Predictors of poor outcome after carotid intervention

A variety of patient factors are known to adversely impact outcomes after carotid endarterectomy (CEA) or carotid artery stenting (CAS). However, their specific impact on complications and mortality and how they differ between CEA and CAS is unknown. The purpose of this study is to identify patient and hospital factors that adversely impact outcomes.

Patients who underwent CEA or CAS between 1998 and 2012 (N = 1,756,445) were identified using the Agency for Healthcare Research and Quality National Inpatient Sample and State Ambulatory Services Databases. A multivariate analysis was completed to evaluate the impact of demographics, patient factors, type of symptoms (transient ischemic attack or cerebrovascular accident), volume of cases (3 per year vs 1-2 interventions), and interventions upon outcomes, perioperative complications (stroke, myocardial infarction, and bleeding), duration of stay, inpatient mortality, and cost. Significant factors were then used as part of a multivariate regression analysis to determine odds ratios. A subgroup analysis using propensity matching evaluating 1:1 risk-matched asymptomatic and symptomatic patients was completed. Patient cohorts were matched on the basis of Charlson scores.

Over the study period a total of 1,583,614 asymptomatic CEA, 7317 asymptomatic CAS, 162,362 symptomatic CEA, and 3149 symptomatic CAS patients were included. Symptomatic disease portends a worse outlook after either CEA or CAS. Costs of the procedure increased with complications with stroke adding the most significant cost burden. For risk-matched asymptomatic and symptomatic patients, female gender (P < .001) and performing one or two cases per year (P < .05) were associated with higher cerebrovascular accident risk. In asymptomatic and symptomatic patients, predictors of myocardial infarction included congestive heart failure (P < .001) and peripheral artery disease (P < .05) and predictors of bleeding included peripheral artery disease (P < .05) and chronic obstructive pulmonary disease (P < .01) for symptomatic patients only. For both asymptomatic and symptomatic patients, predictors of mortality included female gender (P < .001) and performing one or two cases per year (P < .01). Female gender was one of the strongest overall predictors of adverse outcome after CAS (odds ratio, 21.39 for death; P < .001). Low volume (<3 cases per year per practitioner) is a predictor of adverse outcome after CAS only.

Higher rates of postoperative stroke and inpatient mortality for women undergoing CAS is an unexpected finding, and may indicate that this population is vulnerable to complications after endovascular management. Low volume is a predictor of complications and subsequent mortality primarily for CAS. Patients who undergo CEA continue to have superior outcomes compared with matched cohorts who undergo CAS.