18 F-FAPI PET/CT in chronic liver disease: myocardial fibroblast activation and its correlates

This study investigated the relationship between cardiac fibroblast activation and clinical parameters, electrophysiological findings, serum fibrosis markers, and hepatic fibroblast activation in patients with chronic liver disease.

In this prospective study conducted from December 2021 to April 2022, 46 patients with chronic liver disease underwent fluorine-18 ( 18 F)-labeled fibroblast activation protein inhibitor (FAPI) PET/computed tomography (CT) imaging and 12-lead electrocardiogram (ECG). Abnormal cardiac 18 F-FAPI uptake was defined as uptake greater than that of the blood pool.

Among 46 patients with chronic liver disease analyzed, 14 showed positive myocardial FAPI uptake and 32 were negative. Significant differences were observed between positive and negative myocardial 18 F-FAPI PET/CT imaging groups in terms of age ( P  = 0.006), epicardial fat volume (EFV) ( P  = 0.004), Cornell voltage QRS amplitude ( P  = 0.022), and QRS duration ( P  = 0.032). The multivariable logistic regression analysis demonstrated a significant association between EFV [odds ratio (OR) = 1.019; P  = 0.024] and age (OR = 1.162; P  = 0.019) and positive myocardial FAPI uptake. Myocardial maximum target-to-background ratio (TBR max ) was positively correlated with hepatic TBR max ( r  = 0.405; P  = 0.005) and hepatic TBR mean ( r  = 0.412, P  = 0.004). Moreover, myocardial maximum standardized uptake value was positively correlated with serum laminin levels ( r  = 0.367; P  = 0.042).

In patients with chronic liver disease, FAPI PET/CT imaging observed cardiac fibroblast activation, which was associated with electrophysiological parameters, hepatic FAPI uptake, and serum liver fibrosis markers. These findings suggest that 18 F-FAPI PET/CT imaging may offer a noninvasive approach for identifying early myocardial changes in chronic liver disease.