After adjustment for both patient and clinician-level factors, carotid artery stenting (CAS) and carotid endarterectomy (CEA) demonstrated comparable outcomes in Medicare beneficiaries, according to data published in Circulation: Cardiovascular Quality and Outcomes.
CAS has become a less invasive alternative to CEA for patients with severe carotid artery stenosis to prevent stroke. “Although evidence from trials offer guidance for treating patients with carotid artery stenosis, they do not reflect the diversity of patient risk profiles or operator technical variability in the real world,” researchers noted. “The objective of this study was to compare outcomes after CAS and CEA among Medicare patients overall and in subgroups defined by demographic and clinical characteristics.”
Death, stroke/transient ischemic attack (TIA), and periprocedural myocardial infarction (MI) were the main study outcomes. Patients were followed from the date of their procedure until either one of the outcomes occurred, Medicare eligibility was lost, or the end of the study.
Researchers collected data from the Society for Vascular Surgery’s Vascular Registry (SVS-VR), National Cardiovascular Data Registry’s (NCDR) Carotid Artery Revascularization and Endarterectomy (CARE) registry, American Hospital Association’s Annual Survey Database, American Medical Association’s Physician Masterfile, and Medicare denominator, institutional, noninstitutional, and vital status files.
Of the total SVS-VR cases, 71% were linked to CAS procedures and 69% to CEA procedures. There were 1999 patients treated with CAS and 3255 patients with CEA by 337 physicians across 69 facilities (mean age: 76; 59% male). Nearly all of the CAS patients and approximately 50% of the CEA patients were considered high risk for surgery. CAS patients were more often symptomatic compared with CEA patients (47% vs 37%), in a clinical trial (29% vs 0.1%), undergoing the procedure in a nonelective hospitalization (24% vs 13%), and had a worse comorbidity burden.
Of the total CARE cases, 63% were linked to CAS procedures and 70% to CEA procedures. There were 2824 patients who received treatment via CAS and 1231 who received treatment via CEA by 449 physicians across 138 centers. Patient characteristics were similar between the CARE and SVS-VR patients, but CARE patients were less often symptomatic (39% for CAS and 34% for CEA). Both sets of SVS-VR and CARE patients receiving CEA were at a similar high risk for surgery, but only 71% of CAS CARE patients were at high risk compared to nearly all CAS SVS-VR patients.
SVS-VR patients had a longer average follow-up time (CAS mean: 914 days; CEA mean: 888 days) vs CARE patients (CAS mean: 542 days; CEA mean: 667 days).
CAS patients had higher unadjusted periprocedural risks for all outcomes compared with CEA patients, except for MI risk, which was similar among both groups. Across registries, procedure-specific outcome risks were similar, except for stroke/TIA which was lower in the SVS-VR CEA group. Outcome risks remained higher for CAS at 3 years, but stroke/TIA risk for CEA became more comparable across the registries.
According to unadjusted Kaplan-Meier cumulative mortality curves for both SVS-VR and CARE, there appeared to be higher unadjusted mortality risks for CAS. In addition, unadjusted mortality and composite outcome risks were higher for CAS than for CEA across all subgroups in both registries.
However, after adjustment, CAS and CEA outcomes were similar in most subgroups. “Adjusted HRs [hazard ratios] for mortality suggested that CAS and CEA were comparable for patients aged ≤80 years (HR: 1.10; 95% CI [confidence interval]: 0.87-1.40) or asymptomatic (HR: 0.96; 95% CI: 0.73-1.26),” researchers wrote, “but we found a nonsignificant trend, suggesting that CAS was associated with higher mortality among patients >80 years (HR: 1.32; 95% CI: 0.98-1.78) and among patients with symptomatic carotid stenosis (HR: 1.30; 95% CI: 1.10-1.69).”
They concluded, “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 researcher is needed to confirm whether older and symptomatic patients may derive greater benefit from CEA than CAS.”
Jalbert JJ, Nguyen LL, Gerhard-Herman MD, et al. Comparative effectiveness of carotid artery stenting vs carotid endarterectomy among Medicare beneficiaries. Circ Cardiovasc Qual Outcomes. 2016. doi: 10.1161/CIRCOUTCOMES.115.002336.