N-terminal prohormone brain natriuretic peptide as a marker for detecting low functional class patients and candidates for cardiac transplantation: linear correlation with exercise tolerance.
BACKGROUND
N-terminal prohormone brain natriuretic peptide (NT Pro BNP) plasma levels have been associated with indices of left ventricular (LV) function and aerobic capacity in heart failure. The aim of our study was to use NT Pro BNP for the prediction of low functional class patients and also to detect candidates for cardiac transplantation.


METHODS
We studied 100 patients with impaired left ventricular (LV) function. Mean LV ejection fraction (LVEF) was 35% +/- 9%. Blood samples for NT Pro BNP assessment were taken at baseline during treadmill exercise testing. LV cavity diameters, left atrial size, and LVEF were measured by echocardiography.


RESULTS
Plasma levels of NT Pro BNP correlated significantly with peak oxygen consumption (VO(2)) values (r = -0.77, p < 0.001). LVEF correlated well with NT Pro BNP (r = -0.67, p < 0.001). NT Pro BNP plasma levels correlated strongly with New York Heart Association functional class (r = 0.70, p < 0.001). NT Pro BNP values exceeding 335 pg/ml showed 83% sensitivity and 76% specificity for detecting VO(2) values below 20 ml/kg/min (area under the curve [AUC] = 86%, p < 0.001). NT Pro BNP plasma levels exceeding 1,190 pg/ml showed 83% sensitivity and 86% specificity for detecting VO(2) of less than 14 ml/kg/min (AUC = 90%, p < 0.001). NT Pro BNP plasma levels exceeding 1,610 pg/ml showed 87% sensitivity and specificity 82% for detecting VO(2) of less than 10 ml/kg/min (AUC = 90%, p < 0.001). NT Pro BNP plasma levels exceeding 680 pg/ml showed 91% sensitivity and 73% specificity for detecting LVEF of less than 28% (AUC = 86%, p < 0.001).


CONCLUSIONS
NT Pro BNP plasma levels correlate both with LVEF and aerobic capacity, can predict low functional cardiopulmonary exercise capacity in patients with impaired left ventricular function, and are useful for detecting candidates for cardiac transplantation.
Kallistratos
Manolis S
MS
First Cardiology Department, Onassis Cardiac Surgery Center, Athens, Greece. mankal1@otenet.gr
Dritsas
Athanasios
A
Laoutaris
Ioannis D
ID
Cokkinos
Dennis V
DV
D000368:Aged; D015415:Biomarkers / Q000097:blood; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology*; D005260:Female; D016027:Heart Transplantation / Q000009:adverse effects / Q000379:methods*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology; D018579:Patient Selection; D010446:Peptide Fragments / Q000097:blood*; D011237:Predictive Value of Tests; D011336:Probability; D011379:Prognosis; D011446:Prospective Studies; D012372:ROC Curve; D018570:Risk Assessment; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000175:diagnosis*
D015415:Biomarkers; D010446:Peptide Fragments; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain