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Posts Tagged ‘carotid stenting’

A new article has been published in Neurosurgical Focus discussing carotid stenosis, carotid artery stenting and carotid endarterectomy.  It discusses previous trial results including the limitations of previous results and controversies.  The authors also spend a significant portion of the article examining previous trial designs – and how these trial designs may have skewed some of the previously reported results.  Young et. al also discuss the implications of these results in both symptomatic and symptomatic patients with carotid stenosis and compares the outcomes of both stenting and surgery in these groups, including current and on-going studies.

Reminder:

CAS = carotid artery stenting

CEA = carotid endarterectomy (open surgery)

BMT = Basic Medical Treatment (medications)

It’s several pages long, so I have only re-posted partial sections below.

Kate C. Young, Ph.D., M.P.H.; Anunaya Jain, M.B.B.S. M.C.E.M.; Minal Jain, M.B.B.S.; Robert E. Replogle, M.D.; Curtis G. Benesch, M.D., M.P.H.; Babak S. Jahromi, M.D., Ph.D.  (2011, June).  Evidence-based Treatment of Carotid Artery Stenosis. Neurosurg Focus. 2011;30(6).

Abstract

Carotid atheromatous disease is an important cause of stroke. Carotid endarterectomy (CEA) is a well-established option for reducing the risk of subsequent stroke due to symptomatic stenosis (> 50%). With adequately low perioperative risk (< 3%) and sufficient life expectancy, CEA may be used for asymptomatic stenosis (> 60%). Recently, carotid angioplasty and stent placement (CAS) has emerged as an alternative revascularization technique. Trial design considerations are discussed in relation to trial results to provide an understanding of why some trials were considered positive whereas others were not. This review then addresses both the original randomized studies showing that CEA is superior to best medical management and the newer studies comparing the procedure to stent insertion in both symptomatic and asymptomatic populations. Additionally, recent population-based studies show that improvements in best medical management may be lowering the stroke risk for asymptomatic stenosis. Finally, the choice of revascularization technique is discussed with respect to symptom status. Based on current evidence, CAS should remain limited to specific indications.

Introduction

Stroke accounts for 1 in every 18 deaths in the US, and leaves nearly 30% of those afflicted permanently disabled.[3,49] Worldwide, stroke is a leading cause of disability and the third leading cause of death, with 5 million deaths reported annually.[7] In the US alone, each year nearly 800,000 individuals suffer a stroke, with one-quarter of those cases being recurrent strokes.[49] Despite advances in stroke prevention, imaging, treatment, and rehabilitation, the costs of care continue to increase. In 2008, the costs of stroke care were $65 billion/year.[16] The estimated cost of care for patients with stroke in 2010 is $73.7 billion, with overall costs expected to exceed $2 trillion by 2050.[49]

One of the most important causes of ischemic stroke is carotid atheromatous disease, representing approximately 20% of the total incidence of this type of stroke.[31] Severe carotid stenosis is the most important risk factor for recurrent stroke in symptomatic patients with carotid atheromatous disease. Several large randomized trials have shown marked early benefit from CEA. Timely CEA (within 2 weeks from onset of symptoms) results in an absolute risk reduction of 15.6% and a relative risk reduction of 52% over best medical management.[4,18,35,37,41] Results of these large-scale trials and their pooled patient-level meta-analyses have made CEA the standard of care in patients with severe (> 70%) symptomatic carotid stenosis, and have provided Level I/A evidence for decisions regarding symptomatic patients with lesser degrees of stenosis by demonstrating modest benefits of CEA for symptomatic 50%–69% stenosis, and no benefit for stenosis < 50%.[10,41] In contrast, patients with asymptomatic carotid stenosis have a vastly different natural history, with much lower upfront risks of stroke. Two large-scale randomized controlled trials have demonstrated modest benefits achieved over several years from treatment.[18,28] Indeed, significant improvements in stroke prophylaxis achieved by BMT have led to a reappraisal of CEA for asymptomatic stenosis, with current and upcoming trials of carotid revascularization now including an arm for BMT.[1,39]

Over the past decade, CAS has emerged as a potential alternative to CEA. The appeal of CAS has been driven in part by patient, physician, and hospital preferences for less invasive procedures, with underlying assumptions that this would lead to a reduction in complications, length of stay, and cost, although the latter 2 appear to not be borne out in practice.[25,28,38,51] The choice between CEA and CAS has therefore been primarily centered around which technique provides better clinical outcomes. Multiple CAS case series and registries have emerged, of mixed quality and with conflicting data, which will not be reviewed here. Unfortunately, large-scale randomized controlled trials comparing the 2 revascularization techniques have proven controversial, and have not convincingly identified a superior technique.[11,17,22,26,33,34,40,50] The most recent trial, CREST, was designed to avoid prior pitfalls and to reach definitive conclusions regarding choice of revascularization technique for carotid stenosis, although interpretation of its results has not been free of controversy either.[2,5]

Health care is undergoing a radical transformation. The economic environment has challenged health care organizations to deliver optimal services in the face of compromised cash flows, reduced resources, and declining margins. There is an overwhelming need for health care policy makers to audit current practices to ensure incorporation of cost-effective guidelines without compromising quality and outcomes of care. Our objective in this review of trials comparing CEA, CAS, and BMT in patients with carotid artery stenosis was to analyze existing evidence and cite comparative measures to consider while making such treatment decisions.

