MicroRNAs and their role in heart transplantation insights into rejection mechanisms: A narrative review

Heart transplantation is the definitive treatment for patients with advanced heart failure and refractory symptoms. However, allograft rejection-both acute and chronic-remains a major cause of morbidity, leading to graft dysfunction and failure. Traditionally, endomyocardial biopsy (EMB) has been the standard method for screening allograft rejection. MicroRNAs (miRNAs) are small, non-coding RNA sequences that regulate gene expression by binding to the 3' untranslated regions of complementary mRNA transcripts. This review explores the potential of miRNAs as biomarkers for detecting allograft rejection in heart transplant recipients. MiRNAs may serve as non-invasive "liquid biopsies," providing a novel approach to monitor and manage post-transplant patients.