The role of non-coding RNAs in the coronary no-reflow phenomenon: a systematic review

Coronary no-reflow poses a challenge in interventional cardiology. Increasing attention has been directed toward the potential role of non-coding RNAs (ncRNAs) in predicting coronary no-reflow (CNR), with no prior systematic review available to date. We aimed to systematically review the available evidence on the potential clinical utility of ncRNAs in CNR and/or microvascular obstruction (MVO). Embase, MEDLINE Ultimate, PubMed, Scopus, and Web of Science were searched, last on February 9, 2026. Studies enrolling adult patients with CNR and/or MVO that evaluated the expression of ncRNAs or investigated genetic variants within ncRNA-related pathways were included. Risk of bias was not assessed. Upregulation of miR-1, miR-7a/b, miR-98-5p, miR-133a, miR-133b, miR-208a, miR-224-3p, miR-660-5p, long non-coding RNA (lncRNA) TUG1, lncRNA MALAT1, and downregulation of miR-30e, miR-126, miR-155, and miR-542-3p were reported in patients with STEMI with CNR and/or MVO compared with those without CNR/MVO. Almost all ncRNAs were reported by a single study, with the exception of miR-30e, which was consistently reported in three independent studies. Several ncRNAs may demonstrate good performance in identifying patients at risk of CNR and/or MVO occurrence. Nevertheless, the available evidence is scarce and limited by the low robustness of the reported findings. Circulating ncRNAs are promising biomarkers for CNR. Nevertheless, several limitations persist, highlighting the need for further studies with standardized methodology to validate the clinical utility of ncRNAs.