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Original article

Miller MT et al. (2005) Carotid endarterectomy in octogenarians: does increased age indicate "high risk"? J Vasc Surg 41: 231–237   PubMed

Synopsis

Background

The most effective treatment for carotid artery stenosis is carotid endarterectomy (CEA). To date, randomized trials of this procedure versus best medical care have excluded patients aged 80 years or more, and consequently elderly individuals with this condition have been labeled 'high risk' for CEA, and are often treated with medical therapy or angioplasty and stenting.

Objective

To identify whether age of 80 years or more increases morbidity, mortality and length of hospital stay after CEA.

Design and intervention

This retrospective review of the Jobst Vascular Registry, a prospective record of vascular procedures carried out at the Toledo Hospital, Ohio, USA, analyzed all patients undergoing CEA between January 1993 and August 2004. The pretreatment characteristics, postoperative complications, surgical outcomes and length of hospitalization of patients were reviewed. Before CEA, patients underwent duplex ultrasonography and four-vessel cerebral arteriography. Most CEAs were performed under general anesthesia with intraoperative shunting; an autologous vein or synthetic patch was used to close the arteriotomy. Patients were monitored in intensive care for 24 h after CEA and followed up at day 7–10 postsurgery if no adverse events occurred.

Outcome measures

The main outcomes were procedure-related stroke and death. Length of hospital stay, destination after leaving hospital or in-hospital mortality, and complications were secondary outcomes. Operative mortality was defined as all deaths attributable to the procedure regardless of the time of occurrence, and included all deaths occurring within 30 days postoperatively, regardless of cause.

Results

In 1,961 patients in the registry, 2,217 CEAs were carried out: 334 patients aged 80 years or more underwent 360 procedures, and the remaining 1,627 patients under 80 years old underwent 1,857 CEAs. The occurrence of postoperative stroke did not differ significantly between the two age groups: 14 (0.8%) strokes occurred in patients under 80 years versus 4 (1.1%) in patients 80 years old or more. Operative mortality was slightly lower in the younger group, compared with the older group (0.8% versus 1.9%, respectively, P = 0.053). Mortality was similar in all asymptomatic patients, but was higher in older symptomatic than older asymptomatic patients (P = 0.007). The combined rate of stroke, death or both was higher in the older group than in the younger group (3.1% versus 1.5%, respectively, P = 0.041), the difference arising from the significantly higher rate seen in the older symptomatic patients compared with older asymptomatic patients. The average postoperative and total length of hospitalization was shorter in the younger than older group (P = 0.001). The groups had similar adverse event rates. Survival curve analysis demonstrated higher mortality in the older age group, however, this was similar to mortality in the normal, age-adjusted population.

Conclusion

Although increased, the combined stroke and death rate in patients aged 80 years or more falls within acceptable levels in national guidelines and compares favorably with best medical care. Miller et al. stress that patients over 80 years old should not be arbitrarily deemed 'high risk' for CEA.

Commentary

Revascularization is designed to spare vital target organs from the threat of stroke, myocardial infarction or gangrene. Complications of these operative procedures, however, can bring about the disasters they are intended to avert. Since its introduction in 1954, CEA has been associated with the risk of perioperative stroke and death. Research has attempted to establish which patients benefit most from the procedure, which patients should not be exposed to the operative risk and the upper limits of operative complication rates that are commensurate with benefit.

As the application of CEA grew, several centers defined patient characteristics that predicted additional perioperative hazard. In a much-cited, influential report from the Mayo Clinic, USA, old age was listed among the poor prognostic variables.¹ In response, practitioners became reluctant to offer CEA to elderly patients with carotid stenosis. Consistent with this 'conventional wisdom', the designers of the North American Symptomatic Carotid Endarterectomy Trial (NASCET) excluded patients aged 80 years or above for the first 2 of its 9 years. This early exclusion was a mistake, as evidenced by subsequent findings.

In this study, Miller et al. report on 1,961 patients who underwent CEA, including 334 who were aged 80 years or older. The elderly patients tended to have no increase in perioperative stroke, but had double the perioperative mortality compared with patients under 80 years of age. The combined postoperative stroke and death rate in the elderly compared with younger patients was 3.5% versus 1.5%, significantly favoring the young. Despite these results, they concluded that CEA was safe and effective in the elderly. Without controls, however, statements about efficacy are not definitive. A study of potential stroke reduction by the rigorous application of modern medical therapy (especially for the lower-risk asymptomatic patient) is still to come.

More favorable CEA results in the elderly are available. Among the 2,885 patients with symptoms related to carotid stenosis in the NASCET study, who were randomly assigned to best medical care plus CEA or best medical care alone, a number of demographic, clinical and radiologic characteristics were identified at trial entry.² In prospective follow-up, the impact of these variables permitted the investigators to determine who would benefit most or least and who would be harmed by CEA. Characteristics that individually altered the anticipated results included the degree of stenosis, contralateral occlusion, intracranial stenosis, gender and widespread LEUKOARAIOSIS.³ By employing a slightly modified definition of elderly—aged 75 years or more, not 80 years or more—and excluding entry into the trial to patients with recent myocardial infarction or congestive failure, atrial fibrillation, other vital organ dysfunction or progressive cancer, the NASCET trial reported that the 409 randomized elderly patients enjoyed a greater benefit from CEA than did younger patients.⁴ Their risk when undergoing medical treatment alone was higher than the younger patients but the operative risk of stroke or death, possibly because of the exclusions listed, was no higher than in the young. The resultant absolute risk reduction was exceptionally high. The number of elderly people needed to treat with CEA for severe stenosis in order to prevent one stroke in 2 years was reduced to 3 patients, compared with 10 for those aged 65 years or less. Combining the NASCET study results with data from the European Carotid Surgery Trial (ECST) confirmed this special benefit for elderly patients.⁵

Acknowledgments

The synopsis was written by Emma Campbell, Associate Editor, Nature Clinical Practice.

References

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Subject areas under which this article appears: Intervention | Stroke | Vascular disease