Meta-analysis: Carotid Surgery Superior to Stenting in Both Short-, Long-term

Carotid endarterectomy (CEA) is superior to carotid artery stenting (CAS), with lower rates of stroke and the composite of death or stroke, both within 30 days and after 1 year, according to a meta-analysis published online January 13, 2011, ahead of print in Stroke.

Konstantinos P. Economopoulos, MD, PhD, of the University of Athens (Athens, Greece), and colleagues conducted the comprehensive meta-analysis, which included data from 13 randomized trials examining short-term (< 30 days) or long-term (≥ 1 year) outcomes in patients who had undergone CEA (n = 3,723) or CAS (n = 3,754).

The meta-analysis included earlier as well as more recent trials including CREST (Carotid Revascularization Endarterectomy versus Stent Trial), CAVATAS (Carotid and Vertebral Artery Transluminal Angioplasty Study), and SPACE (Stent-supported Percutaneous Angioplasty of the Carotid artery versus Endarterectomy).

Pooled data regarding short-term outcomes indicated that patients who had undergone CAS had higher risks for stroke and the composite of death or stroke, with a borderline trend towards increased death and the composite of death or disabling stroke. However, higher short-term rates of MI and cranial nerve injury were found in patients who had undergone CEA (table 1).

Table 1. Short-term Outcomes: CAS vs. CEA

The researchers also calculated pooled odds ratios for long-term outcomes and found that, similar to the short-term results, CAS was again associated with higher rates of stroke and death or stroke (table 2).

Table 2. Long-term Outcomes: CAS vs. CEA

Although meta-regression did not reveal any significant modifying associations, subsequent analysis found that long-term occurrence of stroke was significantly higher for patients over age 68 who had undergone CAS vs. CEA (pooled OR 1.71; 95% CI 1.19-2.45; P = 0.004). No difference in stroke rate was found for patients aged younger than 68 years.

“CAS represents a therapeutic option that necessitates careful selection of patients,” the researchers conclude. “Taken as a whole, the outcomes of CEA seem superior to CAS, but there may be subgroups, particularly younger patients, in whom the results seem equivalent.”

Practice Should Change

The study provides a more comprehensive analysis of short- and long-term outcomes after the revascularization procedures than previously published meta-analyses, the researchers note, adding that the most recent meta-analysis (Meier P, et al. BMJ. 2010;340:c467) did not include data on long-term outcomes or findings from CREST, CAVATAS, or SPACE.

“The appearance of the results from CREST marked a turning point in the continuum of studies examining CEA vs. CAS, as the inclusion of 2,502 patients has shed light upon both short-term and long-term outcomes,” Dr. Economopoulos said in an e-mail communication with TCTMD. “In addition, the publication of long-term results from the CAVATAS and SPACE studies has created a new context concerning long-term effects.”

Because of this, Dr. Economopoulos said that the results of this more inclusive meta-analysis should affect clinical practice. “Surgical treatment of carotid artery stenosis should change,” he asserted. “Carotid artery stenting should be administered only within the context of a clinical trial.”

Christopher K. Zarins, MD, of the Stanford School of Medicine (Stanford, CA), agreed that the data should influence practice, but added that they likely will not.

“This study confirms the data that are already out there. If a patient wants to avoid a stroke then the best thing to do is CEA,” Dr. Zarins told TCTMD in a telephone interview. “However, there has been a lot of controversy and [resistance to] prospective randomized trials because people do not want to accept it. They want to believe that CAS is the same or better than CEA, but the data are pretty clear. CEA is better than stenting.”

Are Procedures Comparable?

Just last week, an analysis of nearly 13,000 registry patients took issue with meta-analyses on the topic. The paper (Longmore RB, et al. Circ Cardiovasc Interv. 2011;Epub ahead of print) argued that the extreme clinical disparities of patients undergoing CAS or CEA make it nearly impossible to compare the 2 procedures using retrospective data. It listed 7 high-risk factors that are more common among CAS patients, including prior CAS, CEA or MI, increased angina burden, ischemic heart disease, and CAS or CEA restenosis.

Yet both Dr. Economopoulos and Dr. Zarins dismissed the idea that baseline characteristics could affect conclusions drawn from the current meta-analysis.

“We strongly believe that our results are strong enough to persist in the future, especially because the results of the exploratory meta-regression analysis did not reveal any significant modifying effect by cardiovascular disease, diabetes, hypertension, or hyperlipidemia/dyslipidemia,” Dr. Economopoulos said.

Dr. Zarins added that although it is true that some high-risk CAS patients were enrolled in trials, it is also true that some high-risk patients undergo CEA. “I don’t think there is any evidence that the patient populations are very different,” Dr. Zarins stressed. “They are all patients with carotid stenosis.”

Questions for the Future

Looking ahead, the paper proposes, further research could examine subgroups likely to have equivalent outcomes after either revascularization method. Younger patients are an example.

“Longer follow-up from numerous studies would be desirable to establish meaningfulness of age as a long-term effect modifier, since meta-regression with mean age of patients did not yield a significant result,” Dr. Economopoulos noted.

But according to Dr. Zarins, the overall question of whether CEA or CAS is more effective has already been answered. Instead, the question moving forward is whether clinicians will present this information to patients fairly.

“People who do carotid stenting and don’t know how to do CEA will likely continue to do carotid stenting,” Dr. Zarins said. “But it comes down to thinking about why we are treating this condition. The reason is to prevent stroke. If that is the objective, then the best way to prevent stroke in the short- and long-term is CEA.”

 

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Source:
Economopoulos KP, Sergentanis TN, Tsivgoulis G, et al. Carotid artery stenting versus carotid endarterectomy: A comprehensive meta-analysis of short-term and long-term outcomes. Stroke. 2011;Epub ahead of print.

 

 

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