Background: Acute mesenteric ischemia (AMsI) is an infrequent but catastrophic condition associated with high mortality and morbidity. Thromboembolism due to atrial fibrillation (AF) is one of the causes of AMsI, but the overall effect of AF and anticoagulation on outcomes in these patients is not known. The objectives of the study were to evaluate the difference in outcomes in patients with and without AF developing AMsI and the impact of anticoagulation in AF patients on these outcomes.

Methods: We identified patients with a discharge diagnosis of AMsI in the National Inpatient Sample from 2007. Multivariate regression model was used to compare outcomes of AMsI in patients with and without AF, and the impact of anticoagulation on outcomes also was determined.

Results: We identified 48,872 patients with a discharge diagnosis of AMsI, of which 8,306 had a co-diagnosis of AF. Of the 8,306 with AF, 680 patients also had a co-diagnosis of chronic anticoagulation. Patients with AF were more likely to be older and to have hypertension, heart failure, valvular heart disease, peripheral vascular disease, chronic lung disease and renal disease. After adjusting for potential confounders, AF remained independently associated with higher mortality (OR 1.59, 95% CI 1.3-1.9, p=0.0001). Patients on anticoagulation were less likely to have complications including small bowel resections (25% vs 16%, p=0.03), colectomy (25% vs 11%, p=0.0002), shock (10% vs 17%, p=0.02) and need for intubation (10% vs 35%, p=0.0001), but the overall inpatient hospital mortality was not different from those not on chronic anticoagulation. The length of hospital stay and hospital charges were significantly lower in the anticoagulation group.

Conclusions: In patients with acute mesenteric ischemia, those with AF had a significantly higher mortality. Among AF patients, those on anticoagulation had a lower incidence of complications like small bowel resection, colectomy, shock and need for intubation. Length of stay and hospital charges also were significantly lower in the anticoagulation group.