Appraisal Consultation Document: Coronary artery stents
NATIONAL INSTITUTE FOR CLINICAL EXCELLENCE
Appraisal Consultation Document
Coronary artery stents
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The Department of Health and the Welsh Assembly Government have asked the National Institute for Clinical Excellence (NICE or the Institute) to conduct an appraisal of coronary artery stents and provide guidance on its use to the NHS in England and Wales. The Appraisal Committee has had its first meeting to consider both the evidence submitted and the views put forward by the representatives nominated for this appraisal by professional organisations and patient/carer and service user organisations. The Committee has developed preliminary recommendations on the use of coronary artery stents. This document has been prepared for consultation with the formal consultees. It summarises the evidence and views that have been considered and sets out the preliminary recommendations developed by the Committee. The Institute is now inviting comments from the formal consultees in the appraisal process (the consultees for this appraisal are listed on the NICE website). Note that this document does not constitute the Institute's formal guidance on this technology. The recommendations made in Section 1 are preliminary and may change after consultation. The process the Institute will follow after the consultation period is summarised below. (For further details, see the Guide to the Technology Appraisal Process on the Institute's website).
The key dates for this appraisal are: Closing date for comments: Tuesday 15 July 2003 Details of membership of the Appraisal Committee are given in Appendix A and a list of the sources of evidence used in the preparation of this document is given in Appendix B. |
| Note that this document does not constitute the Institute's formal guidance on this technology. The recommendations made in Section 1 are preliminary and may change after consultation. |
| 1 | Appraisal Committee's preliminary recommendations |
| 1.1 | Stents should be used routinely for patients with either stable or unstable angina or with acute myocardial infarction (MI), and where percutaneous coronary intervention (PCI) is the clinically appropriate procedure. |
| 1.2 | The decision to use a bare-metal stent (BMS) or a drug-eluting stent (DES) will depend on the anatomy of the target vessel for stenting and the severity of the disease. |
| 1.3 | The use of either a Cypher (sirolimus-eluting) or Taxus (paclitaxel-eluting) stent is recommended in elective PCI for patients with symptomatic coronary artery disease (CAD), in whom the target artery is less than 3 mm in diameter or the lesion to be stented is longer than 20 mm. |
| 1.4 | If more than one artery is considered clinically appropriate for stenting then the considerations in Sections 1.2 and 1.3 apply to each artery. |
| 1.5 | Antiplatelet drugs must be used for 6 months after the implantation of DES. |
| 1.6 | This guidance specifically relates to the present clinical indications for PCI and excludes conditions (such as many cases of stable angina) that are adequately managed with standard drug therapy. |
| 2 | Clinical need and practice |
| 2.1 | CAD is by far the most common cause of heart disease, resulting from the narrowing of coronary arteries ('stenosis') caused by deposition of atherosclerotic plaque. Coronary artery stenosis may be asymptomatic or may lead to angina, a chest pain that may be severe enough to restrict or prevent exertion. A critical reduction of the blood supply to the heart may result in MI or death. |
| 2.2 | CAD causes about 2100 deaths annually per million of the population in England and Wales (about 110,000 deaths in total), one of the highest rates in the world. CAD is also the cause of considerable morbidity and loss of ability to lead a normal life. Some 1.4 million people in England and Wales suffer from angina, the most common form of such morbidity. |
| 2.3 | Stenotic lesions are categorised as A, B1, B2 and C, where A denotes a relatively short (less than 10 mm) and easily accessible lesion and C lesions that are relatively long (greater than 20 mm) and may be less accessible, tortuous and/or with side branches and may be totally occluded. |
| 2.4 | CAD may affect one or more arteries, which may be of different diameters. Occlusion may be partial or total. |
| 2.5 | A stenosed artery may be treated medically - by modification of risk factors (for example, smoking, obesity and diabetes) and/or by drug treatment (for example beta blockers, nitrates, calcium channel blockers, antiplatelet agents and anticoagulants). |
| 2.6 | If these medical treatments fail or are inappropriate, two invasive therapies are available. The first, coronary artery bypass grafting (CABG), involves major cardiac surgery. The second, so-called balloon angioplasty, or percutaneous transluminal coronary angioplasty (PTCA), involves a non-surgical widening from within the artery using a balloon catheter. When inflated, the balloon increases the lumen (flow diameter) of the artery. |
