Apex Score: Predicting Flares in Small-Bowel Crohn's Disease After Mucosal Healing

Background Optimal strategies for using small-bowel capsule endoscopy (SBCE) in established small-bowel Crohn's disease (CD) remain uncertain. Mucosal healing (MH) has emerged as a valuable predictor of a flare-free disease. We aimed to evaluate the occurrence of disease flare on patients with small-bowel CD and MH, as well as to create a score identifying patients in higher risk for this outcome. Methods We analyzed consecutive patients submitted to SBCE for assessment of MH and included those where MH was confirmed. The incidence of disease flare was assessed during follow-up (minimum 12 months). A score predicting disease flare was created from several analyzed variables. Results From 47 patients with MH, 12 (25.5%) had a flare (versus 48.3% in excluded patients without MH; p = 0.01). Age <= 30 years (OR = 70; p = 0.048), platelet count >= 280 x 10(3)/L (OR = 12.24; p = 0.045) and extra-intestinal manifestations (OR = 11.76; p = 0.033) were associated with increased risk of CD flare during the first year after SBCE with MH. These variables were used to compute a risk-predicting score-the APEX score-which assigned the patients to having low (0-3 points) or high-risk (4-7 points) of disease flare and had excellent accuracy toward predicting disease relapse (AUC = 0.82; 95%CI 0.64-0.99). Conclusion Patients with small-bowel CD and MH were not free of disease flares on the subsequent year, despite presenting lower rates when compared to those without MH. The APEX score demonstrated excellent accuracy at stratifying patients relapse risk and guiding further therapeutic options for patients achieving MH.