Plasma N-terminal atrial natriuretic factor: a predictor of survival in patients with congestive heart failure

Exenatide infusion decreases atrial natriuretic peptide levels by reducing cardiac filling pressures in type 2 diabetes patients with decompensated congestive heart failure

BACKGROUND

The vascular effects exerted by GLP-1 are mediated by several synergistic mechanisms such as involvement of nitric oxide and natriuresis. Recently, it was demonstrated that atrial natriuretic peptide (ANP) is essential for the glucagon-like peptide-1 (GLP-1)-stimulated vascular smooth muscle relaxation that mediates anti-hypertensive action in rodents. Therefore a GLP-1-ANP axis has been suggested. The aim of this study was to investigate whether this effect can be demonstrated in patients with type 2 diabetes and congestive heart failure.

METHODS

The study was a post hoc analysis of a randomized double-blinded, placebo-controlled trial. Twenty male patients with type 2 diabetes and congestive heart failure were randomized to receive a 6-h infusion of exenatide or placebo. Cardiac filling pressures were measured by right heart catheterization, and plasma levels of ANP, N-terminal pro-brain natriuretic peptide, and exenatide were measured at baseline and at the end of the exenatide infusion.

RESULTS

Exenatide infusion resulted in a significant decrease of circulating ANP levels compared with placebo, concomitant with a decrease in pulmonary capillary wedge pressure (PCWP), pulmonary artery pressure (PAP) and right arterial pressure (RAP), and increased cardiac output. There was no correlation between plasma ANP levels and exenatide levels. A negative correlation between ANP levels and PCWP, PAP, and RAP, which remained significant after adjustment for plasma exenatide levels, was demonstrated during exenatide infusion.

CONCLUSIONS

Exenatide infusion decreases cardiac filling pressure and ANP levels. The reduction of ANP levels was primarily because of the reduction in cardiac filling pressure, independent of exenatide levels. It seems unlikely that this was mediated via ANP.

TRIAL REGISTRATION

http://www.isrctn.org/ISRCTN47533126.

Comparison of midregional pro-atrial and B-type natriuretic peptides in chronic heart failure: influencing factors, detection of left ventricular systolic dysfunction, and prediction of death

OBJECTIVES

Midregional pro-atrial natriuretic peptide (MR-proANP) was assessed for the importance of influencing factors, the ability to detect left ventricular systolic dysfunction, and the prognostic power compared with B-type natriuretic peptide (BNP) and amino-terminal pro-B-type natriuretic peptide (NT-proBNP) in chronic heart failure (HF).

BACKGROUND

MR-proANP is a biologically stable natriuretic peptide measured by a recently developed assay, with potential advantages over conventional natriuretic peptides such as BNP and NT-proBNP.

METHODS

We measured MR-proANP, BNP, and NT-proBNP in 797 patients with chronic HF.

RESULTS

All 3 natriuretic peptides were independently influenced by left ventricular ejection fraction (LVEF), glomerular filtration rate (GFR), and the presence of ankle edema. Area under receiver-operator characteristic curves for detection of an LVEF <40% were similar between MR-proANP (0.799 [95% confidence interval (CI): 0.753 to 0.844]), BNP (0.803 [95% CI: 0.757 to 0.849]), and NT-proBNP (0.730 [95% CI: 0.681 to 0.778]). During a median observation time of 68 months, 492 (62%) patients died. In multiple Cox regression analysis each natriuretic peptide was the strongest prognostic parameter among various clinical variables. Proportion of explained variation showed that NT-proANP (4.36%) was a significantly stronger predictor of death than both NT-proBNP (2.47%, p < 0.0001) and BNP (2.42%, p < 0.0001).

CONCLUSIONS

Despite similarities in influencing factors and detection of reduced LVEF, MR-proANP outperformed BNP and NT-proBNP in the prediction of death. A new assay technology and the high biological stability of MR-proANP are potential explanations for these findings.

