Molecular and physiological effects of nesiritide

BACKGROUND

Nesiritide (Natrecor, Janssen-Ortho Inc, Canada), or recombinant human B-type natriurtic peptide (BNP), is a molecule identical in structure to endogenous BNP-32. This peptide is secreted from cardiac myocytes in response to volume and pressure overload. While high levels of circulating BNP are measured by commercially available assays during acute decompensated heart failure (ADHF), the detection of alternate, potentially more active, but undermeasured forms of BNP needs to be considered.

AIM

The present review summarizes the molecular and physiological effects of nesiritide in the setting of hospitalized patients with ADHF. In particular, an overview of the molecular structure and circulating isoforms of BNP is given, followed by a discussion of the vasodilatory, renal, antagonistic neurohormonal, pulmonary, anti-inflammatory and cardiac remodelling effects of recombinant human BNP.

SUMMARY

Nesiritide has beneficial effects in the treatment of ADHF that go beyond the traditional goals of reducing pulmonary capillary wedge pressure, preload and afterload, and relieving symptoms of dyspnea. Therefore, the unique pharmacological profile of this medication provides an additional treatment option for Canadian patients with ADHF.

Safety and Efficacy of Rosuvastatin Therapy for the Prevention of Hyperlipidemia in Adult Cardiac Transplant Recipients

BACKGROUND

Hyperlipidemia after orthotopic heart transplantation (OHT) is associated with immunosuppression. Many OHT patients have increased lipid levels above published guidelines despite treatment with high doses of statins. Treatment with rosuvastatin (ROS) in OHT patients has not yet been evaluated. Therefore, we assessed its efficacy and safety in an OHT population.

METHODS

Twenty-one OHT recipients, median age 66 years, whose lipid levels were sub-optimal on the highest tolerated doses of statins, received ROS in addition to standard immunosuppression. Total cholesterol (TC), low-density lipoprotein (LDL-C) and high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), liver transaminases (AST) and creatinine kinase (CK) were measured before and during treatment with ROS.

RESULTS

After 6 weeks on an average ROS dose of 10 mg/day, a TC:HDL-C ratio of <4 was reached in 76% of patients, and 70% of patients reached an LDL-C level of <2.5 mmol/liter (100 mg/dl). TC decreased to <5.2 mmol/liter (200 mg/dl) in 80% of patients and TG decreased to <2 mmol/liter (175 mg/dl) in 61% of patients. Except for the HDL-C increase, all changes were statistically significant. The decrease in the median TC:HDL-C ratio between baseline and 6 weeks was also statistically significant (p = 0.001). There were no significant changes in CK or AST levels, and no clinical evidence of myositis. One patient developed myalgia and 2 were withdrawn from the study because of mild elevation of CK (<3-fold upper limit of normal [ULN]).

CONCLUSIONS

In the setting of tertiary referral centers, ROS appears to be safe and effective in lowering LDL-C in OHT recipients in whom treatment with other statins failed to achieve target LDL-C. No evidence of liver or muscle dysfunction was noted. Long-term studies are needed to ascertain the effect of ROS therapy on incidence of coronary artery disease (CAD) in this population.