis, endothelialisation and drug-eluting stents

Drug-eluting stents (DES) significantly reduce the risk of restenosis after percutaneous coronary revascularisation, but an increased risk of late stent thrombosis (LST) has been put forward as a major safety concern. Meta-analysis of clinical trials, however, does not support this caveat. Even so, many interventional cardiologists think that LST is associated with DES and related to delayed endothelialisation. This hypothesis is based on autopsy studies and clinical intracoronary angioscopy. In autopsy studies, differences between endothelialisation of DES and baremetal stents (BMS) have been reported. Most preclinical studies, however, have failed to show any significant differences in endothelialisation between DES and BMS. Our own studies, using the porcine coronary artery model, also suggest that DES show no differences in re-endothelialisation. However, DES do delay vascular healing and induce endothelial dysfunction. This paper will review clinical and animal studies which consider re-endothelialisation and LST. (Neth Heart J 2009;17:177-81.).

Assessing the economic merits of managing cytomegalovirus infection in organ and stem cell transplantation

Two preventative approaches exist to manage cytomegalovirus (CMV), a common infection in recipients of organ and stem cell transplants: prophylaxis--the prevention of viraemia--and pre-emptive therapy--the prevention of manifestation of disease in patients who have viraemia. Economic evaluation may provide a helpful framework to inform the choice between these two approaches. However, several issues arise. Direct comparisons of prophylaxis and pre-emptive therapy are rare and there are few epidemiological data that depict the full natural history of CMV infection and disease. There is a need for large, prospective randomised trials that directly compare these two strategies and are of sufficient duration to assess their overall impact on direct and indirect effects of CMV as well as patient quality of life. These methodological issues are relevant to the economic evaluation of preventative measures in other clinical settings and highlight the need for a rigorous evaluative framework to best inform decision making about the optimal strategy for patients.

Interpreting the results of cost-effectiveness studies

In developed nations, health care spending is an increasingly important economic and political issue. The discipline of cost-effectiveness (CE) analysis has developed over several decades as a tool for objectively assessing the value of new medical strategies, by simultaneously examining incremental health benefits in light of incremental costs. The underlying goal of CE research is to allow clinicians and policymakers to make more rational decisions regarding clinical care and resource allocation. This review will provide the reader with an understanding of the theoretical underpinnings of CE analysis, the types of analyses commonly performed and reported in the medical literature, some important strengths and weaknesses of different analytical approaches, and key principles in the interpretation of CE results. Key principles reviewed include the impact of analytic perspective, the importance of proper incremental comparisons, the effect of time horizon, and methods for exploring and describing uncertainty. Illustrative examples from the cardiology literature are discussed.