The effect of altering haemodynamics on the plasma concentrations of natriuretic peptides in heart failure

BACKGROUND

Natriuretic peptide levels reflect haemodynamics in patients with heart failure and may serve as biochemical markers of cardiac filling pressures. The purpose of this study was to detect differences in the kinetic profile between atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP) and their N-terminal fragments N-ANP and N-BNP, in response to rapid and persistent vasodilatation.

METHODS

Sixteen men and four women aged 63.0+/-10.4 (mean+/-S.D.) with symptomatic congestive heart failure (NYHA III) and pulmonary capillary wedge pressure (PCWP)>18 mm Hg, received a 24-h infusion of nitroglycerin (N=8) or nicorandil (N=12). A reduction of PCWP was achieved for the duration of the study. Natriuretic peptides were measured by radioimmunoassay at baseline, 1, 3, 6, 12 and 24 h.

RESULTS

PCWP and right atrial pressure fell rapidly and then increased modestly. ANP and N-ANP demonstrated a similar pattern. In contrast, BNP and N-BNP levels fell steadily throughout the observation period. This was accompanied by a continuous reduction of systemic vascular resistance (SVR). PCWP was highly correlated to the levels of all the natriuretic peptides. Using a longitudinal regression model evaluating responses over time, we found separate, significant relationships between all peptides and haemodynamic variables

CONCLUSION

The atrial natriuretic peptides reflect rapid changes in filling pressures while the B-type peptides respond much slower. B-type peptides are less sensitive to short-term changes in filling pressures, but should reflect changes in SVR better during vasodilator therapy.

Natriuretic peptides in patients with atrial fibrillation and advanced chronic heart failure: determinants and prognostic value of (NT-)ANP and (NT-pro)BNP

AIMS

To study the determinants of natriuretic peptides in advanced chronic heart failure (CHF) patients with and without atrial fibrillation (AF) and to evaluate the prognostic value of natriuretic peptides in AF compared with sinus rhythm patients with advanced CHF.

METHODS AND RESULTS

The study group comprised 354 advanced CHF patients [all New York Heart Association (NYHA) III/IV], including 76 AF patients. AF patients were older (70+/-7 vs. 67+/-8; P=0.01), and non-ischaemic CHF was more common (42 vs. 19%; P=0.002) than in sinus rhythm patients, but left-ventricular ejection fraction was comparable (0.23+/-0.08 vs. 0.24+/-0.07; P=ns). At baseline, (NT-)ANP and NT-proBNP levels were significantly higher in AF patients, compared with those in sinus rhythm. By multivariate regression analysis, AF was identified as independent determinant of (NT-)ANP, but not of (NT-pro)BNP levels. After a mean follow-up of 3.2+/-0.9 (range 0.4-5.4) years, cardiovascular mortality was comparable (55 vs. 47%; P=ns). In both groups, AF and sinus rhythm, NT-proBNP [AF: adjusted HR 5.8 (1.3-25.4), P=0.02; sinus rhythm: adjusted HR 3.1 (1.7-5.7), P<0.001] was an independent risk indicator of cardiovascular mortality.

CONCLUSION

In advanced CHF patients, AF affects (NT-)ANP levels, but not (NT-pro)BNP levels. NT-proBNP is an independent determinant of prognosis in advanced CHF, irrespective of the rhythm, AF, or sinus rhythm.

Long-term effect of social relationships on mortality in patients with congestive heart failure

Congestive heart failure is a major cause of morbidity and mortality within the Western world, and yet psychosocial impact of this disease is under-researched. The aim of this study was to evaluate the possible effects of social relationships (perceived social support and perceived social isolation) on mortality risk in 119 patients with stable, symptomatic congestive heart failure. Fifty-one deaths were registered during the six-year follow-up period, all from cardiac causes. Analysis using proportional hazard models indicated that social isolation was a significant predictor of mortality (relative risk, 1.36; confidence interval, 1.04 to 1.78; p < 0.03), controlling for neuroticism, heart failure severity, functional status, gender, and age. The small sample size was a limitation of the study; therefore, further research is required in order to confirm these findings and to illuminate the mechanisms behind the relationships between social isolation and mortality.

