XL Probe Research Articles

LIVER FIBROSIS AND STEATOSIS IN PATIENTS WITH TYPE 2 DIABETES MELLITUS: A TRANSIENT ELASTOGRAPHY STUDY

Background :The prevalence of non-alcoholic fatty liver disease is notably high among patients with type 2 diabetes mellitus (T2DM). The objective of this study was to assess the potential utility of transient elastography (TE), a technique capable of measuring both fibrosis and liver fat content simultaneously, as a screening tool for hepatic involvement in patients with T2DM. Material and methods : Its a retrospective study spanned from January 2019 to January 2024 and included all patients diagnosed with T2DM who underwent TE. LSM values were determined using a Fibroscan 502 touch (Echosens SA, Paris, France) with the original M or XL probe selected based on the patients body weight or subcutaneous adipose tissue thickness, as per the manufacturers guidelines. TE scans were considered reliable when a minimum of 10 successful acquisitions were obtained, and the interquartile range-to-median ratio of the 10 acquisitions was ≤0.3. Results : A total of 124 patients with T2DM who underwent TE examination were included. 46 males and 78 females. The mean BMI of the patients was 33.2±6.6 kg/m2. The mean LSM was 7.1±3.4 kPa. LSM values exhibited significant correlations with BMI (p<0.001) and AST (p<0.001). The mean CAP value was 317±54 dB/m. Univariate correlation analyses demonstrated significant associations between CAP values and BMI (p<0.001). We found higher ALT levels (p<0.05) in patients with F3/F4 fibrosis. Both patients with mild and severe steatosis had higher ALT levels than those without (both p<0.05). However, ALT values did not differ significantly according to steatosis severity (p=0.69). Conclusion : Our results contribute to the existing body of evidence across various studies, approving the clinical utility of LSM and CAP for concurrent screening of liver fibrosis and steatosis in patients with T2DM.

Performance of continuous controlled attenuation parameter and liver stiffness measurement by the novel SmartExam in metabolic dysfunction-associated steatotic liver disease.

FibroScan® Expert 630 and FibroScan® Mini+430 are novel vibration-controlled transient elastography devices equipped with the same SmartExam software, which allows continuous measurement of controlled attenuation parameter (CAP) during the entire examination. This study aims to compare the CAP variabilities and the quantification for liver fibrosis and steatosis between the conventional FibroScan and the SmartExam-equipped machines in patients with metabolic dysfunction-associated steatotic liver disease (MASLD). This retrospective study included 118 patients with biopsy-proven MASLD who underwent liver biopsy at two tertiary centres between 2021 and 2023. Liver stiffness and steatosis measurements were performed using both FibroScan machines and M and XL probes for each individual. Liver histology was used as the reference standard for liver fibrosis and steatosis staging. Standard deviations of continuous CAP (cCAP) were significantly lower than those of CAP for all probes (p < .0001). CAP variability was significantly associated with body mass index (p < .01), probe selection (p < .001) as well as the random effect of centre. Only the effect of probe selection (p < .001) was significantly associated with cCAP variability. No significant difference was found in the performance of staging liver fibrosis and steatosis between two types of machines at the same cut-offs. The SmartExam-based VCTE reduces the variability of CAP measurement and achieves a similar accuracy as the FibroScan 502 device for the estimation of both hepatic steatosis and fibrosis. Future studies should determine if cCAP is a better tool to monitor changes in steatosis than the original CAP.

Poor Performance of Non-invasive Tests for Advanced Fibrosis in Nonalcoholic Fatty Liver Disease: A Multicentric Asian Study.

Non-invasive tests (NITs) are useful to assess advanced fibrosis (AF) in nonalcoholic fatty liver disease (NAFLD). Data from Asian countries suggest that these tests have poor performance. We aimed to assess diagnostic accuracy of established thresholds of biomarker-based NITs and Transient Elastography (TE) in identifying AF and evaluated the utility of a two-step test approach. Biopsy-proven 641 NAFLD patients (55.2% males, median age 42years) were included from three different centers of Asia. AF (≥ F3) was identified as per histological staging (24.8%). TE had the highest area under the receiver operating characteristic curve (AUROC) 0.82 (0.79-0.86), and all other biomarker-based NITs had low AUROC (< 0.7). NITs performed poorly at established thresholds. The combination of NITs utilizing liver stiffness measurement (LSM) and biomarkers, Agile 3+ and FAST, demonstrated acceptable diagnostic accuracy (AUROC 0.82 and 0.78, respectively), but none were superior to LSM alone. LSM measured using appropriate M and XL probes remained accurate regardless of body mass index (BMI); NFS and APRI scores were less accurate at higher BMI ranges. A two-step approach using NFS rule-out criteria (< -2.97 to rule out) followed by LSM (< 7.3kPa to rule out and ≥ 12.7kPa to rule in) correctly classified 62.4% of patients, with only 10.2% of patients incorrectly classified. NITs have not been validated to identify AF in the Asian NAFLD population, and internationally accepted thresholds yield high false-negative rates. LSM and LSM-based combination tests remain the most accurate.

