Proteomic profiling identifies novel biomarkers and mechanistic pathways in mental stress-induced myocardial ischemia

Background Patients with angina and non-obstructive coronary artery disease (ANOCA) exhibit a high prevalence of mental stress-induced myocardial ischemia (MSIMI), a condition clinically associated with adverse cardiovascular outcomes. However, the pathophysiological mechanisms underlying this phenomenon remain poorly characterized, and the identification of specific biomarkers for early diagnosis represents an unmet clinical need. Method The study cohort comprised 56 ANOCA patients and 25 healthy controls. Participants underwent standardized mental stress testing with concurrent myocardial perfusion imaging under Positron Emission Tomography-Computed Tomography (PET-CT). Blood samples were obtained during resting phases before the mental stress test, for routine clinical testing and plasma proteomic preparation. Plasma specimens were subjected to data-independent acquisition (DIA) mass spectrometry-based quantitative proteomic profiling. Proteomic analysis was conducted to identify differentially expressed proteins (DEPs) between: ANOCA and healthy controls, and MSIMI+ versus MSIMI-. Functional enrichment analyses were performed to characterize the biological significance of identified DEPs. Candidate biomarkers underwent technical validation through enzyme-linked immunosorbent assay (ELISA), establishing a diagnostic model from discovery-phase proteomics to targeted validation. Results Quantitative proteomic profiling identified 175 DEPs in ANOCA patients relative to controls, comprising 156 upregulated and 19 downregulated proteins. Pathway enrichment analysis revealed significant associations with adrenergic signaling in cardiomyocytes, complement/coagulation cascades, and metabolic. Subsequent subgroup analysis demonstrated 95 DEPs distinguishing MSIMI+ from MSIMI- cases (47 upregulated; 48 downregulated). Those proteins are enriched in KEGG pathways related to cardiomyopathy pathways, PI3K-AKT signaling, HIF-1 signaling, and metabolism. ELISA validation confirmed dysregulation of four candidates: insulin-like growth factor-binding protein-5 (IGFBP-5), insulin-like growth factor-1 (IGF-1), leptin receptor (LEPR), and epidermal growth factor receptor (EGFR). Clinical test showed increased body mass index, free light chain ratio and decreased cortisol were significantly associated with MSIMI+. Integration of proteomic signatures with clinical parameters yielded a diagnostic model demonstrating robust predictive capacity in MSIMI+ (AUC = 0.939). Conclusion This study provides first evidence delineating the pathophysiological convergence of mental stress-induced myocardial ischemia (MSIMI) in ANOCA patients. It also validated specific plasma protein biomarkers and constructed diagnostic models in combination with clinical indicators. These findings establish a framework bridging molecular pathogenesis with clinical detection, proposing a non-invasive early diagnosis and a potential targeted intervention of MSIMI.