Background: Centers of Medicare and Medicaid Services (CMS) has defined a set of high-risk criteria to help define patients who would likely benefit from CAS over CEA. The purpose of this study was to evaluate the postoperative outcomes in patients undergoing CAS vs. CEA, and whether those outcomes vary based on the CMS high-risk criteria.
Methods: All patients undergoing CAS or CEA recorded in the Vascular Quality Initiative database (2013-2016) were included. Patients were stratified as being normal-risk (Nr) or high-risk (Hr) for undergoing CEA based on published CMS criteria. 30-day and 2-year outcomes [stroke, myocardial infarction (MI), death] were compared for CAS vs. CEA in both the Nr and Hr groups using 1:1 coarsened exact matching and multivariable Cox proportional hazards modelling.
Results: A total of 55,765 patients (CAS=8,538; CEA=47,227) underwent carotid revascularization during the study period. A significantly higher proportion of CAS were classified as being Hr (75.1% vs. 38.5%; P<0.001). Among Nr patients, 30-day stroke (2.2% vs. 1.0%) and death (4.9% vs. 2.9%) occurred more frequently after CAS vs. CEA (P<0.001), whereas the rate of MI was similar (0.8% vs. 0.6%; P=0.17). Among the Hr patients, 30-day stroke (2.8% vs. 1.3%) and death (7.9% vs. 6.2%) also occurred more frequently after CAS vs. CEA (P<0.001), but the rate of MI was higher after CEA (0.8% vs. 1.1%, P=0.03). After matching 5,440 pairs of patients on 14 preoperative variables, the risk of 2-year stroke/death remained higher after CAS in both the Nr (HR 1.58; 1.17-2.15) and Hr (HR 1.37; 1.13-1.66) groups (Figure).
Conclusions: In this matched cohort of patients, CAS carries a persistently higher risk of stroke/death than CEA regardless of operative risk. However, the performance difference between the two procedures dissipates in the Hr patients. Thus, CAS utilization should be considered in this group.