Prevalence of non-alcoholic fatty liver disease and liver fibrosis in a general population cohort from Argentina

Introduction and ObjectivesSouth America is one of the regions with the highest rates of non-alcoholic fatty liver disease (NAFLD). This study aimed to assess the prevalence and severity of NAFLD in suburban Argentina. Patients and MethodsThe study involved a general community cohort of 993 subjects evaluated sequentially with a comprehensive lifestyle questionnaire, laboratory testing, abdominal ultrasound (US) and transient elastography with XL probe. NAFLD was diagnosed according to standard criteria. ResultsThe prevalence of NAFLD by the US was 37.2% (326/875) overall, 50.3% in subjects with overweight/obesity, 58.6% with hypertriglyceridemia, 62.3% with diabetes/hyperglycemia and 72.1% with all three risk factors. Male gender (OR 1.42, 95% CI 1.03–1.47, p = 0.029), age (50–59 years: OR 1.98, 95 CI 1.16–3.39, p = 0.013 and ≥60 years: OR 1.86, 95% CI 1.13–3.09, p = 0.015), BMI (25–29: OR 2.87, 95% CI 1.86–4.51, p<0.001 and ≥30: OR 9.57, 95% CI 6.14–15.20, p<0.001), diabetes/hyperglycemia (OR 1.65, 95% CI 1.05–2.61, p = 0.029) and hypertriglyceridemia (OR 1.73, 95% CI 1.20–2.48, p = 0.002) were independent predictors of NAFLD. Among patients with steatosis, 22.2% (69/311) had ≥F2 fibrosis (overweight 25%, hypertriglyceridemia 32%, diabetes/hyperglycemia 34%). BMI (OR 5.22, 95% CI 2.64–11.74, p<0.001), diabetes/hyperglycemia (OR 2.12, 95% CI 1.05–4.29, p = 0.04) and hypertriglyceridemia (OR 1.94, 95% CI 1.03–3.68, p = 0.040) were independent predictors of liver fibrosis. ConclusionsThis general population study from Argentina showed a high prevalence of NAFLD. Significant liver fibrosis was present in 22% of subjects with NAFLD. This information adds to the existing knowledge of NAFLD epidemiology in Latin America.

Assessment of hepatic steatosis before and after laparoscopic sleeve gastrectomy

Background Nonalcoholic fatty liver disease (NAFLD) is the cause of the new epidemic of chronic liver disease. Most patients are asymptomatic and accidentally diagnosed by imaging. Unfortunately, NAFLD can progress to inflammation, NASH, fibrosis, cirrhosis, HCC, decompensated cirrhosis, death, and/or liver transplantation might be required. Laparoscopic sleeve gastrectomy (LSG) has positive effects on the comorbidities associated with obesity. FibroScan and controlled attenuation parameter (CAP) can assess NAFLD non-invasively by measuring an area a hundred times larger than a biopsy sample. Aim To assess hepatic steatosis pre and post LSG by laboratory investigations and imaging (fibroscan and CAP). Methods Thirty patients were included in a prospective observational study according to the inclusion criteria. Full medical history, preoperative laboratory investigations and imaging were recorded. All patients underwent LSG and were followed up for 6 months postoperatively. Data were coded and analysed by using (SPSS) version 29. Results LSG was associated with a significant improvement in the controlled attenuation parameter CAP values, stiffness values and accordingly grades of steatosis and fibrosis as well as a highly significant decrease in BMI, and on follow-up fibroscan 6 months postoperatively. There was a significant improvement in total cholesterol, triglycerides, LDL and HDL. Conclusion LSG is associated with a significant improvement in BMI, lipid profile, CAP measurement and liver stiffness measurements which means improvement of steatosis. In morbidly obese candidates of bariatric surgery, Fibroscan with CAP (using the XL probe) was used as a simple non-invasive tool for detecting steatosis and fibrosis.

Accuracy and concordance of two-dimensional shear-wave elastography using transient elastography as the reference in chronic viral hepatitis and HIV infection in Rio de Janeiro, Brazil.