| 2.7 | Recently, most PTCA procedures have involved the use of stents, which are thin wire mesh structures that act as permanent prosthetic linings to keep the artery inflated and maintain its patency. PCI is a generic term to encompass PTCA with or without adjunct techniques such as stenting. |
| 2.8 | For disease in a single artery, PCI with a stent has been the more frequent treatment; for disease in two arteries, patient numbers for stent and CABG have been similar, but for more than two affected arteries, CABG has been much more frequently used. |
| 2.9 | The major problem with balloon angioplasty is restenosis of the artery, which has three main causes. The first, recoil of the artery, happens when the balloon is deflated. It usually occurs immediately or within hours of completion of the procedure, and requires emergency CABG. This situation can be practically eliminated by using a stent. The two subsequent problems, mostly arising during the first 6 months, comprise 'remodelling' of the artery caused by an overgrowth of the cells lining the artery in response to the irritation caused by the catheter used in angioplasty, and the development of scar tissue (which tends to be made worse by the introduction of a foreign body such as a stent). A repeat procedure is consequently required in approximately 20% of patients with simple lesions. This rate of re-intervention is much higher (up to 50%) for arteries with small diameters, saphenous vein grafts, long lesions, total occlusions and in people with diabetes. |
| 2.10 | Recent advances in stent technology have reduced some of the problems of restenosis, as well as lowering the cost of stents. In addition, the use of antiplatelet drugs and other therapeutic strategies to prevent thrombosis have improved long-term outcomes. |
| 2.11 | One of the main criteria for assessing the clinical effectiveness of stents compared with standard balloon angioplasty is their ability to reduce the incidence of subsequent attacks of angina as well as adverse events, which include death, MI and the need for further revascularisation procedures (CABG or repeat PCI). |
| 2.12 | Patients for whom both a CABG and a PCI involving stenting are appropriate techniques would, other things being equal, choose PCI in almost all cases, as the procedure is less invasive, has a lower chance of death during the operation, and involves a much shorter and less painful recuperation time. |
| 2.13 | Some 39,000 PCI procedures were undertaken in the UK in 2001, equating to 663 per million of the population, a rate that had increased at an average of 14% per year over the previous 10 years. The rate for the UK remains below that of the EC average, which exceeds 1000 per million of the population. |
| 2.14 | In the UK, the proportion of PCI procedures using stents rose steeply between 1993 and 1999, from below 10% to nearly 80%, and has continued to increase more slowly, to about 85% in 2001. |
| 2.15 | The number of CABG procedures performed each year in the UK has increased from 15,700 in 1991 to 24,700 in 1999/2000, or from 292 to 464 per million of the population. Growth has slowed considerably since the first half of the 1990s. |
| 2.16 | The Institute previously issued guidance on coronary artery stents in May 2000. The main recommendation of that guidance was the same as in Section 1.1 of this Appraisal Consultation Document. At the time of the original guidance, however, sufficient evidence about the use of stents in small-diameter arteries or for drug-eluting stents was not available, so recommendations for the use of stents did not extend to either of these areas. |
| 2.17 | The National Service Framework target set in March 2000 for revascularisations (PCIs and CABGs) is 1500 per million of the population (750 for both types of intervention). At current growth rates, the combined target will be reached by about 2005. |
| 2.18 | List prices for both BMS and DES differ between manufacturers, and some manufacturers produce more than one stent in each class, at different prices. Prices for BMS range from about £600 to £900 and for DES from about £1,300 to £1,500 per stent. The difference between BMS and DES is about £500 to £600 for stents that are the same apart from their drug-eluting properties. Costs may vary in different settings because of negotiated procurement discounts. |
| 3 | The technology |
| 3.1 | Methods of reducing restenosis include: coating the stent with an appropriate drug; introducing an emitter of radioactive particles at the stenting site (brachytherapy); and creating the slow release of a drug from the stent, making the stent 'drug-eluting'. The drug is held temporarily in place within a polymer 'painted' onto the metallic stent. There is little evidence in favour of coating the stent directly with an active drug (without a polymer); additionally, this topic (and brachytherapy) is outside the scope of this appraisal. |
