Ability of Pelvic Magnetic Resonance Imaging to Predict Clinical Course of Perianal Fistula in Paediatric Crohn's Disease Patients

Which magnetic resonance imaging feature is associated with treatment response in perianal fistulizing Crohn's disease?

PURPOSE

Perianal fistulae are disabling complications of Crohn's Disease. Magnetic resonance imaging features could predict treatment response. This study aimed to determine which magnetic resonance imaging features were predictive of long-term clinical outcome in real life.

METHODS

Consecutive patients with magnetic resonance imaging performed in a tertiary center were retrospectively analyzed. Clinical outcome was defined as a need for surgical drainage of perianal fistulae or hospitalization. Clinical data and magnetic resonance imaging features (MAGNIFI-CD and Van Assche indices, degree of fibrosis) were studied.

RESULTS

Fifty-two patients were included between 2016 and 2019 with a mean follow-up of 38 months [29;48]. A higher MAGNIFI-CD index (17/25 versus 11/25; p < 0.01) was associated with an unfavorable long-term clinical outcome. The MAGNIFI-CD index showed an area under the curve of 0.74 (p = 0.006) to predict the clinical outcome of perianal Crohn's disease, compared to 0.67 (p < 0.05) for the Van Assche index. At a threshold of 13 for the MAGNIFI-CD index, sensitivity was 75% (CI95% [59%; 86%]) and specificity was 69% (CI95% [44%; 86%]). No association was found between the degree of fibrosis and clinical outcome, but the association of a high degree of fibrosis (≥ 80%) and of a low MAGNIFI-CD index (≤ 13) was predictive of clinical outcome (p < 0.01).

CONCLUSION

The MAGNIFI-CD index could be used to predict clinical outcome in perianal Crohn's disease. In combination with a high degree of fibrosis, a low MAGNIFI-CD index, may help to identify patients with the best prognosis.

Development of an MRI-Based Prediction Model for Anti-TNF Treatment Failure in Perianal Crohn's Disease: A Multicenter Study

BACKGROUND & AIMS

Clinical and radiologic variables associated with perianal fistula (PAF) outcomes are poorly understood. We developed prediction models for anti-tumor necrosis factor (TNF) treatment failure in patients with Crohn's disease-related PAF.

METHODS

In a multicenter retrospective study between 2005 and 2022 we included biologic-naive adults (>17 years) who initiated their first anti-TNF therapy for PAF after pelvic magnetic resonance imaging (MRI). Pretreatment MRI studies were prospectively reread centrally by blinded radiologists. We developed and internally validated a prediction model based on clinical and radiologic parameters to predict the likelihood of anti-TNF treatment failure, clinically, at 6 months. We compared our model and a simplified version of MRI parameters alone with existing imaging-based PAF activity indices (MAGNIFI-CD and modified Van Assche MRI scores) by De Long statistical test.

RESULTS

We included 221 patients: 32 ± 14 years, 60% males, 76% complex fistulas; 68% treated with infliximab and 32% treated with adalimumab. Treatment failure occurred in 102 (46%) patients. Our prediction model included age at PAF diagnosis, time to initiate anti-TNF treatment, and smoking and 8 MRI characteristics (supra/extrasphincteric anatomy, fistula length >4.3 cm, primary tracts >1, secondary tracts >1, external openings >1, tract hyperintensity on T1-weighted imaging, horseshoe anatomy, and collections >1.3 cm). Our full and simplified MRI models had fair discriminatory capacity for anti-TNF treatment failure (concordance statistic, 0.67 and 0.65, respectively) and outperformed MAGNIFI-CD (P = .002 and < .0005) and modified Van Assche MRI scores (P < .0001 and < .0001), respectively.

CONCLUSIONS

Our risk prediction models consisting of clinical and/or radiologic variables accurately predict treatment failure in patients with PAF.

Comparative Effectiveness of Biologic Therapies in Preventing Penetrating Complications in Patients With Crohn's Disease

BACKGROUND & AIMS

Comparative effectiveness of biologics in preventing penetrating disease (PD) in Crohn's disease (CD) is not well established. We compared the risk of developing luminal and perianal PD (LPD and PPD) between biologics used as first-line therapies.

METHODS

Adults (>17 years) with CD who initiated their first biologic (anti-tumor necrosis factor [anti-TNF], ustekinumab [UST], or vedolizumab [VDZ]) were identified from Merative Commercial Database (2006 and 2020). We excluded preexisting PD using a minimum look-back period of 1 year. Cohorts were balanced by inverse probability of treatment weighting based on age, sex, comorbidities, prior CD surgery, and CD severity. Pairwise comparisons were performed by Cox proportional hazards models, adjusted for immunomodulator exposure, and with biologic exposure treated as a time-dependent variable based on a medication possession ratio of 0.8.

RESULTS

Our analysis included 40,693 patients: 93% anti-TNF, 3% UST, and 4% VDZ. After inverse probability of treatment weighting all comparisons were well balanced. Anti-TNF was protective against LPD (hazard ratio, 0.66; 95% confidence interval, 0.55-0.78; P < .0001) and PPD (hazard ratio, 0.88; 95% confidence interval, 0.80-0.96; P = .0045) compared with VDZ and LPD (hazard ratio, 0.37; 95% confidence interval, 0.30-0.46; P < .0001) compared with UST. There were no significant differences in the risk of LPD and PPD between VDZ and UST. These results were similar after limiting the study period to after 2016.

CONCLUSIONS

Anti-TNF therapy was associated with a lower risk of LPD and PPD compared with VDZ, and lower risk of LPD compared with UST. Further studies are needed to validate these findings and to determine potential reasons for these differences.