Correlation of Serum and Pericardial Fluid Amino Terminal Pro-B-type Natriuretic Peptide

Objective: To investigate the correlation of pericardial fluid and serum NT-proBNP levels in patients during coronary artery bypass grafting (CABG).

Study Design: Crossectional study.

Place and Duration of the Study: This study was conducted over a period of one year from March 2010 to March 2011 in Physiology Department Ziauddin University, Clifton Karachi.

Methodology: A crossectional study was done on 50 patients, undergoing CABG. Both the samples of serum and pericardial fluid were collected during CABG and NT-proBNP levels were assessed by an electrochemiluminescence immunoassay. The log transformation of NT-proBNP concentrations was done. We investigated the correlation of the pericardial fluid and serum levels of log NT-proBNP.

Results: Pericardial fluid log NT-proBNP was estimated to be 2.7±0.54 pg/ml in contrast to a serum level of 2.2±0.6 pg/ml in 50 CABG patients. It was found that pericardial fluid NT-proBNP levels were significantly correlated with its serum levels with an r value of 0.85 and a p-value of < 0.0001. The pericardial fluid- serum ratio has been estimated to be 1.25.

Conclusion: Serum NT-proBNP levels have significant correlation with its pericardial fluid levels. It can be used alone in the clinical practice provided kidneys function normally.