Association between CMR derived hepatic T1 times, tricuspid regurgitation severity, and outcomes

Abstract Background Hepatic T1 times have been shown to predict adverse clinical outcomes. However, up to date, the various causes contributing to changes in hepatic T1 times are not fully understood. So far, strong correlations with liver congestion and hepatic fibrosis have been demonstrated. Valvular heart disease, especially tricuspid regurgitation (TR), can lead to congestive hepatopathy (CH) and might significantly increase liver T1 values. In contrast, hepatic steatosis – commonly present in patients with cardiovascular disease - would result in lower T1 values. Currently, no studies are investigating the relationship between hepatic T1 times and TR. Methods We retrospectively measured hepatic T1-times, displayed on standard cardiac T1-maps, in an all-comer CMR cohort. Only patients, who underwent a comprehensive transthoracic echocardiogram within three weeks of CMR were included. Results 1029 participants (67±17 y/o, 44% female) had mean hepatic T1-times of 605±79ms. Overall, 41% (417) presented with non/trace, 38% (391) mild, 13% (135) moderate, 8% (85) severe, massive, and torrential tricuspid regurgitation. Liver T1 times were significantly correlated with TR severity (no/trace: 586±72ms; mild: 601±74ms; moderate: 634±84ms; severe/massive/torrential: 665±83ms; r= 0.25, p<0.001). Additionally, when adjusted for higher NT-proBNP levels, and right ventricular function in a linear regression model, TR severity was associated with hepatic T1 times (p<0.001). During follow-up (mean 53±36months), a total of 326 (32%) events occurred. Patients with higher T1 times and more severe tricuspid regurgitation were more likely to suffer events (adj.HR 1.44 [95%CI:1.23-1.69] per 100ms increase, p<0.001). Conclusion Tricuspid regurgitation exerts a notable influence on hepatic T1 times which is likely attributable to hepatic congestion. Importantly, hepatic T1 times were associated with outcomes even after adjustment for NTproBNP, LVEF, and RVEF. This underscores the importance of hepatic T1 times as both a marker of tricuspid regurgitation and an independent predictor of clinical outcomes.