Responses of atrial natriuretic peptide and brain natriuretic peptide to exercise in patients with chronic heart failure and normal control subjects.

Atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) are known to be elevated in patients with chronic heart failure at rest. While it is known that during exercise the circulating level of ANP increases in patients with heart failure, the response of BNP to exercise in these patients relative to control subjects is unclear. Ten patients with stable chronic heart failure and 10 normal control subjects performed symptom-limited exercise with respired gas analysis. All patients had depressed left ventricular ejection fractions (LVEF). Patients had lower peak oxygen consumption PVo2) than the control group [median (range) 1.18 (0.98-1.76) vs. 1.94 (1.53-2.31) L min-1; P < 0.001]. Circulating plasma levels of ANP and BNP were higher at rest in patients than in control subjects [ANP 335 (140-700) vs. 90 (25-500) pg mL-1; BNP 42 (25-50) vs. 20 (10-20) pg mL-1], and at peak exercise [ANP 400 (200-1000) vs. 130 (10-590); BNP 46 (40-51) vs. 20 (10-30)]. The rise in ANP at peak exercise was significant in patients compared with the resting level, but not in control subjects. For BNP, there was a significant rise in patients but no change in control subjects. The circulating plasma levels of both peptides showed a strong negative correlation with LVEF (ANP, P < 0.005; BNP, P < 0.0001) and, to a less extent, with RVEF. It is possible that BNP may give a better indication of cardiac function.