Abstract Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): This work was supported by a Leiden University Medical Center MD/PhD research grant to V.Q. Sier and Dr. R. Noordam is supported by an innovation grant from the Dutch Heart Foundation. Purpose The onset and symptomatology of coronary artery disease (CAD) are different for men and women, yet insights into sex-specific biological mechanisms causing CAD are limited. To increase insight in the onset of CAD in men and women, we performed a sex-specific proteome-wide association analysis using data from a large cohort of middle-aged participants from the UK Biobank. Methods Associations between 2,923 plasma proteins and CAD incidence (angina pectoris, acute myocardial ischemia, chronic myocardial ischemia) were examined in European-ancestry participants from the UK Biobank who were free of CAD at baseline. Plasma samples were collected at baseline (2006-2010), and CAD incidence was monitored continuously for a median (interquartile range) follow-up of 5,013 (4775-5251) days. Using Cox proportional hazard modelling, the associations between CAD incidence and plasma protein levels were examined, adjusted for age, sex, body mass index, socioeconomic status, type 2 diabetes mellitus, and cholesterol-lowering and insulin drug use at baseline. The Metascape portal was employed for pathway analyses to identify (sex-specific) biological pathways. Results In a total sample comprising 40,829 individuals (55% women, mean age (sd) 56.9 (8.10)), featuring 3,155 incident CAD cases, our sex-combined model demonstrated significant associations between 93 proteins and hazard for CAD. Pathway analyses identified early plasma proteomic changes related to cytokine-cytokine receptor interactions (p=3.42e-17), matrix remodelling (p=9.24e-14, p=1.08 e-9), regulation of innate and adaptive immune cells (p=1.92e-12, p=3.88e-9), and angiogenesis (p=5.34e-9). Stratification by sex revealed distinct sex-specific proteomic patterns linked to CAD incidence, with 10 female-specific and 49 male-specific significant proteins. Through interaction analyses, we demonstrated that 8 proteins were distinctly associated with a significant increased hazard in women, while 20 proteins were significantly associated with increased hazard for CAD in men. Pathway analyses identified a significant female-specific relation between CAD incidence and matrix remodelling (p=9.72e-15, p=3.19e-13), angiogenesis/hypoxia (p=1.41e-12), and inflammatory signalling (p=7.18e-10, p=8.01e-10) pathways, whereas male-specific top pathways related to inflammatory signalling (p=9.58e-25), matrix remodelling (p=1.22e-17), and immune cell response/recruitment (p=3.08e-16, p=8.34e-12). Conclusion Using large-scale association analyses of proteomics data with CAD, we identified sex-specific proteomic profiles. Distinct patterns in more angiogenic (women) and more immune cell response (men) profiles were found. These findings contribute novel insights to the development of CAD, potentially guiding future sex-specific research and clinical strategies for disease prevention.Proteome-wide analysis for CAD incidence