Percutaneous treatment of peripheral vascular disease: the role of diabetes and inflammation

Peripheral arterial disease (PAD) is a growing health problem for many Americans and often occurs along with other cardiovascular risk factors, including diabetes mellitus (DM), low-grade inflammation, hypertension, and lipid disorders. Intermittent claudication (IC), an early manifestation of PAD, commonly leads to reduced quality of life for patients who are limited in their ambulation. While recent wide adoption of percutaneous peripheral interventional (PPI) techniques has increased the number patients being aggressively treated for IC, the overall effectiveness of PPI for the treatment of IC is not well known, especially for DM patients who have both hemodynamic and functional obstacles to treatment success. This review is designed to illustrate how treatment outcomes for IC can be measured by different modalities and how diabetes and inflammation can influence those outcomes. In the setting of greater concern for health care resources and clinical accountability, better understanding of treatment outcomes and efficacy will help us manage these complex challenges.

Price disparity of percutaneous coronary intervention devices in Japan and the United States in 2006

BACKGROUND

The price disparity between Japan and foreign countries for medical devices is a controversial issue. Price differences existed between Japan and USA for various medical devices in early 2005, so in the present study, a more precise and detailed investigation of the latest market prices of medical devices between Japan and USA was conducted in 2006, focusing on coronary stents and percutaneous transluminal coronary angioplasty (PTCA) catheters, for an evaluation of the efficacy of current Japanese policies.

METHODS AND RESULTS

Japanese market prices were obtained from 31 university hospitals, and US market prices were obtained from 1 hospital chain and 2 group-purchasing organizations. The price ratio (Japanese market price/US market price) was determined to be 1.2-1.4 for drug-eluting stents (DES), 1.6-2.4 for non-DES, and 4.1-5.1 for PTCA catheters.

CONCLUSIONS

Results showed that the price disparity was relatively small for DES, but still significant for non-DES and PTCA catheters. Radical measures must be taken to improve the fundamental causes of price disparity and might include reviewing the implementation of the Japanese Pharmaceutical Affairs Law, abolishing the reimbursement price system for medical devices, and establishing centers of clinical excellence.

The impact of general usage of stents on short- and long-term health care costs following percutaneous coronary intervention

BACKGROUND

The general usage of stents during percutaneous coronary intervention (PCI) reduces the need for subsequent repeated revascularizations when compared with balloon dilatation. The aim was to evaluate the impact of stenting on short- and long-term in-hospital care costs after PCI.

METHOD AND RESULTS

Patients who underwent PCI from July 1992 to June 1993 (group A, n = 166; 4.2% stents) and from July 1996 to June 1997 (group B, n = 233; 61.4% stents) were included. The clinical outcome and all in-hospital care costs during 2.5 years following the procedures were analyzed. During the study period the number of deaths and acute myocardial infarctions was similar in the groups, but repeated revascularization occurred more often in group A than in group B (53.6 vs. 39.5%; p = 0.007). The initial procedural cost per patient was higher in group B than in group A (EUR 7,653 +/- 5,071 vs. EUR 6,048 +/- 3,242; p = 0.002), but after 2.5 years the costs were similar in the 2 groups (not significant).

CONCLUSION

General usage of stents increases immediate health care cost compared with balloon dilatation, but despite reduction in subsequent revascularization, there is no reduction in long-term in-hospital costs.

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.

[Benefits and risks of drug-eluting stents]

The March 8, 2007-issue of the New England Journal of Medicine contained 5 original articles, 2 commentaries and 1 editorial on drug-eluting coronary stents versus bare metal stents. Over the past 5 years, multiple randomised, controlled trials have shown that drug-eluting stents reduce recurrent stenosis and the need for additional revascularisation procedures. Drug-eluting stents are now used in a large proportion of percutaneous coronary interventions. Following publications reporting a risk of late thrombosis with sudden occlusion, the promises and uncertainties regarding the benefits and risks are now heavily debated. It can be concluded that these first-generation drug-eluting stents, provided that they are used for indications in accordance with the randomised trials, result in a clear reduction in the need for additional revascularisation procedures without an effect on long-term case fatality and myocardial infarction. There is a small but serious risk of sudden thrombosis and occlusion. The task for the future will be to develop stents that do reduce recurrent stenosis but allow a normal endothelisation of the treated coronary artery segment. When drug-eluting stents have reached that stage, they will be clearly advantageous.

