Outpatient management of heart failure

C-type natriuretic peptide and heart failure

C-type natriuretic peptide (CNP) is a peptide produced by the vascular endothelium with vasodilative properties. It shares structural and physiological properties with the atrial and brain natriuretic peptides (ANP and BNP), whose central role in the pathophysiology of heart failure (CHF) is firmly established. The role of CNP, first isolated from porcine brain, has not been yet completely determined. The transcription of the gene, that in man is located on chromosome 2, is regulated by factors such as tumor necrosis factor and interleukin-1. Two mature forms of the peptide exist: CNP-53, that predominates in tissues and CNP-22, found mainly in plasma. As recently found, CNP is produced directly in the myocardium and an increase in plasma levels of this peptide and of its precursor was observed in CHF. The aim of this review was to examine the current literature relating to cardiovascular functions of CNP and in particular to its role in CHF. In fact, CNP may represent an important new local autocrine and endocrine mediator in CHF although further evaluations are required to define its full pathophysiological role in this disease.

Brain natriuretic peptide in the prediction of recurrence of angina pectoris

BACKGROUND

Circulating levels of brain natriuretic peptide (BNP) provide prognostic information for patients with heart failure, but little is known about its prognostic usefulness in patients with stable angina pectoris. We investigated whether BNP could be used as a marker for the prediction of anginal recurrence after successful treatment.

DESIGN

Brain natriuretic peptide levels of 77 patients with stable angina pectoris were measured at enrolment and after confirmation of successful treatment (i.e. no anginal attack for at least 6 months: chronic phase) with percutaneous transluminal coronary angioplasty and/or conventional medication. Then, we prospectively followed them up for 25.9 +/- 1.4 months, with the endpoint being a recurrence of anginal attacks.

RESULTS

An anginal attack recurred in seven patients. In patients without recurrence, BNP levels in the chronic phase (21 +/- 12 [median +/- median absolute deviation] pg mL-1) were lower than those measured at enrolment (46 +/- 25 pg mL-1, P < 0.0001), whereas the levels in patients with recurrence increased during the same period (from 36 +/- 16 to 72 +/- 42 pg mL-1, P < 0.05). A univariate analysis revealed that the BNP level measured in the chronic phase was the significant predictor of future anginal recurrence. Analysis of the receiver operating characteristic curve indicated that the cutoff level of BNP in the chronic phase was 68 pg mL-1. The Kaplan-Meier method revealed that the incidence of anginal recurrence was higher in patients with higher (71.4%) than lower levels of BNP (2.9%; P < 0.0001).

CONCLUSIONS

Measurement of BNP levels after successful therapy is clinically useful for the prediction of recurrence of anginal attacks in patients with angina pectoris.