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

OBJECTIVE: There is a paucity of observational data including long term outcomes after invasive treatment for carotid artery stenosis.

METHODS: This retrospective study utilised 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 utilised. Kaplan-Meier analysis and 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 of asymptomatic stenosis) and 2.1% (urgent CAS of acute stroke patients) at 30 days, and between 4.1% and 8.4% at 1 year, respectively. The rate for any stroke varied between 0.6% (CEA of asymptomatic stenosis) and 2.5% (CAS of symptomatic patients) at 30 days, and between 2.5% and 6.4% at 1 year, respectively. The combined rate for any stroke and mortality at 1 year was 6.3% (CEA of asymptomatic stenosis), 8.7% (CAS of asymptomatic stenosis), and 12.5% (urgent CAS of acute stroke patients). After 5 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 mortality of invasively treated asymptomatic patients.