Longer sustained Fontan circulation is associated with prolonged hepatic T1 relaxation time on T1 mapping

Abstract

Funding Acknowledgements Type of funding sources: None. Background Patients with single ventricle defects may develop Fontan-associated liver disease. T1 mapping has been successfully used for evaluating chronic liver disease in adults. Liver T1 mapping has been also studied in the pediatric patients with single ventricles, and these patients show higher T1 relaxation times compared to the healthy controls. Purpose Our objective was to study the relationship between the cardiac MRI (CMR) T1 mapping relaxation time of the liver and 1) CMR derived hemodynamic parameters, 2) peripheral venous pressure (PVP) measured from a cubital cannula 3) systemic ventricle morphology [LV vs. RV], 4) the age of patient, and 5) alanine transaminase (P-ALAT) levels. Methods This retrospective study included 46 patients with functional single ventricle, which underwent routine CMR at our hospital. Table 1 shows demographic and clinical data of the study population. Statistical analysis were performed with IBM SPSS Statistics v.25 software using independent samples t test, Mann-Whitney U-test or Pearson correlation as appropriate. A p-value less than 0.05 was considered significant. Results The average T1 relaxation time of the liver was longer in patients with RV morphology (p = 0.004). There was a significant moderate positive correlation between the age of the patients and hepatic T1 relaxation time (r = 0.45, p = 0.002), and between hepatic T1 relaxation time and P-ALAT levels (r = 0.5, p = 0.016) (Fig.1). No significant correlations were detected between the T1 times of the liver and hemodynamic parameters of the heart (all tested parameters are listed in the Table1). Ejection fraction and PVP showed a non-significant weak correlation with a hepatic T1 relaxation times (r=-0.3, p = 0,056 and r = 0.3, p = 0,070, respectively). Conclusions T1 mapping times of the liver may reflect Fontan-associated liver disease. We observed connections between the hepatic T1 relaxation times and 1) patients age, 2) systemic ventricle morphology and 3) P-ALAT levels.