Myosteatosis as a prognostic biomarker for post-transplant survival and cardiometabolic outcomes: A retrospective study

Background: Metabolic health significantly impacts long-term survival among liver transplant (LT) recipients. Emerging evidence suggests that metabolic health in the general population is related to skeletal muscle quality. However, this has not been well investigated in the transplant patient population. While myosteatosis, characterized by fat infiltration into skeletal muscle, has been closely associated with metabolic health in the general population, it has not been thoroughly explored as a risk factor for outcomes in LT recipients. Methods: In this retrospective cohort study of 503 adult LT recipients at the University Health Network, we evaluated the prognostic value of myosteatosis on post-transplant survival and cardiometabolic outcomes. Pre-transplant contrast-enhanced CT scans of LT recipients within 6 months prior to transplantation were analyzed using the nnU-Netv2 convolutional neural network, and myosteatosis was quantified by skeletal muscle radiation attenuation adjusted for BMI. Results: The mean age of LT recipients was 56.89 years; patients with myosteatosis were significantly older (58.69 y) than those without (54.96 y). LT recipients were predominately male (75.9%). Cox proportional hazards models showed that myosteatosis independently predicted both all-cause mortality (HR 1.50 [95% CI 1.06–2.12]; p = 0.024) and the incidence of post-transplant metabolic dysfunction–associated steatotic liver disease (MASLD) (hazard ratio [HR] 2.25 [95% CI 1.28–3.98]; p = 0.0051). Notably, cardiovascular disease, diabetes mellitus, and malignancy did not differ significantly by myosteatosis status. Conclusions: The presence of myosteatosis could identify LT recipients at higher risk for metabolic complications. As a modifiable and non-invasive biomarker, the presence of myosteatosis could guide personalized interventions to improve long-term outcomes. [Formula: see text]