N-terminal pro-B-type natriuretic peptide as a marker of disease severity in patients with pericardial effusions

Abstract

Background/aims: N-terminal pro-B-type natriuretic peptide (NT-proBNP) has recently been introduced as a useful marker in diagnosing underlying disease in patients with dyspnea and for determining the prognosis of patients with heart failure. The purpose of this study was to evaluate the value of the NT-proBNP as a marker of disease severity in patients with pericardial effusions.

Methods: We enrolled 69 consecutive patients who showed moderate or large pericardial effusion with preserved left ventricular (LV) systolic function; 42 patients finally participated in the study, and 13 (31.0%) of them showed cardiac tamponade. We analyzed the etiologies, the clinical and echocardiographic variables, and the serum NT-proBNP levels in these patients.

Results: The mean NT-proBNP level was 751+/- 1002 ng/L (range 5 to 5289), and the median level was 385 ng/L (interquartile range 152 to 844). The NT-proBNP levels were higher in those patients with jugular venous distension (p=0.002), pulsus paradoxus (p=0.016), heart rate > or = 100/min (p=0.006), cardiac tamponade (p=0.001), large pericardial effusion (p=0.029), exaggerated respiratory variation of the transmitral inflow (p=0.006), or plethora of the inferior vena cava (p=0.01). The NT-proBNP levels showed significant correlation with heart rate (r=0.517, p<0.001) and the diameter of the inferior vena cava (r=0.329, p=0.03).

Conclusions: NT-proBNP may be useful as a marker of disease severity in patients suffering from pericardial effusion, but further prospective studies with more patients will be needed.

Figure 1

Distribution of ln NT proBNP in patients with pericardial effusion, according to heart rate (A) and presence or absence of jugular venous distension, pulsus paradoxus, and cardiac tamponade (B, C and D). The plots display the median, and 25^th and 75^th percentiles (lower and upper limits of the boxes), along with error bars. JVD, jugular venous distension; PP, pulsus paradoxus; Tamp, cardiac tamponade.

Figure 2

Correlation between ln NT-proBNP level and heart rate (A), and between ln NT-proBNP level and IVC diameter (B).

Figure 3

Receiver-operating characteristic curve analysis of ln NT-proBNP level, according to cardiac tamponade. Area under the curve was 0.83 (95% confidence interval [CI] 0.70-0.96), and optimal cut off value for prediction of the presence of cardiac tamponade was 436 ng/L.

Figure 4

Model chi-square test demonstrating the increased diagnostic value of NT-proBNP when combined with clinical parameters for the diagnosis of cardiac tamponade. Clinical parameters include systolic blood pressure and heart rate.