Evaluate the accuracy and agreement of two-dimensional shear-wave elastography (2D-SWE) LOGIQ-S8 with transient elastography in patients from Rio de Janeiro, Brazil. This retrospective study compared liver stiffness measurements (LSMs) using transient elastography (M and XL probes) and 2D-SWE GE-LOGIQ-S8 performed by a single experienced operator on the same day in 348 consecutive individuals with viral hepatitis or HIV infection. Suggestive and highly suggestive compensated-advanced chronic liver disease (c-ACLD) were defined by transient elastography-LSM ≥10 kPa and ≥15 kPa, respectively. Agreement between techniques and accuracy of 2D-SWE using transient elastography-M probe as the reference was assessed. Optimal cut-offs for 2D-SWE were identified using the maximal Youden index. Three hundred five patients [61.3% male, median age = 51 [interquartile range (IQR), 42-62] years, 24% with hepatitis C virus (HCV) ± HIV; 17% with hepatitis B virus (HBV) ± HIV; 31% were HIV mono-infected and 28% had HCV ± HIV post-sustained virological response] were included. The overall correlation (Spearman's ρ ) was moderate between 2D-SWE and transient elastography-M ( ρ = 0.639) and weak between 2D-SWE and transient elastography-XL ( ρ = 0.566). Agreements were strong ( ρ > 0.800) in people with HCV or HBV mono-infection, and poor in HIV mono-infected ( ρ > 0.400). Accuracy of 2D-SWE for transient elastography-M ≥ 10 kPa [area under the receiver operating characteristic (AUROC) = 0.91 (95% confidence interval [CI], 0.86-0.96); optimal cut-off = 6.4 kPa, sensitivity = 84% (95% CI, 72-92), specificity = 89% (95% CI, 84-92)] and for transient elastography-M ≥ 15 kPa [AUROC = 0.93 (95% CI, 0.88-0.98); optimal cut-off = 7.1 kPa; sensitivity = 91% (95% CI, 75-98), specificity = 89% (95% CI, 85-93)] were excellent. 2D-SWE LOGIQ-S8 system had a good agreement with transient elastography and an excellent accuracy to identify individuals at high risk for c-ACLD.

Deep attenuation transducer to measure liver stiffness in obese patients with liver disease

PurposeDeep attenuation transducers (DAX) are capable of imaging at diagnostic depths of up to 40 cm. The feasibility of DAX for liver stiffness measurement (LSM) has not been reported clinically. We aimed to assess the feasibility and reliability of DAX for LSM.MethodsOverall, 219 patients with chronic liver disease were enrolled. The success rate (acquired after ≥ 10 valid measurements) and inadequate measurements (interquartile range/median ≥ 0.3) for DAX were compared with those of conventional convex (c-convex) probes and M and XL probes of vibration-controlled transient elastography.ResultsLSM was successfully performed for all patients using DAX through all degrees of skin-to-liver capsular distance (SCD). Especially in patients with an SCD ≥ 30 mm, the difference in the rate of acquisition of 10 valid measurements was remarkable: M probe (8/33, 24.2%), XL probe (26/33, 78.8%), c-convex probe (33/43, 76.7%), and DAX (44/44, 100%). In patients with an SCD ≥ 30 mm, the inadequate measurement rate of M probe (1/8, 12.5%), XL probe (8/26, 30.8%), and c-convex probe (6/33, 18.2%) was higher than that of DAX (1/43, 2.3%). The areas under the curve for diagnosis of F4 with shear wave speed by c-convex and DAX were 0.916 and 0.918, respectively. Between DAX and c-convex probes, the intraclass correlation coefficient of 0.937 (95% CI 0.918–0.952) was excellent. Bland–Altman plots revealed that there was no statistically significant bias.ConclusionLiver stiffness measured by DAX is feasible and reliable for all patient populations, while the XL probe is limited to use in obese patients.

Real-world assessment of SmartExam, a novel FibroScan computational method: A retrospective single-center cohort study.

SmartExam is a novel computational method compatible with FibroScan that uses a software called SmartDepth and continuous controlled attenuation parameter measurements to evaluate liver fibrosis and steatosis. This retrospective study compared the diagnostic accuracy of conventional and SmartExam-equipped FibroScan for liver stiffness measurement (LSM). The liver stiffness and the associated controlled attenuation parameters of 167 patients were measured using conventional and SmartExam-Equipped FibroScan as well as reference methods like magnetic resonance elastography (MRE) and magnetic resonance imaging-based proton density fat fraction (MRI-PDFF) measurements to assess its diagnostic performance. M or XL probes were selected based on the probe-to-liver capsule distance for all FibroScan examinations. The liver stiffness and controlled attenuation parameter (CAP) correlation coefficients calculated from conventional and SmartExam-equipped FibroScan were 0.97 and 0.82, respectively. Using MRE/MRI-PDFF as a reference and the DeLong test for analysis, LSM and the area under the receiver operating characteristic curve for CAP measured by conventional and SmartExam-equipped FibroScan showed no significant difference. However, the SmartExam-equipped FibroScan measurement (33.6s) took 1.4 times longer than conventional FibroScan (23.2s). SmartExam has a high diagnostic performance comparable with that of conventional FibroScan. Because the results of the conventional and SmartExam-equipped FibroScan were strongly correlated, it can be considered useful for assessing the fibrosis stage and steatosis grade of the liver in clinical practice, with less variability but little longer measurement time compared with the conventional FibroScan.

