Long Term Outcomes After Invasive Treatment of Carotid Artery Stenosis: a Longitudinal Study of German Health Insurance Claims

Abstract

Objective: There is a paucity of observational data including long term outcomes after invasive treatment for carotid artery stenosis. Methods: This retrospective study used nationwide insurance claims from the third largest provider in Germany, DAK-Gesundheit. Patients who underwent inpatient carotid endarterectomy (CEA) or carotid artery stenting (CAS) between 1 January 2008 and 31 May 2017 were included. The Elixhauser comorbidity scores from longitudinally linked hospital episodes were used. KaplaneMeier analysis and the log rank test were used to determine long term stroke free survival. Multivariable regression models were developed to adjust for confounding.

Results: A total of 22 637 individual patients (41.6% female, median age 72.5 years) were included, of whom 15 005 (66.3%) were asymptomatic and 17 955 (79.3%) underwent CEA. After a median of 48 months, 5 504 any stroke or death events were registered. The mortality rate varied between 0.4% (CEA for asymptomatic stenosis) and 2.1% (urgent CAS for acute stroke patients) at 30 days, and between 4.1% and 8.4% at one year, respectively. The rate for any stroke varied between 0.6% (CEA for asymptomatic stenosis) and 2.5% (CAS for symptomatic patients) at 30 days, and between 2.5% and 6.4% at one year, respectively. The combined rate for any stroke and mortality at one year was 6.3% (CEA for asymptomatic stenosis), 8.7% (CAS for asymptomatic stenosis), and 12.5% (urgent CAS for acute stroke patients). After five years, the overall stroke rate was 7.4% after CEA and 9.0% after CAS. In adjusted analyses, both older age and van Walraven comorbidity score were associated with events, while treatment of asymptomatic stenosis was associated with lower event rates.

Conclusion: The current study revealed striking differences between previous landmark trials and real world practice. It further suggested excess deaths among invasively treated asymptomatic patients.