Study protocol for a systematic review and meta-analysis of comorbidities and stroke characteristics associated with troponin elevation after acute stroke

INTRODUCTION: It is unknown which comorbidities and stroke characteristics are associated with elevated cardiac troponin (cTn) levels after stroke. The main objective of this systematic review and meta-analysis is to assess the association of elevated cTn with preexisting cardiovascular comorbidities (eg, coronary artery disease, heart failure and structural heart disease), specific stroke characteristics (eg, infarct/haemorrhage size, stroke severity, insular cortex involvement) and renal failure after ischaemic stroke (IS) or intracranial haemorrhage (ICH). The secondary objective is to evaluate the association of elevated cTn with stroke recurrence and death. METHODS AND ANALYSIS: We will include all cross-sectional, case–control, cohort studies and clinical trials involving IS and ICH adult patients (≥18 years), published between 1 January 1990 and 31 December 2020 in English or Spanish, reporting the proportion with elevated cTn. We will search PubMed, EMBASE and Web of Science by applying predefined search terms. Two reviewers will independently screen titles and abstracts, retrieve full texts, extract the data in a predesigned form, and assess the risk of bias. We will apply random-effects or fixed-effects meta-analyses to estimate the association between cardiovascular comorbidities, stroke characteristics and renal failure with cTn elevation. We will report results as risk ratios or ORs. We will perform sensitivity analyses for subtypes of cTn (cTn-I and cTn-T), regular versus high-sensitivity assays, and type of stroke (IS vs ICH). We will estimate heterogeneity by using t(2) Q and I(2) measures. We will use funnel plots, Rosenthal’s Fail-Safe N, Duval and Tweedie’s trim and fill procedure, and Egger’s regression intercept to assess publication bias. ETHICS AND DISSEMINATION: This review will be based on published data and does therefore not require ethical clearance. The results will be published in peer-reviewed journals. PROSPERO REGISTRATION NUMBER: CRD42020203126.