| 3.2 | Although a number of drugs have been trialled for their drug-eluting properties, only three have been granted a CE licence for use within EC countries: paclitaxel, which inhibits cell division, is eluted from the Taxus stent; sirolimus, an immunosuppressive agent previously known as rapamycin, a synthetic adrenocortical steroid that reduces inflammation, is eluted from the Cypher stent; and dexamethasone, a synthetic adrenocortical steroid that reduces inflammation. These drugs may be eluted at different speeds, depending on the presence or absence of additional polymer coatings on the stent. |
| 3.3 | Because the performance of DES depends critically on the particular drug being used, each DES should be regarded as a separate technology. However, at this stage, studies comparing different DES directly have not been performed. |
| 3.4 | DES require longer use of antiplatelet drugs than BMS. |
| 4 | Evidence and interpretation |
| The Appraisal Committee considered evidence from a number of sources (see Appendix B). | |
| 4.1 | Clinical effectiveness |
| 4.1.1 | The Assessment Report considers three sets of comparison: PCI without stents versus PCI with BMS; PCI with stents versus CABG; and BMS versus DES. |
| 4.1.2 | Assessment of the relative effectiveness of stents (or in deciding between different stents) relates to the likelihood of restenosis discovered on follow-up and the requirement for repeat intervention. Repeat intervention may be identified as a result of following the trial protocol that requires a repeat angiographic examination at a predetermined interval (so-called 'protocol-driven' reintervention) or following recurrence of symptomatic angina in the patient (that is, 'clinically-driven' reintervention). The frequency of protocol-driven reinterventions is higher than that of clinically-driven reinterventions, because angiography is usually mandatory at 6 months according to the trial protocol whereas in clinical practice it is carried out only after recurrence of symptoms. Accordingly, the differences observed between the treatment and control arms of clinical trials are likely to be higher in than would be expected to occur in clinical practice. |
| Stents versus PCI without stents | |
| 4.1.3 | Fifty randomised controlled trials (RCTs) were analysed comparing the use of stents against PCI without stents. In 12 trials involving 5700 patients where a composite endpoint of revascularisation, MI or death (MACE) was reported, the MACE rate was significantly different at 6 months' follow-up: 23.0% for PCI (without stents) versus 15.4% for stents, an odds ratio (OR) of 1.66 (95% confidence interval [CI], 1.45 to 1.90). The difference was smaller after 12 months' follow-up, but still statistically significant; for this subsample of some 3500 patients, the MACE rate for PCI was 22.0% and for stents was 18.9% (OR 1.33; 95% CI, 1.12 to 1.58). |
| 4.1.4 | For the outcome of acute MI, significant differences were obtained at follow-ups of 36 days, 6 months and 12 months (OR 1.66, 2.36 and 2.36, respectively). |
| 4.1.5 | No significant differences were reported for deaths, because it was a rare event and the trials were not powered to detect differences. |
| 4.1.6 | Thus, the two types of event that stents are shown to prevent are restenosis and acute MI. |
| 4.1.7 | According to the joint professional submission, restenosis is greater in small vessels, because a given tissue regrowth will have a greater proportionate effect in a vessel of smaller diameter. In eight out of nine studies, restenosis rates were lower in the stent arm than in the PCI arm, and in two of these studies, the difference was statistically significant. The meta-analysis is also stated to show a significant advantage for stents. However, restenosis rates are still high, even with stents. |
| 4.1.8 | According to the joint professional submission, the restenosis rate increases by an estimated 8 to 13 percentage points with every 10 mm increase in the length of BMS required. |
| Stents versus CABG | |
| 4.1.9 | There were six RCTs in the meta-analysis. None of the trials involved DES. |
| 4.1.10 | For single-vessel disease, the MACE rate at 6 months' follow-up in two trials involving a total of 300 patients was 12.6% for CABG and 25.8% for stents (OR 0.41; 95% CI, 0.22 to 0.74). The higher MACE rate for stents reflects the greater rate of restenosis for this procedure. |
| 4.1.11 | For multiple-vessel disease, the MACE rate in two trials involving a total of 2300 patients at 12 months' follow-up was 12.3% for CABG and 24.5% for stents (OR 0.43; 95% CI, 0.34 to 0.54). |
| 4.1.12 | At 36 days' follow-up, the data on acute MIs favours stents, but the difference is no longer significant at 6 and 12 months. |
| 4.1.13 | No significant differences were reported for deaths, because death was a rare event and the trials were not powered to detect differences. |
| BMS versus DES | |
