Drug eluting stents: maximising benefit and minimising cost

Drug-eluting stents: from evidence to policy

Drug-eluting stents are a major breakthrough in cardiology, with the Cypher (Cordis Corporation) and Taxus (Boston Scientific) stents preventing 60-70% of repeat coronary revascularizations, compared with bare metal stents. Both evidence- and risk-based application of drug-eluting stents is expected to create relevant financial and equity problems to most public hospitals, as the cost of drug-eluting stents is over 1000 higher than traditional stents. In the perspective of third-party payers, drug-eluting stents are cost-effective revascularization strategies for a large portion of patients actually undergoing stenting. However, adequate guidelines and reimbursement strategies are still awaited in several countries.

First-in-man evaluation of the MOMO cobalt-chromium carbon-coated stent

AIMS

Bare metal stents continue to be used for the interventional treatment of coronary artery disease. We report the clinical and angiographic results of a multicentre, single-arm evaluation of safety and feasibility of the MOMO stent (Japan Stent Technology Co., Ltd, Okayama Research Park Incubation Centre, Okayama, Japan).

METHODS AND RESULTS

The MOMO stent is a novel thin-strut cobalt-chromium carbon-coated stent for the treatment of de novo coronary artery disease (CAD). In this prospective, non-randomised, single-arm study, 40 patients (stable and unstable angina) with single-vessel CAD were recruited into the study from three centres. Patients with lesions ≤15 mm in length and with a target vessel diameter of ≥3 mm were eligible. Angiographic follow-up was performed at six months. Quantitative coronary angiography (QCA) was used to measure acute gain and late luminal loss (LLL). Intravascular ultrasound (IVUS) was performed in 15 consecutive patients from two centres to assess the degree of neointimal proliferation within the stented segment at six-month follow-up. The MOMO stent performed well without any procedural complications with an acute procedure and technical success rate of 100%. Repeat revascularisation was performed in six patients (15%) during the six-month follow-up. Ischaemia-driven revascularisation was documented in three patients (7.5%). No myocardial infarction, stent thrombosis or cardiac death was observed. One non-cardiac death was reported secondary to lung cancer. Binary restenosis was 12.5% (n=5), and the LLL was 0.54±0.3 mm.

CONCLUSIONS

This first-in-man experience demonstrates proof of concept of the safety and feasibility of the MOMO cobalt-chromium carbon-coated stent for patients with single focal de novo lesions presenting with stable and unstable CAD.

Rational use of drug-eluting stents: a comparison of different policies

Long-term results of recent landmark trials document both benefits and risks of drug-eluting stents (DES) for coronary revascularization. Interestingly, the conclusions drawn from these data vary widely since significant differences in DES penetration rates become obvious when the utilization of this technology is compared between hospitals or even countries. Based on the recommendations of the European Society of Cardiology, the FDA as well as data derived from the BASKET-LATE study, we propose that a maximum penetration rate of 50% for DES seems appropriate at present. Analysis of the length/diameter distribution combined with the use of validated restenosis reference charts allows identification of high-risk patients regarding restenosis risk and modeling the use of DES depending on financial resources and clinical indication. Such algorithm provides the rational for preprocedural risk stratification and efficient use of resources.

Physician factors as an indicator of technological device adoption

This paper analyzes a sample interventional cardiologist's demographic, academic, and professional characteristics to provide an understanding of their technological device adoption styles. The study sample consisted of 15 physicians from two large Midwestern hospitals, one an academic medical center and the other a medium-sized community hospital. Interventional cardiologists were identified through their online physician profile and respective departments. A questionnaire was developed to assess each physician's self-perceived adoption style, their awareness of the new technology, their participation in clinical trials, organizational support, and how various factors influence their adoption of new technology. Lastly, a database of bare metal and drug eluting stents was examined to document the number of stents used by each physician. Pragmatic and observational findings are presented from the questionnaire, physician profile, to database on stent use. The paper concludes with a discussion of the managerial and forecasting implications and methods to promote technology adoption.

Intracoronary photodynamic therapy reduces neointimal growth without suppressing re-endothelialisation in a porcine model

OBJECTIVE

To examine the effects of intracoronary PhotoPoint photodynamic therapy (PDT) with a new photosensitiser, MV0611, in the overstretch balloon and stent porcine models of restenosis.