Liver Stiffness Values in Persons with Normal Histology

Most studies to date have focused on liver stiffness measurement (LSM) in patients with different chronic liver diseases, and normal LSM is defined based on normal liver function tests or the absence of fibrosis. Very few studies have defined LSM based on completely normal liver biopsies. The current study was done to define the distribution of LSM values in individuals with normal liver biopsies. All prospective liver donors presenting to Medanta, the Medicity hospital between September 2020 and September 2021 fulfilling the eligibility criteria were included in this study. A total of 63 donors (36 females and 27 males) were included in the study, 37 (58.7%) donors had normal liver biopsies, and 26 (41.2%) donors showed the presence of non-alcoholic fatty liver disease. LSM values in the normal liver histology group were 5.01±1.99kPa by the M probe and 5.34±2.25kPa by the XL probe. Even though the correlation was weak (r=0.29, P=0.03), M probe LSM correlated positively with body mass index. There was a good correlation between the LSM measured by the M probe and the XL probe (r=0.73, P=<0.001). LSM value in the biopsy-proven normal liver histology group was 5.01±1.99 by the M probe and 5.34±2.25 by the XL probe.

Evaluation of Hepatic Fibrosis by Fibroscan® in Infections Chronic HbeAg Negative

Introduction: The Fibroscan® is a non-invasive test that assesses liver fibrosis by measuring the degree of liver elasticity. It occupies an important place in the evaluation of hepatic fibrosis in patients with chronic liver disease.The aim is to evaluate the interest of Fibroscan® in the evaluation of hepatic fibrosis in chronic HbeAg negative infections. Materials and methods: All patients with a chronic HbeAg negative infection from April 2019 to June 2022 were included. Chronic HbeAg negative infection is defined by: a normal clinical examination, a normal abdominal ultrasound, normality of transaminases at several times, AgHbs positive, AgHbe negative, and viral DNA less than 2000 IU/ml on quarterly monitoring over 1 year. The interpretation of the Fibroscan® results took into account 10 measurements validated by the device with the interquartile range (IQR) &lt; 30% of the median and a success rate &gt; 60%. Results: Out of a total of 753 Fibroscans® performed, 163 patients had a chronic HbeAg negative infection, i.e. 21.6%. The mean age of the patients was 49.6 ± 11.2. We note a female predominance of 52.1% with a sex ratio of 0.9. The median elasticity value was 5.6 Kpa (2.5 – 20 Kpa). Fibrosis was non-significant in 83.3% and fibrosis was significant in 16.6% (moderate fibrosis: 12%; severe: 1.3% and cirrhosis: 3.3%). There was a failure of the fibroscan in 13 patients (7.9%) with a BMI &gt; 35 kg/m2 despite the XL probe. Conclusion: Fibroscan® showed the absence of significant fibrosis in the majority of patients with chronic HbeAg negative infection. It allowed the diagnosis of significant fibrosis and cirrhosis in 16.6% of cases. The fibroscan is an excellent non-invasive examination for the evaluation of fibrosis in chronic HbeAg negative infections.

Clinical Performance of Transient Elastography With Comparison to Quantitative Magnetic Resonance Imaging, Ultrasound, and Biopsy in Children and Adolescents With Known or Suspected Fatty Liver Disease.

Background: Performance of vibration-controlled transient elastography (VCTE) is inadequately validated in pediatric nonalcoholic fatty liver disease (NAFLD). We aimed to assess the technical performance of VCTE in pediatric NAFLD and define the agreement between VCTE and reference standards of imaging and/or biopsy. Methods: This prospective study recruited participants with known or suspected NAFLD who underwent a research VCTE examination (FibroScan Mini 430). Ten valid VCTE liver stiffness measurements (kPa) and controlled attenuation parameter (CAP) (dB/m) measurements were obtained for each participant. Available clinically acquired MR elastography and magnetic resonance imaging proton density fat fraction (PDFF), liver ultrasound shear wave elastography, and biopsy served as references standards. Results: Eighty-four consecutive participants were included (55 males, mean age 15.0 ± 3.5 years, mean BMI 36.6 ± 9.4 kg/m2). VCTE examinations were complete in 80/83 participants. 37/83 participants were examined with an XL probe. There was no significant correlation between CAP and PDFF [n = 16; r = 0.17 (95% confidence interval [CI]: -0.34 to 0.61), p = 0.5] or between VCTE liver stiffness and MR elastography stiffness [n = 27; r = 0.31 (95% CI: -0.07 to 0.62), p = 0.10]. For prediction of any fibrosis stage ≥1 on biopsy (n = 9/15 participants), VCTE median liver stiffness >5.1 kPA had an area under receiver operating characteristic curve of 0.52 (95% CI: 0.26-0.78) with a sensitivity of 88.9% and specificity of 16.6% (p > 0.99). Conclusions: Complete VCTE examinations could be obtained in most pediatric patients with NAFLD. Neither VCTE liver stiffness nor CAP correlated well with measures of liver fat or stiffness by established imaging modalities and biopsy.

