Biomarkers of Heart Failure in Pleural Fluid.
Chest. 2009 Apr 10;
Authors: Porcel JM, Martínez-Alonso M, Cao G, Bielsa S, Sopena A, Esquerda A
Background The objective of this study was to compare the diagnostic accuracy of pleural fluid B-type natriuretic peptide (BNP), amino-terminal proBNP (NT-proBNP) and ST2, which are biomarkers of myocyte stress, for diagnosing pleural effusions due to heart failure (HF). BNP and ST2 have not been previously evaluated in pleural fluid. Methods The three biomarkers were measured in the pleural fluid of 90 cardiac and 91 noncardiac effusions by commercially available methodologies. The area under the receiver operating characteristic curve (AUC) quantified the overall diagnostic accuracy of the tests. Results Pleural fluid NT-proBNP, BNP and ST2 demonstrated AUCs of 0.96, 0.90 and 0.59, respectively, for diagnosing effusions due to HF. The respective cutoff values of 1300 pg/mL and 115 pg/mL for NT-proBNP and BNP had the best discriminating properties. The reference level for BNP was particularly accurate in men > 75 years of age (AUC 0.98), but age, gender and serum creatinine did not influence the NT-proBNP levels. Of the 20 patients whose cardiac effusions were misclassified as exudates by Light's criteria, 18 (90%) and 14 (70%) would have been correctly categorized by NT-proBNP and BNP, respectively, whereas only 10 (50%) would have been appropriately classified by the serum-pleural protein gradient. Conclusions Pleural fluid NT-proBNP is very useful in establishing the diagnosis of HF-associated effusions, and it confirms this diagnosis better than pleural BNP. The measurement of NT-proBNP rather than serum to pleural protein gradient is recommended for identifying mislabeled cardiac transudates. Pleural fluid ST2 is not helpful in diagnosing HF.
PMID: 19363209 [PubMed - as supplied by publisher]