Optimal cut-off value of elevated cardiac troponin concentrations for myocardial injury predicts clinical outcomes in adult patients with COVID-19: a dose–response analysis protocol for systematic review

INTRODUCTION: Acute myocardial injury in patients with COVID-19 infection has been recognised as one important complication associated with in-hospital mortality. The potential dose–response effect of cardiac troponin (cTn) concentrations on adverse clinical outcomes has not been systematically studied. Hence, we will conduct a comprehensive dose–response meta-analysis to quantitatively evaluate the relationship between elevated cTn concentrations and in-hospital adverse clinical outcomes in patients with COVID-19. METHODS: We will search PubMed, EMBASE, Cochrane Library and ISI Knowledge via Web of Science databases, as well as preprint databases (medRxiv and bioRxiv), from inception to October 2021, to identify all retrospective and prospective cohorts and randomised controlled studies using related keywords. The primary outcome will be all-cause mortality during hospitalisation. The secondary outcome will be major adverse event (MAE). To conduct a dose–response meta-analysis of the potential linear or restricted cubic spline regression relationship between elevated cTn concentrations and all-cause mortality or MAE, studies with three or more categories of cTn concentrations will be included. Univariable or multivariable meta-regression and subgroup analyses will be conducted to compare elevated and non-elevated categories of cTn concentration. Sensitivity analyses will be used to assess the robustness of our results by removing each included study at one time to obtain and evaluate the remaining overall estimates of all-cause mortality or MAE. ETHICS AND DISSEMINATION: In accordance with the Institutional Review Board/Independent Ethics Committee of Fuwai Hospital, ethical approval was waived for this systematic review protocol. This meta-analysis will be disseminated through a peer-reviewing process for journal publication and conference communication. PROSPERO REGISTRATION NUMBER: CRD42020216059.