March 1st, 2010
If It’s Your Carotid, Endarterectomy or Stenting?
Richard A. Lange, MD, MBA
The results from 2 carotid endarterectomy vs stenting trials are in….and they are disparate. ICSS showed worse outcome with carotid stenting (higher rates of the composite of stroke, death, and procedural MI) versus carotid endarterectomy, whereas CREST showed similar efficacy and safety for both. Interestingly, in both studies the rate of nondisabling stroke was significantly higher with stenting, and older patients had a higher risk for events with stenting than with endarterectomy.
If you had a significant carotid stenosis, which procedure would you choose, and why?
Operator Experience?
During the press conference Wayne Clark emphasized the long lead-in period for CREST. By all accounts the operators were highly experienced by the time the trial got underway. I don’t know what the comparable training period was in ICSS. It would be interesting to compare the experience of the CREST and ICSS investigators.
None of the above
These studies compare stenting to surgery for a disease best managed medically. There are inadequate trials looking for optimal medical management for carotid artery disease but I can assure you that appropriate medical management results in remarkably few events. I have not seen an ischemic stroke in over 6 years in a very busy Internal Medicine practice where half of the patients are over age 65.
It is time the NIH sponsored quality studies looking at the effect of LDL control plus niacin, omeg-3 fatty acids, and vit D in the prevention of stroke. When this study is finally done, it will lay to rest all surgical and stenting intervention for this disease.
Competing Interests: I have an ownership interest in a facility that can perform carotid ultrasound and coronary calcium imaging. I despise the consequences of strokes.
The Importance of Neurons and Funding
The ptient populations, stenting experience, and use of distal protection devices differed between the CREST and ICSS studies. Yet both studies showed a higher incidence of stroke (nondisabling) with stenting than endarterectomy. Since I don’t have any neurons to spare, I think I’d pick endarterectomy over stenting if I had symptomatic carotid disease.
Dr. Blanchet brings up an excellent point. Should we revascularize severe (>70% stenosis) asymptomatic carotid stenosis or simply provide optimal (i.e., improved) medical therapy? Unfortunately, the Transatlantic Asymptomatic Carotid Intervention Trial (TACIT) comparing optimal medical therapy to revascularization (with CEA or stenting) is in limbo after numerous failed attempts to secure industry or government funding. This s a shame since 70% of carotid revascularization procedures are performed in asymptomatic individuals.
CEA or CAS for asymptomatic disease is wrong
We don’t need a COURAGE study to show this. What is needed is optimal medical therapy and serial plaque imaging to ensure atheroma is not progressing.
Interesting… but practical?
Can serial plaque imaging accurately assess whether or not medical therapy is effective (i.e., reliably determine if a 75% has progressed to 80% or remained stable)? I’m skeptical.
Not stenosis, total plaque area
A la the Tromso study and several others.
Good enough?
Dan raises an interesting point. Is demonstration of plaque area “stability” via imaging sufficient evidence that optimal medical therapy is appropriate for individuals with asymptomatic significant carotid stenosis?
could also look at microemboli detection through transcranial doppler
Effects of Intensive Medical Therapy on Microemboli and Cardiovascular Risk in Asymptomatic Carotid Stenosis
J. David Spence, MD; Victoria Coates, BA, HBSc; Hector Li, MD; Arturo Tamayo, MD; Claudio Muñoz, MD, PhD; Daniel G. Hackam, MD, PhD; Maria DiCicco, RVT; Janine DesRoches, RVT; Chrysi Bogiatzi, MD; Jonathan Klein, MD; Joaquim Madrenas, MD, PhD; Robert A. Hegele, MD
Arch Neurol. 2010;67(2):180-186. Published online December 14, 2009 (doi:10.1001/archneurol.2009.289).
Objective To assess the effect of more intensive medical therapy on the rate of transcranial Doppler (TCD) microemboli and cardiovascular events in patients with asymptomatic carotid stenosis (ACS).
Design A prospective study.
Setting A teaching hospital.
Patients Four hundred sixty-eight patients with ACS greater than 60% by Doppler peak velocity.
Main Outcome Measures We compared (1) the proportion of ACS patients who had microemboli on TCD, (2) cardiovascular events, (3) rate of carotid plaque progression, and (4) baseline medical therapy, before and since 2003.
