Identification of a miRNA Based-Signature Associated with Acute Coronary Syndrome: Evidence from the FLORINF Study

Abstract

Background: The discovery of novel biomarkers that improve risk prediction models of acute coronary syndrome (ACS) is needed to better identify and stratify very high-risk patients. MicroRNAs (miRNAs) are essential non-coding modulators of gene expression. Circulating miRNAs recently emerged as important regulators and fine-tuners of physiological and pathological cardiovascular processes; therefore, specific miRNAs expression profiles may represent new risk biomarkers. The aims of the present study were: i) to assess the changes in circulating miRNAs levels associated with ACS and ii) to evaluate the incremental value of adding circulating miRNAs to a clinical predictive risk model.

Methods and results: The study population included ACS patients (n = 99) and control subjects (n = 103) at high to very high cardiovascular risk but without known coronary event. Based on a miRNA profiling in a matched derivation case (n = -6) control (n = 6) cohort, 21 miRNAs were selected for validation. Comparing ACS cases versus controls, seven miRNAs were significantly differentially expressed. Multivariate logistic regression analyses demonstrated that among the seven miRNAs tested, five were independently associated with the occurrence of ACS. A receiver operating characteristic curve analysis revealed that the addition of miR-122 + miR-150 + miR-195 + miR-16 to the clinical model provided the best performance with an increased area under the curve (AUC) from 0.882 to 0.924 (95% CI 0.885-0.933, p = 0.003).

Conclusions: Our study identified a powerful signature of circulating miRNAs providing additive value to traditional risk markers for ACS.

Keywords: acute coronary syndrome; biomarker; cardiovascular disease; microRNA.

Figure 1

Study design and workflow. Cases (men and women) were patients who experienced an acute coronary syndrome (ACS patients) and were included one week after the acute ischemic event; controls (men and women) were asymptomatic subjects at high to very high cardiovascular risk without any coronary disease. Twenty-one miRNA candidates identified in the miRNA-profiling from the derivation cohort were analyzed in the validation phase. Nineteen samples from the 99 ACS patient cohort and 23 samples from the 103 control subject cohort were excluded because of poor RNA quality. In the validation cohort (ACS, n = 80; controls, n = 80), seven miRNAs were significantly differentially expressed in cases and controls and tested for logistic regression and ROC analyses.

Figure 2

Plasma miRNA levels in the validation population. The box plots show the expression levels of miR-122-5p, miR-150, miR-16, miR-186, miR-195, miR-223-5p and miR-92a measured by RT-qPCR in ACS (n = 80) and control subjects (n = 80). The dots represent the outlier values plotted as individual points. The relative miRNA expression levels were normalized to cel-miR-39 and calculated by −ΔCt.