The cost of new therapies in cardiovascular care. Time for hope or despair for developing countries

In recent years, remarkable therapeutic advances have been made in the field of interventional cardiology with the introduction of statins, thienopyridines, such as clopidogrel and drug-eluting stents. Only a small minority in developing countries can afford these new treatment modalities, while the public health system would be rapidly bankrupted if it were to provide these modalities for all patients who might benefit from it. The purpose of this review article is to provide insight regarding the cost-effectiveness of these new treatment strategies and to address the added costs resulting upon their adoption and their appropriateness in developing countries.

Covered self-expandable metal stents in pancreatic malignancy regardless of resectability: a new concept validated by a decision analysis

BACKGROUND AND STUDY AIMS

The current treatment model for the management of malignant biliary obstruction is to place a plastic stent for unstaged pancreatic cancer. In patients with unresectable disease but a life expectancy of more than 6 months, self-expandable metal stents (SEMS) are favored because of their more prolonged patency. We analyzed the efficacy and cost-effectiveness of covered SEMS (CSEMS) in patients with pancreatic cancer and distal biliary obstruction without regard to surgical resectability.

PATIENTS AND METHODS

Between March 2001 and March 2005, 101 consecutive patients with obstructive jaundice secondary to pancreatic cancer underwent placement of a CSEMS. Patients with resectable tumor were offered pancreaticoduodenectomy. A model was developed to compare the costs of CSEMS and polyethylene and DoubleLayer stents.

RESULTS

A total of 21 patients underwent staging laparoscopy, of whom 16 had a resection (76%). The 85 patients who did not have a resection had a mean survival of 5.9 months (range 1-25 months) and a mean CSEMS patency duration of 5.5 months (range 1-16 months). Life-table analysis demonstrated CSEMS patency rates of 97% at 3 months, 85% at 6 months, and 68% at 12 months. In a cost model that accounted for polyethylene and DoubleLayer stent malfunction and surgical resections, initial CSEMS placement (3177 euros per patient) was a less costly intervention than either DoubleLayer stent placement (3224 euros per patient) or polyethylene stent placement with revision (3570 euros per patient).

CONCLUSIONS

Covered SEMS are an effective treatment for distal biliary obstructions caused by pancreatic carcinoma. Their prolonged patency and removability makes them an attractive option for biliary decompression, regardless of resectability. The strategy of initial covered SEMS placement might be the most cost-effective strategy in these patients.

Cost effectiveness analysis of minimally invasive internal thoracic artery bypass versus percutaneous revascularisation for isolated lesions of the left anterior descending artery

OBJECTIVE

To compare the cost effectiveness of percutaneous transluminal coronary artery stenting with minimally invasive internal thoracic artery bypass for isolated lesions of the left anterior descending artery.

DESIGN

Cost effectiveness analysis.

DATA SOURCES

Embase, Medline, Cochrane, Google Scholar, and Health Technology Assessment databases (1966-2005), and reference sources for utility values and economical variables.

METHODS

Decision analytical modelling and Markov simulation were used to model medium and long term costs, quality of life, and cost effectiveness after either intervention using data from referenced sources. Probabilistic sensitivity and alternative analyses were used to investigate the effect of uncertainty about the value of model variables and model structure.

