Pericardiocentesis versus window formation in malignant pericardial effusion: trends and outcomes

Objectives Malignant pericardial effusion (MPE) in patients with cancer is associated with poor prognosis. This study aimed to compare clinical outcomes in patients with cancer who underwent pericardiocentesis versus pericardial window formation.Methods In the present study, 765 consecutive patients with cancer (mean age 58.4 years, 395 men) who underwent pericardial drainage between 2003 and 2022 were retrospectively analysed. All-cause death and MPE recurrence were compared based on the drainage method (pericardiocentesis vs pericardial window formation) and time period (period 1: 2003-2012; period 2: 2013-2022).Results Pericardiocentesis was performed in 639 (83.5%) patients and pericardial window formation in 126 (16.5%). There was no difference in age, sex distribution, proportion of metastatic or relapsed cancer, and chemotherapy status between the pericardiocentesis and pericardial window formation groups. Difference was not found in all-cause death between the two groups (log-rank p=0.226) regardless of the period. The pericardial window formation group was associated with lower MPE recurrence than the pericardiocentesis group (6.3% vs 18.0%, log-rank p=0.001). This advantage of pericardial window formation was more significant in period 2 (18.1% vs 1.3%, log-rank p=0.005). In multivariate analysis, pericardial window formation was associated with lower MPE recurrence (HR: 0.31, 95% CI: 0.15 to 0.63, p=0.001); younger age, metastatic or relapsed cancer, and positive malignant cells in pericardial fluid were associated with increased recurrence.Conclusion In patients undergoing pericardial drainage for MPE, pericardial window formation showed mortality outcomes comparable with pericardiocentesis and was associated with lower incidence of MPE recurrence.