S1228 EUS-Guided Shear Wave Elastography Appears to Be More Accurate Than Transient Elastography in Predicting Liver Fibrosis Staging in Patients With Obesity

Introduction: Transient elastography (TE) is a non-invasive clinical tool used to assess liver stiffness measurement (LSM) and can be correlated to liver fibrosis staging. Obesity can make elastography challenging to perform due to increased abdominal wall thickness, with high failure rates for TE. Fibroscan XL probes have lower failure rates, though it is unclear if readings are reliable or correlate well with liver biopsies. EUS guided shear wave elastography (EUS-SWE) can potentially circumvent this limitation, as liver parenchyma via EUS can be visualized under a thin subcentimeter gastric or duodenal wall, which does not change appreciably with body habitus. We aim to determine whether TE or EUS-SWE correlate better with liver biopsy fibrosis staging for patients with obesity. Methods: A retrospective chart review was performed for patients with obesity at a single tertiary hospital from Dec 2021 to May 2022. Patients with obesity (BMI≥30) with LSM concerning for advanced fibrosis (F3 or F4) were referred for EUS-SWE and EUS guided liver biopsy, both of which performed in the left liver lobe. LSM (reported in kPa) were correlated with fibrosis staging on liver biopsy and were considered accurate if they fell within cutoff ranges: kPa ≤7 = F0-1, kPa 7-8 = F2, kPa 8-12 = F3, and kPa >12 = F4. No established cutoffs exist for EUS-SWE, so stiffness values were compared to that for TE on which were closer to TE cutoff ranges. Results: 12 consecutive patients with obesity underwent TE, EUS-SWE, and EUS guided liver biopsy. The mean age was 55.3 [range 18-69], 9 (75%) were females, and mean BMI was 44.9 [range 30.2-67.8]. LSM ranged from 9.1 to 41.9 kPa. Only 2 (17%) patients’ TE results correlated accurately with liver fibrosis staging on biopsy; see Table. Assuming similar fibrosis staging cutoff ranges for TE, EUS-SWE accurately downgraded 8 (67%) patients and demonstrated no change for 4 (33%) patients. EUS-SWE was closer to biopsy LSM cutoffs for 9 (75%) patients, while TE was more accurate in only 1 (8%) patient. Conclusion: In this small cohort of patients with obesity with possible advanced fibrosis, TE appeared to overdiagnose fibrosis stage, while EUS-SWE appeared to downgrade LSM appropriately for patients who were overdiagnosed. Larger cohort studies are ongoing to allow proper interpretation of EUS-SWE stiffness values and compare its utility and accuracy to TE. Table 1. - Individual patient data with basic demographics, transient elastography data, EUS shear wave elastography data, and data comparison and analysis Patient # Age Gender BMI TE LSM Value (kPa) Fibrosis Staging Based on TE Cutoff Fibrosis Stage on Biopsy (TE cutoffs) TE LSM as Compared to Fibrosis Staging on Biopsy EUS-SWE Stiffness (kPa) Closer to Biopsy Cutoffs? TE vs EUS-SWE How Did EUS-SWE Compare to TE via Fibrosis Staging ? 1 58 Female 62.4 9.1 F3 F0 (kPa≤7mmHg) Overstaged 5 EUS-SWE Downgraded 2 68 Female 39 9.9 F3 F0 (≤7) Overstaged 4.9 EUS-SWE Downgraded 3 59 Female 32.6 9.4 F3 F0 (≤7) Overstaged 6.3 EUS-SWE Downgraded 4 63 Female 32.8 15.7 F4 F0 (≤7) Overstaged 7.3 EUS-SWE Downgraded 5 48 Male 67.8 41.9 F4 F0 (≤7) Overstaged 7.3 EUS-SWE Downgraded 6 63 Female 38 9.4 F3 F0 (≤7) Overstaged 2 EUS-SWE Downgraded 7 56 Male 43.6 9.6 F3 F3 (8-12) Appropriate Stage 10.5 EUS-SWE No Change 8 18 Female 61.1 34.6 F4 F2 (7-8) Overstaged 19.6 EUS-SWE Downgraded 9 53 Female 32.6 20.5 F4 F4 (≥12) Appropriate Stage 21.7 Same No change 10 55 Male 34.9 12.2 F4 F2 (7-8) Overstaged 12.2 Same No Change 11 53 Female 30.2 14 F4 F3 (8-12) Overstaged 15.2 TE No Change 12 69 Female 64.1 14.7 F4 F2 (7-8) Overstaged 10.2 EUS-SWE Downgraded

M probe comes first: Impact of initial probe choice on diagnostic performance of vibration controlled transient elastography.

