Augmented response in plasma brain natriuretic peptide to dynamic exercisein patients with left ventricular dysfunction and congestive heart failure

Objectives. We have previously demonstrated that patients with symptomatic congestive heart failure (CHF), but not with asymptomatic left ventricular dysfunction (LVD), have augmented plasma atrial natriuretic peptide (ANP) r esponse to exercise. Plasma brain natriuretic peptide (BNP) response to exe rcise is less extensively studied. The aim of this study was to determine w hether responses of plasma BNP during exercise normalized for exercise work load are altered in patients with LVD and CHF. Subjects and methods. Twenty-nine patients with LVD, 32 patients with CHF ( NYHA classes II-III) and 27 age-matched control subjects were studied. Vent ilatory, plasma ANP and BNP responses were assessed during symptom-limited cardiopulmonary exercise testing. Plasma natriuretic peptide levels were me asured at rest and immediately after peak exercise. The increment in plasma BNP was divided by the increment in oxygen uptake (VO2) from rest to peak exercise, and this ratio [BNP exercise ratio: (peak BNP - rest BNP)/(peak V O2 - rest VO2)] was compared amongst the three groups. Results. Peak VO2 (Control, LVD and CHF: 28.2 +/- 1.7, 21.1 +/- 1.8, 16.2 /- 0.6 mL min(-1) kg(-1), respectively), anaerobic threshold and peak workl oad became smaller as heart failure worsened. Resting and peak plasma ANP l evels were significantly higher only in CHF, whilst resting and peak plasma BNP levels displayed a significant and continuous increase from normal sub jects to LVD and CHF. The ANP exercise ratio (1.25 +/- 0.36, 2.61 +/- 0.57, 7.72 +/- 1.65, anova P = 0.0002) was significantly higher only in patients with CHF, whilst the BNP exercise ratio (0.35 +/- 0.10, 2.60 +/- 0.69, 4.9 8 +/- 0.97, anova P = 0.0001) was significantly higher in patients with LVD and became progressively higher in patients with CHF. Conclusions. These data showed that the BNP exercise ratio, an exercise pla sma BNP response normalized with exercise workload, was augmented in patien ts with LVD, and became progressively higher in CHF, suggesting that an aug mented exercise BNP ratio exists early in the course of developing CHF.