Left atrial diameter is a simple indicator of a deficiency in atrial natriuretic peptide secretion in patients with mitral stenosis: efficacy of postoperative supplementation with synthetic human alpha-atrial natriuretic peptide

OBJECTIVE

With regard to a deficiency in atrial natriuretic peptide (ANP) secretion, the relationship between plasma ANP and left atrial diameter measured by echocardiography was examined and the efficacy of postoperative supplementation was evaluated.

METHODS

(1) Ninety-six patients with mitral valve disease from 1997 to 2002 (M:F = 65:31, mean-age 65.3 +/- 8.9 years) were studied for relationship analyses. (2) Twenty-six patients with mitral stenosis and left atrial diameter > or = 60 mm undergoing mitral valve replacement (M:F = 17:9, mean-age 67.4 +/- 7.5 years) were randomly allocated to one of two groups; ANP-treated group (n = 13, 0.05 microg/kg/min of synthetic human alpha-ANP was postoperatively administered) and Control group (n = 13).

RESULTS

(1) There were significant positive correlations between left atrial diameter and plasma renin-activity (r = 0.690, P < 0.01) and between left atrial diameter and plasma aldosterone (r = 0.757, P < 0.01). The maximum value of plasma ANP was 249.5 pg/mL accompanied with 56.2 mm of left atrial diameter in 29 patients suffering from mitral stenosis. There was a significant negative correlation between left atrial diameter and ANP in patients with left atrial diameter > 56.2 mm (r = - 0.725, P < 0.0001), whereas there was a significant positive correlation in patients with left atrial diameter < or = 56.2 mm (r = 0.529, P = 0.0066). (2) At 24 hours after operation, the ANP-treated group showed significantly lower plasma renin-activity (9.2 +/- 3.3 versus 36.2 +/- 7.4 ng/mL/h) and aldosterone (113.6 +/- 36.9 versus 473.8 +/- 95.8 pg/mL) than the Control group.

CONCLUSIONS

Left atrial diameter can be a simple and useful indicator of a deficiency in endogenous ANP secretion in patients with mitral stenosis, and postoperative ANP supplementation contributes to suppressing further activation of renin-angiotensin system during the immediate postoperative period.

Jumonji represses atrial natriuretic factor gene expression by inhibiting transcriptional activities of cardiac transcription factors

Mice with a homozygous knockout of the jumonji (jmj) gene showed abnormal heart development and defective regulation of cardiac-specific genes, including the atrial natriuretic factor (ANF). ANF is one of the earliest markers of cardiac differentiation and a hallmark for cardiac hypertrophy. Here, we show that JMJ represses ANF gene expression by inhibiting transcriptional activities of Nkx2.5 and GATA4. JMJ represses the Nkx2.5- or GATA4-dependent activation of the reporter genes containing the ANF promoter-enhancer or containing the Nkx2.5 or GATA4-binding consensus sequence. JMJ physically associates with Nkx2.5 and GATA4 in vitro and in vivo as determined by glutathione S-transferase pull-down and immunoprecipitation assays. Using mutational analyses, we mapped the protein-protein interaction domains in JMJ, Nkx2.5, and GATA4. We identified two DNA-binding sites of JMJ in the ANF enhancer by gel mobility shift assays. However, these JMJ-binding sites do not seem to mediate ANF repression by JMJ. Mutational analysis of JMJ indicates that the protein-protein interaction domain of JMJ mediates the repression of ANF gene expression. Therefore, JMJ may play important roles in the down-regulation of ANF gene expression and in heart development.

N-terminal pro B type natriuretic peptide, but not the new putative cardiac hormone relaxin, predicts prognosis in patients with chronic heart failure

OBJECTIVE

To determine whether the plasma concentration of the putative new cardiac hormone relaxin is predictive of clinical outcome in patients with chronic heart failure (CHF).

DESIGN

Plasma relaxin and N-terminal pro B type natriuretic peptide (NT pro BNP) concentrations were measured in 87 patients admitted in an emergency with CHF caused by left ventricular systolic dysfunction. These were related to death and death or readmission with CHF over the following year.

SETTING

Western Infirmary, Glasgow, UK.

