Background: The effectiveness of comprehensive stroke center (CSC) capabilities on outcome of carotid endarterectomy (CEA) and carotid artery stenting (CAS) remains uncertain. We performed a nationwide study to examine whether CSC capabilities influenced in-hospital outcome of CEA and CAS.
Methods: We analyzed 12,943 carotid artery stenosis patients treated with CEA or CAS in 350 certified training hospitals in Japan. Data between April 1, 2013 and May 31, 2015 was obtained from Japanese Diagnosis Procedure Combination Database. Among the institutions that responded, outcome was assessed by in-hospital mortality, ischemic stroke and myocardial infarction. CSC capabilities were evaluated from the 749 certified training institutions in Japan, which responded to a questionnaire survey regarding CSC capabilities that queried the availability of personnel, diagnostic techniques, specific expertise, infrastructure, and educational components recommended for CSCs. Total CSC scores of the participating hospitals were classified into quartiles (Q1: 0-15, Q2: 16-17, Q3: 18-19, Q4: 20-24).
Results: The proportion of CEA and CAS were 5068 and 7875 (2013: 1685 and 2590, 2014: 1668 and 2564, 2015: 1715 and 2721). Between CEA and CAS, mortality rates were 0.24% and 0.75%, ischemic stroke were 8.41% and 7.56% and myocardial infarction were 0.76% and 0.17%. These outcomes had no differences among the years. There was tendency that mortality rates were lower with high total CSC scores in patients with CEA (Q1: 0.42%, Q2: 0.26%, Q3: 0.12%, Q4: 0%, P=0.16), but there were no differences with CAS (Q1: 1.0%, Q2: 0.74%, Q3: 0.63%, Q4: 0.83%, P=0.73). Ischemic stroke were significantly lower with high CSC scores in CEA (Q1: 9.76%, Q2: 10.77%, Q3: 9.14%, Q4: 6.59%, P<0.05) and CAS (Q1: 9.86%, Q2: 8.76%, Q3: 7.14%, Q4: 6.98%, P<0.05). Myocardial infarction had no correlation with CSC scores in CEA (Q1: 0.21%, Q2: 0.35%, Q3: 0%, Q4: 0.36%, P=0.37) and CAS (Q1: 0.3%, Q2: 0%, Q3: 0.31%, Q4: 0.16%, P=0.19).
Conclusion: It is reported using the data of Nationwide Inpatient Sample that operator volume was an important predictor of postprocedural outcomes in CAS. We demonstrated that CSC capabilities were associated with reduced in-hospital ischemic stroke in patients with CEA and CAS.