Patient risk factors associated with embolic stroke volumes after revascularization

Objective: Previous research has shown that subclinical, microembolic infarcts result in long-term cognitive changes. Whereas both carotid endarterectomy (CEA) and carotid artery stenting (CAS) have potential for microembolic events, CAS has been shown to have a larger volume of infarct. We have previously shown that large-volume infarction is associated with long-term memory deterioration. The purpose of this study was to identify independent risk factors that trend toward higher embolic volumes in both procedures. Methods: A total of 162 patients who underwent carotid revascularization procedures were prospectively recruited at two separate institutions. Preoperative and postoperative brain magnetic resonance images were compared to identify procedure-related microinfarcts. A novel semiautomated approach was used to define volumes of infarcts for each patient. Patient-related factors including comorbidities, symptomatic status, and medications were analyzed. Tweedie regression analysis was used to identify risk factors associated with procedure-related infarct volume. Variables with an unadjusted P value of <= .05 were included in the multivariate analysis. Results: There were 80 CAS and 82 CEA procedures performed and analyzed for the data set; 81% of CAS patients had procedure-related new infarcts with a mean volume of 388.15 +/- 927.90 mm(3) compared with 30% of CEA patients with a mean volume of 74.80 +/- 225.52 mm(3). In the CAS cohort, increasing age (adjusted coefficient +/- standard error, 0.06 +/- 0.02; P < .01) and obesity (1.14 +/- 0.35; P < .01) were positively correlated with infarct volume, whereas antiplatelet use (-1.11 +/- 0.33; P < .001) was negatively correlated with infarct volume. For the CEA group, diabetes (adjusted coefficient +/- standard error,1.69 +/- 0.65; P < .01) was identified as the only risk factor positively correlated with infarct volume, whereas increasing age (-0.10 +/- 0.05; P = .03) was negatively correlated with infarct volume. Conclusions: Risk factors for CAS- or CEA-related infarct volumes are identified in our study. Although the result warrants further validation, this study showed that advanced age, obesity, and diabetes independently predicted volume of microinfarcts related to CAS and CEA. These data provide valuable information for patient factor-based risk stratification and preoperative consultation for each procedure.