| 4.1.14 | There were 12 RCTs comparing BMS with DES. Of these, seven involved paclitaxel, four sirolimus, one everolimus and one actinomycin stents. The first two sets of trials are considered separately below, and the last two trials have not been considered here because they involve products that have not been licensed. There does not appear to be an RCT for the third DES with a CE mark, eluting dexamethasone. |
| 4.1.15 | Paclitaxel-eluting stents |
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4.1.15.1
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MACE rates for the paclitaxel DES were not significantly lower at 36 days or at 1 year, but they were lower at 6 months (7.4% for DES versus 15.3% for BMS: OR 0.48; 95% CI, 0.31 to 0.73). From a random effects model (which takes account of heterogeneity of results between trials), even the 6-month data of MACE rates are not statistically significant (OR 0.58; 95% CI, 0.24 to 1.43). Most of the MACE events refer to restenosis. However, the two trials of the Taxus DES stent (which has gained a CE mark) involving 583 patients yielded a MACE rate at 6 months of 7.2% for DES versus 18.4% for BMS (OR 0.35; 95% CI, 0.21 to 0.59), and at 12 months of 9.7% for DES versus 20.5% for BMS (OR 0.41; 95% CI, 0.25 to 0.67). |
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4.1.15.2
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Paclitaxel DES have not been demonstrated to show an advantage over BMS in either mortality or acute MI. However, in the TAXUS trials at 6 months, the MI rate for DES was 1.7% compared with 5.9% for BMS (OR 0.35; 95% CI, 0.12 to 0.99). The statistical significance of this result was not maintained at 12 months [2.8% for DES versus 5.8% for BMS: (OR 0.56; 95% CI, 0.23 to 1.37)]. |
| 4.1.16 | Sirolimus-eluting stents |
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4.1.16.1
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MACE rates for the sirolimus DES were not significantly lower at 36 days, but they were lower at 9 months and at 1 year (at 9 months, 7.4% for DES versus 18.9% for BMS [OR 0.34; 95% CI, 0.23 to 0.47]). Most of the MACE events refer to restenosis. The trials of the Cypher sirolimus DES (which has gained a CE mark) show lower MACE rates compared with BMS at 9 months (OR 0.32; 95% CI, 0.16 to 0.45), 12 months (OR 0.31; (95% CI, 0.22 to 0.43), and 24 months (OR 0.46; 95% CI, 0.22 to 0.97). |
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4.1.16.2
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Sirolimus-eluting stents in general have not been shown to have either a mortality or acute MI advantage over BMS in trials, and neither do the DES within the subset of Cypher stent trials. |
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4.1.16.3
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According to the joint professional submission, in larger arteries, sirolimus DES have shown very low rates of restenosis, approaching zero. In small diameter arteries, sirolimus DES have shown lower rates of restenosis than BMS (for example, 7% versus 20% restenosis at 9 months in the SIRIUS trial for vessels of mean diameter 2.3 mm). |
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4.1.16.4
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In patients with diabetes and those with longer lesions, rates of restenosis using sirolimus DES have been higher than those of the 'average' patient, but still much lower than the BMS control. |
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4.1.16.5
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According to the joint professional submission, for every 10 mm increase in the length of the stent, the increase in restenosis rate using DES has fallen to 1 to 1.6 percentage points. |
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4.1.17
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Multivariate analysis of data from the TAXUS trials shows that once the effect of small diameter arteries and long lesions has been allowed for, the difference in performance between DES and BMS for people with diabetes is not statistically significantly different from that of people without diabetes. |
| 4.2 | Cost effectiveness |
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4.2.1
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The most recent evidence comes from models supplied by four manufacturers and one from the Assessment Report, including an Addendum. The manufacturer models show that DES are cost effective against BMS, and that BMS are cost effective against PCI (without stents) and also against CABG. However, these models are relatively short-run, ranging from 6 months to 2 years. |
| Stents versus PCI without stents | |
| 4.2.2 | For patients with moderate or severe angina, PCI has been shown to be a cost-effective alternative to conventional medical treatment. Since the previous appraisal (by the Institute in 2000) of stents versus balloon angioplasty, several further studies have demonstrated the cost effectiveness of stents in a number of patient populations and clinical settings, including elective stenting and stenting immediately following an acute MI. The Appraisal Committee took this aspect as given, and did not discuss the matter further. |
