Serum miRNA-499 and miRNA-210: A potential role in early diagnosis of acute coronary syndrome.

In clinical practice, there is still a need for novel biomarkers, which can reliably rule in or rule out acute coronary syndrome (ACS) immediately on admission. This is of particular interest in patients with unstable angina (UA) and non-ST-segment elevation myocardial infarction (NSTEMI) in whom diagnostic uncertainty is high. The aim of the present study is to evaluate the potential role of miRNA-499 and miRNA-210 as novel molecular biomarkers for early diagnosis of UA and NSTEMI suspected patients presented at the emergency unit. A total of 110 patients presenting to the intensive care unit (ICU) within 24 h of onset of chest pain suggestive of ACS were enrolled in the study. They included 37 UA, 48 NSTEMI and 25 noncardiac chest pain (NCCP) patients. Immediately at enrollment, blood samples were taken for estimation of serum miRNA-499 and miRNA-210 expression levels by real time PCR. miRNA-499 and miRNA-210 expression levels were significantly increased in UA and NSTEMI patients compared with NCCP patients (P < 0.001). Receiver operating characteristic (ROC) curve analysis revealed that the area under curve (AUC) of miR-499 for the diagnosis of UA and NSTEMI was 0.98 and 0.97, respectively; while the AUC of miRNA-210 was 0.84 and 0.90, respectively. The important finding of our study was that the AUC of miRNA-499 for the diagnosis of ACS patients with symptoms onset <3 h was 0.89, while the AUC of miRNA-210 was 0.86. Interestingly, combining miRNA-499 and miRNA-210 significantly improved the diagnostic value by increasing the AUC to 0.96, P < 0.001. In conclusion, serum miRNA-499 and miRNA-210 are associated with UA and NSTEMI and with those presenting within 3 h of symptom onset. Both miRNAs might be potentially novel biomarkers for accelerating the diagnosis of ACS patients in emergency unit.