METHODS

28 pigs were injected with 3 mg/kg of MV0611 systemically 4 h before the procedure. Animals were divided into either the balloon overstretch injury (BI) group (n = 19) or the stented group (n = 9). After BI, a centred delivery catheter was positioned in the artery to cover the injured area, and light (532 nm, 125 J/cm(2)) was applied to activate the drug (n = 10). Control arteries (n = 9) were not activated by light. In the stented group, the drug was light activated before stent deployment. Serial sections of vessels were processed 14 days after treatment in the BI group and 30 days after treatment in the stented group for histomorphometric or immunohistochemical analysis.

RESULTS

Intracoronary PDT significantly reduced intimal thickness in both BI and stented arteries (about 65%: 0.22 (SEM 0.05) mm v 0.62 (0.05) mm, p < 0.01; and about 26%: 0.40 (0.04) mm v 0.54 (0.04) mm, p < 0.01, respectively). PDT increased luminal area by

CONCLUSION

Intracoronary PhotoPoint PDT with MV0611 reduces intimal proliferation without suppressing re-endothelialisation in a porcine model of restenosis.

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MESH Headings

• Angioplasty, Balloon
• Animals
• Cell Proliferation
• Coronary Restenosis/prevention & control
• Coronary Vessels/injuries
• Feasibility Studies
• Female
• Immunohistochemistry
• Male
• Mesoporphyrins/pharmacokinetics
• Mesoporphyrins/therapeutic use
• Photochemotherapy/methods
• Photosensitizing Agents/pharmacokinetics
• Photosensitizing Agents/therapeutic use
• Random Allocation
• Stents
• Swine
• Tunica Intima

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Grants Collapse

Affiliation(s)

R Waksman Division of Cardiology, Washington Hospital Center, Washington, DC, USA.
I M Leitch
J Roessler
H Yazdi
R Seabron
F Tio
R W Scott
R I Grove
S Rychnovsky
B Robinson
R Pakala
E Cheneau

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Economic evaluation of drug-eluting stents in Japan

Stenting with a sirolimus-eluting stent (SES) dramatically reduces the risk of restenosis compared to bare metal stent (BMS) implantation. However, before SES can be widely adopted in clinical practice, it is essential to conduct an economic evaluation of this effective but expensive device. Our study was undertaken to estimate the three-year cumulative medical costs of stenting using SES compared to BMS. The data on clinical sequelae of stenting using BMS were derived from our previous study, based on data collected from three Japanese hospitals. We estimated that the probability of PTCA required for revascularization would be 0.224 times in SES implantation compared than in BMS implantation based on the SIRIUS study result. The medical costs for procedures were obtained from published articles and were adjusted to the March 2005 level. Our simulation showed the expected three-year cumulative medical cost per patient to be approximately 200,000 yen lower in the SES group(2,233,000 yen ) than in the BMS group (2,431,000 yen ). Sensitivity analyses with different presumptions confirmed that the economic advantage of SES over BMS was quite robust. We concluded that the use of SES would be a cost-saving option as compared with BMS implantation within the context of the Japanese healthcare system.

Cost-Benefit of Drug Eluting Stents—Time for a Reality Check

BACKGROUND

Drug-eluting stents (DES) are currently being used in preference to bare stents in the public hospital system in 'high risk' lesions on the basis of cost-effectiveness analyses using data from trials which exaggerate their impact and do not include several categories of 'high risk'. This study aimed to assess the real cost-effectiveness of DES using prospectively collected outcome data from consecutive patients in the immediate pre-DES era.

METHODS AND RESULTS

A prospective database on all percutaneous coronary interventions (PCI) performed by one operator in the two years prior to DES introduction (July 2000-June 2002) was used in which 12-month follow-up was complete in 96%. In 490 patients, 510 PCI were undertaken on 650 lesions (298 'high risk') using 686 stents. Angiography-proven clinical restenosis occurred in 31 lesions (5%) in 27 patients (12 focal, 19 diffuse; 11 treated with CABG, 14 with repeat PCI [4 re-restenosed-3 re-rePCI, 1 CABG] and 2 treated medically) with 2 deaths (both post-CABG). If all 'high risk' lesions had been treated with DES (assuming 0% clinical restenosis) then 22 lesions in 18 patients would not have restenosed avoiding 8 CABG and 13 re-PCI. Assuming A 5186 dollars cost for re PCI and A 18,496 dollars for CABG, DES will only be cost neutral for 'high risk' lesions when the premium for DES reduces to 617 dollars (currently 1500 dollars) and for all lesions at 452 dollars.

