Introduction: Atrial fibrillation (AF) is a common comorbidity found in patients hospitalized due to different conditions. Its presence may lead to hemodynamic consequences that can affect patients mortality and morbidity. There are no large data studies evaluating the impact of atrial fibrillation in patients with acute pancreatitis. We aimed to determine if there is any difference in outcomes of patients admitted with acute pancreatitis in presence of AF versus non-AF population. Methods: A retrospective cohort study was done using the United States 2013 National Inpatient Sample, the largest publically available inpatient database in the United States. All patients with ICD-9 CM codes for a diagnosis of acute pancreatitis were included. No exclusion criteria were used. We considered inhospital mortality as primary outcome. Secondary outcomes were morbidity measured by intensive care unit (ICU) admission, shock, multi-organ dysfunction (MOD) and malnutrition; resource utilization measured by abdominal ultrasound (US), abdominal CT scan (ACT), length of hospital stay (LOS), total parenteral nutrition (TPN) use and total hospitalization charges. Patients were classified as having AF or no AF diagnosis based on ICD-9 CM codes. Odds ratios and means were calculated using multivariate regression analysis, after being adjusted for age, sex, race, Charlson Comorbidity Index, median income in the patient's zip code, hospital region, rural location, size and teaching status.Table 2Results: A total of 274,785 patients with acute pancreatitis were included. 14,085 (5.1%) had a diagnosis of atrial fibrillation. Mean age was 51 years and 47% were female. Mortality rate was 0.8% overall, 3.3% in AF and 0.6% in non-AF patients. Adjusted odds ratios, means and p values are shown in Table 1. On multivariate analysis, patients with AF had higher mortality rates (OR 1.87; 95% CI 1.41 - 2.49, p= < 0.01) compared to non-AF population. Regarding morbidity, ICU admission, shock and MOD were more common in AF patients, no malnutrition differences were found. For resource utilization, total charges, LOS, US and TPN use were higher in the AF group; ACT use was the same in both groups.Table 1: Adjusted Odds Ratios, Means and p-values for variables evaluated in patients diagnosed with acute pancreatitis with atrial fibrillation versus without atrial fibrillationConclusion: Atrial fibrillation is associated with increased risk of mortality and morbidity in patients admitted with AP. Additionally, AF affects resource utilization in patients with AP, as measured by LOS, hospitalization charges, TPN use and imaging tools like US.