| Stents versus CABG | |
| 4.2.3 | The model from the Assessment Report extrapolates results to 5 years. Longer models are needed to determine cost effectiveness, because nearly all patients who have stents fitted live longer than 5 years, and it is impossible to give a proper answer to the question of cost effectiveness by taking a short-term perspective. |
| 4.2.4 | However, the main problems with a 5-year model are that there are no data beyond 3 years, and little from years 2 to 3, and that the extrapolation is very sensitive to the functional form chosen for the survival curve of patients who have undergone either stenting or CABG. |
| 4.2.5 | The benefits/disbenefits of BMS compared with CABG in terms of quality-of-life differences derive from stents being a less invasive procedure on one hand, but having higher rates of restenosis on the other. Neither of these two effects in terms of QALYs has been estimated to be very great, which means that if there were any appreciable difference in mortality between the two therapies, this factor would determine which of the therapies had the greater benefits. However, none of the meta-analyses from the trials shows any mortality benefit from either BMS or DES compared with CABG in the first 2 years. Under this scenario, all the measurable benefits from using stents rather than CABG therefore derive from an increase in the quality of life. Since stenting is considerably cheaper than CABG, under the 2-year models, it is therefore more cost effective. |
| 4.2.6 | The model used in the Assessment Report, however, estimated a survival benefit for CABG over stents of the order of 0.07 QALYs, after the model was extrapolated to 5 years. This benefit would be enough to make CABG the preferred technology (in terms of both clinical and cost effectiveness) for patients who were candidates for both stents and CABG. The clinician consultees to the appraisal process, however, vigorously challenged this, stating that previous studies had not reached this conclusion. |
| BMS versus DES | |
| 4.2.7 | The quality-of-life component of the QALY differences between BMS and DES is small, because it relates only to the extent of the differences in restenosis rates. No differences in mortality have been demonstrated. Thus the greatest benefits of DES over BMS will occur for categories of patients for whom the absolute difference in restenosis rates are greatest. |
| 4.2.8 | The Addendum to the Assessment Report showed that for single-vessel disease, DES were estimated to be cost-saving compared with BMS at 12 months for patients with diabetes and long lesions, that the estimated cost per QALY for patients without diabetes and long lesions was £15,000 and for all patients with narrow vessels was £16,000. These estimates were derived from patient-level data derived from the TAXUS II trial. For the total population of patients with single-vessel disease, the cost per QALY was £94,000. This estimate was derived from registry data. |
| 4.2.9 |
These estimates are sensitive to five factors:
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| 4.2.10 | There are no RCT data for two-vessel disease. The estimated incremental cost per QALY gained from DES compared with BMS for all non-diabetic patients is £195,000. This estimate is derived from registry data. |
| 4.3 | Consideration of the evidence |
| 4.3.1 | The Committee reviewed the evidence available on the clinical and cost effectiveness of BMS and DES, having considered evidence on the nature of the condition and the value placed by users on the benefits of BMS and DES from clinical experts and those who represent patients with angina. It was also mindful of the need to ensure that its advice took account of the efficient use of NHS resources. |
| Stents versus PCI without stents | |
| 4.3.2 | The Committee considered that no new evidence had been found since the previous appraisal to change its view that where PCI is being undertaken, the use of stents is likely to be both clinically and cost effective. |
| BMS versus DES | |
| 4.3.3 | The Committee considered the sirolimus-eluting Cypher stent and the paclitaxel-eluting Taxus stent as a 'class' of intervention, a view taken because there were no head-to-head trials of the two stents and the clinical experts advise that there was no evidence that would allow them to favour one drug-eluting agent over the other. |
| 4.3.4 | The Committee considered that for single-vessel disease, restenosis rates were in general low using BMS in the majority of patients requiring PCI, and that therefore the routine use of DES was not justified. However, this was not the case for patients presenting with either small diameter arteries or long lesions, where the risk of restenosis using BMS was considerably higher and the absolute reduction in restenosis rates would justify the use of DES. |
