P1148Transmural Improvement May Be a Practical and Acceptable Treatment Target in Crohn’s Disease

Abstract Background Transmural remission is associated with improved long-term outcomes in Crohn’s disease (CD), yet it is seldom achieved in routine practice. Identifying alternative therapeutic targets, such as transmural improvement, may support individualized treatment strategies. Methods A retrospective study was performed, including consecutive CD patients who underwent paired endoscopy and MRI enterography. Endoscopic remission was defined as SES-CD ≤3, corresponding to the absence of mucosal ulcers aside from small aphthae (5 mm) or erosions, 50% segment involvement, and no stricture. Endoscopic improvement was defined as ≥ 50% reduction in SES-CD from baseline. Outcomes included CD-related surgery, hospitalization, steroid use, treatment change, and phenotype progression. Multivariable regression assessed predictors of adverse outcomes. Results A total of 411 patients were included. Transmural improvement, although inferior to transmural remission, yielded better outcomes than no transmural improvement for surgery (0.8% vs 16.3% vs 46.8), hospitalization (4.1% vs 30.8% vs 55.4), steroid use (8.3% vs 34.6% vs 51.1), treatment change (12.4% vs 51.9% vs 67.2), and phenotype progression (5.9% vs 15.4% vs 31.0) (all p ≤ 0.035). Transmural improvement reduced the risk of surgery (HR 0.294; p 0.001), hospitalization (HR 0.465; p 0.001), steroid use (HR 0.604; p = 0.011), treatment change (HR 0.690; p = 0.025), and phenotype progression (OR 3.332; p = 0.002). Among patients with transmural improvement, stricturing disease predicted surgery (HR 4.043; p = 0.008) and hospitalization (HR 3.704; p = 0.005). Conclusion Transmural improvement may be an acceptable alternative treatment target in CD patients unable to achieve transmural remission. However, in stricturing disease, transmural improvement may be insufficient, as these patients remain at higher risk for adverse outcomes. Conflict of interest: Dr. Tubal Bronze, Sérgio Manuel: No conflict of interest Fernandes, Samuel Raimundo: None to declare Rodrigues, Inês: No conflict of interest Saraiva, Sofia: No conflict of interest Ana Rita, Gonçalves: No conflict of interest Ana, Valente: No conflict of interest Correia, Luis: No conflict of interest