Major Finding: The composite adverse event rate during up to 4 years of follow-up was 7.2% for stenting and 6.8% for endarterectomy, with the adverse event rate after stenting rising significantly higher than after surgery among patients older than 70 years.
Data Source: The Carotid Revascularization Endarterectomy vs. Stenting Trial (CREST), which randomized 2,502 patients with either symptomatic or asymptomatic carotid stenosis to treatment by endarterectomy or carotid stenting with embolic protection at 117 U.S. and Canadian sites.
Disclosures: CREST was funded by the National Institute of Neurological Disorders and Stroke. Dr. Clark and Dr. Brott said they had no other relevant disclosures.
SAN ANTONIO — The largest-ever, head-to-head comparison of stenting versus surgery for treating severe carotid artery stenosis showed a marked effect of age, with patients older than 70 having fewer adverse outcomes after carotid endarterectomy and patients younger than 70 having fewer complications following carotid angioplasty and stenting.
Although the highly anticipated results from the decade-long Carotid Revascularization Endarterectomy vs. Surgery Trial (CREST) seemed, in simplest terms, to show a dead heat between carotid stenting and surgery, the results reported at the International Stroke Conference actually revealed statistically significant and clinically important differences between the two treatments. (See box.)
The statistically significant interaction between patient age and outcome will likely play a major role when physicians and patients now decide which intervention to favor for a specific patient.
The CREST results also showed another significant difference between carotid surgery and stenting: Surgery led to a 1.2% increased absolute rate in the incidence of periprocedural myocardial infarctions, while stenting produced a 1.8% increase absolute rate of periprocedural strokes. This finding will force patients and their physicians to consider which complication they would rather risk.
The patients in CREST answered that question, at least in part, via another outcome measure. Assessment of patient physical and mental quality of life with the 36-item Short Form (SF-36) Health Survey a year after treatment showed that patients who developed new strokes, even “minor” strokes, had significant reductions from baseline in both their mental and physical well-being, while patients who developed new myocardial infarctions had, on average, no significant changes in their SF-36 mental and physical scores, Dr. Wayne M. Clark reported while presenting the CREST results.
“This study, at the bottom line, was an endorsement for surgery,” commented Dr. James C. Grotta, chairman of neurology at the University of Texas in Houston.
The CREST findings also renewed concerns about the appropriateness of any invasive intervention, be it stenting or surgery, for asymptomatic carotid stenosis. The findings raised questions about how CREST differed from another large comparison of stenting and surgery, the International Carotid Stenting Study (ICSS), the results of which also appeared online, coincidentally, on the same day as the CREST report (Lancet 2010 Feb. 26 [doi:10.1016/S0140-6736(10)60239-5
Some experts noted that the CREST stenting results came from selected, experienced operators and that it would be a leap to expect comparable results from less-experienced physicians.
CREST randomized 2,502 patients with either symptomatic carotid stenosis or asymptomatic, severe carotid stenosis (at least 60% blockage) at 108 sites in the United States and 9 in Canada. The patients' average age was 69 years, a third were women, and 47% were asymptomatic. The analysis showed no significant effect from gender or symptom status on outcomes.
Impact of Age
The age effect produced the sharpest distinction between stenting and surgery, and confirmed evidence that began emerging a few years ago that carotid stenting poses a special problem for elderly patients. “As we went into this [trial], most of us thought that the less invasive procedure would be best suited for the older patients,” said Dr. Thomas G. Brott, professor and director of neurology at the Mayo Clinic in Jacksonville, Fla., and co–principal investigator for CREST.
The problem has been attributed to the increased difficulty and danger of placing stents and embolic protection devices through elderly patients' tortuous and atherosclerotic arteries.
“It's likely that putting in the embolic protection device sets off strokes. Until we have more data to show whether or not the age effect is real, I will take it into account in my patients,” commented Dr. J. Donald Easton, a neurologist at the University of California, San Francisco.
“I'm tending to look at the age cut-point very carefully,” said Dr. Philip B. Gorelick, professor of neurology and rehabilitation and director of stroke research at the University of Illinois in Chicago.
Dr. Clark reported the age effect as a continuous variable, without specifying any point estimates. But based on the line graph he showed, patients who underwent stenting at age 65 had a roughly 20% reduced risk for an adverse perioperative or long-term outcome compared with those who underwent surgery. At age 60 the relative benefit from stenting was about 35%. At age 50, the rate of adverse outcomes after stenting was less than half the rate after endarterectomy.