Outcomes of malignant pericardial effusion associated with solid cancers based on treatment modality.
Authors: Kannayiram Sandhya Shri , Murthi Mukunthan , Mariappan Aathi Lakshmi , Velagapudi Sujitha , Khanal Smriti , Desai Palak 
Published: June 2022

e18712 Background: Malignant pericardial effusions (MPE)/Cardiac Tamponade (CT) are often severe manifestations of malignancy, and patients with significant effusions have reduced survival. The most commonly associated solid cancers with MPE are cancers of the lung (L), Breast (B), Esophagus (E), Stomach (S), and Melanoma (M). The data on in-hospital outcomes of MPE based on the treatment modality is relatively limited. Methods: We performed a retrospective study using the National Inpatient Sample (NIS) database from 2016-2019 and identified all admissions with a concomitant discharge diagnosis of MPE/CT and solid cancer (L/B/E/S/M) using ICD 10 codes. These patients were divided into 3 subgroups based on the method of treatment: percutaneous pericardiocentesis only (PP), surgical pericardiotomy only (SP), or both (PP+SP). The three subgroups were compared for outcomes of inpatient mortality, Length of stay (LOS), and total hospitalization charges (THCG). Statistical analysis was done using t-test, chi-square test, and multivariate logistic analysis. Results: 63,939 patients met inclusion criteria (combining the five cancers as above). Of those, 8925, 6119, and 929 patients underwent PP, SP, and both, respectively. The mean age of patients in all three groups was 62 years. Majority of the patients in the three groups were of white ethnicity (69.8%, 72.03%, 60.89 %) and were admitted in large-sized (60%) urban teaching hospitals (82%) and had Medicare (45%). The PP and SP group had more females (54%,56%), and the PP+SP group had a higher proportion of males (53%). 13%,9%, and 14% of the PP, SP, and PP+ SP group patients died during the hospitalization. In comparison to PP group, patients in SP group had a significant decrease in mortality (aOR 0.77, 95% CI 0.61-0.97, p = 0.02*) and the mortality did not change in PP+SP group (aOR 1.10, 95% CI 0.69-1.74, p = 0.6).The mean LOS was 8 days, 9 days, and 12 days in PP, SP, and PP+ SP groups (p < 0.0001*), and the THCG per admission was higher by $28,457 in the SP group and $60,282 in the PP+SP group (p < 0.0001*). Furthermore, Black patients with MPE (aOR = 1.463,95% CI = 1.09-1.95, p = 0.01*) and Failure to thrive comorbidity (aOR = 2.47,95% CI = 1.37-4.4, p = 0.003*) had an increase in mortality regardless of the procedure type. Conclusions: Patients with MPE who underwent surgical pericardiotomy had lower mortality than those who underwent percutaneous pericardiocentesis. In addition, surgical and combined interventions resulted in higher healthcare resource utilization (LOS and THCG). This study highlights the treatment-based mortality difference and notes important trends in demographics. These findings suggest a mindful decision on the type of treatment intervention for MPE. Further studies are needed to evaluate the reasons for racial differences in MPE outcomes and ways to mitigate them. *p value = < 0.05 was considered statistically significant ;aOR = Adjusted Odds Ratio.