81 Background: Recent data suggest an association between cardiovascular disease burden and biliary cancer patients. However, the outcomes of hospitalized patients for biliary-pancreatic malignancy with concurrent acute decompensated heart failure (ADHF) are not well understood. Therefore, our objective is to assess the impact of ADHF on patients hospitalized for biliary-pancreatic malignancy. Methods: We used the 2020 U.S. National Inpatient Sample (NIS) to study patients hospitalized for biliary tract and pancreatic malignancy with concurrent acute decompensated heart failure (ADHF) identified by ICD-10 CM codes. Adjusted odds ratios (aORs) for predefined outcomes were determined via multivariable logistic and linear regression analyses. The primary outcome examined was inpatient mortality, while secondary outcomes included complications related to various body systems. Results: We identified 43,009 patients with a primary discharge diagnosis of biliary tract and pancreatic cancer. The mean age was 68.5 years; 49.4% were female. Caucasians accounted for 68%, followed by Hispanics (13%). Of these, 6.27% (3,699/43,009) had a concurrent diagnosis of heart failure. In the survey's multivariable logistic and linear regression analysis, accounting for patient and hospital confounding factors, ADHF demonstrated significant associations with higher in-hospital mortality (aOR 1.63; 95% CI 1.09, 2.44, p = 0.015). In addition, a significant association between ADHF and various adverse in-hospital outcome was observed including prolonged mean length of stay (Beta 1.45; 95% CI 0.67, 2.24, p < 0.001), increased mean total hospital cost (Beta 3,757; 95% CI: 2,641, 36,630, p = 0.024), elevated risk of shock (aOR 2.75; 95% CI: 1.77, 4.26, p < 0.001), higher risk of sepsis (aOR 1.71, 95% CI: 1.09, 2.68, p = 0.018), increased risk of acute respiratory failure (aOR 3.18, 95% CI: 2.25, 4.51, p < 0.001), and heightened risk of acute kidney injury (aOR 1.57; 95% CI: 1.24, 1.99, p < 0.001). Conclusions: Among patients hospitalized for biliary-pancreatic malignancy, concurrent ADHF is linked to increased mortality risk and various in-hospital adverse complications. Additional long-term studies are required for a comprehensive understanding of this association.