Diagnostic Value of Circulating MicroRNAs for Middle Aged Coronary Artery Disease Patients: A Case-control Study

Introduction: Coronary Artery Disease (CAD) remains a major problem worldwide. New and useful biomarkers for early diagnosis are necessary. MicroRNAs (miR) are short, non-coding RNAs that post transcriptionally regulate gene expression through degradation and translational repression of mRNAs. Aim: The current case-control study was designed to assess strength and relevance of diagnostic miR-126, 122 and Vascular Endothelial Growth Factor (VEGF) level in the diagnoses of angiographically proven CAD cases. Materials and Methods: Circulating levels of miR-126 and miR122 and VEGF levels were measured in serum from 100 middle aged 46-58 years patients with CAD and 100 patients without CAD through quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Results: Circulating miR-122 level was significantly higher in CAD cases compared to control (1.60 +/- 1.06 and 0.93 +/- 0.43, p=0.001), however miR-126 was significantly lowered in CAD cases compared to control (0.82 +/- 0.51 and 1.01 +/- 0.47, p=0.02). Circulating VEGF level was significantly higher in CAD cases compared to control (182.97 +/- 156.49 and 105.49 +/- 103.88, p=0.02). Circulating miR-122, 126 and VEGF level did not show any association with demographic and clinical parameters. Area Under the Curve (AUC) for circulating miR-122, 126 and VEGF were 0.700, 0.644 and 0.649 with sensitivity and specificity of 66.67%, 56.41%, 61.18% and 70%, 60% and 64%, respectively. The combined diagnostic efficacy of miR- 122 and 126 showed higher sensitivity and specificity. Conclusion: Circulating miR-122 and 126 might be novel, noninvasive biomarkers for early diagnosis of CAD. Further exposition of the role of miR-122, 126 and VEGF in the progression of CAD will add to the understanding of the disease process leading to a new diagnostic approach. However, further studies on larger patient cohorts are required to validate the findings.