Diagnostic Value of Lactate Dehydrogenase in Pericardial Effusions in Patients Undergoing Pericardiocentesis

Abstract

Background/Aims: Unlike pleural effusions or ascites, few studies have examined the role of chemical and cell-count parameters in the etiologic diagnosis of pericardial effusion. We determined the cut-off points of chemical parameters that can differentiate the causes of pericardial effusion. Methods: This study included 45 patients who underwent pericardiocentesis from 2003 to 2010. We examined the cell count and chemistry of blood and pericardial fluid, and divided the patients into a systemic group (the pericardium and myocardium were not invaded directly, such as in uremia and hypothyroidism) and a local inflammation group (the pericardium or myocardium was involved directly, such as in malignancy, tuberculosis, infection, and connective tissue disease). Results: Common causes of pericardial effusion requiring pericardiocentesis were malignancy (42.8%), iatrogenic (11.9%), and tuberculosis (9.5%). The pericardial lactate dehydrogenase (LDH) level and pericardial/serum (P/S) LDH ratio were higher in the local inflammation group than the systemic group (288.33 ± 143.9 vs. 2,372.07 ± 3,916.00 IU/L, p = 0.002, and 5.7 vs. 0.6, p = 0.007, respectively). The discrimination accuracy of the P/S LDH ratio (1.12) and pericardial fluid LDH level (435 IU/L) for predicting local inflammation was significant, as evidenced by the respective areas under the receiver operating characteristic curves of 0.84 (sensitivity 81.4%, specificity 81.5%) and 0.88 (sensitivity 83.3%, specificity 81.5%). Conclusions: The LDH level (435 IU/L) of pericardial fluid and P/S LDH ratio (1.12) in patients with a pericardial effusion can help to differentiate between systemic causes and other diseases directly involving the pericardium. (Korean J Med 2012;82:194-199)