Probe choice (M or XL) in transient elastography can be made by the user's own measure of skin-to-liver-capsule distance (SCD) or with an automated tool (AUTO). We studied how AUTO depends on initial probe choice. Three fictive clinics were considered: The "M-first clinic" uses AUTO from the M probe, the "XL-first clinic" uses AUTO from the XL probe and a "reference clinic" measures SCD independently. Agreement and discrepancies to the reference clinic were measured. 200 patients with chronic liver disease were prospectively included (58% female, 56 years, BMI 28.1 kg/m²). Fleiss' kappa for agreement in probe selection was 0.11 (95% CI -0.09 to 0.31), but accuracy was above 0.8 for both. Probe failure occurred for 16 (M-first clinic), 4 (XL-first clinic) and 3 patients (reference clinic). Use of XL probe given M probe failure improved performance of the M-first approach. The odds ratio for discrepancy in the XL-first vs M-first clinic is 2.4 (95% CI 1.2 to 5.2, p=0.012) for liver fibrosis and 4.8 (95% CI 1.8 to 16.1, p < 0.001) for steatosis. Agreement in AUTO between M and XL probes is poor although each has acceptable accuracy. The M-first approach leads to fewer discrepancies and should be adopted as a standard.

The Utility and Diagnostic Accuracy of Transient Elastography in Adults with Morbid Obesity: A Prospective Study.

Patients with morbid obesity are at high risk for nonalcoholic fatty liver disease (NAFLD) complicated by liver fibrosis. The clinical utility of transient elastography (TE) by Fibroscan in patients with morbid obesity (body mass index (BMI) ≥ 40 kg/m2) is not well-defined. We examined the diagnostic accuracy of Fibroscan in predicting significant liver fibrosis (fibrosis stage ≥2) in morbidly obese patients (BMI ≥ 40 kg/m2). Patients scheduled for bariatric surgery were prospectively enrolled. Intraoperative liver biopsy, liver-stiffness measurement (LSM) by Fibroscan (XL probe), and biochemical evaluation were all performed on the same day. The endpoint was significant liver fibrosis defined as fibrosis stage ≥2 based on the Nonalcoholic Steatohepatitis Clinical Research Network. The optimal LSM cutoff value for detecting significant fibrosis was determined by using the Youden Index method. Routine clinical, laboratory, and elastography data were analyzed by stepwise logistic regression analysis to identify predictors of significant liver fibrosis and build a predictive model. An optimal cutoff point of the new model’s regression formula for predicting significant fibrosis was determined by using the Youden index method. One hundred sixty-seven patients (mean age, 46.4 years) were included, of whom 83.2% were female. Histological assessment revealed the prevalence of steatohepatitis and significant fibrosis of 40.7% and 11.4%, respectively. The median LSM was found to be significantly higher in the significant fibrosis group compared to those in the no or non-significant fibrosis group (18.2 vs. 7.7 kPa, respectively; p = 0.0004). The optimal LSM cutoff for predicting significant fibrosis was 12.8 kPa, with an accuracy of 71.3%, sensitivity of 73.7%, specificity of 70.9%, positive predictive value of 24.6%, negative predictive value of 95.5%, and ROC area of 0.723 (95% CI: 0.62–0.83). Logistic regression analysis identified three independent predictors of significant fibrosis: LSM, hemoglobin A1c, and alkaline phosphatase. A risk score was developed by using these three variables. At an optimal cutoff value of the regression formula, the risk score had an accuracy of 79.6% for predicting significant fibrosis, sensitivity of 89.5%, specificity of 78.4%, positive predictive value of 34.7%, negative predictive value of 98.3%, and ROC area of 0.855 (95% CI: 0.76–0.95). Fibroscan utility in predicting significant liver fibrosis in morbidly obese subjects is limited with accuracy of 71.3%. A model incorporating hemoglobin A1c and alkaline phosphatase with LSM improves accuracy in detecting significant fibrosis in this patient population.

Validation and Performance of FibroScan®-AST (FAST) Score on a Brazilian Population with Nonalcoholic Fatty Liver Disease.

FAST score has a good performance for diagnosing the composite of NASH + NAS ≥ 4 + F ≥ 2. However, it has not been evaluated in Latin American individuals with nonalcoholic fatty liver disease (NAFLD). We aimed to analyze the performance of the FAST score in a Brazilian NAFLD population. Cross-sectional study was held in ≥ 18years NAFLD patients diagnosed by ultrasonography and submitted to liver biopsy (LB). Liver stiffness (LSM) and CAP measurements were performed with FibroScan®, using M (BMI < 32kg/m2) or XL probes. Area under receiver operating characteristic (AUROC) curves were calculated as well as sensitivity (S), specificity (Spe), positive predictive value (VPP) and negative predictive value (NPV) for the previously established FAST score cut-offs. Among 287 patients included (75% female; mean age 55 ± 10years), NASH + NAS ≥ 4 + F ≥ 2 was reported in 30% of LB. For the FAST cut-off of 0.35, the S and NPV to rule out NASH + NAS ≥ 4 + F ≥ 2 were 78.8% and 87.8%, respectively. Regarding the cut-off of 0.67, the Spe and PPV to rule-in NASH + NAS ≥ 4 + F ≥ 2 were 89.1%, 61.8%, respectively. The AUROC of FAST for all included patients was 0.78 (95% CI 0.72-0.84) and for those with ≥ 32kg/m2 was 0.81 (95% CI 0.74-0.88). FAST score has a good performance in a Brazilian NAFLD population, even in patients with higher BMI when the XL probe is adopted. Therefore, FAST can be used as a noninvasive screening tool mainly for excluding the diagnosis of progressive NASH, reducing the number of unnecessary liver biopsies.

