Study of Medicare Patients Finds Comparable Outcomes for CAS and CEA

April 29, 2016—A study of the effectiveness of carotid artery stenting (CAS) versus carotid endarterectomy (CEA) among Medicare beneficiaries concluded that the outcomes after CAS and CEA were comparable after adjusting for both patient- and provider-level factors. Jessica J. Jalbert, PhD, et al published the study online ahead of print in Circulation: Cardiovascular Quality and Outcomes.

The investigators linked Medicare data (2000–2009) to the Society for Vascular Surgery (SVS) Vascular Registry (2005–2008) and the National Cardiovascular Data Registry's (NCDR) Carotid Artery Revascularization and Endarterectomy (CARE) registry (2006–2008/2009). 

Follow-up for Medicare patients was conducted from the procedure date until death, stroke/transient ischemic attack, periprocedural myocardial infarction, or a composite endpoint for these outcomes. High-dimensional propensity scores were derived using registry and Medicare data to control for patient factors and adjusted for provider factors in a Cox regression model comparing CAS with CEA.

As summarized in Circulation: Cardiovascular Quality and Outcomes, the study was composed of 5,254 SVS Vascular Registry (1,999 CAS; 3,255 CEA) and 4,055 CARE Registry (2,824 CAS; 1,231 CEA) Medicare patients.

The investigators noted that CAS patients versus CEA patients had a higher comorbidity burden and were more likely to be at high surgical risk (SVS Vascular Registry, 96.7% vs 44.5%; CARE registry, 71.3% vs 44.7%). Unadjusted outcome risks were higher for CAS and mortality risks remained elevated for CAS after adjusting for patient-level factors. 

After further adjustment for provider factors, differences between CAS and CEA were attenuated or no longer present. The performance was comparable across subgroups defined by sex and degree of carotid stenosis, but there was a nonsignificant trend suggesting a higher risk of adverse outcomes in older (> 80 years of age) and symptomatic patients undergoing CAS, reported the investigators in Circulation: Cardiovascular Quality and Outcomes.