Incidence and associated in-hospital mortality of myocardial injury characterised by elevated cardiac troponin in adult patients with traumatic brain injury: protocol for a systematic review and meta-analysis

Introduction Myocardial injury is a relatively common complication of traumatic brain injury (TBI). However, the incidence and clinical impact of myocardial injury characterised by elevated cardiac troponin (cTn) levels after TBI are still poorly known. The objective of our study is to assess the global incidence of myocardial injury characterised by elevated cTn in adult patients with TBI and its association with in-hospital mortality.Methods and analysis The protocol of our systematic review and meta-analysis is performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Protocols guidelines. We will search the Medline, Embase, Cochrane Library, Scopus and Web of Science databases from inception to 1 January 2024, for observational studies in any language that reported the incidence of elevated cTn and/or in-hospital mortality associated with elevated cTn among adult patients with TBI. Two reviewers will independently assess study eligibility, extract the data and assess the risk of bias. ORs and 95% CIs will be used with a random-effects or fixed-effects model according to the estimated heterogeneity among studies assessed by the I2 index. We will perform a quantitative synthesis for the incidence of elevated cTn and in-hospital mortality data. If sufficient data are available, we will perform subgroup analysis and meta-regression to address the heterogeneity. In addition, we will perform a narrative analysis if quantitative synthesis is not appropriate.Ethics and dissemination Ethics approval was not required for this study. We intend to publish our findings in a high-quality, peer-reviewed journal.PROSPERO registration number CRD42023454686.