Risk Factors and Mortality of Acute Mesenteric Ischemia in IBD Patients: A United States Nationwide Inpatient Sample Database Study 2009-2018

Introduction: Inflammatory bowel disease (IBD), ulcerative colitis (UC) or Chron’s disease (CD), is associated with high morbidity and mortality. Various comorbidities are associated with mortality in IBD, thromboembolism being an established risk factor. Meta-analyses have shown a significant increase in acute mesenteric ischemia in IBD patients prompting evaluation of associated risk factors. Methods: This is a nationwide retrospective observational serial cross-sectional analysis using the National Inpatient Sample (NIS) database. Adults from 2009 to 2018, hospitalized with a primary ICD-9/10 diagnosis of AMI and secondary diagnosis of IBD, were included. Univariate and multivariate logistic regression was used for binary outcomes and linear regression analysis was used for continuous outcomes, with a 95% confidence interval (C.I.). A P-value < 0.05 was statistically significant in this subset. Results: From 2009-2018; 1,718,736 patients with IBD were admitted. Incidence of AMI admission in IBD patients was 0.34% (N=5843). UC had AMI admission rates of 0.55% (95% CI: 0.50-0.59) vs CD with AMI 0.32% (95% C.I.: 0.31-0.35, P< 0.01). For patients admitted with AMI, mean age was 60.97 years [60.16-61.78], females were 66.89% [64.81-68.91] and Caucasians were 77.12% [75.07-79.06]. On multivariate logistic regression analysis, risk factors for AMI in IBD patients were Age >60 adjusted Odds Ratio aOR=2.24 (95% CI: 1.95-2.57, P< 0.01), female aOR=1.47 (95% CI: 1.29-1.67, P< 0.01), UC aOR=2.45 (95% CI: 2.16-2.78, P< 0.01), malnutrition aOR=1.31(95% CI: 1.11-1.54, P< 0.01), coronary artery disease (CAD) aOR =1.54 (95% CI: 1.29-1.84, P< 0.01), chronic obstructive pulmonary disorder (COPD) aOR=1.38 (95% CI: 1.14-1.66, P< 0.01). Mortality in IBD patients admitted with AMI was 1.32 % (95% CI: 0.91-1.92). Mortality and hospital resource utilization were significantly higher in IBD patients admitted with AMI vs without AMI. Conclusion: UC, Age >60, CAD, malnutrition, female gender, and COPD were significantly associated with AMI in IBD with strongest association first. Patients with UC had a statistically higher AMI admission rate compared to CD. Mortality and resource utilization among patients with IBD and AMI was significantly higher compared to those without AMI. Identifying IBD patients with intervenable comorbidities associated with increased AMI incidence could yield better risk stratification reducing mortality and spending while increasing safety.