Predicting Transcarotid Artery Revascularization Adverse Outcomes by Imaging Characteristics

Approximately 20-30% of ischemic strokes are caused by internal carotid artery stenosis. Stroke is the leading cause of disability and the second leading cause of death in the United States. Second generation transcarotid arterial revascularization (TCAR) stenting, using the ENROUTE flow reversal technology to prevent embolic stroke during the stenting process, has demonstrated stroke and death outcomes equivalent to carotid endarterectomy with reduced cranial nerve injury. However, at present, it is not known whether imaging characteristics obtained preoperatively can predict outcomes of TCAR procedures.This retrospective cohort study included patients who underwent TCAR with flow reversal at three hospitals within a single hospital network who had computed tomography angiography, magnetic resonance imaging angiography, or preoperative diagnostic angiogram to determine whether carotid and lesion characteristics could predict patients who experienced major adverse critical events (MACE) versus those who did not. MACE was defined as myocardial infarction at 30 days, restenosis/persistent stenosis (peak systolic velocity within the stent >230 cm/sec by postoperative ultrasound), stroke within any time of follow-up, or death within 1 year of TCAR. Student's t-tests and Chi-squared tests were used to compare imaging characteristics, such as presence of pinpoint stenosis, calcification within the common carotid artery at the take-off from the aorta, and plaque length in millimeters. Binomial logistic regression was used to examine the likelihood that imaging characteristics were associated with MACE.Of 220 patients who underwent TCAR in our network, seven were excluded because flow reversal was not used or appropriate imaging had not been performed prior to TCAR. Of the 213 patients who were included in analysis, the median length of follow-up was 10.8 months (interquartile range: 3.4-33.1 months). Twelve percent (26/213) experienced MACE and a model based on imaging characteristics was statistically significant in predicting MACE with 68% accuracy (P = 0.005). The presence of pinpoint stenosis was highly predictive of MACE (hazards ratio: 3.34, confidence interval: 1.2 to 9.3, P = 0.021). A shorter clavicle to carotid bifurcation distance was associated with an increased likelihood of experiencing MACE (P = 0.009) but it was weakly predictive (hazards ratio: 1.03, confidence interval: 1.01 to 1.05).Preoperative imaging characteristics, such as pinpoint stenosis and clavicle to carotid bifurcation distance, can be used to predict adverse outcomes in TCAR placement.