Prognostic Role of T1 Mapping Parameters in Patients with Heart Failure with Preserved Ejection Fraction: A Systematic Review

Abstract

Introduction Diffuse myocardial fibrosis plays a key role in the pathophysiology of heart failure with preserved ejection fraction (HFpEF). Cardiac magnetic resonance (CMR) parameters such as native myocardial T1 relaxation time and extracellular volume fraction (ECV) are evolving imaging-based biomarkers of myocardial fibrosis. Therefore, we performed a systematic review to synthesize the available data on the prognostic value of T1 and ECV in patients with HFpEF. Methods and Results We searched PubMed, Embase and Cochrane Central for relevant studies using predefined search criteria and endpoints. Studies with overlapping patient population were excluded. Four studies were included in the review (TABLE). All included studies were prospective, single-center observational cohorts. Of the 1507 participants, 62% were women, mean age was 74.7± 8.3 years, and mean left ventricular EF was 63.2 ± 9.3%. Two of the 4 studies reported outcomes in relation to native T1 value. Both of them found no significant association of T1 value with adverse cardiovascular outcomes. One study found that lower post contrast T1 times were significantly associated with adverse cardiac events (HR-0.99; 95% CI-0.98-0.99). Three studies reported outcomes in relation to ECV and all of them found that higher ECV was associated with increased risk for adverse cardiovascular events or mortality. Two of the studies also assessed histological ECV (by endomyocardial biopsy) and demonstrated strong correlation between histologically determined ECV and CMR quantification of ECV (R=0.494; P=0.037). Conclusion Estimation of ECV may provide important prognostic information in patients with HFpEF and has the potential to improve risk stratification.