Results Among 468 ACS patients, 199 were enrolled between January 1, 2000, and December 31, 2002; and 269 were enrolled between January 1, 2003, and July 30, 2007. Microemboli were present in 12.6% before 2003 and 3.7% since 2003 (P < .001). The decline in microemboli coincided with better control of plasma lipids and slower progression of carotid total plaque area. Since 2003, there have been significantly fewer cardiovascular events among patients with ACS: 17.6% had stroke, death, myocardial infarction, or carotid endarterectomy for symptoms before 2003, vs 5.6% since 2003 (P < .001). The rate of carotid plaque progression in the first year of follow-up has declined from 69 mm2 (SD, 96 mm2) to 23 mm2 (SD, 86 mm2) (P < .001).
Conclusions Cardiovascular events and microemboli on TCD have markedly declined with more intensive medical therapy. Less than 5% of patients with ACS now stand to benefit from revascularization; patients with ACS should receive intensive medical therapy and should only be considered for revascularization if they have microemboli on TCD.
abstract 2
Absence of Microemboli on Transcranial Doppler Identifies Low-Risk Patients With Asymptomatic Carotid Stenosis
J. David Spence, MD; Arturo Tamayo, MD; Stephen P. Lownie, MD; Wai P. Ng, MD Gary G. Ferguson, MD, PhD
From the Stroke Prevention & Atherosclerosis Research Centre (J.D.S., A.T.), Robarts Research Institute, and the London Health Sciences Centre (J.D.S., S.P.L., W.P.N., G.G.F.), University of Western Ontario, London, Canada; currently at the University of Manitoba (A.T.), Winnipeg, Canada.
Correspondence to J. David Spence, Stroke Prevention & Atherosclerosis Research Centre, 1400 Western Rd, London, Ontario, Canada N6G 2V2. E-mail dspence@robarts.ca
Background and Purpose— Carotid endarterectomy clearly benefits patients with symptomatic severe stenosis (SCS), but the risk of stroke is so low for asymptomatic patients (ACS) that the number needed to treat is very high. We studied transcranial Doppler (TCD) embolus detection as a method for identifying patients at higher risk who would have a lower number needed to treat.
Methods— Patients with carotid stenosis of 60% by Doppler ultrasound who had never been symptomatic (81%) or had been asymptomatic for at least 18 months (19%) were studied with TCD embolus detection for up to 1 hour on 2 occasions a week apart; patients were followed for 2 years.
Results— 319 patients were studied, age (standard deviation) 69.68 (9.12) years; 32 (10%) had microemboli at baseline (TCD+). Events were more likely to occur in the first year. Patients with microemboli were much more likely to have microemboli 1 year later (34.4 versus 1.4%; P<0.0001) and were more likely to have a stroke during the first year of follow-up (15.6%, 95% CI, 4.1 to 79; versus 1%, 95% CI, 1.01 to 1.36; P<0.0001).
Conclusions— Our findings indicate that TCD– ACS will not benefit from endarterectomy or stenting unless it can be done with a risk <1%; TCD+ may benefit as much as SCS if their surgical risk is not higher. These findings suggest that ACS should be managed medically with delay of surgery or stenting until the occurrence of symptoms or emboli.
See also Rothwell et al.
(Stroke. 2010;41:e11.)
© 2010 American Heart Association, Inc.
Original Contributions
Low Risk of Ipsilateral Stroke in Patients With Asymptomatic Carotid Stenosis on Best Medical Treatment
A Prospective, Population-Based Study
Lars Marquardt, MD; Olivia C. Geraghty, MRCP; Ziyah Mehta, PhD Peter M. Rothwell, PhD
From the Stroke Prevention Research Unit, Department of Clinical Neurology, University of Oxford, Oxford, UK.
Correspondence to Prof Peter M. Rothwell, Stroke Prevention Research Unit, University Department of Clinical Neurology, Level 6, West Wing, John Radcliffe Hospital, Oxford, OX3 9DU, UK. E-mail peter.rothwell@clneuro.ox.ac.uk
Background and Purpose— The annual risk of ischemic stroke distal to 50% asymptomatic carotid stenoses was 2% to 3% in early cohort studies and subsequent randomized trials of endarterectomy. This risk might have fallen in recent years owing to improvements in medical treatment, but there are no published prognostic data from studies initiated within the last 10 years.
