Neuro-hormonal activation predicts ventilatory response to exercise and functional capacity in patients with heart failure.
BACKGROUND
Heart failure (HF) is characterised by reduced tolerance to effort, associated with progressive fatigue and dyspnoea. Neuro-hormonal activation is a hallmark of HF and influences its clinical evolution.


OBJECTIVE
To evaluate the relationship between neuro-hormonal activation, exercise capacity and ventilatory efficiency.


RESULTS
154 HF patients (127 males, 62 +/- 1 years) underwent cardiopulmonary exercise testing and resting blood sampling for assay of plasma brain natriuretic peptide (BNP), NT-proBNP, norepinephrine, epinephrine, aldosterone and plasma renin activity (PRA). BNP and NT-proBNP levels correlated with peak oxygen consumption (VO2) (both R = -0.53, p < 0.001), VE/VCO2 slope (R = 0.56; p < 0.001 and R = 0.58; p < 0.001, respectively) and maximum workload (R = -0.49; p < 0.001 and R = -0.47; p < 0.001, respectively). Norepinephrine correlated slightly less with peak VO2 (R = -0.38, p < 0.001), VE/VCO2 (R = 0.45; p < 0.001) and maximum workload (R = -0.35; p < 0.001). There was a significant inverse correlation between left ventricular ejection fraction and BNP (R = -0.48, p < 0.001), NT-proBNP (R = -0.42; p < 0.001) and norepinephrine (R = -0.43; p < 0.001). Weaker correlations were found for PRA, exercise parameters and ejection fraction. ROC curves showed that BNP was able to identify patients with peak VO2 < 14 ml/min/kg (cut-off 98 pg/ml, AUC 0.775) and a VE/VCO2 > 35 (cut-off 183 pg/ml, AUC 0.797), as well as NT-proBNP (cut-off 537 pg/ml, AUC 0.799 and cut-off 1010 pg/ml, AUC 0.768, respectively) and norepinephrine (cut-off 454 pg/ml, AUC 0.716 and cut-off 575 pg/ml, AUC 0.783, respectively).


CONCLUSIONS
Haemodynamic impairment (as indicated by BNP and NT-proBNP plasma values) and sympathetic activation predict exercise capacity and ventilatory efficiency in HF patients.
Passino
Claudio
C
CNR Institute of Clinical Physiology, National Research Council, Via Moruzzi 1, 56124 Pisa, Italy. passino@ifc.cnr.it
Poletti
Roberta
R
Bramanti
Francesca
F
Prontera
Concetta
C
Clerico
Aldo
A
Emdin
Michele
M
D000450:Aldosterone / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D018450:Disease Progression; D004837:Epinephrine / Q000097:blood*; D005080:Exercise Test; D017079:Exercise Tolerance / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000097:blood / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D020097:Natriuretic Peptide, Brain / Q000097:blood*; D009638:Norepinephrine / Q000097:blood*; D010101:Oxygen Consumption / Q000502:physiology; D010446:Peptide Fragments / Q000097:blood*; D011379:Prognosis; D011446:Prospective Studies; D011498:Protein Precursors / Q000097:blood; D012123:Pulmonary Ventilation / Q000502:physiology*; D012083:Renin / Q000097:blood*; D012720:Severity of Illness Index
D015415:Biomarkers; D010446:Peptide Fragments; D011498:Protein Precursors; C109794:pro-brain natriuretic peptide (1-76); D020097:Natriuretic Peptide, Brain; D000450:Aldosterone; D012083:Renin; D009638:Norepinephrine; D004837:Epinephrine