Comparison of Hospital Outcomes of Transcarotid Artery Revascularization with Flow Reversal (TCAR) Vs. Carotid Endarterectomy (CEA)

Abstract

Introduction - TransCarotid Artery Revascularization with flow reversal (TCAR) offers a less invasive option to carotid endarterectomy (CEA) in high risk patients and has the lowest reported overall stroke rate for any prospective trial of carotid artery stenting (CAS). This study compares initial in-hospital outcomes of CEA and TCAR using the Society for Vascular Surgery (SVS) Vascular Quality Initiative (VQI) TCAR Surveillance Project (TSP) done in collaboration with the Centers for Medicare & Medicaid Services (CMS) to create more information for future coverage decisions. Methods - The SVS TSP isdesigned to evaluate the safety and efficacy of TCAR in real world practice, using a contemporary comparison to CEA.Patients enrolled in this project were compared to those undergoing CEA during the same time period (2016-2017). The primary outcome was a composite of in-hospital stroke and death. Average treatment effects were estimated via augmented inverse-probability weighting (AIPW). Additional analysis was performed using multivariable logistic regression as well as various matching techniques such as propensity score matching and coarsened exact matching (CEM).Adjusted analysis accounted for age, gender, race, insurance status, CAD, CHF, CKD, COPD, symptomatic status, restenosis, prior vascular procedures, degree of ipsilateral stenosis and preoperative medication use. Results - A total of 637 patients underwent TCAR compared to 12,049 patients who underwent CEA. Patients undergoing TCAR were older (median age 74 vs.71 years), more likely to be symptomatic (33.6% vs. 27.9%),and had more medical comorbidities such as CAD (47.3% vs.26.6%), CHF (19.8% vs.11.1%), COPD (26.5% vs. 22.3%), CKD (39.9% vs. 33.6%), and prior vascular procedures compared to CEA patients (All p<0.01). The majority of TCAR procedures were done under general anesthesia (79.0% vs.90.3% in CEA, p<0.001). On average, TCAR was 36.7 minutes shorter than CEA (78.0±33.9 vs. 114.7±42.5, p<0.001). On univariate analysis, there were no differences in the rates of in-hospital stroke/death (1.3% vs. 1.7%, p=0.42), overall neurological events (2.0% vs.1.9%, p=0.83), in-hospital MI (0.7% vs.1.1%, p=0.31) and 30-day mortality (0.5% vs. 0.9%, p=0.08) between CEA and TCAR, respectively. Patients undergoing CEA had higher rates of cranial nerve injury (2.8% v.0.8%, p<0.01) and postoperative hypertension (18.3% vs. 11.6%, p<0.001) compared to TCAR patients. On multivariable analysis and using different matching methods, there were no differences in overall stroke, stroke/death or overall neurologic events (Figure 1). The absolute difference in adjusted stroke/death rates between the two groups was 0.3% [95%CI: -1.7%, 1.0%, p=0.64]. Conclusion - Despite a substantially higher medical risk in patients undergoing TCAR, preliminary analysis of the SVS-VQI TCAR Surveillance Project showed similar in-hospital stroke/death rates between TCAR and CEA after multivariable adjustment and rigorous matching. Further studies with larger sample sizes and longer follow will be needed to establish the equivalence of TCAR compared to CEA.