Malignant pericardial effusion: A high-risk marker for in-hospital mortality and cardiovascular collapse in cancer patients.

Abstract

e24032 Background: Malignant pericardial effusion (MPE) is a known complication of advanced malignancy and may reflect aggressive tumor biology or acute hemodynamic compromise However, its independent association with in-hospital mortality across major cancer types remains incompletely defined. We evaluated whether MPE predicts in-hospital mortality and adverse outcomes among patients hospitalized with malignancy. Methods: We conducted a retrospective cohort study using the National Inpatient Sample (NIS). Adult hospitalizations with a primary admission diagnosis of lung cancer, breast cancer, or lymphoma were identified and stratified based on the presence of malignant pericardial effusion using ICD-10 code I31.31. The primary outcome was in-hospital mortality. Secondary outcomes included length of stay (LOS), cardiac tamponade, and cardiogenic shock. Multivariable logistic and linear regression models were used to adjust for demographics and comorbidity burden. Adjusted odds ratios (aORs) and adjusted mean differences are reported. Results: A total of 5,388,493 hospitalizations were included, of which 1,005 (0.01%) had malignant pericardial effusion. The cohort comprised lung cancer (51.6%), lymphoma (27.1%), and breast cancer (22.0%). Patients with MPE were younger (mean age 62.3 vs 67.0 years, p < 0.001), more often female (63.2% vs 58.1%), and had a higher proportion of Hispanic and Asian patients (p < 0.001). Overall in-hospital mortality was 7.0%. Mortality was significantly higher among patients with MPE compared with those without (12.4% vs 7.0%, p < 0.001). After multivariable adjustment, MPE remained independently associated with increased in-hospital mortality (aOR 1.88, p = 0.004). Mean LOS was longer in the MPE group (8.9 vs 6.1 days), corresponding to an adjusted increase of 2.47 days (p < 0.001). Additionally, MPE was strongly associated with cardiac tamponade (aOR 158.2, p < 0.001) and cardiogenic shock (aOR 4.40, p < 0.001). Conclusions: Among patients hospitalized with lung cancer, breast cancer, or lymphoma, malignant pericardial effusion is independently associated with significantly higher in-hospital mortality, prolonged length of stay, and severe cardiovascular complications. These findings highlight MPE as a high-risk clinical marker that may warrant early recognition and heightened inpatient monitoring.