Published online before print May 15, 2003, doi: 10.1161/01.STR.0000076522.30688.FF
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(Stroke. 2003;34:1471.)
© 2003 American Heart Association, Inc.
Original Contributions |
Editorial Comment: How Appropriate Is Carotid Endarterectomy?
Capital Health, Walter C. Mackenzie Health Sciences Centre, Edmonton, Alberta, Canada
Because evidence for the efficacy of many treatments was lacking, methodology to measure appropriateness was developed in the 1980s at RAND to provide a contemporary means of determining if health care interventions were done appropriately; that is, if they were worth doing in specific situations.1 One of the first such studies examined Medicare patients from that era undergoing carotid endarterectomy and found the startling result that two thirds had surgery for uncertain or inappropriate reasons.2 Subsequently, the publication of major randomized controlled trials3–5 has provided evidence for the efficacy of endarterectomy in many scenarios to guide practitioners, so now one might expect an improved rate of appropriateness. Indeed, this was demonstrated by Halm et al6 in this issue of Stroke, where they showed in a population of patients from 6 New York hospitals in 1997–1998 that only 15% of patients were operated on for less than appropriate reasons. Appropriateness can also be used even more directly to improve quality. Recently, Findlay and colleagues7 showed that appropriateness, used in repeated audit cycles involving feedback to the operating surgeons, resulted in marked improvement in both appropriateness and outcomes.
The role of comorbid disease in determining both appropriateness and outcome of endarterectomy is another important result of the current study.6 Some indications, especially for asymptomatic cases, were deemed inappropriate because of high comorbidities. This view was borne out by the excess stroke and/or death rate (OR 2.8; CI 1.1 to 7.5, P=0.03) found in asymptomatic cases with high comorbidities. This should caution physicians to consider such issues in case selection and to remember that the patients studied in the clinical trials that demonstrated efficacy were screened to ensure low comorbidity.
The high stroke and/or death rate (10.3%) in those undergoing combined endarterectomy and coronary bypass grafting is a sober reminder that this is a hazardous combination.6 There is no randomized controlled trial evidence supporting its use. Furthermore, a recent large review of endarterectomy cases in mid-American states showed an even higher negative outcome rate (17.4%).8
One of the most striking results of the current study is that 72.5% of the patients had asymptomatic carotid stenosis.6 This reflects the remarkable surge of American enthusiasm for surgery in this setting sparked by publication of the ACAS trial on endarterectomy for asymptomatic stenosis in 1995 and especially the prepublication alert released by the NIH.9 This enthusiasm was apparently not blunted by the fact that the potential gain per patient in terms of the absolute risk reduction in asymptomatic cases is so much lower than in those with symptomatic stenosis 
70% (5.9%5 versus 15.9%10 over 5 years) because of their lower baseline risk. The number needed to treat to prevent 1 stroke over 5 years for high-grade symptomatic patients is only 6.3, whereas for asymptomatic cases it is 17. This means that a surgeon must operate on almost 3 asymptomatic patients for every 1 symptomatic case to have an equivalent effect on stroke prevention. In contrast to the American experience, however, recent endarterectomy audits in Canada and Australia have found that only 36% and 31% of cases, respectively, were asymptomatic.7,11
Because of the narrow margin of benefit for asymptomatic patients, the American Heart Association recommended in its guidelines that the 30-day stroke and/or death rate should be below 3% to make this procedure worth doing.12 That the complication rate in the current study for such cases was only 2.26% is encouraging and shows what might be achieved.6 However, it raises the important issue of generalizability. What is the performance in the broader community? The results of the large multistate study showing a complication rate of 4.5% in 7604 patients without carotid symptoms suggest that there is cause for concern. In fact, the appropriateness of endarterectomy for asymptomatic cases has been controversial,13,14 and Canadian guidelines15 and appropriateness processes7 have judged it to be in the uncertain category. It is hoped that the soon-to-be-completed Asymptomatic Carotid Surgery Trial will provide useful guidance.
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- Brook, RH. The RAND/UCLA appropriateness method.In Methodological Perspectives.AHCPR Publication No. 95-0009. Rockville, Md: AHCPR; 1995: 59–70.
- Winslow CM, Solomon DH, Chassin MR, et al. The appropriateness of carotid endarterectomy. N Engl J Med. 1988; 318: 721–727.[Abstract]
- Barnett HJ, Taylor DW, Eliasziw M, et al. Benefit of carotid endarterectomy in patients with symptomatic moderate or severe stenosis. N Engl J Med. 1998; 339: 1415–1425.
[Abstract/Free Full Text] - European Carotid Surgery Trialists’ Collaborative Group. Randomised trial of endarterectomy for recently symptomatic carotid stenosis: final results of the MRC European Carotid Surgery Trial (ECST). Lancet. 1998; 351: 1379–1387.[CrossRef][Medline] [Order article via Infotrieve]
- Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. Endarterectomy for asymptomatic carotid artery stenosis. JAMA. 1995; 273: 1421–1428.[Abstract]
- Halm EA, Chassin MR, Tuhrim S, Hollier LH, Popp AJ, Ascher E, Dardik H, Faust G, Riles TS. Revisiting the appropriateness of carotid endarterectomy. Stroke. 2003; 34: 1464–1471.
[Abstract/Free Full Text] - Findlay JM, Nykolyn L, Lubkey TB, et al. Auditing carotid endarterectomy: a regional experience. Can J Neurol Sci. 2002; 29: 326–332.[Medline] [Order article via Infotrieve]
- Kresowik TF, Bratzler D, Karp HR, et al. Multistate utilization, processes, and outcomes of carotid endarterectomy. J Vasc Surg. 2001; 33: 227–235.[CrossRef][Medline] [Order article via Infotrieve]
- Gross CP, Steiner CA, Bass EB, Powe NR. Relation between prepublication release of clinical trial results and the practice of carotid endarterectomy. JAMA. 2000; 284: 2886–2893.
[Abstract/Free Full Text] - Rothwell PM, Eliasziw M, Gutnikow SA, et al. Analysis of pooled data from the randomized controlled trials of endarterectomy for symptomatic carotid stenosis. Lancet. 2003; 361: 107–116.[CrossRef][Medline] [Order article via Infotrieve]
- Middleton S, Donnelly N. Outcomes of carotid endarterectomy: how does the Australian state of New South Wales compare with international benchmarks? J Vasc Surg. 2002; 36: 62–69.[CrossRef][Medline] [Order article via Infotrieve]
- Biller J, Feinberg WM, Castaldo JE, et al. Guidelines for carotid endarterectomy: a statement for healthcare professionals from a special writing group of the Stroke Council, American Heart Association. Stroke. 1998; 29: 554–562.
[Free Full Text] - Barnett HRM, Eliasziw M, Meldrum H, Taylor W. Do the facts and figures warrant a 10-fold increase in the performance of carotid endarterectomy on asymptomatic patients? Neurology. 1996; 46: 603–608.
[Free Full Text] - Barnett HJM, Meldrum HE, Eliasziw M. The appropriate use of carotid endarterectomy. Can Med Assoc J. 2002; 166: 1169–1179.
[Abstract/Free Full Text] - Findlay JM, Tucker WS, Ferguson GG, et al. Guidelines for the use of carotid endarterectomy: current recommendations from the Canadian Neurosurgical Society. Can Med Assoc J. 1997; 157: 653–659.[Abstract]
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