RESULTS

Stenting was the dominant strategy in the first two years, being both more effective and less costly than bypass surgery. In the third year bypass surgery still remained more expensive but became marginally more effective. As the incremental cost effectiveness was 1,108,130.40 pounds sterling (1 682,146.00 euros; $2,179,194) per quality adjusted life year (QALY), the additional effectiveness could not be said to justify the additional cost at this stage. By five years, however, the incremental cost effectiveness ratio of 28,042.95 pounds sterling per QALY began to compare favourably with other interventions. At 10 years the additional effectiveness of 0.132 QALYs (range -0.166 to 0.430) probably justified the additional cost of 829.02 pounds sterling (range 205.56 pounds sterling to 1452.48 pounds sterling), with an incremental cost effectiveness of 6274.02 pounds sterling per QALY. Sensitivity and alternative analysis showed the results were sensitive to the time horizon and stent type.

CONCLUSIONS

Minimally invasive left internal thoracic artery bypass may be a more cost effective medium and long term alternative to percutaneous transluminal coronary artery stenting.

The costs and quality-of-life outcomes of drug-eluting coronary stents: a systematic review

OBJECTIVES

While the efficacy of drug-eluting coronary stents (DES) has been demonstrated by several clinical trials, the impact of DES on health-care costs and recipient quality of life (QOL) is controversial. We performed a systematic review of the published literature on DES costs and the QOL effects of restenosis and target vessel revascularization (TVR).

METHODS

Among 536 potential articles initially identified by a broad search, 12 publications ultimately met inclusion criteria. Data were independently abstracted, evaluated for quality and relevance, and summarized by two reviewers. Excessive heterogeneity among these studies prevented formal meta-analysis, thus a narrative synthesis of the literature was performed.

RESULTS

In four economic studies, DES recipients had 1,600 dollars-3,200 dollars higher up-front costs than recipients of bare metal stents, but the differences in total costs after 1 year were less pronounced (200 dollars-1,200 dollars), and estimates of the average cost of an avoided revascularization ranged widely (1,800 dollars-36,900 dollars). All eight QOL studies indicated that restenosis was associated with lower QOL, but only two studies quantified this in terms of quality-adjusted life years (QALYs), with estimates ranging from 0.06 to 0.08. An additional study estimated that the median willingness to pay to prevent restenosis was 2,400 dollars-3,600 dollars.

CONCLUSIONS

There is a lack of convergence in the literature on the cost of DES in avoiding TVR. There is more agreement that the average QALY benefit of an avoided revascularization is 0.04-0.08. This implies that use of DES in patients where the average cost per avoided revascularization exceeds 8,000 dollars may be less likely to be cost-effective.

Drug-eluting stent: a review and update

The development of stent has been a major advance in the treatment of obstructive coronary artery disease since the introduction of balloon angioplasty. However, neointimal hyperplasia occurring within the stent leading to in-stent restenosis is a main obstacle in the long-term success of percutaneous coronary intervention (PCI). The recent introduction of drug-eluting stents (DES) contributes a major breakthrough to interventional cardiology. Many large randomized clinical trials using DES have shown a remarkable reduction in angiographic restenosis and target vessel revascularization when compared with bare metal stents. The results of these trials also appear to be supported by evidence from everyday practice and noncontrolled clinical trials. However, the expanded applications of DES, especially in treating complex lesions such as left main trunk, bifurcation, saphenous vein graft lesions, or in-stent restenosis, are still under evaluation with ongoing studies. With the availability of different types of DES in the market, the issue of cost should not be a deterrent and DES will eventually be an economically viable option for all patients. The adoption of DES in all percutaneous coronary intervention may become a reality in the near future. In this review article, we summarize the recent development and progress of DES as well as compare and update the results of clinical trials.

Airway stenting: Applications and practice management considerations

BACKGROUND

Airway stenting is a procedure that is performed increasingly often, and the availability of metallic stents placed by flexible bronchoscopy may have contributed to the increased usage. These procedures have an impact on the required physician skill set and practice management. We review the indications for airway stenting, and how the requirement of combined therapies and technical aspects of central airway stenting pertain to practice management.

PROCEDURE

We compared several reimbursement scenarios for managing stent placement using the Centers for Medicare and Medicaid Services relative value units (RVUs) and average reimbursement amounts. We also compared the reimbursement to other commonly performed activities performed by pulmonary and critical care physicians. An analysis of Medicare facility outpatient and inpatient payment for procedures using silicone and metallic stents was also conducted.

