BACKGROUND: Cardiovascular magnetic resonance T1 mapping is a non-invasive tool for quantifying tissue alterations in the myocardium. Its prognostic value in non-ischemic dilated cardiomyopathy (DCM) remains unclear. The purpose of this study was to synthetize available data and explore the prognostic value of T1 mapping in DCM.METHODS: We searched Pubmed, Embase, Cochrane Library and Scopus for cohort studies up to 28 March 2020 that reported prognostic data for cardiovascular magnetic resonance T1 mapping in patients with DCM. Hazard ratios (HRs) were pooled using random-effects meta-analysis. Values were expressed as standard deviation (SD) of normal controls. Heterogeneity was assessed with the I statistic.RESULTS: Eight studies were included in the meta-analysis, with a total of 1242 patients. Extracellular volume fraction (ECV) had high prognostic value for a composite outcome of mortality and morbidity with HR 1.38 (95% confidence interval, 1.18-1.61). Native T1 was also shown to have high prognostic value for a composite outcome of mortality and morbidity with HR 1.20 (95% confidence interval, 1.14-1.27). Heterogeneity was moderate for the ECV analysis (I = 64%).CONCLUSIONS: ECV and native T1 could potentially be used to improve risk stratification in DCM. Future studies should investigate the prognostic value of T1 mapping by separating mortality and morbidity as primary outcomes and evaluate its incremental value in addition to standard risk stratification criteria.