Asymptomatic Carotid Artery Stenosis Patients Treated at High Volume Centers with Carotid Artery Stenting Are Associated with Decreased 30-day and 90-day Readmission Rates

Introduction: Carotid artery stenosis can be treated with endovascular carotid artery stenting (CAS). Previous studies have shown that high volume centers are associated with improved patient outcomes, including decreased length of stay and mortality. Unplanned hospital readmissions are increasingly used as a metric of patient outcome and is associated with significant hospital and insurance expenses. Readmission rates as an outcome has yet to be investigated between high and low volume centers for patients undergoing CAS.

Methods: The National Readmissions Database (NRD) was analyzed retrospectively from 2010-2015 to evaluate the association between hospital procedural volume and patient outcomes in asymptomatic and symptomatic CAS patients, reported as national estimates. Univariate and multivariate analyses of patient and hospital characteristics were conducted to evaluate associations with 30-day readmissions, 90-day readmissions, index mortality, discharge disposition, major complications, and neurological complications.

Results: A total of 36,128 asymptomatic patients and 8,390 symptomatic patients who underwent CAS were identified with the NRD. 20,630 asymptomatic patients (57.1%) and 4,373 symptomatic patients (52.1%) were treated at a medical center with a high CAS volume, defined as the top 10% of hospitals performing >= 79 procedures a year. Asymptomatic patients treated at high volume centers were less likely to undergo 30-day (OR 0.88, 95% CI 0.80-0.95, p =0.003) and 90-day readmission (OR 0.91, 95% CI 0.85-0.99, p =0.037) compared to asymptomatic patients at low volume centers. There was no significant difference in 30-day or 90-day readmission status between symptomatic CAS patients treated at high vs. low volume centers.

Conclusion : Asymptomatic CAS patients will benefit from treatment at high volume medical centers, while symptomatic CAS patients may not have a significant change in patient outcome.