Prognostic Value of Myocardial T1 Mapping and Extracellular Volume Fraction in Heart Failure: A Meta-Analysis.

BACKGROUND

Heart failure (HF) is a global health burden. Myocardial fibrosis is a crucial promotor in HF progression which can be characterized noninvasively by cardiac magnetic resonance T1 mapping.

OBJECTIVES

This study aims to systemically evaluate the prognostic value of myocardial T1 mapping and extracellular volume fraction (ECV) covering the entire spectrum of HF through a meta-analysis.

METHODS

We searched PubMed, Web of Science, and SCOPUS for studies examining the prognostic value of T1 mapping in HF with reduced and preserved ejection fraction. Baseline level, mean difference, and HRs were pooled for meta-analysis. Subgroup analyses were conducted according to HF subtypes and clinical characteristics.

RESULTS

Nineteen studies with 5,384 patients (56.2% male) were included in the analysis. Patients with adverse outcomes (mortality, HF-related event, or composite outcome) had higher native T1 and ECV values than those without (weighted mean difference: 41.17 ms and 4.73%, respectively). Both native T1 and ECV were positively associated with endpoints for the entire HF group (HR of 1% increase in ECV: 1.20 [95% CI: 1.13-1.28]; HR of >1% increase: 1.56 [95% CI: 1.40-1.75]; HR binary: 2.62 [95% CI: 2.07-3.32]; HR of 1-ms increase in native T1: 1.02 [95% CI: 1.01-1.03]; HR of ≥10-ms increase: 1.08 [95% CI: 1.05-1.11]; HR binary: 2.93 [95% CI: 2.03-4.23], all P < 0.05). For subgroup cohorts, native T1 had no significant prognostic value in HF with preserved ejection fraction (P > 0.05). Younger patients with HF with severe cardiac insufficiency (NYHA functional class III-IV), persistently increasing ECV, or negative late enhancement who exhibited abnormal T1 mapping were at higher risk of adverse outcomes.

CONCLUSIONS

ECV has consistent prognostic implications across HF spectrum, regardless of HF types, clinical characteristics, and various etiology. Native T1 is less predictive than ECV, particularly in HF with preserved ejection fraction.