Background: Coronary artery occlusion does not always manifest with ST-elevation, and some patients can have patent coronary vessel. Aim: We evaluated circulating microRNA (miRNA) profiles to discriminate subjects with infarct-related artery (IRA) occlusion. Methods and results: Patients (n = 43) with uncomplicated acute coronary syndrome and positive troponins were classified with respect to patent vs. occluded IRA or ST-elevation vs. non-ST elevation MI (STEMI vs. NSTEMI). Expression levels of serum miRNAs (miR-1, -16, -34a, -122, -124, -208b, -133a/b, -375, and -499) were analysed. Out of 16 STEMI and 27 NSTEMI patients, IRA occlusion was noted in 12 and 15 patients, respectively. The remaining four STEMI and 12 NSTEMI patients had patent IRA. STEMI patients had higher troponin T levels and a 3.83-fold higher miR-134 expression (p < 0.025). Patients with the occluded vs. patent IRA had higher levels of miR-133a (fold change: 7.00), miR-133b (4.57), miR-34a (5.50), miR-124 (2.55), and miR-134 (3.45) but no difference in troponin T levels. Receiver operator characteristic analysis identified decision-making miRNAs in occluded vessels: miR-124 (AUC: 0.787, p < 0.001), miR-133b (AUC: 0.704, p = 0.006), and miR-134 (AUC: 0.686, p = 0.016). With respect to STEMI, only miR-134 showed a discriminating value (AUC: 0.725, p = 0.002). Conclusions: The degree of IRA occlusion determines circulating miRNA expression, and specific miRNAs may be useful in indicating patients requiring urgent coronary revascularisation. Background: Coronary artery occlusion does not always manifest with ST-elevation, and some patients can have patent coronary vessel. Aim: We evaluated circulating microRNA (miRNA) profiles to discriminate subjects with infarct-related artery (IRA) occlusion. Methods and results: Patients (n = 43) with uncomplicated acute coronary syndrome and positive troponins were classified with respect to patent vs. occluded IRA or ST-elevation vs. non-ST elevation MI (STEMI vs. NSTEMI). Expression levels of serum miRNAs (miR-1, -16, -34a, -122, -124, -208b, -133a/b, -375, and -499) were analysed. Out of 16 STEMI and 27 NSTEMI patients, IRA occlusion was noted in 12 and 15 patients, respectively. The remaining four STEMI and 12 NSTEMI patients had patent IRA. STEMI patients had higher troponin T levels and a 3.83-fold higher miR-134 expression (p < 0.025). Patients with the occluded vs. patent IRA had higher levels of miR-133a (fold change: 7.00), miR-133b (4.57), miR-34a (5.50), miR-124 (2.55), and miR-134 (3.45) but no difference in troponin T levels. Receiver operator characteristic analysis identified decision-making miRNAs in occluded vessels: miR-124 (AUC: 0.787, p < 0.001), miR-133b (AUC: 0.704, p = 0.006), and miR-134 (AUC: 0.686, p = 0.016). With respect to STEMI, only miR-134 showed a discriminating value (AUC: 0.725, p = 0.002). Conclusions: The degree of IRA occlusion determines circulating miRNA expression, and specific miRNAs may be useful in indicating patients requiring urgent coronary revascularisation.

Ischemic event in one arterial territory increases the risk of a subsequent ischemic event. Circulating microRNAs (miRs) emerge as a potential clinical tool to assess risk of subsequent atherothrombotic events such as cardiovascular death (CVD), myocardial infarction (MI) and ischemic stroke (IS). In this prospective study, we searched for athero-specific miRs related to cardiovascular event risk in patients with symptomatic coronary, carotid lesion, or both territories involvements. The choice of particular miRs was based on database research (Pub-Med, Bethesda, MD, USA) taking into consideration the relationship with development of atherosclerosis and potential prognostic value. Levels of circulating miRs (miR-1-3p, miR-16-5p, miR-34a-5p, mir-122-5p, miR-124-3p, miR-133a-3p, miR-133b, miR-134-5p, miR-208b-3p, miR-375 and miR-499-5p) were compared in 142 patients with an acute ischemic event resulting from carotid and/or coronary artery stenosis, who underwent revascularization for symptomatic lesion. A 6-year prospective evaluation of CVD/MI/IS risk was performed. Patients with two-territory as compared to single-territory involvement differed in levels of miR-1-3p (p = 0.016), miR-16-5p (p < 0.001), miR-34a-5p (p = 0.018), miR-122-5p (p = 0.007), miR-124-3p (p < 0.001) and miR-499-5p (p < 0.001). During follow-up, 62 (43.7%) episodes of CVD/MI/IS occurred. In multivariate Cox analysis, miR-122-5p (HR = 1.0006, 95%CI = 1.0001–1.0011) and peripheral artery disease (PAD) (HR = 2.16, 95%CI = 1.26–3.70) were associated with CVD/MI/IS risk; miR-1-3p (HR = 2.73, 95%CI = 1.22–6.12) and PAD (HR = 3.47, 95%CI = 1.88–6.41) with CVD; miR-122-5p (HR = 1.0001, 95%CI = 1.000–1.0002) and creatinine level (HR = 1.02, 95%CI = 1.01–1.04) with IS, and miR-16-5p (HR = 1.0004, 95%CI = 1.0001–1.0008) with MI. Expression of miR-1-3p, miR-16-5p and miR-122-5p during incident ischemia may be possible risk factors of secondary cardiovascular event(s).