Carotid Endarterectomy vs Carotid Stenting

May 13, 2016
Veronica Hackethal, MD

A retrospective cohort study of Medicare patients sought to determine if carotid endarterectomy or carotid stenting provided better outcomes.

Real world results from Medicare beneficiaries show similar outcomes for carotid endarterectomy (CEA) and carotid artery stenting (CAS), after adjusting for patient and provider factors, according to a study published online in Circulation: Cardiovascvular Quality Outcomes.1

“CAS patients tended to have higher unadjusted outcome risks. When accounting for patient- and provider-level factors, CAS and CEA performance was comparable, but estimates for mortality favored CEA when adjusting for patient-level factors only, [suggesting provider characteristics and proficiency may impact CAS effectiveness]” wrote first author Jessica Jalbert, PhD (Brigham and Women’s Hospital, Harvard Medical School Boston), and colleagues.

“We found a nonsignificant trend suggesting that CEA may be associated with a lower risk of adverse outcomes in older and symptomatic patients,” they added.

In 2004, the Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy (SAPPHIRE) trial reported that CAS is not inferior to CEA in patients at high surgical risk.2 Subsequently, the Center for Medicare and Medicaid Services issued a National Coverage Determination (NCD) requiring coverage of CAS in patients at high surgical risk.

However, the relative benefits of CAS vs CEA were muddied in 2010, when the Carotid Revascularization Endarterectomy versus Stenting Trial (CREST) trial suggested that CEA and CAS yielded similar outcomes in high surgical risk patients. But results also suggested that CAS patients had more strokes and CEA patients had more myocardial infarctions during the periprocedural period.3

In the retrospective cohort study, researchers linked Medicare data from 2000-2009 to the Society for Vascular Surgery’s Vascular (SVSV) Registry for 2005-2008, and the National Cardiovascular Data Registry’s Carotid Artery Revascularization and Endarterectomy (CARE) Registry for 2006-2008/2009.  Follow-up occurred from the procedure date until death. 

The analysis included 5254 patients from the SVSV Registry (1999 CAS; 3255 CEA) and 4055 patients from the CARE Registry (2824 CAS; 1231 CEA) Medicare patients. Researchers used propensity scores to control for variance between patients in the two different databases. Outcomes assessed included death, stroke, periprocedural myocardial infarction, and a composite endpoint. Researchers adjusted for patient factors (age, sex, race, health service use, comorbidities, year of procedure), and provider factors (past year procedure volume, teaching status, stroke center, ownership type, hospital size).

Key Results:

• Higher levels of comorbidity and higher surgical risk for CAS vs CEA patients

♦ SVSV Registry: 96.7% vs 44.5%

♦ CARE Registry: 71.3% vs 44.7%

• Higher unadjusted outcome risks for death and stroke for CAS vs CEA

• Higher mortality risks for CAS vs CEA after adjusting for patient factors (hazard ratio, 1.24; 95% confidence interval, 1.06-1.46)

♦ Weakened association after adjusting for provider factors (hazard ratio for mortality, 1.13; 95% confidence interval, 0.94-1.37)

• Similar effectiveness for CAS and CEA for all outcomes after adjusting for patient and provider factors

• Higher risk for adverse outcomes for CAS in older (>80) (HR, 1.32; 95% CI, 0.98–1.78) and symptomatic patients (HR, 1.30; 95% CI, 1.01–1.69), though results were not significant

“Our finding that controlling for provider-level factors in addition to patient-level factors further drove estimates towards the null suggests that provider characteristics affecting outcomes differed between CAS and CEA and are likely more variable in CAS,” the authors wrote.

Older patients over 80 years may benefit from CEA, perhaps related to higher stroke risk, increased arterial tortuosity, and increased lesion calcification, they pointed out.

“CAS seems to be as effective as CEA for the treatment of carotid artery stenosis among Medicare beneficiaries under the NCD, especially when performed by qualified providers, but further research is needed to confirm whether older and symptomatic patients may derive greater benefit from CEA than CAS,” the authors concluded.

Take-home Points

• Retrospective cohort study of Medicare beneficiaries found similar effectiveness for CAS and CEA for all outcomes after adjusting for patient and provider factors.

• Risk of mortality was higher for CAS vs CEA after adjusting for patient factors, suggesting provider characteristics and proficiency may impact CAS effectiveness.

• Nonsignificant trend for increased risk for adverse outcomes for CAS in older and symptomatic patients.

• More research is needed to verify whether older and symptomatic patients benefit more from CEA than CAS.

Dr. Johnston is a full-time employee of Eli Lilly.

One or more authors reports being a noncompensated advisor, a board member, a consultant, advisory board membership, committee chair, service in, grants, research support and/or XXX for one or more of the following: Abbott Vascular, Boston Scientific, Cordis Corporation, Covidien Vascular, Medtronic, VIVA Physicians (a not-for-profit education and research consortium), Optum Insight, WHISCON, Abbott, Angiodynamics, Surefire, Gore and Cook, SCAI CAS Expert Consensus Document Writing Committee, the Society for Vascular Medicine, the American College of Cardiology (Peripheral Vascular Disease Committee), and the Michigan chapter of the American College of Cardiology, the Clinical Events Committee for the Roadster trial sponsored by Silk Road Medical, the AHRQ, US DHHS,  Johnson & Johnson, Sanofi-Aventis.

References:

1. Jalbert JJ, et al. Comparative effectiveness of carotid artery stenting versus carotid endarterectomy among Medicare beneficiaries. Circ Cardiovasc Qual Outcomes. 2016 Apr 26.

2. Yadav JS, et al. for Stenting and Angioplasty with Protection in Patients at High Risk for Endarterectomy Investigators. Protected carotid-artery stenting versus endarterectomy in high-risk patients. N Engl J Med. 2004;351:1493-1501.

3. Brott TG, et al for CREST Investigators. Stenting versus endarterectomy for treatment of carotid-artery stenosis. N Engl J Med. 2010;363:11-23.

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