| 4.3.5 | The Committee considered the risk factors predicting the likelihood of higher rates of restenosis after the use of BMS. They were persuaded that the main determinants of risk were the target vessel diameter and the complexity of the arterial lesion, in particular the length of the stenosis. They recognised that the combination of small vessel disease and long lesions was particularly prevalent in patients with CAD who also had diabetes. Whilst in general patients with diabetes have higher restenosis rates than those without diabetes following PCI with BMS, the Review Group's analysis indicates that these higher rates arise predominantly from the fact that a much higher proportion of patients with diabetes needing PCI have disease of small diameter arteries and long lesions than is true for the general population of patients requiring PCI. |
| 4.3.6 | The Committee discussed how the RCTs comparing BMS with DES relate to current clinical practice. In particular, the decision to re-intervene following an initial PCI with stent procedure in the trials was often made on the basis of protocol-driven angiographic examinations at certain fixed times (for example at 6 months), rather than the recurrence of clinical symptoms. It is likely that the trials would encourage reintervention that might not be required in clinical practice, where routine re-angiography is not usual. Thus, the Committee was aware that the relative difference in restenosis rates between BMS and DES identified in the trials could overestimate the extent of the difference that would actually be seen in clinical practice. The Addendum to the Assessment Report attempted to correct for this potential overestimate of the benefit of DES versus BMS. The Committee decided that whether or not the correction factor was applied the guidance in Section 1 would not be materially affected. |
| 4.3.7 | The Committee considered the treatment with a DES for more than one target vessel in a person with symptomatic coronary disease. They were aware that the evidence from the RCTs relates to the use of DES in single-vessel disease. However, the experts indicated that treatment of more than one vessel in an individual patient during PCI may be required. This is because despite additional investigations it is frequently difficult to determine which of several vessels identified at angiography is the most likely cause of the patient's symptoms. The Committee considered that the risk of a need for future intervention following an initial PCI is likely to be dependent on the degree of stenosis of any of the affected vessels. The appropriateness of DES or BMS for each diseased artery in turn would therefore depend on considering the artery's characteristics in isolation from those of other diseased arteries. They were therefore persuaded that planned treatment of more than one vessel in a single patient should be based on the requirements laid out in the guidance for a single vessel. |
| Stents versus CABG | |
| 4.3.8 | Having reviewed the models in the Assessment Report and the submissions from manufacturers, together with the views of cardiologist consultees, the Committee concluded that the guidance offered in 2000 should be maintained. While it was clear that models with outcomes up to 2 years favoured stents in terms of cost effectiveness, the conclusions to be drawn from longer-term models depended critically on whether a survival advantage accrues to CABG. The Committee concluded that no convincing case had been made on this matter. Its considerations ranged over what may happen to patients requiring one or other of these procedures in different age ranges, and whether the conclusions about the most appropriate procedure would be the same for younger patients (who are more likely to need a repeat procedure) as for older ones. In none of the cases considered was there sufficient evidence of effect to be able to reach any conclusion. |
| 5 | Proposed recommendations for further research |
| 5.1 | Ongoing trials include TAXUS I, II, IV, V and VI for paclitaxel-eluting stents, RAVEL, SIRIUS and E-SIRIUS for sirolimus-eluting stents and FUTURE for everolimus-eluting stents. |
| 5.2 | Until now, trials have been restricted to single-artery studies for the sake of simplicity and ease of interpretation. Extrapolation of results to more than one artery critically depends on untested assumptions. Trials in more than one artery are therefore required, in order to confirm or otherwise the appropriateness of the extrapolations. |
| 5.3 | To compare long-term outcomes, particularly with respect to stents against CABG, much longer trial follow-ups are required. |
| 5.4 | New BMS designs should be tested against DES. |
| 5.5 | The differences between clinical and protocol-driven angioplasty require further study. |
| 5.6 | Head-to-head trials of those DES that have been shown to be better than BMS are required. |