RELIABILITY FACTORS FOR THE MEASUREMENT OF HEPATIC STEATOSIS BY MEANS OF A CONTROLLED ATTENUATION PARAMETER BY TRANSIENT ELASTOGRAPHY

The controlled attenuation parameter (CAP) allows the indirect measurement of liver fat and the indirect the indirect measurement of liver fat and stiffness by transient elastography. Its diagnostic utility has been validated, but the factors for its reliability are unknown. Therefore, the objective is to evaluate the predictors of CAP quality by transient elastography. Retrospective, observational design of transient elastography studies from January 2015 to December 2019 for fatty liver screening, fibrosis evaluation and esophageal varices screening, using Fibroscan 502 Touch with M and XL probes according to the manufacturer's recommendations. Sociodemographic and clinical data and reliability measures were evaluated: degree of liver stiffness (kpa), decibels / meter (db/m), interquartile ranges (IQR <40 and IQR <30), number of total and valid measurements. The data are shown in measures of central tendency and dispersion; for the reliability factors, a univariate and multivariate logistic regression analysis was performed. 1153 studies were analyzed, 52.6% (n = 606) were men, with a median age of 54 years [IQR 44-63] and BMI 27.4 kg / m2 [IQR 24.1-29.7]. The main indication was fatty liver screening 48.8% (n = 558), the median CAP was 262 (215-313) db / m with an interquartile range of 34 (24-47). In 26.2% (n = 302) an incorrect probe was used. The factors associated with reliability with IQR <40 were the XL probe (OR 0.34 CI95% 0.26-0.45), age <54 years (OR 0.71 CI95% 0.55-0.92) and IQR kPa <30 (OR 0.48 CI95% 0.28-0.82) and for the reliability of IQR <30 the use of the XL probe (OR 0.31 CI95% 0.23-0.42) and IQR kPa <30 (OR 0.35 CI95% 0.17-0.71). Evaluating only screening studies (n = 558), the use of the XL probe and age <54 years maintained an independent association for IQR <40 and with respect to IQR <30, only the XL probe maintained this association. Table 1. Current recommendations for quality CAP studies are to obtain valid measurements with IQR <30 and <40, although there is little evidence to support this. It was demonstrated that regardless of the indication, degree of fibrosis and BMI, the use of the XL probe favors the quality of the study and an adequate evaluation of liver stiffness (IQR kPa <30). The main factor that favors the reliability of the CAP IQR <40 and 30 is the use of the XL probe regardless of the indication for use and the body mass index. The authors declare that there is no conflict of interest.

Accuracy of controlled attenuation parameter for assessing liver steatosis in individuals with morbid obesity before bariatric surgery.

The ultrasound-based controlled attenuation parameter (CAP) is a non-invasive tool widely validated for assessing liver steatosis across different etiologies. However, few studies, with liver biopsy available, have investigated its performance in individuals with morbid obesity. Herein, we aimed to evaluate the diagnostic accuracy of CAP in participants with morbid obesity from the MAFALDA study before bariatric surgery. A total of 120 individuals with valid examinations within three months from bariatric surgery were included. Clinical, laboratory, FibroScan® (XL probe), and liver biopsy data were collected using standardized procedures. The overall accuracy of CAP for detecting liver steatosis was estimated by the area under the receiver-operating characteristics curve (AUROC). Optimal cut-offs were chosen at points with the highest Youden index. The AUROCs of CAP for detecting S≥S1, S≥S2, and S=S3 were 0.91 (95% CI 0.86-0.97), 0.83 (95% CI 0.76-0.90), and 0.86 (95% CI 0.79-0.94), respectively. The best CAP cut-offs for S≥S1, S≥S2, and S=S3 were 300dB/m (95% CI 275-316), 328dB/m (95% CI 296-345), and 344dB/m (95% CI 343-352), respectively. CAP values were independently influenced by steatosis grade (estimate 20.60, 95% CI 12.70-28.40, P=1.05×10-6 ). The AUROC of FibroScan-AST (FAST) score for detecting progressive non-alcoholic steatohepatitis was 0.76 (95% CI 0.66-0.86). In individuals with morbid obesity, CAP measured by XL probe is an accurate non-invasive tool for grading liver steatosis. Measurement of liver fat content by CAP may help identify those eligible for bariatric procedures and estimate the effect of bariatric surgery on hepatic steatosis. The ultrasound-based controlled attenuation parameter (CAP) by using the XL probe has an excellent performance for grading liver steatosis among individuals with morbid obesity. CAP may represent an accurate tool for the non-invasive assessment of liver steatosis among individuals with morbid obesity before and after bariatric surgery.

