miRNA miRNA on the Wall, Who Is the Most Cardio-Specific of Them All? Circulating microRNAs as Potential Biomarkers in Acute Coronary Syndrome

The severe and acute manifestation of coronary artery disease (CAD) is acute coronary syndrome (ACS); therefore, prompt diagnosis can save lives. Cardiac biomarkers that are accepted to use in evaluating ACS are creatine kinase muscle/brain subtype (CK-MB), cardiac troponin I (CTnI), or cardiac troponin T (CTnT). However, these markers have several drawbacks, such as prolonged time to rise for prompt diagnosis and elevation in patients with chronic kidney diseases (CKD). Lately, potential, novel candidates for cardiac ischemia biomarkers have been developed, one of which is micro-ribonucleic acids (miRNAs). miRNAs are potential due to their remarkable reproducibility and stability. Several miRNAs, such as, miR-1, miR-133a, miR-133b, miR-208a, miR-208b, and miR-499a, greatly rise in concentration in the plasma or serum of patients with acute cardiac ischemia, signifying their cardiac specificity and promising biomarkers in patients with ACS. This systematic review aims to elucidate the role of cardio-specific miRNA in acute myocardial ischemia (AMI) and its relationship with other cardiac biomarkers.