Noncoding RNAs as Prognostic Biomarkers After Myocardial Infarction: A Scoping Review

Background Prognosis after myocardial infarction (MI) remains heterogeneous despite contemporary reperfusion and secondary prevention, and biomarkers that capture post‐MI recovery, treatment response, and long‐term risk are still limited. Noncoding RNAs have therefore attracted interest as biomarkers of post‐MI risk and recovery. Methods We conducted a scoping review of human studies evaluating circulating or blood‐derived noncoding RNAs, including microRNAs, long noncoding RNAs, circular RNAs, and tRNA‐derived small RNAs/tRNA‐derived fragments, measured after MI in relation to prognostic phenotypes, clinical outcomes, or treatment‐response end points. Results Forty‐six studies were included. Most were observational, focused on plasma or serum microRNAs, and used quantitative reverse transcription–polymerase chain reaction, but sample size, sampling phase, normalization strategy, end point definition, follow‐up duration, and validation approaches varied substantially. Reported associations clustered around reperfusion‐related injury/no reflow or microvascular obstruction, left ventricular remodeling or dysfunction, clinical events, including major adverse cardiovascular events and mortality, and a smaller group of treatment‐response phenotypes. Directional signals included miR‐30e, miR‐660‐5p, TUG1 , and MALAT1 for no reflow; LIPCAR , MICRA , miR‐320a, miR‐1254, and miR‐22‐3p for remodeling or ventricular recovery; miR‐145, miR‐223‐3p, miR‐126‐3p/miR‐223‐3p, HCG11 /miR‐532‐3p, and exosomal miR‐186‐5p dynamics for clinical events; and BANCR or selected tRNA‐derived small RNAs/tRNA‐derived fragments for treatment‐response heterogeneity. The most plausible candidates were phenotype specific rather than universal, with event‐related microRNA models, imaging‐linked remodeling markers, and no‐reflow/microvascular obstruction–associated candidates appearing more mature than isolated injury‐linked diagnostic microRNAs or single‐study treatment‐response signals. Conclusions Overall, noncoding RNAs show promise as adjunctive post‐MI biomarkers, but clinical translation requires phase‐aligned sampling, assay standardization, external validation, and direct testing of incremental value beyond established clinical, imaging, and protein‐biomarker models.