Hepatic artery resistive index (HARI) and non-alcoholic fatty liver disease (NAFLD) fibrosis score in NAFLD patients: cut-off suggestive of non-alcoholic steatohepatitis (NASH) evolution

Abstract

Purpose of the study Conventional ultrasound (US) is reliable to reveal the presence of non-alcoholic fatty liver disease (NAFLD), but it is neither sensitive nor specific to reveal fibrosis clues, except in advanced stages where signs of cirrhosis are evident. NALFD fibrosis score is a noninvasive parameter that predicts well the presence of significant fibrosis, but correlations with US parameters are lacking. The aim of this study was, therefore, to compare resistive index of hepatic artery (HARI) of NAFLD patients with different severity degrees of diffuse fatty liver disease vs HARI of controls, and to compare HARI of NAFLD patients with different NAFLD fibrosis scores vs HARI of controls. Methods This was a spontaneous, no-profit observational study conducted in our US department between December 2013 and July 2014. Patients with NAFLD with different severity of disease and healthy controls were included. Echogenicity and size of liver and spleen, maximum portal vein velocity, RI, peak systolic velocity (PSV), and end diastolic velocity (EDV) of splenic artery, PSV, EDV, and RI of hepatic artery, and NAFLD fibrosis score were acquired and compared between groups.Results HARI was significantly lower in NAFLD patients than controls (p \ 0.0001). A significant difference was also found between the groups of NAFLD severity (p \ 0.0001). There was also a difference between HARI of NAFLD patients with different NAFLD fibrosis scores vs HARI of controls (p \ 0.0001) with a positive correlation between HARI and NAFLD fibrosis score. Conclusion and discussion Conventional Doppler US can be helpful to detect NAFLD patients with the risk of fibrous tissue accumulation. HARI tends to exceed the range of controls for patients with NAFLD fibrosis score greater than 0.675. The detection of HARI greater than 0.9 in NAFLD patients, regardless of the US degree of severity of steatosis, might suggest the execution of biopsy to predict the risk of progression to steatohepatitis and fibrous tissue accumulation. Low values of HARI may be expression of lower risk, which does not necessitate any biopsy.Keywords Hepatic artery resistive index Á Non-alcoholic fatty liver disease Á NAFLD fibrosis score Á Non-alcoholic steatohepatitis Á Ultrasound Á Color Doppler Sommario Scopo dello studio L'ecografia convenzionale è risultata affidabile nel rilevare la presenza di steatosi epatica, tra cui la forma non alcolica (NAFLD), ma non è né sensibile né specifica nel rivelare indizi suggestivi di fibrosi, tranne che in fase avanzata dove sono presenti segni conclamati di cirrosi. Il NALFD fibrosis score è un parametro non invasivo che predice bene la presenza di fibrosi significativa, ma non ci sono dati in letteratura riguardanti una possibile correlazione con i parametri ecografici. Lo scopo di questo studio è stato quindi quello di confrontare HARI dei pazienti con NAFLD a differente grado di severità di steatosi epatica vs l'HARI dei controlli, e di confrontare HARI dei pazienti affetti da NAFLD a differente NAFLD fibrosis score...

Nonalcoholic Fatty Liver Disease: A Challenge from Mechanisms to Therapy

“…To make the matter more complex, the spleen and the liver show different patterns concerning resistivity, evaluated by an ultrasound-based non-invasive technique. Splenic artery resistive index was increased while hepatic artery resistive index was significantly reduced in severe NAFLD [42]. In a study in NAFLD patients with metabolic syndrome, it was confirmed that both the reduction in portal vein flow velocity and vasodilation of intrahepatic arteries were a compensatory way to restore the liver circulation, but the increased spleen volume was likely linked to the organomegaly typical of obese patients [43].…”

Can portal vein pulsatility index be used as predictive parameter with hepatic artery resistive index for liver fibrosis in nonalcoholic hepatosteatosis?

“…In a study by Tana C et al, HARI was significantly lower in NAFLD patients than controls and, likewise, significant differences were found between subgroups [10]. In another study, Mihmanli I et al found HARI value significantly lower in fatty liver patients [11].…”

Cardiovascular Risk in Non-Alcoholic Fatty Liver Disease: Mechanisms and Therapeutic Implications

“…NAFLD patients show increased prevalence of arterial rigidity and consequent hypertension, and the degree of arterial dysfunction is higher in patients with NASH [71]. The evidence of increased arterial stiffness in NAFLD patients has been demonstrated indirectly by the finding of a positive correlation between the hepatic artery resistive index, an ultrasound parameter which assesses the rigidity of hepatic artery and the NAFLD fibrosis score, a non-invasive scoring system which is useful to predict the amount of scarring in the liver [72,73].…”