| 6 | Preliminary views on the resource impact for the NHS |
| This section outlines the Appraisal Committee's preliminary assessment concerning the likely impact on NHS resources if the recommendations in Section 1 were to be implemented. When guidance is issued, this section is intended to assist NHS planners and managers in its implementation. Therefore the Institute particularly welcomes comments and information from those who would be involved in the implementation of the guidance so that this section can be made as helpful and robust as possible. | |
| 6.1 | The future proportion of DES stents will depend on the proportion of stented arteries that are either narrow or contain long lesions. It is estimated that this will be about 20-30% of all stents. The additional cost without offset would be 8,000-12,000 stents at £525 per stent (£4.2-6.3 million per year). If this were to reduce restenosis by about 10 to 15 percentage points in the patients treated with DES, the cost, after restenosis savings were taken into account, would be about £2 million per year. The cost savings are likely to be realised in the form of a reduction in treatment for restenosis, thus allowing an additional 10% or so of patients to undertake PCI with an unchanged medical capacity. |
| 7 | Proposals for implementation and audit |
| This section presents proposals for implementation and audit based on the preliminary recommendations for guidance in Section 1. | |
| 7.1 | Clinicians carrying out PCIs should review their current practice and policies to take account of the guidance set out in Section 1. |
| 7.2 | Local guidelines, protocols or care pathways that refer to PCIs and/or stents should incorporate the guidance. |
| 7.3 | To measure compliance locally with the guidance, the following criteria could be used. Further details on suggestions for audit are presented in Appendix C. |
|
7.3.1
|
Stents are used routinely in PCIs carried out in patients with stable or unstable angina or acute MI. |
|
7.3.2
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A Cypher or a Taxus stent is used in elective PCI for people with symptomatic coronary artery disease in whom the target artery is less than 3 mm in diameter or in which the lesion to be stented is longer than 20 mm. If more than one artery is to have a stent inserted, the same considerations apply to each artery. |
|
7.3.3
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Antiplatelet drugs are used for 6 months after a DES has been implanted. |
|
7.4
|
Local clinical audits on the care of patients with CAD also could include measurement of compliance with national standards, including standards in the NSF. |
| 8 | Related guidance |
| 8.1 | National Institute for Clinical Excellence (2000) Guidance on coronary artery stents in the treatment of ischaemic heart disease NICE Technology Appraisal Guidance No.4. London: National Institute for Clinical Excellence. Available from www.nice.org.uk Note: the present appraisal is both a review of guidance No. 4 and an extension of it to drug-eluting stents. |
| 9 | Proposed date for review of guidance |
| 9.1 | The review date for a technology appraisal refers to the month and year in which the Guidance Executive will consider any new evidence on the technology, in the form of an updated Assessment Report, and decide whether the technology should be referred to the Appraisal Committee for review. |
| 9.2 | It is proposed that the guidance on this technology is reviewed in October 2004 (new CE marks only) and October 2006 otherwise. |
| Professor David Barnett |
| Chairman, Appraisal Committee |
| June 2003 |
| Appendix A. Appraisal Committee members |
| NOTE The Appraisal Committee is a standing advisory committee of the Institute. Its members are appointed for a 3-year term. A list of the Committee members who took part in the discussions for this appraisal appears below. The Appraisal Committee meets twice a month other than in December, when there are no meetings. The Committee membership is split into two branches, with the chair, vice-chair and a number of other members attending meetings of both branches. Each branch considers its own list of technologies and topics are not moved between the branches. |
| Committee members are asked to declare any interests in the technology to be appraised. If it is considered there is a conflict of interest, the member is excluded from participating further in that appraisal. |
| The minutes of each Appraisal Committee meeting, which include the names of the members who attended and their declarations of interests, are posted on the NICE website. |
| Professor Ron Akehurst |
| Dean, School of Health Related Research, University of Sheffield |
| Dr A E Ades |
| MRC Senior Scientist, MRC Health Services Research Collaboration, University of Bristol |
| Dr Tom Aslan |
| General Practitioner, Stockwell, London |
| Professor David Barnett (Chair) |
| Professor of Clinical Pharmacology, University of Leicester |
