Abstract Body: Background and Objectives: Left subclavian artery (LSA) is more prone to atherosclerosis than the right one. The study was designed to investigate whether aortic arch types (AAT) was associated with the lateralization of subclavian artery stenosis (SAS).
Methods: In this observational prospective registry study, we reviewed the digital subtraction angiography (DSA) database from our comprehensive stroke center between 2015-2023. Patients (age ≥ 18 years) with clinically manifest atherosclerotic vessel disease or risk factors for atherosclerosis and a normal branching pattern of the aortic arch were included. AAT and degree of SAS were determined by DSA. Breslow-Day test and multinomial logistic regression models were performed to identify the association between AAT and SAS.
Results: A total of 7,470 patients (mean [SD] age, 57.4 [14.9] years; 5,098 [68.3%] male and 2,372 [31.8%] female; 2,430 [32.5%] aged < 60 years) were included. Among the 7,470 patients, 771 (10.3%) were detected with SAS, including 518 (6.9%) on the left side, 173 (2.3%) on the right side and 80 (1.1%) on the bilateral side. Frequency of AAT Ι, ΙΙ and ΙΙΙ were 1,741 (23.3%), 5,047 (67.6%), and 682 (9.1%) respectively. LSA is more susceptible to atherosclerotic stenosis than right subclavian artery (RSA) with AAT Ι (any degree stenosis: 6.0% vs 2.4%, p < 0.001) and ΙΙ (any degree stenosis: 8.4% vs 2.9%, p < 0.001). We found no significant difference in occurrence of stenosis between LSA and RSA among patient with AAT ΙΙΙ (any degree of stenosis: 10.4% vs 9.2%, p = 0.521) (Figure1). The Breslow-Day test showed that there existed significant differences in the odd ratio (ORs) for the side of subclavian artery across each stratum of AAT (p <0.001) (Figure 2). AAT ΙΙΙ was independently associated with LSA stenosis (OR 0.65, 95% confidential interval [CI] 0.23-0.79, p = 0.027) and RSA stenosis (OR 2.01, 95% CI 1.20-3.42, p = 0.011).
Conclusions: AAT was associated with the preferential lateralization of SAS to the left side. Considering the complex interrelationship between vascular geometry, local hemodynamics, vascular aging and atherosclerosis, the finding needs to be validated with longitudinal studies and the underlying mechanism should be further explored with hemodynamics assessments in upcoming research.