MicroRNAs in Cardiovascular Diseases and Forensic Applications: A Systematic Review of Diagnostic and Post-Mortem Implications

MicroRNAs (miRNAs) are small non-coding RNA molecules approximately 20–22 nucleotides in length that regulate gene expression at the post-transcriptional level. By binding to target messenger RNAs (mRNAs), miRNAs inhibit translation or induce degradation, thus influencing a wide array of biological processes including development, inflammation, apoptosis, and tissue remodeling. Owing to their remarkable stability and tissue specificity, miRNAs have emerged as promising biomarkers in both clinical and forensic settings. In recent years, increasing evidence has demonstrated their utility in cardiovascular diseases, where they may serve as diagnostic, prognostic, and therapeutic tools. This systematic review aims to comprehensively summarize the role of miRNAs in cardiovascular pathology, focusing on their diagnostic potential in myocardial infarction, sudden cardiac death (SCD), and cardiomyopathies, and their applicability in post-mortem investigations. Following PRISMA guidelines, we screened PubMed, Scopus, and Web of Science databases for studies up to December 2024. The results highlight several miRNAs—including miR-1, miR-133a, miR-208b, miR-499a, and miR-486-5p—as robust markers for ischemic injury and sudden death, even in degraded or formalin-fixed autopsy samples. The high stability of miRNAs under extreme post-mortem conditions reinforces their potential as molecular tools in forensic pathology. Nevertheless, methodological heterogeneity and limited standardization currently hinder their routine application. Future studies should aim to harmonize analytical protocols and validate diagnostic thresholds across larger, well-characterized cohorts to fully exploit miRNAs as reliable molecular biomarkers in both clinical cardiology and forensic medicine.