Abstract 125: Inflammatory Markers Influence Microembolization in Patients Undergoing Carotid Interventions

Abstract

INTRODUCTION: Despite the use of embolic protection and improvement in surgical technique for carotid interventions, perioperative cerebral microembolization is still relatively common. Susceptibility to microembolization is largely uncontrolled and the effects remain poorly understood. We hypothesized that inflammation may play a role in this process and sought to identify plasma markers predicting embolization in patients undergoing carotid interventions.

METHODS: Patients scheduled for carotid interventions at an academic center were prospectively recruited to the study. MRI with diffusion-weighted imaging (DWI) was performed prior to and within 48 hours following the procedure and used to identify new cerebral microemboli. Blood samples were collected at the time of intervention prior to carotid interrogation (Pre) and at 24 hours following intervention (Post). Plasma was isolated and analyzed by a 27-plex Luminex assay. The assay was performed in triplicate and Significance Analysis of Microarrays (SAM) identified significant inflammatory markers. Mann-Whitney U tests were performed to further evaluate these findings.

RESULTS: 71 male patients were included with an average age of 70 years; 38 underwent CAS and 33 underwent CEA. 59% of the cohort exhibited postoperative DWI lesions. Post plasma samples were collected for all patients, and Pre samples were collected for a cohort of 19 patients. We observed significantly lower levels of several cytokines in patients with procedure-related DWI lesions, particularly platelet-derived growth factor (PDGF) (150.8 vs 389.6pg/ml, p<.001). Patients with more complex plaques were also observed to have lower levels of PDGF. For the cohort with both Pre and Post samples, there was a significantly greater decrease in PDGF for patients with DWI lesions compared to those who did not. (U=382, Z=-2.6, p=.008).

CONCLUSIONS: Lower plasma levels of cytokines were observed in patients with procedure-related DWI lesions, suggesting that patients who illicit an inappropriate immune response may be more susceptible to procedure-related microembolization. Impaired PDGF response may indicate poor repair mechanism to injury. Further investigation is warranted.