Clinical Characteristics and Outcomes of Patients Undergoing Pericardiocentesis for Pericardial Effusion: A Single-Center Experience with Exploratory Inflammatory Biomarker Analysis.

Objective: We aim to characterize patients undergoing pericardiocentesis for clinically significant pericardial effusion and explore differences in inflammation-based biomarkers according to malignancy status and one-year outcome. Methods: We retrospectively evaluated 113 consecutive patients who underwent pericardiocentesis between January 2021 and January 2026. Clinical, laboratory, pericardial fluid, cytopathological, recurrence, and mortality data were analyzed. NLR, PLR, SII, SIRI, and PIV were assessed as secondary exploratory biomarkers. Results: Malignancy-associated pericardial effusion was present in 36 patients (31.9%), while 77 (68.1%) had non-malignant effusion. The malignancy-associated group had more frequent dyspnea (77.8% vs. 55.8%; p = 0.025), effusion >15 mm (80.6% vs. 58.4%; p = 0.021), hemorrhagic fluid (75.0% vs. 54.5%; p = 0.038), and recurrence (38.9% vs. 20.8%; p = 0.042). Malignant cells were identified in pericardial fluid cytology in 15/36 patients (41.7%). One-year mortality was 22.2% versus 13.0% (p = 0.211). NLR, PLR, SII, SIRI, and PIV did not differ significantly according to malignancy status or one-year mortality; NLR, PLR, and SIRI were higher in the exploratory lung cancer subgroup. Conclusions: Malignancy-associated pericardial effusion showed distinct clinical and fluid characteristics. No statistically significant associations were detected between the evaluated inflammation-based biomarkers and malignancy status or one-year mortality; however, the exploratory design and limited number of outcome events warrant cautious interpretation.