Carotid plaque magnetic resonance imaging and recurrent stroke risk A protocol for systematic review and meta-analysis

Background & Aims: Carotid atherosclerotic plaque is an important cause of carotid artery stenosis. The features of carotid atherosclerotic plaque detected by relevant magnetic resonance imaging (MRI), such as lipid core, plaque hemorrhage, and fibrous cap rupture, have been confirmed to be associated with the occurrence of the first cerebral ischemic event. Meanwhile, the features of carotid atherosclerotic plaque can be used as biomarkers to predict the occurrence of cerebral ischemic event. However, the mechanism of recurrent stroke is still unclear. A systematic review and meta-analysis will be performed to summarize the association between features of carotid artery plaque detected by MRI and recurrent stroke, so as to find biomarkers that can predict recurrent stroke. Methods: Electronic search will be performed in PUBMED, EMBASE, Cochrane Controlled Register of Trials (CENTRAL) from inception to October 30, 2018. We will include cohort studies with an average follow-up time of > 1 month in which lipid-rich/necrotic cores (LRNC), intraplaque hemorrhage (IPH), and thinned or ruptured fibrous caps (TRFC) are associated with recurrent ipsilateral stroke or ischemic events. We will perform heterogeneity assessment before carrying out meta-analysis. According to the heterogeneity, we select random effect model or fixed effect model for meta-analysis of the included cohort studies. Results: Review Manager 5.3 software will be used to calculate the combined hazard ratio value and 95% confidence interval (CI). This meta-analysis will provide high-quality data analysis of LRNC, IPH, and TRFC and ipsilateral recurrent stroke or ischemic events, including biomarkers as major predictors. Conclusion: The systematic review will provide evidence to assess the association between features of carotid plaque and ipsilateral recurrent stroke or ischemic events.