| Dr Sheila Bird |
| MRC Biostatistics Unit, Cambridge |
| Dr Richard Cookson |
| Senior Lecturer, Health Economics, School of Health Policy and Practice, University of East Anglia, Norwich |
| Professor Terry Feest |
| Clinical Director & Consultant Nephrologist, Richard Bright Renal Unit, & Chair of UK Renal Registry, Bristol |
| Professor Gary A Ford |
| Professor of Pharmacology of Old Age/Consultant Physician, Newcastle upon Tyne Hospitals NHS Trust |
| Ms Bethan George |
| Interface Liaison Pharmacist, Tower Hamlets PCT and Royal London Hospital, Whitechapel |
| Dr Trevor Gibbs |
| Head, Global Clinical Safety & Pharmacovigilance, GlaxoSmithKline, Greenford |
| Mr John Goulston |
| Director of Finance, St Bartholoemew's Hospital & the London NHS Trust |
| Dr Terry John |
| General Practitioner, The Firs, London |
| Mr Muntzer Mughal |
| Consultant Surgeon, Lancashire Teaching Hospitals NHS Trust, Chorley |
| Judith Paget |
| Chief Executive, Caerphilly Local Health Board, Torfaen |
| Mr James Partridge |
| Lay Representative; Chief Executive, Changing Faces, London |
| Mrs Kathryn Roberts |
| Nurse Practitioner, Hyde, Cheshire |
| Ms Anne Smith |
| Lay Representative; Trustee, Long-Term Medical Conditions Alliance |
| Professor Andrew Stevens (Vice-Chair) |
| Professor of Public Health, University of Birmingham |
| Dr Cathryn Thomas |
| General Practitioner, & Senior Lecturer, Department of Primary Care & General Practice, University of Birmingham |
| Dr Norman Vetter |
| Reader, Department of Epidemiology, Statistics and Public Health, College of Medicine, University of Wales, Cardiff |
| Dr David Winfield |
| Consultant Haematologist, Royal Hallamshire Hospital, Sheffield |
| Appendix B. Sources of evidence considered by the Committee | |
| The following documentation and opinion was made available to the Committee: | |
| A. |
The Assessment Report for this appraisal was prepared by Liverpool Reviews and Implementation Group, University of Liverpool.
|
| B. |
The following organisations accepted the invitation to participate in this appraisal. They were invited to make submissions and comment on the draft scope and Assessment Report. They are also invited to comment on the ACD and consultee organisations are provided with the opportunity to appeal against the FAD. I Manufacturer/sponsors:
II Professional/specialist and patient/carer groups:
|
| C. |
The following individuals were selected from clinical expert and patient advocate nominations from the professional/specialist and patient/carer groups. They participated in the Appraisal Committee discussions and provided evidence to inform the Appraisal Committee's deliberations. They gave their expert personal view on coronary artery stents by attending the initial Committee discussion and/or providing written evidence to the Committee. They are invited to comment on the ACD.
|
| Appendix C. Detail on criteria for audit of the use of coronary artery stents | |||
| Possible objective for an audit | |||
| An audit could be carried out to ensure that stents are being used appropriately in patients undergoing PCIs. | |||
| Possible patients to be included in the audit | |||
| An audit could include all patients having a PCI for stable or unstable angina, acute MI or symptomatic CAD in a suitable time period, for example, 3 months. | |||
| Measures that could be used as a basis for an audit | |||
| The measures that could be used in an audit of stents are as follows. |
|
Criterion
|
Standard
|
Exception
|
Definition of Terms
|
|
1. Stents are used when a PCI is performed in an individual having any of the following: a. stable angina or |
100% of individuals having a PCI for stable or unstable angina or acute MI | None | Clinicians will have to agree locally on any exceptions for audit purposes. |
|
2. A Cypher or a Taxus stent is used in an elective PCI for an individual with symptomatic CAD when either or the following occurs: a. The target artery is < 3mm in diameter or |
100% of individuals having an elective PCI for symptomatic CAD | None | Clinicians will have to agree locally on any exceptions for audit purposes. |
| 3. Antiplatelet drugs are prescribed for 6 months after a DES has been implanted | 100% of individuals having a DES implanted | None | Clinicians will have to agree locally on antiplatelet drugs for audit purposes. |
| Calculation of compliance with the measure | ||
| Compliance (%) with each measure described in the table above is calculated as follows. | ||
|
Number of patients whose care is consistent with the criterion plus number of patients who meet any exception listed |
||
|
|
X 100 | |
|
Number of patients to whom the measure applies |
||
| Clinicians should review the findings of measurement, identify whether practice can be improved, agree on a plan to achieve any desired improvement and repeat the measurement of actual practice to confirm that the desired improvement is being achieved. | ||
This page was last updated: 30 March 2010