Methods— In a population-based study of all patients with transient ischemic attack (TIA) or stroke in the Oxford Vascular Study, we studied the risk of TIA and stroke in patients with 50% contralateral asymptomatic carotid stenoses recruited consecutively from 2002 to 2009 and given intensive contemporary medical treatment.
Results— Of 1153 consecutively imaged patients presenting with stroke or TIA, 101 (8.8%) had 50% asymptomatic carotid stenoses (mean age, 75 years; 39% women; 40% age 80 years). During 301 patient-years of follow-up (mean, 3 years), there were 6 ischemic events in the territory of an asymptomatic stenosis, 1 minor stroke (initially 50% to 69% stenosis), and 5 TIAs (2 initially 50% to 69% stenosis; 3 to 70% to 99% stenosis), 3 of which led to subsequent endarterectomy. The average annual event rates on medical treatment were 0.34% (95% CI, 0.01 to 1.87) for any ipsilateral ischemic stroke, 0% (95% CI, 0.00 to 0.99) for disabling ipsilateral stroke, and 1.78% (95% CI, 0.58 to 4.16) for ipsilateral TIA.
Conclusions— In the first study of the prognosis of 50% asymptomatic carotid stenosis to be initiated in the last 10 years, the risk of stroke on intensive contemporary medical treatment was low. Larger studies are required to determine whether this apparent improvement in prognosis is generalizable.
finally….an opinion piece that summarizes much of these data
(Stroke. 2009;40:e573.)
© 2009 American Heart Association, Inc.
Topical Review
Medical (Nonsurgical) Intervention Alone Is Now Best for Prevention of Stroke Associated With Asymptomatic Severe Carotid Stenosis
Results of a Systematic Review and Analysis
Anne L. Abbott, PhD, MBBS, FRACP
From the Baker IDI Heart & Diabetes Institute, and the National Stroke Research Institute (at Austin Health), both in Melbourne, Victoria, Australia.
Correspondence to Dr Anne Abbott, Baker IDI Heart & Diabetes Institute, PO Box 6492, St Kilda Road Central, VIC 8008 Australia. E-mail a.abbott@nsri.org.au
Larry B. Goldstein MD Peter M. Rothwell PhD, FRCP, FMedSci Section Editors:
Significant advances in vascular disease medical intervention since large randomized trials for asymptomatic severe carotid stenosis were conducted (1983–2003) have prompted doubt over current expectations of a surgical benefit. In this systematic review and analysis of published data it was found that rates of ipsilateral and any-territory stroke (+/–TIA), with medical intervention alone, have fallen significantly since the mid-1980s, with recent estimates overlapping those of operated patients in randomized trials. However, current medical intervention alone was estimated at least 3 to 8 times more cost-effective. In conclusion, current vascular disease medical intervention alone is now best for stroke prevention associated with asymptomatic severe carotid stenosis given this new evidence, other cardiovascular benefits, and because high-risk patients who benefit from additional carotid surgery or angioplasty/stenting cannot be identified.
primo non nocere
It seems that unless there are DATA to refute what Dan Hackman has provided, there should be a moratorium on revascularization of asymptomatic carotid lesions outside of investigational protocols.
Competing Interests: I hate strokes.
Medical therapy unless +TCD?
The studies provided by Dr. Hackam (including his own) show that improved medical therapy has substantially reduced the risk of stroke/TIA in patients with asymptomatic carotid stenosis. However ~10% of such patients have + transcranial Doppler (TCD), and their risk of stroke is high. I would ask Dr. Hackman, if he is sufficiently convinced by the data that he would offer revascularization to these patients?
I think based on another recent systematic review, I definitely would…
Stroke. 2009;40:3711.)
© 2009 American Heart Association, Inc.
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Original Contributions
Doppler Embolic Signals in Cerebrovascular Disease and Prediction of Stroke Risk
A Systematic Review and Meta-Analysis
Alice King, BSc (Hons) Hugh S. Markus, DM, FRCP
From Clinical Neuroscience, St. George’s University of London, London UK.
