Usefullness of MicroRNAs in Predicting the Clinical Outcome of Patients with Acute Myocardial Infarction During Follow-Up: A Systematic Review.

Background: Myocardial infarction (MI) is reported as the leading cause of mortality and morbidity worldwide. It is associated with a 30% mortality rate. Echocardiography, coronary angiography, and biomarkers like cardiac troponins are employed as prognostic tests. Although these biomarkers are the gold standard for the diagnosis of MI, they are not accurate as prognostic markers due to their lack of specificity. Studies have suggested that dysregulation of specific microRNAs (miRNAs) influences post-MI complications during follow-up. However, the findings of these studies have several inconsistencies. This systematic review was performed to investigate the potential of miRNAs to predict clinical outcomes post-MI. Methodology: Pubmed and Google Scholar databases were used for identifying research articles published from inception till August 2021; the search terms included "microRNAs" AND "prognosis" AND "myocardial infarction" or "acute coronary syndrome." All the articles included were critically analyzed using STROBE guidelines. Results and Conclusion: Several miRNAs were elevated in MI patients, including miR-208b, miR-499, and miR-375 . Association of these miRNA levels with the outcome of MI, such as all-cause mortality and major adverse cardiovascular events during follow-up, were also reported. However, none of the studies included in this systematic review exhibited promising evidence that these miRNAs can be utilized as ideal biomarkers for prognosis post-MI. Understanding the molecular mechanisms involved in the pathogenesis and progression of MI is crucial. Hence, these findings can be used as a guide when performing further experimental studies to identify useful post-MI prognostic markers.