Chronic Serial Infusion of Nesiritide Is Not Associated with Worsening Renal Function in Chronic Decompensated Heart Failure Patients with Renal Insufficiency: An Analysis from the FUSION-II Trial

Clinical implications of defective B-type natriuretic peptide

Our understanding of the natriuretic peptide system continues to evolve rapidly. B-type natriuretic peptide (BNP), originally thought to be a simple volume-regulating hormone that is produced in response to cardiac stretch, has been shown to also play important roles in modulating bronchodilation, endothelial function, and cardiac remodeling. Recent data demonstrate that elevated levels of BNP in patients with heart failure do not represent a simple ratcheting up of normal production in response to increased stimulus. Instead, we now know that chronic stimulation of BNP synthesis induces a reversion to fetal gene expression, resulting in production of high molecular weight forms of BNP that are functionally deficient. Standard point-of-care BNP assays are immunoassays that will detect any molecule containing the target epitopes. Consequently, these assays cannot distinguish between defective, high molecular weight forms of BNP and normal, physiologically active BNP. In 2 separate evaluations, mass spectroscopy detected little, if any, normal BNP in patients with heart failure, despite the appearance of high circulating levels of immunoreactive BNP (iBNP) using commercial assays. Therefore, these commercial assays should be considered to be only an indication of myocardial stress. They do not measure physiologic BNP activity. This accounts for the "BNP paradox," namely, that administration of exogenous recombinant human BNP (rhBNP, nesiritide) has substantial clinical and hemodynamic impact in the presence of high levels of circulating iBNP using commercial assays. In addition to its short-term hemodynamic impact, rhBNP may have other important effects in this setting, and further investigation is warranted.

Nesiritide improves hemodynamics in children with dilated cardiomyopathy: a pilot study

BACKGROUND

This study aimed to obtain hemodynamic measurements of nesiritide in children with dilated cardiomyopathy.

METHODS

A prospective, randomized, double-blinded, placebo-controlled pilot study was conducted in the pediatric intensive care unit at the University of California, Los Angeles. All subjects younger than 21 years admitted to the pediatric intensive care unit with a diagnosis of dilated cardiomyopathy and submitted to cardiac catheterization were randomized to receive either nesiritide or placebo. Right heart catheterization with Swan-Ganz catheter placement was performed. Nesiritide was infused over 24 h. Hemodynamic data were obtained before, during, and after the 24-h nesiritide infusion. The measures obtained included pulmonary capillary wedge pressure (PCWP), central venous pressure, mean pulmonary arterial pressure (MPAP), systolic arterial blood pressure (SBP), cardiac index, and systemic vascular resistance.

RESULTS

The study included 20 children: 9 randomized to nesiritide and 11 to placebo. At 24 h, the mean decreases in PCWP, MPAP, and SBP were significantly greater for nesiritide than for placebo: PCWP (-5.3 vs. 1.2 mmHg; p = 0.02), MPAP (-8.0 vs. 0.4 mmHg; p = 0.006), SBP (-7.9 vs. 2.6 mmHg; p = 0.04).

CONCLUSIONS

Nesiritide significantly decreases PCWP, MPAP, and SBP in children with dilated cardiomyopathy.