Comparison of 30-day readmission rates and risk factors between carotid artery stenting and endarterectomy

Objective: The aim of this study was to analyze the rates, reasons, and risk factors of 30-day readmission, both planned and unplanned, after carotid revascularization as well as to evaluate major outcomes associated with those readmissions. Methods: Using the Premier Healthcare database, we retrospectively identified patients undergoing carotid endarterectomy (CEA) and carotid artery stenting (CAS) between 2009 and 2015. The primary outcome was 30-day all-cause readmission. Secondary outcomes included mortality and overall cost associated with readmissions. Univariate and multivariate analyses were used and further validated using coarsened exact matching on baseline differences between CEA and CAS patients. Results: A total of 95,687 patients underwent carotid revascularization, 13.5% of whom underwent CAS. Crude 30-day readmission rates were 6.5% after CEA vs 6.1% after CAS (P = .10). Stroke, bleeding, pneumonia, and respiratory failure were the most common reasons for readmission after both CEA and CAS (6.7% vs 8.3%, 6.9% vs 5.3%, 3.4% vs 2.4%, and 4.4% vs 3.9%; all P > .05). Myocardial infarction and wound complications were more likely to be an indication for readmission after CEA (4.1% vs 2.5% and 4.1% vs 1.5%, respectively; P < .05). On the other hand, readmissions due to vascular or stent-related complications were more likely after CAS compared with CEA (5.8% vs 3.8%; P = .003). On multivariate analysis, CEA was found to be associated with 41% higher odds of readmission than CAS (adjusted odds ratio, 1.41; 95% confidence interval, 1.29-1.54; P < .001). Age, female gender, emergency/urgent procedures, concomitant cardiac procedures, rural hospitals, and Midwest region were significantly associated with 30-day readmission. Other risk factors included major preoperative comorbidities (diabetes, congestive heart failure, renal disease, chronic obstructive pulmonary disease, peripheral vascular disease, and history of cancer) as well as the occurrence of postoperative stroke and renal complications during the index admission and nonhome discharge. Coarsened exact matching between CEA and CAS patients also yielded higher adjusted rates of readmission after CEA (6.2% vs 4.9%; P < .001). On the other hand, patients readmitted after CAS had a longer length of hospital stay (5 days vs 4 days; P = .001), increased readmission mortality (6.2% vs 2.8%; P < .001), and higher rehospitalization costs ($8903 vs $7629; P = .01) compared with those readmitted after CEA. Conclusions: Our results show that CAS is associated with lower 30-day readmission rates compared with CEA. However, CAS readmissions are more complex and are associated with higher mortality and costs. We have also identified patients who are at high risk of readmissions, which can help focus attention on interventions that can improve the management of these patients and reduce readmission rates.