Abstract Background Patients with carotid artery disease undergoing carotid endarterectomy (CEA) have a high risk of experiencing Major Adverse Cardiovascular Events (MACE) after surgery. The occurrence of MACE in CEA-treated patients is not predicted by common cardiovascular (CV) risk factors. Purpose We aimed to identify the association between plasma and plaque inflammatory cytokines and the incidence of MACE in the follow-up after CEA. We hypothesized that MACE is related to a higher level of circulating inflammatory cytokines at the time of surgery. Methods We prospectively enrolled patients with carotid artery disease undergoing CEA. Plasma and carotid plaques were collected during the surgery. Inflammatory cytokines (MCP-1/CCL2, IL-8/CXCL8, IFN-gamma, IL-10, IL-1beta/IL-1F2, IL-6, PDGF-AA, PDGF-AB/BB, TNF-alpha, VEGF) were measured in plasma and tissue homogenates using a customized 10-plex Luminex assay. Baseline demographics and clinical data for all the patients were extracted from electronic health records. MACE after CEA was defined as a composite measure of nonfatal cardiac events such as myocardial infarction with or without revascularization, cerebrovascular events (ischemic stroke, TIA, and amaurosis fugax), and all-cause mortality. Results Of 107 patients who underwent CEA with a median age of 73 (67-78) years, 57 (53.2%) experienced MACE during a median follow-up of 5.2 [2.2-9.3] years: 23 (40.3%) cardiac events, 9 (15.7%) CVA, and 25 (43.8%) all-cause mortality. Plaque cytokines levels did not differ between the groups with and without MACE in the follow-up after CEA. Instead, plasma cytokines were associated with MACE in the follow-up after CEA, as summarized in Figure 1. In the logistic regression analysis, plasma levels of MCP-1/CCL2, IFN-gamma, and TNF-alpha were independent predictors of MACE in follow-up post-CEA in univariate and multivariable models adjusted for CV risk factors such as age, BMI, systolic and diastolic blood pressure, low-density lipoprotein, high-density lipoprotein, and glucose level: MCP1/CCL2 (HR 1.009 [1.002-1.015]; p=0.007), IFN-gamma (HR 1.368 [1.014-1.845]; p=0.040), and TNF-alpha (HR 1.121 [1.022-1.228]; p=0.015) (Table 1). Conclusions Plasma levels of CCL2, IFN-gamma, and TNF-alpha are associated with the high incidence of MACE in the follow-up after CEA, indicating that these are potential biomarkers of MACE in this patient population and potential therapeutic targets in patients' progression of systemic atherosclerosis.Plasma cytokines and MACE after CEACytokines logistic regression analysis