Decreased circulating microRNA-22 expression as a potential biomarker for predicting a higher risk of recurrent ischemic stroke related to inner carotid artery stenosis: a multicenter study.

Carotid endarterectomy has proved to be beneficial in the prevention of stroke in patients with carotid artery stenosis ≥ 70%, while the benefit in symptomatic patients with moderate stenosis (50-69%) was undetermined, and some of them may be at higher risk of recurrent ipsilateral stroke (RIS). To date, it's hard to define vulnerable populations and novel biomarkers should be exploited. Thus, we aim to explore the predictive role of miR-22 in the presence of RIS and the prognosis of symptomatic patients with moderate stenosis. 400 patients were prospectively recruited, and miR-22 levels were assessed. The incidence of RIS and major adverse cardiovascular and cerebrovascular events (MACCE)-free survival were presented and the risk factors for RIS and MACCE-free survival were investigated. The area under the curve (AUC) was also investigated for RIS. The degree of carotid artery stenosis was negatively associated with miR-22 level (P < 0.001). The median value of miR-22 was 4.16 in the overall distribution, patients with miR-22 levels ≥ 4.16 had a significantly improved MACCE-free survival (P = 0.012) and lower incidence of RIS (P = 0.020) compared with miR-22 levels < 4.16. The multivariable cox regression analysis demonstrated that patients with lower miR-22 levels were prone to the presence of RIS (P < 0.001). The AUC of miR-22 in predicting RIS was 0.662 (95% CI, 0.550-0.774). This study implies that lower miR-22 levels may play a predictive role in the higher incidence of RIS in patients with moderate stenosis. Moreover, lower miR-22 levels can also prognosticate a higher risk for MACCE in these patients.