P289 Bowel Stiffness Assessed by Shear-wave Ultrasound Elastography Predicts Disease Behavior Progression in Patients with Crohn’s Disease

Abstract

Abstract Background There is a lack of reliable predictors of disease behavior progression in patients with Crohn’s disease (CD). Real-time shear-wave elastography (SWE), a novel method for evaluating tissue stiffness, is reportedly helpful in determining the prognosis of liver cirrhosis or breast cancer. However, its value for assessing CD has not yet been investigated. We aimed to explore the value of SWE and other ultrasound parameters at diagnosis in predicting CD behavior progression. Methods We retrospectively collected data from CD patients with the non-stenotic non-penetrating disease (B1 phenotype based on the Montreal classification). All patients underwent intestinal ultrasound with SWE measurement at baseline and were followed up. The endpoint was defined as disease behavior progression to stricturing (B2) or penetrating (B3) disease. A multivariate Cox regression model was used to explore the association between baseline SWE and subsequent outcome. We also established a multivariate nomogram to predict the risk of disease behavior progression and evaluated its performance with receiver operating characteristic curve and decision curve analysis. Results A total of 130 CD patients with B1 phenotype were enrolled. Twenty-seven patients (20.8%) developed B2 or B3 disease, with a median follow-up of 33 months. Multivariate analysis identified that SWE ≥12.75 kPa was the only independent predictor of disease behavior progression (HR 1.08, 95% CI 1.03-1.12, P=0.001, Fig 1A). A restricted cubic spline with multiple covariates adjusted showed an approximately linear positive correlation between SWE and the risk of disease behavior progression, with a cut-off of 12.75 kPa (Fig 1B). We further established a multivariate nomogram incorporating SWE and other clinical characteristics to predict the risk of disease behavior progression quantitatively (Fig 1C). Compared to the model composed solely of SWE, the multivariate nomogram showed a higher but less significant performance (0.738 vs. 0.792, p=0.169, Fig 1D). However, the decision curve analysis showed that the model outperformed the single indicator of SWE in predicting endpoint events, especially those occured after 12 months of baseline (Fig 1E). Conclusion Intestinal stiffness assessed using SWE is an independent predictor of disease behavior progression in patients with CD. CD patients with SWE ≥12.75 kPa at diagnosis are prone to progress toward stricturing or penetrating diseases, which warrants timely intervention.