Objective <p>This study aimed to identify biomarkers associated with MIRI and elucidate their potential mechanisms through integrated bioinformatics and experimental validation.</p> Methods <p>snRNA-seq data (GSE227088) from MIRI samples underwent batch effect removal and quality control to construct a nuclear landscape. Cell type-specific clusters (cardiomyocyte-enriched cluster) were identified by comparing cell proportions between Sham and MIRI groups. Differential expression analysis revealed the lncRNA Mhrt as significantly upregulated in cardiomyocyte cluster (avg_log2FC &gt; 2). Single-gene GSEA and pseudotime trajectory analyses were performed to explore lncRNA Mhrt’s role in MIRI progression. Subsequently, in the microarray dataset (GSE160516), genes associated with lncRNA Mhrt were identified using WGCNA, followed by enrichment analysis. The diagnostic efficacy of lncRNA Mhrt was evaluated based on the AUC of the ROC curve and its differential expression between the Sham and MIRI groups, and validated by qRT-PCR.</p> Results <p>In GSE227088, MIRI-related cardiomyocyte cluster and the significantly expressed lncRNA Mhrt (|avg_log2FC| &gt;2) were identified. Enrichment analysis suggested its potential role in regulating mitochondrial functions such as oxidative phosphorylation to influence MIRI pathogenesis. Pseudotime analysis indicated its possible involvement in cardiomyocyte redifferentiation. Validation in GSE160516 showed that lncRNA Mhrt had extremely high diagnostic efficacy in distinguishing between the Sham and MIRI groups (ROC curve AUC = 1) with significant intergroup expression differences, which was further validated by qRT-PCR.</p> Conclusion <p>This study highlights lncRNA Mhrt as a potential biomarker for MIRI, implicating its regulatory role in oxidative phosphorylation-mediated pathological processes. These findings advance understanding of MIRI mechanisms and provide a foundation for therapeutic development.</p>