Angiotensin-converting enzyme inhibitor-induced bowel angioedema: clinical features, diagnostic challenges, and recovery predictors from survival analysis: a systematic review of current reported cases.

Background: Angiotensin-converting enzyme inhibitor-induced bowel angioedema (ACEi-IAE) is a rare and frequently under-recognized condition. Its nonspecific gastrointestinal symptoms could lead to missed diagnoses, unnecessary procedures and inappropriate treatments. Given the scarcity of studies, we conducted a systematic review to summarize the clinical characteristics of ACEi-IAE, the diagnostic approach and factors predicting delayed recovery. Methods: Electronic databases, including MEDLINE, OVID and EMBASE, were used to identified eligible studies from inception to November 2024. Eligible cases were required to have a clear diagnosis of ACEi-IAE. Kaplan-Meier and multivariate Cox regression analyses were used to identify factors associated with delayed recovery time. Results: Our systematic review included 81 eligible studies, comprising 117 ACEi-IAE cases with a mean age of 50 years, of which 83% were female. Patients were mainly African Americans (50%) taking lisinopril (71%). All patients (100%) presented with abdominal pain and other non-specific features. The median recovery time was 48 h after discontinuing ACEi. Patients who had been taking lisinopril for a longer than average period (25.9 months) had a statistically significantly lower hazard ratio for recovery (adjusted hazard ratio [aHR] 0.39, 95% confidence interval [CI] 0.19-0.81; P=0.012), as did patients who had radiographic evidence of jejunal edema (aHR 0.29, 95%CI 0.11-0.74; P=0.010). Diagnostic criteria were proposed and summarized based on the findings. Conclusions: Clinicians should be aware of ACEi-induced bowel angioedema, particularly in ACEi users with non-specific abdominal pain. Implementation of our proposed diagnostic criteria is recommended to prevent unnecessary investigation and inappropriate treatment.