Nesiritide

Nesiritide is a recombinant form of human B-type natriuretic peptide (BNP), a 32-amino acid peptide hormone that is naturally secreted by ventricular cardiomyocytes in response to volume overload and increased wall stress. Approved by the FDA in 2001 and marketed as Natrecor, nesiritide was developed by Scios (later acquired by Johnson & Johnson) as a hemodynamic and symptomatic therapy for acute decompensated heart failure (ADHF).

Nesiritide binds to natriuretic peptide receptor A (NPR-A) on vascular smooth muscle and endothelial cells, activating guanylyl cyclase and increasing intracellular cyclic GMP (cGMP) levels. This leads to smooth muscle relaxation and vasodilation of both arteries and veins, reducing both preload and afterload on the heart. Additionally, nesiritide promotes natriuresis and diuresis through direct renal tubular effects and suppression of the renin-angiotensin-aldosterone system and sympathetic nervous system. These combined effects reduce pulmonary capillary wedge pressure and systemic vascular resistance while improving cardiac output.

Nesiritide's clinical journey has been marked by controversy. Initial approval was based on relatively small studies showing rapid improvement in hemodynamics and dyspnea compared to placebo. However, subsequent meta-analyses raised concerns about potential worsening of renal function and a possible association with increased mortality, leading to a significant decline in use and calls for a definitive large-scale clinical trial.

The ASCEND-HF trial, the largest trial ever conducted in acute heart failure at the time (enrolling over 7,000 patients), showed that nesiritide had a modest but statistically significant effect on dyspnea at 6 hours but did not reduce mortality or rehospitalization at 30 days compared to placebo. The trial also did not confirm the previously raised concerns about worsening renal function. The modest clinical benefit demonstrated by ASCEND-HF, combined with the availability of other vasodilators, has resulted in very limited use of nesiritide in current clinical practice.