CONCLUSIONS

Current strategies for use of DES are not cost-effective. DES should be reserved for restenosis until the price comes down.

Which Parameter Should Be Chosen as Primary Endpoint for Randomized Drug-Eluting Stent Studies?

In Europe, 1,108 percutaneous coronary interventions (PCIs) per one Mio inhabitants are currently annually performed, most of them with stent implantation. Drug-eluting stents have been the focus of attention of interventional coronary therapy since the RAVEL study was first presented in September 2001 at the European Society of Cardiology Meeting. Ever since, numerous studies have assessed the effects of various antiproliferative and anti-inflammatory substances and a variety of different stents was used as platform, either covered with polymer carriers of different chemical and physical properties or without a polymer carrier. CE- or FDA-certified drug-eluting stents are increasingly replacing the use of bare metal stents to reduce in-stent restenosis. Today, physicians have a choice of several approved drug-eluting stents and, therefore, need some evidence-based guidance through the "jungle of information" to make the right decisions. Even when focusing on randomized trials, differences between the studies regarding primary endpoints and sample sizes exist, making it difficult to compare the various drug-eluting stent studies. Randomized studies use either nonclinical (i.e., angiographic diameter stenosis, in-stent MLD, or in-stent late lumen loss) or clinical (i.e., TVF, TVR, and MACE) parameters as primary endpoints. Choosing an angiographic parameter as primary endpoint results in two major limitations: first, a significant improvement of an angiographic "surrogate" parameter does not necessarily translate into a better clinical outcome (DELIVER-I); second, conclusions regarding possible improvements of clinical outcome are underpowered, because the sample size calculation is based on the primary endpoint. Usually the number of patients needed is lower for angiographic than for clinical endpoints. Until today, only three trials with a primary clinical endpoint have shown a significantly positive impact on patients' outcome: the SIRIUS trial (Cypher stent) with its reduction of primary endpoint TVF (21.0% vs 8.6%), the TAXUS-IV trial (Taxus stent) with its reduction of primary endpoint TVR (12.0% vs 4.7%) and TAXUS-VI in long lesions with its reduction of primary endpoint TVR (19.4% vs 9.1%). Although the angiographic results of other drug-eluting stents are encouraging, they will have to prove their clinical impact based on adequately powered randomized trials with a primary clinical endpoint at an adequate time interval.

Hybrid Coronary Revascularization in the Era of Drug-Eluting Stents

Left internal mammary artery to left anterior descending coronary artery bypass grafting integrated with percutaneous coronary angioplasty (hybrid procedure) offers multivessel revascularization with minimal morbidity in high-risk patients. This is caused in part by the avoidance of cardiopulmonary bypass-related morbidity and manipulation of the aorta coupled with minimally invasive techniques. Hybrid revascularization is currently reserved for particularly high-risk patients or those with favorable anatomic variants however, largely because of the emergence of off-pump coronary artery bypass grafting, which permits more complete multivessel revascularization, with low morbidity in high-risk groups. The wider introduction of hybrid revascularization is limited chiefly by the high number of repeat interventions compared with off-pump coronary artery bypass grafting, which occurs because of the target vessel failure rate of percutaneous coronary intervention. Other demerits are the costs and logistic problems associated with performing two procedures with differing periprocedural management protocols. Recently, drug-eluting stents have reduced the need for repeat intervention after percutaneous coronary intervention, and this has raised the possibility that the results of hybrid revascularization may now equal or even better those of off-pump coronary artery bypass grafting. Although undoubtedly effective at reducing in-stent restenosis, drug-eluting stents will not address the issues of incomplete revascularization or the logistic problems associated with hybrid. Uncertainty regarding the long-term effectiveness of drug-eluting stents in many patients, as well as their high cost when compared with those of off-pump coronary artery bypass grafting surgery, also militates against the wider introduction of hybrid revascularization.