Background: Recent studies have demonstrated that acute myocardial infarction induces a distinctive miRNA signature, suggesting that miRNAs may serve as diagnostic markers. Although many studies have investigated the use of miRNAs in the detection of cardiac injury, some had small sample sizes (<100 patients) or reported different results for the same miRNA. Here, the role of circulating miRNAs for use as biomarkers of myocardial infarction is summarized and analyzed.
Methods and results: Medline, SCI, Embase, and Cochrane databases were searched up to January 2013 for studies that evaluated associations between miRNAs and myocardial infarction. Relevant publications were identified by searching for combinations of "myocardial infarction," "miRNAs," and their synonyms. Methodological quality was scored using a standardized list of criteria, and diagnostic performance was assessed using estimates of test sensitivity and specificity. These values were summarized using summary receiver-operating characteristic curves. Nineteen studies met the inclusion criteria: 15 studies reported sensitivity, specificity, and AUC, but 4 studies did not. Total miRNAs: sensitivity: 0.78 (95%CI: 0.77-0.80; P = 0.0000); specificity: 0.82 (95%CI: 0.80-0.83; P = 0.0000). miR-499: sensitivity: 0.88 (95%CI:0.86-0.90; P = 0.0000); specificity: 0.87 (95%CI:0.84-0.90; P = 0.0000). miR-1: sensitivity: 0.63 (95%CI:0.59-0.66; P = 0.0000); specificity: 0.76 (95%CI:0.71-0.80; P = 0.0000). miR-133a: sensitivity: 0.89 (95%CI:0.83-0.94; P = 0.0047); specificity: 0.87 (95%CI:0.79-0.92; P = 0.0262). miR-208b: sensitivity: 0.78 (95%CI:0.76-0.81; P = 0.0581); specificity: 0.88 (95%CI:0.84-0.91; P = 0.0000). The correlation between miRNAs and other diagnostic biomarkers of myocardial infarction was obvious.
Conclusion: MiRNAs, especially miR-499 and miR-133a, may be suitable for use as diagnostic biomarkers of myocardial infarction.