Defining Endoscopic Remission in Crohn's Disease: MM-SES-CD and SES-CD Thresholds Associated with Low Risk of Disease Progression.

OBJECTIVE: We assessed Modified Multiplier Simple Endoscopic Score for Crohn's disease (MM-SES-CD) and SES-CD thresholds that are best associated with low likelihood of long-term disease progression.

DESIGN: Data from 61 patients with early CD who participated in the CALM long-term extension study were used as the derivation cohort and validated using the McMaster IBD database (n=99). The primary outcome was disease progression (new internal fistula/abscess, stricture, perianal fistula or abscess, CD-related hospitalization or surgery) since the end of the CALM trial. Optimal MM-SES-CD and SES-CD thresholds were determined using the maximum Youden index. Receiver operating characteristic curve analyses compared threshold scores of remission definitions on disease progression.

RESULTS: In the derivation cohort, based on the maximum Youden index, the optimal thresholds associated with a low likelihood of disease progression were MM-SES-CD <22.5 and SES-CD <4. A significantly greater proportion of patients with a MM-SES-CD ≥22.5 had disease progression as compared to patients in the derivation cohort with MM-SES-CD <22.5 [10/17 (58.8%) vs. 3/44 (6.8%), p<0.001]. Similarly, a significantly greater number of patients with SES-CD ≥ 4 had disease progression compared to those with a SES-CD <4 [11/25 (44.0%) vs. 2/36 (5.6%), p<0.001]. Compared to other clinical or endoscopic remission definitions, which demonstrated poor to fair accuracy, MM-SES-CD <22.5 performed the best for predicting disease progression [AUC: 0.81 (95%CI: 0.68-0.94), p<0.001]. These thresholds were confirmed in the validation cohort.

CONCLUSIONS: Achievement of MM-SES-CD <22.5 or SES-CD <4 in patients with ileocolonic or colonic CD is associated with low risk of disease progression and may be suitable targets in clinical trials and practice for endoscopic healing.