When Should a Carotid Endarterectomy be Considered for Symptomatic Internal Carotid Artery Stenosis in the Elderly?

Abstract & commentary

Synopsis: With respect to the prevention of ipsilateral ischemic stroke, elderly patients with 50-99% symptomatic carotid artery stenosis benefited more from carotid endarterectomy than
did younger patients, and they were not at increased risk of
perioperative stroke or death.

Source: Alamowitch S, et al. Lancet. 2001;357:1154-1160.

Advances in early diagnosis and in effective treatment of multiple illnesses, which commonly occur in the elderly, have resulted in significant recent increases in longevity. Two large randomized, controlled, research trials1,2 have clearly demonstrated that carotid endarterectomies reduce the risk of stroke in middle-aged and young-elderly (ie, age 60-75 years) patients with severe carotid stenosis. However, relatively few studies have evaluated the benefits of carotid endarterectomy in the old-elderly (ie, > 75 years of age) patient.

Alamowitch and colleagues reported the findings of a study performed by the North American Symptomatic Carotid Endarterectomy Trial (NASCET) group. The results of carotid endarterectomies in patients age 75 years or older were compared with patients who were 65-74 years old and to a third group consisting of patients who were younger than 65 years of age. Among patients with 70-99% carotid artery stenosis, the absolute risk reduction of ipsilateral stroke with carotid endarterectomy was 28.9% for patients aged 75 years or older, 15.1% for those who were 65-74 years old, and 9.7% for the group younger than 65 years of age. Among patients with a 50-69% stenosis, the absolute risk reduction was significant only in those patients who were older than 75. The perioperative risk of stroke and death at any degree of stenosis was only 5.2% for the oldest group, 5.5% for the 65-74-year-old group, and 7.9% for the younger than 65 year old group. In summary, with respect to the prevention of ipsilateral ischemic stroke, elderly patients with 50-99% symptomatic carotid artery stenosis benefited more from carotid endarterectomy than did younger patients, and they were not at increased risk of perioperative stroke or death simply because of their advanced age.

Comment by Harold L. Karpman, MD, FACC, FACP

Multiple conferences and meetings have been mounted to ensure that elderly people are afforded the best available methods of care and that they are not denied specific treatment strategies which are known to be effective simply because of their advanced age.3-5 In an American Heart Association conference held in Washington, DC, in January, 2000, the consensus of the participants was that aggressive treatment can add years of useful life to elderly patients and that age alone should not be a reason for denying therapy that has been demonstrated to be effective.

The data presented by Alamowitch and the NASCET Group in the recent issue of Lancet clearly demonstrated that the absolute benefit from endarterectomy in patients with carotid arterial stenosis increases with age and, in fact, is greatest in patients who are older than 75. These findings were confirmed by the Carotid Endarterectomy Trialists’ Collaboration (CETC) study, which collated detailed data from individual patients from all available randomized, controlled trials. Analysis of the CETC data also revealed that: 1) the benefits from surgery were greatest among patients who were older than 75 years old, 2) there was no increase in operative risk in the elderly, and 3) the risk of stroke in patients with high-grade internal carotid artery stenosis who were not subjected to surgery was found to be quite significant.

What is most important at this time is to clearly recognize that age alone should not be a deterrent to surgically treating the patient with hemodynamically significant carotid arterial stenosis. The average patient enrolled in the NASCET study was part of a relatively select group of elderly patients with carotid artery disease who differed from most other elderly patients in the community in that they were afflicted with a lower frequency of associated disease, especially cardiac disease. Therefore, carotid endarterectomy in routine clinical practice is statistically most likely to benefit the reasonably fit patient over the age of 75 years who had been subjected to a scrupulous clinical examination in order to exclude those patients who are at increased risk from anesthesia or from developing cardiac complications even when the surgery is performed by skilled surgeons.

There is simply no justification for not investigating symptomatic carotid arterial disease in the older age groups especially in the fit individual who is found to have an appropriate risk profile.7 Even though symptomatic elderly patients may not wish to undergo a surgical procedure, they should be encouraged to consider the surgical option since trial evidence has now clearly demonstrated that these patients are the ones who are most likely to benefit from the procedure and the operative risks are quite minimal.

References

1. European Carotid Surgery Trialists’ Collaborative Group. Lancet. 1998;351:1379-1387.

2. Barnett HJ, et al. N Engl J Med. 1998;339:1415-1425.

3. Launer IJ, Hofman A. Neurology. 2000;54(suppl 5):
S1-3.

4. DiCarlo A, et al. Neurology. 2000;54(suppl 5):S28-33.

5. Schmitt R, et al. Neurology. 2000;54(suppl 5):S34-37.

6. Rothwell PM, et al. Cerebrovasc Dis. 2000;10
(suppl2): 108.

7. Rothwell PM, Warlow CP on behalf of the ECST Collaborators. Lancet. 1999;353:2105-2110.