A novel imaging index for predicting adverse progression in acute-on-chronic liver failure related to hepatitis B virus: the low erector spine index

BACKGROUND: It is widely known that muscle mass influences the outcomes of many chronic diseases. Erector spine mass is a convenient parameter obtained from routine abdominal computed tomography (CT). The clinical application value of erector spine mass, and whether erector spine mass could predict the outcome of disease has not been studied. AIM: To evaluate the role of the erector spine index (ESI) calculated based on abdominal CT imaging in the progression of acute-on-chronic liver failure related to the hepatitis B virus (HBV-ACLF). METHODS: We performed a retrospective study of 118 HBV-ACLF patients and calculated the ESI (the total erector spine area normalized for height(2) in meters) for each patient through abdominal CT. The findings were analyzed regarding the progression of HBV-ACLF and the ESI at baseline, including mortality and the development of complications. RESULTS: The ESI level was associated with mortality and the development of complications. During the 90-day follow-up period, patients with a low ESI (<12.05 cm(2)/m(2)) had higher mortality than those with a high ESI (≥ 12.05 cm(2)/m(2)) (51.7% vs. 26.7%), and the cumulative survival rates were 71.0%±4.6 and 85.8%±3.9, respectively (log-rank P = 0.003). The hazard ratios (HRs) calculated using univariable and multivariable analyses were 2.23(95% confidence interval (CI): 1.25–4.21, P = 0.005) and 2.52 (95% CI: 1.34–9.24, P = 0.011), respectively. Patients with a low ESI (<12.05 cm(2)/m(2)) had higher incidences of kidney dysfunction (43.5% vs. 23.2%, P = 0.029; log-rank P = 0.017) and hepatic encephalopathy (39.6% vs. 14.0%, P = 0.003; log-rank P = 0.010) than those with a high ESI. A low ESI was an independent risk factor for kidney dysfunction (adjusted HR = 1.36, 95% CI: 1.05–2.93, P = 0.043) and the development of hepatic encephalopathy (adjusted HR = 2.26; 95% CI: 2.05–3.13, P = 0.036). In addition, the presence of hepatic encephalopathy (the odds ratio (OR) = 2.26, 95% CI: 2.05–3.18, P = 0.006), spontaneous bacterial peritonitis (OR = 3.95, 95% CI: 1.01–5.46, P = 0.037), and kidney dysfunction (OR = 4.47, 95% CI: 1.02–9.64, P = 0.032) was independently associated with a low ESI in patients. CONCLUSION: A low ESI is an independent risk factor for mortality in patients with HBV-ACLF, as well as the development of kidney dysfunction and hepatic encephalopathy. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12876-023-02995-x.