Background and study aimsLiver fibrosis is the underlying causeof hepatitis C virus (HCV)-related disease progression to endpoints such as cirrhosis, liver failure, and hepatocellular carcinoma. The aim of our study was to assess changes in hepatic fibrosis in patients with chronic HCV who had a fibrosis evaluation at two time points at least six months apart. Patients and MethodsThis was a retrospective cohort study that included patients who had failed interferon therapy and received HCV retreatment with direct-acting antivirals (DAAs) at least six months later. Patients were evaluated previously for fibrosis according to liver biopsy and fibrosis biomarkers were evaluated before pegylated interferon and ribavirin (PEG/RBV) therapy. Fibrosis was re-evaluated with fibrosis-4 (FIB-4) scores before starting DAAs. ResultsA total of 3,049 patients were included [age 43.47 ± 9.07 years, 55.20 % males] and baseline histopathology showed F1, F2, and F3 in 16.86 %, 46.21 %, and 36.93 %, respectively. The mean time interval between the last dose of previously failed IFN-therapy to the first dose of DAAs was 2.38 (±1.07) years. Overall, there was a significant increase in FIB-4 scores at retreatment times (from 11.71 ± 1.13 to 22.26 ± 1.68, p < 0.001). Patients with baseline FIB-4 < 1.45 (n = 1,569) and between 1.45 and 3.25 (n = 1,237) had significant increases in their FIB-4 at the retreatment time point [median difference; 0.41 (0.91) and 0.24 (1.5), p < 0.001, respectively], whereas patients with FIB-4 > 3.25 had significant reduction of their FIB-4 score at a retreatment timepoint [−0.98 (2.93), p ≤ 0.001]. ConclusionFibrosis progressed in most patients, even within six months for some patients, and this indicates retreatment of non-system vascular resistance patients even if they do not have significant fibrosis.