Correspondence to Hugh Markus, Clinical Neuroscience, St. George’s University of London, Cranmer Terrace, London, SW17 0RE, UK. E-mail hmarkus@sgul.ac.uk
Background and Purpose— Asymptomatic embolic signals (ES) detected using transcranial Doppler have been reported in patients with potential cerebral embolic sources. They may be useful in risk stratification and in assessing therapies. First, it is essential to show whether they predict stroke risk.
Methods— A systematic review and meta-analysis was performed to determine the prognostic value of ES in different potential cerebral embolic sources. Studies were identified that used transcranial Doppler to detect ES and included prospective stroke/TIA follow-up. Numbers of ES-positive and ES-negative patients were extracted with stroke/TIA and stroke alone outcomes.
Results— ES are most frequent in large artery disease, less frequent in cardioembolic stroke, and infrequent in lacunar stroke. Data relating ES to future stroke risk were available for acute stroke, large artery disease, and the perioperative period of carotid endarterectomy. For symptomatic carotid stenosis, ES predicted stroke alone (OR, 9.57; 95%CI, 1.54 to 59.38; P=0.02) and stroke/TIA (OR, 6.36; 95% CI, 2.90–13.96; P<0.00001). For asymptomatic carotid stenosis, ES predicted stroke alone (OR, 7.46; 95% CI, 2.24–24.89; P=0.001) and stroke/TIA (OR, 12.00; 95% CI, 2.43–59.34; P=0.002) but with heterogeneity (P=0.004). In acute stroke ES predicted stroke alone (OR, 2.44; 95% CI, 1.17–5.08; P=0.02) and stroke/TIA (OR, 3.71; 95% CI, 1.64–8.38; P=0.002). A high frequency of ES immediately after carotid endarterectomy predicted stroke alone (OR, 24.54; 95% CI, 7.88–76.43; P<0.00001) and stroke/TIA (OR, 32.04; 95% CI, 11.36–90.39; P<0.00001).
Conclusion— ES predict stroke risk in acute stroke, symptomatic carotid stenosis, and postoperatively after carotid endarterectomy; in asymptomatic carotid stenosis, data are less robust. In these conditions ES may be useful in risk stratification and in assessing thera
got cut off…
Conclusion— ES predict stroke risk in acute stroke, symptomatic carotid stenosis, and postoperatively after carotid endarterectomy; in asymptomatic carotid stenosis, data are less robust. In these conditions ES may be useful in risk stratification and in assessing therapeutic efficacy. For other embolic sources, further prospective data are required.
And which type of therapy/revascularization?
In the “high risk” patient with asymptomatic carotid stenosis (i.e., positive transcranial Doppler). Would you (a) place patient on optimal medical therapy and reassess whether TCD improves; (b) refer for carotid stenting; or (c) refer for carotid endarterectomy?
TCD in asymptomatic vs symptomatic stenosis
Richard, I use TCD to help me sort out patients with ambiguous clinical stories to see if or not their symptoms are really referrable to the stenosis (particularly when the story is not clear). In that case, we really have a symptomatic carotid stenosis and I would refer for intervention and optimal medical therapy.
In asymptomatic stenosis I do not routinely order TCD – rather, given the prognosis evidence I have cited, the rates of ipsilateral referrable stroke are just not high enough to warrant the 3% risk of stroke in the very best hands with intervention. Rather, we do optimal medical therapy, which is a multipronged thing.
I monitor for robust plaque regression and titrate medications accordingly – this has dramatically reduced our stroke rates (paper in press in Stroke, and as you saw, data already published in other journals).
The thing about CEA or CAS for asymptomatic carotid stenosis – Henry Barnett, the PI of NASCET, pointed out that it cannot possible prevent all stroke, only the strokes referrable to that lesion. In an analysis of the contralateral artery (the asymptomatic side) in the NASCET study, very few follow-up strokes were due to the contralateral lesion during follow-up. A one or two inch stent does nothing to fix the 2000 miles of vasculature each patient has – although no one is disregarding the importance of optimal medical therapy in every patient, both intervened and non-intervened. I think the asymptomatic carotid lesion is lower risk than the symptomatic coronary stenosis in the COURAGE study and the high grade lesion in the renal artery of the ASTRAL study.