Diagnostic Accuracy of Controlled Attenuation Parameter Measured by Transient Elastography for the Non-invasive Assessment of Liver Steatosis: a Prospective Study

Abstract

Background & Aims: A novel non-invasive tool based on the evaluation of ultrasound attenuation using transient elastography (TE) has been developed, called controlled attenuation parameter (CAP). We aim to establish the histopathological parameters that significantly influence CAP, the cutoff values and their performance in predicting each steatosis grade on a group of biopsied patients with chronic liver diseases (CLD) from Romania.Methods. We prospectively analyzed 201 consecutive CLD patients who underwent CAP measurements using TE. Steatosis, liver fibrosis and necroinflammatory activity were staged and graded during the pathological analysis of bioptic specimens. Univariate and multivariate regression analyses were applied to identify the variables correlated with CAP values. The diagnostic performance of CAP for steatosis prediction was assessed using an AUC analysis.Results. Among the histopathological factors correlating with CAP, the multivariate analysis found steatosis as the only factor independently influencing CAP values (p<0.001). Maximal diagnostic accuracy (DA) was obtained for the prediction of ≥34-66% (S2) fatty load and of 67-100% (S3) fatty load (82.06%, respectively 81.59%) while, for the prediction of ≥11-33% (S1) fatty load, DA reached only 76.11%. The negative predictive value for the exclusion of ≥S2 and S3 was 93.5% and 98.7%, respectively. AUCs calculated between each two steatosis grades were: 0.772 (S0 vs S1), 0.874 (S0 vs S2), 0.904 (S0 vs S3), 0.659 (S1vs S2), 0.777 (S1 vs S3), and 0.665 (S2 vs S3).Conclusion. Steatosis is the only histopathological factor independently influencing CAP. Maximal DA could be obtained for the prediction of ≥S2 and S3 (82.06% and 81.59%), while for the prediction of S1, the accuracy reached only 76.11%.

Screening for Liver Fibrosis and Steatosis in a Large Cohort of Patients with Type 2 Diabetes Using Vibration Controlled Transient Elastography and Controlled Attenuation Parameter in a Single-Center Real-Life Experience

“…For this reason, CAP by FibroScan evolved to be a reference method in the last years. Several studies demonstrated that the accuracy of CAP in comparison with liver biopsy is higher than 80% [21,22], and this is quite enough for daily practice. The introduction of CAP on both M and XL probes of FibroScan increased the feasibility of the method [23].…”

“…Published data show that the prevalence of NAFLD varies between 42.6 and 69% in T2DM patients [20,21], while a previous study from our area showed a prevalence of NAFLD in T2DM patients of up to 87.1% [22]. The prognosis of these patients is different if they present only simple steatosis-non-alcoholic fatty liver (NAFL)-or if they have already developed NASH, early NASH (no or mild fibrosis), fibrotic NASH (significant/advanced fibrosis), or NASH cirrhosis [23].…”

Lobeglitazone, a Novel Thiazolidinedione, Improves Non-Alcoholic Fatty Liver Disease in Type 2 Diabetes: Its Efficacy and Predictive Factors Related to Responsiveness

“…Because this was not a liver-biopsy proven study, we could not assess alterations in hepatic inflammation and hepatocellular ballooning following treatment. Regarding CAP, previous studies have analyzed the association of CAP values with liver histology, particularly in NAFLD patients with high-grade steatosis and elevated BMI, and have verified the utility of CAP as a non-invasive tool for diagnosing and monitoring NAFLD patients (27)(28)(29)(30). However, despite its relatively high accuracy in detecting hepatic steatosis, the agreement between histologic analysis and CAP in hepatic fat quantification varies among individuals with mild steatosis (27).…”

Effect of Meal Ingestion on Liver Stiffness and Controlled Attenuation Parameter

“…However, these are costly and some are not easily available, not standardized, or have controversial performance [6]. Recently, the controlled attenuation parameter (CAP) was developed and demonstrated good accuracy for the detection and quantification of steatosis in patients with chronic liver disease from various etiologies [7, 8]. Furthermore, CAP is measured simultaneously with liver stiffness (LS) using transient elastography (TE) [2, 9].…”