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Incidence, risk factors and prognostic effect of imaging left ventricular diastolic dysfunction in patients with COVID-19: protocol for a systematic review

Introduction Recent reports linked acute COVID-19 infection in critical patients to cardiac structure and function abnormalities. The left ventricular (LV) diastolic dysfunction could result in obvious adverse prognostic impacts. The aim of this meta-analysis is to summarise the incidence, risk factors and the prognostic effect of imaging LV diastolic dysfunction in adult patients with COVID-19. Methods Databases to be used for the pertinent literature are PubMed, EMBase, ISI Knowledge via Web of Science, and preprint databases (MedRxiv and BioRxiv) (until May 2023) to identify all cohort studies in adult patients with COVID-19. The primary outcome will be the incidence of LV diastolic dysfunction assessed by echocardiography or cardiac MRI. Secondary outcomes will include the risk factors for LV diastolic dysfunction and the association with all-cause mortality during hospitalisation. Additional outcomes will be septal or lateral é, average E/é, E/A, peak tricuspid regurgitation velocity, left atrial volume index and LV wall thickness. Univariable or multivariable meta-regression and subgroup analyses will be conducted for related risk factors and the association of LV diastolic dysfunction with all-cause mortality. 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 LV diastolic dysfunction incidence and related risk factors, association with all-cause mortality and other LV diastolic dysfunction parameters. Ethics and dissemination There was no need for ethics approval for the systematic review protocol according to the Institutional Review Board/Independent Ethics Committee of Fuwai Hospital. This meta-analysis will be disseminated through a peer-reviewed journal for publication. PROSPERO registration number CRD42021256666; URL: https://www.crd.york.ac.uk/prospero/