Prognostic Value of Hepatic Native T1 and Extracellular Volume Fraction in Patients with Pulmonary Arterial Hypertension

Background Right heart failure may lead to impaired liver perfusion and venous congestion, resulting in different extents of liver fibrosis. However, whether hepatic tissue deterioration determined by native T1 mapping and extracellular volume fraction using cardiac magnetic resonance imaging is associated with poor outcomes in patients with pulmonary arterial hypertension remains unclear. Methods and Results A total of 131 participants with pulmonary arterial hypertension (mean age, 36 +/- 13 years) and 64 healthy controls (mean age, 44 +/- 18) between October 2013 and December 2019 were prospectively enrolled. Hepatic native T1 and extracellular volume fraction values were measured using modified Look-Locker inversion recovery T1 mapping sequences. The primary end point was all-cause mortality; the secondary end point was all-cause mortality and repeat hospitalization attributable to heart failure. Cox regression models and Kaplan-Meier survival analysis were used to identify the association between variables and clinical outcome. During a median follow-up of 34.5 months (interquartile range: 25.3-50.8), hepatic native T1 (hazard ratio per 30-ms increase, 1.22 [95% CI, 1.07-1.39]; P=0.003) and extracellular volume fraction (hazard ratio per 3% increase, 1.18 [95% CI, 1.04-1.34]; P=0.010) values were associated with a higher risk of death. In the multivariate Cox model, hepatic native T1 value (hazard ratio per 30-ms increase, 1.15 [95% CI, 1.04-1.27]; P=0.009) remained as an independent prognostic factor for the secondary end point. Conclusions Hepatic T1 mapping values were predictors of adverse cardiovascular events in participants with pulmonary arterial hypertension and could be novel imaging biomarkers for poor prognosis recognition.