Pericardial effusion in cancer patients is associated with a poor prognosis. The treatment objectives should include symptom relief and minimizing recurrences that require further intervention. Current guidelines recommend pericardiocentesis as a Class I indication for these patients, yet some studies support pericardial window as a strategy with comparable clinical outcomes and lower recurrence, although evidence remains insufficient. This study aimed to compare clinical outcomes (recurrence and all-cause mortality) based on the selected drainage method (pericardiocentesis versus pericardial window) and over a 10-year interval to adjust results to advancements in chemotherapy treatments. 

Malignant pericardial effusion in cancer patients usually arises from tumor invasion, though it can also be a secondary effect of treatment. Regardless of the cause, it is linked to poor prognosis, significant quality of life reduction, treatment interruption, and high recurrence rates. In severe cases or those compromising the patient’s hemodynamic stability, evacuation is indicated. Techniques for this include percutaneous and surgical approaches, with various studies aiming to demonstrate superiority regarding mortality, recurrence, recovery, etc. The significant increase in cancer patient survival, along with the emergence of new drugs and therapies, emphasizes the need to prevent recurrence in patients with neoplastic pericardial effusion and review the strategies for achieving this. 

This single-center retrospective cohort study included 874 cancer patients who underwent pericardial drainage between January 2003 and December 2022, excluding those undergoing concurrent cardiac surgery or those with effusion from unidentified causes. Patients were compared based on the drainage method used (pericardiocentesis versus pericardial window) over two time periods (2003–2012 and 2013–2022). The choice of procedure followed clinical judgment and clinical guideline recommendations. The analyzed outcomes were effusion recurrence (need for reintervention or reappearance of pericardial effusion with a separation of pericardial layers >20mm on follow-up echocardiogram) and all-cause mortality. Subgroups were created to analyze factors associated with recurrence. The log-rank test compared clinical outcomes between the two groups, and a multivariate model was constructed using clinical variables with p < .100 in univariate analysis and variables with established clinical significance from prior studies.

The mean follow-up was 91 days. There was no difference in all-cause mortality (death within the first 24 hours and at 30 days) between the two groups. Recurrence of pericardial effusion was significantly higher in the pericardiocentesis group (18%) than in the pericardial window group (6.3%, p = .01). Comparing outcomes by period, as expected, survival rates improved in the second period, with a trend toward less frequent pericardial window procedures. Although all-cause mortality did not differ between groups over time, 30-day mortality was higher in the pericardial window group (p = .01). Conversely, effusion recurrence was greater in the pericardiocentesis group than in the pericardial window group during the second period (p = .005). In univariate analysis, pericardial window was associated with lower effusion recurrence, while younger age (<55 years), metastatic or relapsed cancer, and positive malignant cell cytology in pericardial fluid were risk factors for recurrence (p = .001). 

COMMENTARY: 

Malignant pericardial effusion significantly impacts cancer patients by reducing quality of life, survival, and necessitating interruptions in specific therapy. Despite the importance of recurrence prevention, the first-line intervention remains controversial. Some prior studies have shown positive results using open, percutaneous, and minimally invasive techniques (mediastinoscopy/videothoracoscopy) for preventing recurrence, but with a limited number of patients. Other retrospective studies have found similar outcomes when comparing pericardiocentesis and pericardial window regarding recurrence, associating the latter with higher complication and mortality rates. This study ultimately included 765 individuals, allowing for a more robust statistical analysis than in previous studies. Although mortality outcomes showed no differences, recurrence rates were lower in those who underwent a pericardial window (18% vs. 6.3%). 

An additional contribution was the comparison of both techniques over two different time periods. The improvement and increased interest in new drugs and therapies for cancer patients are evident. The study also confirmed the advantage of pericardial window in the most recent period (2013–2022). Minimally invasive approaches, such as videothoracoscopy, seem better suited to the patient’s condition, offering an alternative to pericardiocentesis by providing pleuropericardial communication and not merely draining the cavity, thus reducing the recurrence risk. 

In terms of factors associated with recurrence, previous studies have shown that the primary cancer type, age, and chemotherapy response could be linked. This study found that younger age (<55 years), metastatic cancer, and positive malignant cell cytology in pericardial fluid are associated with higher recurrence, suggesting that cancer patients with these characteristics might initially benefit from a pericardial window as a drainage method, although randomized studies are needed to explore this new hypothesis. 

REFERENCE: 

Lee J, Kim K, Gwak S, Lee H, Cho I, Hong G, et al. Pericardiocentesis versus window formation in malignant pericardial effusion: trends and outcomes. Brittish Medical Journal. 2024 Feb; 110:863–871. doi:10.1136/heartjnl-2023-323542.