Dynamic Plasma Exosomal miRNA Profiling Uncovers Molecular Trajectories of Cardiac Repair following Cone Reconstruction for Ebstein’s Anomaly

Objective: Cone reconstruction (CR) is the preferred surgical treatment for Ebstein’s anomaly (EA). However, the molecular mechanisms underlying postoperative cardiac repair remain unclear. This study investigated the dynamic changes of plasma exosomal microRNAs (miRNAs) in EA patients before and after CR, exploring their association with postoperative cardiac function recovery and potential molecular mechanisms. Methods: Plasma samples were collected from 10 EA patients undergoing CR preoperatively, 1 day postoperatively, and 7 days postoperatively, along with samples from 10 healthy controls. Plasma exosomes were isolated using size-exclusion chromatography. Exosomal miRNAs were extracted and sequenced, followed by differential expression, functional enrichment, time-series clustering, and correlation analyses with clinical parameters. Results: Typical exosomes and miRNA profiles were identified. Preoperatively, EA patients exhibited distinct exosomal miRNA signatures enriched in pathways related to cardiac development, extracellular matrix (ECM) remodeling, and apoptosis regulation. On postoperative day 1, miRNAs associated with inflammation and myocardial stress (miR-208a-3p, miR-208b-3p, and miR-499a-5p) were upregulated. By postoperative day 7, molecular pathways shifted toward structural remodeling and functional recovery, involving ECM organization and heart contraction regulation. Time-series clustering delineated an ordered molecular cascade associated with acute stress responses and structural remodeling. Five miRNAs persistently downregulated in the EA group were identified, potentially involved in key pathological processes including epigenetic regulation, metabolic processes, and muscle development. Notably, miR-224-5p, miR-548as-5p, and miR-30c-5p were significantly associated with right ventricular fractional area change, while miR-338-3p correlated with N-terminal pro-B-type natriuretic peptide dynamics. Conclusion: This study provides the first comprehensive dynamic landscape of plasma exosomal miRNAs in EA patients undergoing CR, with temporally coordinated molecular characteristics related to acute stress protection, structural remodeling, and functional recovery. Key miRNAs (miR-224-5p, miR-30c-5p, and miR-338-3p) may serve as potential molecular biomarkers and therapeutic targets for postoperative cardiac recovery, offering new insights into the molecular basis of CR-mediated cardiac repair in EA.