Accurate reflection of hepatic venous pressure gradient by spleen stiffness measurement in patients with low controlled attenuation parameter values

Abstract

Background and Aim: Spleen stiffness measurement (SSM) is useful for assessing portal hypertension. It is unclear whether SSM values are appropriate because vibration-controlled transient elastography (VCTE) does not generate B-mode images. This study aimed to confirm whether the controlled attenuation parameter (CAP) measured in the spleen can predict the accuracy of SSM. Methods: This retrospective study enrolled 349 patients who underwent SSM using VCTE from January 2012 to December 2020. Consecutive patients were classified into the pilot set (SSM and hepatic venous pressure gradient [HVPG] were measured) and the validation set (SSM was measured without HVPG). In the pilot set, scatter plots with a nonparametric contour line were created. Logistic regression analysis was performed to predict outliers outside the 50% contour line. Results: The values of CAP could distinguish the outliers in scatter plots between the HPVG and SSM in both univariate and multivariate analyses (cutoff, 118 dB/m). The correlation of SSM with HVPG (r = 0.718; P < 0.001) was significantly better in the low CAP (≤118 dB/m) group than in the high CAP (>118 dB/m) group (r = 0.330; P < 0.001). The area under the receiver operating characteristic curve of SSM in predicting high-risk varices was better in the low CAP group than in all patients or in the high CAP group in the pilot set (0.881, 0.854, and 0.843, respectively) and in the validation set (0.893, 0.821, and 0.814, respectively). Conclusion: For patients with CAP <118 dB/m, SSM is a feasible predictor of HVPG.