Prognostic significance of T1 mapping parameters in heart failure with preserved ejection fraction: a systematic review.

Heart failure with preserved ejection fraction (HFpEF) accounts for almost one-half of all heart failure (HF) patients and continues to increase in prevalence. While mortality with heart failure with reduced ejection fraction (HFrEF) has decreased over the past few decades with use of evidence-based HFrEF therapy, mortality related to heart failure with HFpEF has not changed significantly over the same time period. The combination of poor prognosis and lack of effective treatment options creates a pressing need for novel strategies for better patient characterization. We conducted a systematic review to evaluate the prognostic value of cardiac magnetic resonance (CMR)-derived T1 relaxation time and extracellular volume fraction (ECV) in HFpEF patients. PubMed, Embase, and Cochrane Central were searched for relevant studies. The primary outcomes of interest were hospitalization for HF and all-cause mortality. Five studies with 2741 patients were included. Four studies reported correlation of outcomes with ECV, 2 studies reported correlation of outcomes with native T1 time, and 1 study reported correlation of outcomes with post-contrast T1 time. All five studies showed significant correlation of CMR-derived parameters with adverse outcomes including event-free survival to cardiac event, all cause, and cardiac mortality. CMR-determined ECV is strongly correlated with adverse outcomes in HFpEF cohorts.