P0474Transmural healing redefines remission in Crohn’s Disease: long-term outcomes from an argentine reference center

Abstract Background Mucosal healing (MH) is a key therapeutic target in Crohn’s disease (CD), yet endoscopy may underestimate residual inflammation. Cross-sectional imaging often reveals persistent transmural activity despite MH, and the long-term significance of transmural healing (TH) and its prognostic value require further investigation. This study aimed to assess the prognostic significance and clinical impact of transmural healing in Crohn’s disease. Methods We conducted a retrospective single-center cohort study including adults with confirmed CD who underwent magnetic resonance enterography (MRE), Doppler ultrasound (US), or CT enterography between Sept 2014 and Oct 2024, with ≥1 year of follow-up. Demographics, treatments, and disease course were retrieved. Univariate and multivariate analyses assessed associations between TH and adverse outcomes. Kaplan-Meier survival analysis evaluated long-term outcomes; curves were compared using the log-rank test. p 0.05 was considered significant. Results Of 514 CD patients, 92 met inclusion criteria. Mean age was 48 years (range 19–77), 35% were female, and median disease duration was 12 years. Median follow-up was 42 months (range 12–122). Ileal disease was present in 53.3%, ileocolonic in 45.7%. Behavior was non-stricturing/non-penetrating in 52.2%, stricturing in 40.2%, penetrating in 7.6%; perianal disease in 19.6%. Thirty-eight percent had prior bowel resection. At evaluation, 68% received biologics, 41.3% had prior anti-TNF exposure, and 15.2% used corticosteroids. MRE was performed in 70.7%, CT enterography in 4.3%, Doppler US in 25%; 27.2% had 1 modality. TH was achieved in 42.4%. In univariate analysis, compared to those without TH, patients with TH had lower rates of clinical relapse (12.8% vs 58.5%, p 0.001), corticosteroid use (2.6% vs 20.8%, p = 0.010), treatment optimization (5.1% vs 24.5%, p = 0.013), and escalation (10.3% vs 60.4%, p 0.001). Kaplan-Meier curves confirmed that patients achieving TH had a lower risk of clinical relapse (log-rank p 0.01) Figure 1. On multivariate analysis, TH was independently associated with reduced risk of relapse, therapy intensification, and corticosteroid use (HR 0.28, 95% CI 0.11–0.72, p = 0.008). Conclusion In this cohort of patients with longstanding CD, TH was associated with improved long-term outcomes. These findings support the inclusion of TH as a therapeutic target in future CD consensus guidelines. However, prospective randomized studies are required to assess the impact of TH on CD management. Conflict of interest: Abarca, Lucia: No conflict of interest Gómez, Estanislao Jesus: No conflict of interest Marturano, Maria Victoria: No conflict of interest Baron, Pablo Ezequiel: No conflict of interest Grana, Maria Florencia: No conflict of interest Gonzalez, Raquel Analia: No conflict of interest