Le CAP (Controlled attenuation parameter), un indicateur de risque et de sévérité du syndrome métabolique ?

ObjectivesThe aim of this study is to investigate the relationship between CAP (Controlled Attenuation Parameter) values and the different components of the metabolic syndrome. Materials and methodsThis is a cross-sectional study including all patients over 18 years of age with chronic liver disease who were referred to our center for a non-invasive assessment of liver fibrosis. The measurement of hepatic elasticity and CAP was carried out concomitantly using the M or XL probe of Fibroscan® by trained operators. ResultsThe prevalence of metabolic syndrome in patients with CAP ≥238dB/m was higher than in patients with CAP<238dB/m, and significantly increased with the severity of hepatic steatosis (p<0.001). CAP values were higher in patients with metabolic syndrome and significantly increased with the increase in the number of metabolic syndrome components (p<0.001). In univariate analysis, there was a statistically significant positive linear relationship between CAP values and components of metabolic syndrome except for blood glucose and HDLc level. In multivariate analysis, only waist circumference and triglycerides level were significantly related to CAP values. ConclusionThis study shows that there is a significant correlation between CAP and the different components of the metabolic syndrome. CAP could be an indicator of risk and severity of metabolic syndrome.

Comparative Utility of Transient and 2D Shear Wave Elastography for the Assessment of Liver Fibrosis in Clinical Practice.

The aim of the study was to investigate the feasibility and correlation of liver stiffness measurements (LSM) between 2D-shear wave elastography (2D-SWE) and transient elastography (TE) in patients with chronic liver disease. Over 4months, 421 patients with chronic liver disease of any cause underwent LSM by 2D-SWE and TE (M and/or XL probe) and controlled attenuation parameter at the same visit. LSM was not feasible by TE in 16 (3.8%) and by 2D-SWE in 17 (4.0%) patients. Median LSM were 8.9 and 8.7kPa with TE and 2D-SWE, respectively, having a strong correlation (r = 0.774, p < 0.001) in the total cohort and in any cause of liver disease (r = 0.747-0.806, p < 0.001). There was a strong agreement on diagnosis of severe fibrosis (k-statistic: 0.841, p < 0.001) or cirrhosis (k-statistic: 0.823, p < 0.001). Both methods had increased failure rates in patients with obesity and/or increased waist circumference. Among 104 obese patients, TE was more feasible than 2D-SWE (92.3% vs 85.6%, p < 0.001]. LSM by 2D-SWE are strongly correlated to LSM by TE independently of the etiology of chronic liver disease, stage of fibrosis, degree of liver steatosis, and patients' characteristics. TE with the XL probe may be superior in a minority of obese patients.

S1186 Evaluation of the FAST Score as a Predictor of Fibrotic NASH in Hispanics

Introduction: Background: The Fibroscan-AST (FAST) score was developed to predict the presence of “at risk” NASH (NAFLD activity score (NAS) ≥4 and Fibrosis ≥2) using liver stiffness measurement (LSM) as assessed by Fibroscan, controlled attenuated parameter (CAP) and AST. Limited data exist on the using the FAST score in Hispanics who are at higher risk for fibrotic NASH. Therefore, the aim of this study was to evaluate the performance of the FAST score against liver biopsy in a cohort of Hispanics. Methods: Consecutive patients with suspected NAFLD who had liver biopsy and LSM/ AST performed within a 6-month period were included. NASH, NAS, and fibrosis stage were assessed using the NASH CRN criteria. M and XL probes were chosen based on the automated machine recommendation. Patients were excluded if they had > 5% change in body weight. C statistics were used to assess FAST accuracy and sensitivity, specificity, NPV, and PPV were calculated. Results: 245 patients were included with mean age of 57 years, mean BMI of 34.5 (± 4.8) kg/m2, mean HbA1C of 6.2%, 50% had type 2 diabetes. Fibrotic NASH on liver biopsy was present in 25% of patients. The FAST score had good overall accuracy in predicting “at risk” NASH with AUC of 0.75 (95% CI: 0.68 – 0.82). At the low cutoff value (< 0.35) corresponding to 90% sensitivity (rule out zone), the FAST had a good NPV of 89%. However, at the high cutoff value ( >0.67) corresponding to 90% specificity (rule in zone), the FAST score had low PPV of 48.3%. 117 patients were in the rule out zone, 62 were in the rule in zone, and 66 were classified as indeterminate. Conclusion: The FAST score performed well to exclude the presence of “at risk” NASH in Hispanics. The FAST score had low PPV and was less accurate in making a positive diagnosis of “at risk” NASH in the Hispanic population. These findings may have implications on how to optimize the use of this score in this high-risk population for both inclusion in NASH therapeutic trials and for selecting patients for pharmacologic treatment.