Extracellular vesicles from patients with coronary artery disease (CAD) demonstrate enhanced pro-coagulatory activity

Aims Extracellular vesicles (EVs) carry unique repertoires of biologically active cargo that hold promise as novel biomarkers and future interventional targets for cardiovascular diseases (CVDs). However, it is unclear as to how the number, location, cellular origin, and size of these EVs within the circulation relate to the development of CVDs such as coronary artery disease (CAD). The current study compared these novel markers in arterial and venous blood samples in individuals undergoing coronary assessment with angiography.. EVs were then characterized from those presenting with and without CAD. Methods and Results Arterial and venous blood samples were collected from individuals with confirmed CAD following coronary angiography and a matched cohort in whom there was no evidence of disease. EV fractions were isolated from 500µL of platelet free plasma (PFP) by size exclusion chromatography. EVs were analyzed by Nanoparticle Tracking Analysis and flow cytometry to characterize number, size and cellular origin. A thrombin generation assay was used to assess the pro-coagulatory activity of the isolated circulating EVs. Proteomics was used to determine the protein cargo carried within the EVs. Coagulatory activity of EVs isolated from CAD patients was significantly higher in when compared to controls, although the numbers of EVs did not differ. There were higher numbers of endothelial-derived EVs in arterial blood compared with venous blood. Linear regression models revealed that plasma triacylglycerol concentration and age independently predicted circulating EV numbers in CAD patients. Proteomics revealed several proteins associated with coagulation upregulated in patients with CAD. Conclusions Although the absolute numbers of EVs in CAD patients were not elevated, EVs in CAD patients had greater pro-coagulant activity, highlighting a potentially important role for EVs in the pathogenesis of CAD. Clinical Perspective What is new? CAD patients displayed a greater EV-induced thrombin generation capability when compated to those with no disease. The proteomic profile of arterial-derived EVs in patients with CAD demonstrated several proteins associated with coagulation that may be a risk factor for developing a future event. What are the clinical implications? The identification of EVs in patients with CAD with upregulated coagulation proteins may be a novel biomarker for the development of future events and may identify a high risk patient group that may benefit for more aggressive cardiovascular risk intervention.