Effects of brain natriuretic peptide on exercise hemodynamics and neurohormones in isolated diastolic heart failure

Background Experimental models suggest that brain natriuretic peptide (BNP) can modify left ventricular diastolic performance. The aim of this study was to evaluate the effects of BNP on resting and exercise hemodynamics and neurohormones in patients with isolated diastolic heart failure. Methods and Results Six patients with isolated diastolic heart failure were studied. After baseline hemodynamic measurements were obtained with use of thermistor-tipped pulmonary artery catheters, patients were randomized to receive infusion of BNP or placebo in a single-blind, crossover study. Hemodynamic and neurohormonal parameters were measured at rest after 30 minutes of infusion and during incremental supine bicycle exercise. BNP did not significantly affect resting hemodynamics but attenuated the rise in both pulmonary capillary wedge pressure (placebo, 23+/-2 mm Hg; BNP, 16+/-2 mm Hg; P<.01) and mean pulmonary artery pressure (placebo, 34+/-3 mm Hg; BNP, 29+/-3 mm Hg; P<.05) during exercise without affecting changes in heart rate, systemic blood pressure, or stroke volume. In response to BNP, there was significant suppression of plasma aldosterone concentration (placebo, 551+/-107 pmol/L; BNP, 381+/-56 pmol/L; P<.05). Conclusions BNP infusion causes beneficial hemodynamic and neurohormonal effects during exercise in patients with isolated diastolic heart failure.