RESULTS

Professional reimbursement is identical regardless of stent type, method of insertion, and anesthesia administered. The net facility reimbursement largely depends on stent costs. The RVUs alone are a poor comparator for the reimbursement of therapeutic bronchoscopy because of Correct Coding Initiatives edits. Considering the time necessary for performing advanced therapeutic bronchoscopy, the professional fees are not attractive. The net facility reimbursement largely depends on stent costs.

CONCLUSION

The placement of airway stents is not reimbursed at competitive rates and may even lead to a net loss for the facility. The practice management benefits of central airway therapy are probably best obtained by a multidisciplinary airway team with an established cost center structure.

Use of the U.S. and U.K. Scoring Algorithm for the EuroQol-5D in an Economic Evaluation of Cardiac Care

BACKGROUND

Most studies that have used the EuroQol-5D instrument (EQ-5D) have used a scoring algorithm based on preferences solicited from the U.K. population. An algorithm recently was developed for the U.S. population, with studies showing meaningful differences in the results obtained using the 2 algorithms. We recently published an economic evaluation assessing the use of drug-eluting stents in patients undergoing percutaneous coronary intervention (PCI).

OBJECTIVES

Using the aforementioned economic evaluation, we describe the EQ-5D utility scores resulting from use of U.S. and U.K. algorithms and explore the differences in the incremental cost-utility ratio (ICER) resulting from use of the different EQ-5D estimates.

METHODS

EQ-5D data were obtained from the Alberta Provincial Project for Outcomes Assessment in Coronary Heart (APPROACH) disease registry. Individual responses were scored once with each algorithm. The within-individual difference was calculated (U.S. score-U.K. score). The mean, SD, and range were compared using paired t tests. The resulting ICERs were compared using probabilistic sensitivity analysis.

RESULTS

The U.K. mean was statistically different from the U.S. mean (0.83, SD 0.20 vs. 0.87, SD 0.15, P<0.001). The mean within individual difference was 0.04 with a wide range (-0.02 to +0.41). The resulting ICER are CAN $58,635 (95% confidence interval $198,248-$34,406) per quality-adjusted life year and CAN $58,229 (95% confidence interval $116,818-$38,779) per quality-adjusted life year for the U.K. and U.S. algorithms, respectively (P value: 0.07).

CONCLUSIONS

The algorithms produce quite notable differences within individuals. The effect on the mean score is less pronounced. In the context of our economic evaluation, however, the impact of using the U.S. algorithm on the ICER is negligible.

Targeted stent use in clinical practice based on evidence from the BAsel Stent Cost Effectiveness Trial (BASKET)

AIM

It is unknown which patients benefit most from drug-eluting stents (DES) against bare-metal stents (BMS) in a long-term clinical outcome.

METHODS AND RESULTS

To address this question, data from 826 consecutive patients with angioplasty, randomized 2:1 to DES vs. BMS, with an 18-month follow-up for cardiac death/myocardial infarction (MI) and non-MI-related target-vessel revascularization (TVR) were analysed for interactions between stent type and patient/vessel characteristics predicting events. Rates of 18-month TVRs were lower with DES vs. BMS use (7.5 vs. 11.6%, P = 0.05), but similar for both stents regarding cardiac death/MI (DES, 8.4%; BMS, 7.5%; P = 0.70). Significant interactions between stent type and two multivariable event predictors were identified: small stents (<3.0 mm) and bypass graft stenting. In these patient groups together (n = 268, 32%), DES reduced non-MI-related TVR (HR = 0.44; P = 0.02) and cardiac death/MI (HR = 0.44; P = 0.04), whereas in the other 558 patients (68%) TVR rate was similar (HR = 0.75; P = 0.38) and cardiac death/MI rate increased after DES (HR = 2.07; P = 0.05).

CONCLUSION

Patients with angioplasty of small vessels or bypass grafts seem to benefit from DES use, in long-term outcome, in contrast to patients with large native vessel stenting where there might even be late harm. Still, this hypothesis needs to be tested prospectively.