P15 Screening and prevalence of MASLD-associated liver fibrosis in a bariatric cohort – a pilot study in a Tier 3 weight management service

<h3>Introduction</h3> Metabolic dysfunction-associated steatotic liver disease (MASLD) is a well-recognised cause of advanced liver disease for which obesity is a predominant risk factor. Patients with BMI &gt;35 have access to obesity/bariatric services but evidence regarding optimal screening for progression to MASLD-related liver fibrosis in this cohort is lacking. Our pilot study describes a novel, joint Bariatric-Hepatology pathway within a Tier 3 weight management service aiming to establish a screening pathway for liver fibrosis in an asymptomatic population. <h3>Method</h3> Retrospective review of the records of patients screened for liver fibrosis using FIB-4 on a Tier 3 weight management programme. Patients subsequently underwent vibration-controlled transient elastography (VCTE) according to FIB-4 score, and VCTE scores were stratified based on BAVENO VII consensus. <h3>Results</h3> Data was collected on 1015 patients encompassing 941 ‘low risk’ (92%), 69 ‘medium risk’ (7%), and 5 ‘high risk’ (1%) based on standardised FIB-4 cutoffs. Of the ‘low risk’ group, 18 patients underwent VCTE (mean age 45; mean HbA1c 45.8; mean BMI 47) and within this sub-group, liver stiffness measurement (LSM) was &gt;8kPa in 7/18 (39%) and &gt;15kPa in 3/18 (17%). Notably, only 2/18 (11%) had HbA1c &gt;48. Of the ‘medium risk’ group, 28 patients underwent VCTE (mean age 55.8; mean HbA1c 49.3; mean BMI 49.2) and within this sub-group, liver stiffness measurement (LSM) was &gt;8kPa in 20/28 (71%), &gt;15kPa (assumed compensated advanced chronic liver disease (cACLD)) in 13/28 (46%) and &gt;25kPa (assumed clinically significant portal hypertension (CSPH)) in 5/28 (18%). Of those with assumed cACLD, mean HbA1c was 70.5 and 11/13 (85%) had at least two additional metabolic risk factors. Of the ‘high risk’ group, all patients who underwent VCTE (n=3) had scores in the cACLD range and 1/3 had assumed CSPH. <h3>Discussion</h3> A joint Bariatric-Hepatology pathway was successfully implemented in a Tier 3 weight management pathway identifying a high prevalence of unrecognised liver disease and prompting pre-bariatric assessment and Hepatology input. As expected, the majority of patients with liver fibrosis had metabolic risk factors. ‘Medium risk’ FIB-4 had a high positive predictive value in our cohort compared to existing literature. In comparison, ‘low risk’ FIB-4 (projected to exclude advanced liver fibrosis in ~90% of patients) had a poor negative predictive value in our cohort (61%). Existing evidence suggests that FIB-4 alone is insufficient in high-risk clinical conditions including obesity and diabetes with high false negative rates which was correlated by our findings. Combining non-invasive tests might reduce misclassification.