P192 Comparison of Endoscopic Scoring System and Simplified Magnetic Resonance Index of Activity in Patients with Small Bowel Crohn’s Disease: Basis for Therapeutic Plan?

Abstract Background The newly derived simplified magnetic resonance index of activity (MARIAs) has not been verified in comparison with balloon-assisted enteroscopy (BAE) for patients with small-bowel Crohn’s disease (CD). We studied the correlation of MARIAs with simple endoscopic score for Crohn's disease (SES-CD) of ileum based on magnetic resonance enterography (MRE) and BAE, respectively, in patients with small-bowel CD. In addition, we determined the impact of these tools on clinical decision-making. Methods Fifty patients with small-bowel CD who underwent BAE and MRE concurrently within three months from September 2020 to June 2021, followed by the reference date of December 2021, were enrolled. The primary outcome was correlation between the active score of ileal SES-CD (ileal SES-CDa)/ileal SES-CD and MARIAs based on BAE and MRE in segmented ileum. The active/severe disease index was set as ileal SES-CDa/ileal SES-CD of 5/7 and MARIAs of 1/2. The secondary outcome was the basis for step-up treatment. Results The ileal SES-CDa/ileal SES-CD and MARIAs showed strong associations (R=0.76, p<0.001/R=0.78, p<0.001). The AUROC of MARIAs for ileal SES-CDa ≥ 5 was 0.92 (95% CI: 0.88-0.97). The AUROC of the MARIAs for ileal SES-CD ≥ 7 was 0.92 (95% CI: 0.87-0.97). Among the 26 patients who experienced step-up treatment after BAE and MRE, 23 patients showed active disease on both BAE and MRE. Conclusion We validated the applicability of MARIAs compared to the BAE-based ileal SES-CDa/SES-CD. Assessment of disease activity based on both BAE and MRE could optimize the management of small-bowel CD patients.