Young et al summarizes their findings:

Summary

Patients with symptomatic stenosis > 70% should undergo carotid revascularization. There is clear evidence that CEA is superior to BMT for such a group, with an absolute risk reduction of 15.6%. The benefits of CEA for 50%–69% stenosis, although significant, were modest compared with those in patients with 70% stenosis. Therefore, revascularization is recommended for 50%–69% symptomatic stenosis, with the understanding that aggressive lipid management and other antiplatelet agents have been added to the BMT regimen since NASCET and ECST were conducted, and may be useful in this population. Based on meta-analysis and recent data, CEA remains the procedure of choice for revascularization of symptomatic stenosis ≥ 50%; however, CAS is a potential alternative for patients with specific high-risk factors for CEA (for example, contralateral occlusion, radiation therapy, restenosis). Also, CAS has other, less well-defined indications, such as severe chronic obstructive pulmonary disease or the somewhat ambiguous “high risk” criteria.

We found that CEA has a modest benefit for asymptomatic stenosis, given at least a 3–5 year life expectancy after surgery. In contrast, CAS has a dubious benefit for asymptomatic stenosis; procedural morbidity and mortality rates approach or exceed 3%, whereas the procedural risks with CEA remain much lower. With the declining incidence of stroke due to asymptomatic lesions and the current natural history, SPACE-2 and other trials are well justified to compare BMT against CAS or CEA. The CAS procedure for asymptomatic stenosis should remain relegated to clinical trials, which should also include an arm for BMT.

What  does all of this mean:

Surgery is better than medications for severe stenosis, particularly in symptomatic patients.

Stenting is a viable option is symptomatic patients with high risks of surgical complications (complications as defined above).  Stenting should not be used in asymptomatic patients.

Basic medical treatment is a useful therapy, particularly in patients with borderline asymptomatic (50-60%) surgical stenosis, and combined with other treatments in patients with greater stenosis (or symptomatic).

Note:

Does this preclude stent technology in the future – No.  as stenting technology advances, stenting may become a more viable option for larger groups of people.

 

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Once again – it looks like technology pushes ahead past patient care.  Despite continued questions about the use of carotid stenting, and questions about research methods used in some of the most recent trials – the FDA is discussing expanding the guidelines for carotid stenting. 

 As readers know, I have a difficult time with this because I consider it to be catering/ fostering patient fears.. Patients are (understandably) afraid of surgery – so let’s just sell them something easier..  even if surgery remains the gold standard, and the safer option..

Frank Veith, famous vascular surgeon shares these sentiments – which I have re-posted here.  As my long time readers know from previous discussions CAS= carotid artery stenting  and CEA = carotid artery endarterectomy.

(transcript from video speech – Medscape) 

Carotid Guidelines: CAS equal to CEA?

Good morning. I’m Frank Veith, Professor of Vascular Surgery at New York University Medical Center and the Cleveland Clinic. This morning I’m going to talk a little bit about the recent guidelines from the American Heart Association,[1] and a number of other important organizations, that have been recently published, and although it’s a little premature to comment on them because they haven’t been read and absorbed completely, I think it’s worth making a comment.

The guidelines appeared to state that carotid stenting was equivalent to carotid endarterectomy, and even though prestigious organizations produced these guidelines, it is my opinion that this conclusion is a little bit premature and unjustified, in view of the data that have accumulated over the past 5 years. The 1 trial that suggested equivalence of carotid endarterectomy and carotid stenting, was the CREST [Carotid Revascularization Endarterectomy versus Stenting Trial], and even though the article in the New England Journal of Medicine [2] stated as a conclusion, that equivalent results could be achieved by the 2 procedures, I believe that this conclusion is flawed, because the conclusion was only reached on the basis of a common composite endpoint, which included not only stroke and death, but also myocardial infarction.

The carotid stenting patients suffered more strokes and deaths, whereas the carotid endarterectomy patients suffered more myocardial infarctions, and when all those adverse events were added up, they were in fact, equivalent, but the flaw is, at least in my opinion, that it’s not justified to equate a minor stroke with a minor myocardial infarction. A minor myocardial infarction, although it can have some serious adverse consequences, is not the equivalent of a minor stroke. In a minor stroke, even though the patient may recover measurable neurologic function completely, his brain is not the same. He has immeasurable defects in mood, intelligence, attitude, and so forth, so I believe that a minor stroke (strokes being what both procedures are designed to prevent) is not the equivalent of a minor myocardial infarction.

In addition, all the other trials and population-based studies demonstrate a significantly higher incidence of strokes following carotid stenting than following carotid endarterectomy. You can’t ignore these trials and certainly can’t ignore the population-based studies, which are other valid pieces of evidence. So I believe, as an enthusiast for carotid stenting, that carotid stenting will ultimately play a very major role in the treatment of carotid artery disease, but I don’t think the data yet justify the conclusion that the 2 treatments are equivalent, or that carotid stenting should generally be an acceptable alternative to carotid endarterectomy.

At present, we really don’t have that evidence in hand, although I believe it will come in the future. I might add in closing that, many of the points that I made were made by other speakers at our 2010 Veith symposium,[3] held here in New York in November, and many additional points will be made at next year’s meeting, which will be held in November of 2011. Thank you.

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