MAIN OUTCOME MEASURES

Plasma concentrations of relaxin and NT pro BNP; time to death or hospitalisation caused by heart failure.

RESULTS

Plasma concentrations of both relaxin and NT pro BNP were greatly increased. Of the 43 patients with NT pro BNP above the group median concentration, 23 (53%) died and 30 (70%) died or were hospitalised with CHF. Among the 44 with concentrations below the median, these numbers were 5 (11%) and 12 (27%), respectively (p < 0.0001 and p < 0.0001, respectively). Plasma NT pro BNP concentration remained an independent predictor of an adverse clinical outcome in a multivariate analysis. Of the 42 patients with a relaxin concentration above the median, 13 (31%) died and 20 (48%) died or were hospitalised. Below the median, these numbers were 15 of 45 (33%) and 22 of 45 (49%) (p = 0.76 and p = 0.84, respectively).

CONCLUSIONS

NT pro BNP is a powerful and independent predictor of outcome in CHF, whereas relaxin, also secreted by the heart in increased amounts in CHF, is not.

Variability of Nt-proANP and C-ANP

BACKGROUND

Natriuretic peptides are frequently measured in patients with chronic cardiac failure (CCF). We set out to compare the variability of atrial natriuretic peptide (C-ANP) and its precursor N-terminal pro-ANP (Nt-proANP) to decide which would be more suitable for routine use.

METHODS

Ten males with compensated CCF (age range 62-76 years) were studied, with matched controls. Blood was withdrawn every 2 min for 90 min from a forearm vein, and plasma C-ANP and Nt-proANP were measured by radioimmunoassay.

RESULTS

Levels were elevated in the patient group [C-ANP: median 268 (range 171-423) vs. 40 (28-56) ng L-1, P < 0.0002 Mann-Whitney U-test; Nt-proANP: 1955 (562-4451) vs. 621 (409-961) pmol L-1, P < 0.003]. A similar number of 'peaks' was observed in both groups with both peptides, about one every 10 min, and their relative height was similar in both groups. Variability was greater for C-ANP than for Nt-proANP in both patients [coefficient of variation of means 51 (range 36-70) vs. 3.6 (2.1-6.2)%, P < 0.01; sign test] and controls [65 (49-83) vs. 8.9 (4.7-13.5)%, P < 0.01].

CONCLUSION

Nt-proANP is less variable than C-ANP and hence more suited for diagnostic or prognostic use.

Relations between medical history, clinical findings and plasma N-terminal proatrial natriuretic peptide in patients in primary health care

BACKGROUND

recent studies indicate that measurement of natriuretic peptides may be a valuable tool to improve the quality of the diagnosis of heart failure in general practice.

AIM

the aim of the present study was to examine the relationship between the plasma level of the natriuretic peptide N-terminal proANP and symptoms and signs of heart failure in patients from general practice in the Oslo area.

METHODS AND RESULTS

we undertook a survey of 499 patients consecutively enrolled from the practice of 27 practitioners. One hundred and twenty-nine patients were classified as having possible or some degree of heart failure. The plasma concentration of N-terminal proANP increased with severity of heart failure as judged from clinical examination. In multivariate analysis age, history of heart disease, plasma creatinine, use of beta-blockers and digitalis, oedemas and atrial fibrillation were the main determinants of plasma N-terminal proANP.

CONCLUSION

while there was an overall increase in N-terminal proANP values with increasing symptoms and degree of heart failure, no single finding was closely related to N-terminal proANP. Treatment effects and diagnostic errors may both influence the relationship between N-terminal proANP and clinical findings. The current study has demonstrated the feasibility of using N-terminal proANP by general practitioners for the potentially improved diagnosis of heart failure. Further research is required to determine the precise role of this assay in clinical practice.

Social relationships and mortality in patients with congestive heart failure

The present study was undertaken to evaluate the possible effects of social relationships (perceived social support, and perceived social isolation) upon mortality risk among patients with congestive heart failure (CHF). Proportional hazard models were used to evaluate the effects of different social factors on mortality among 119 clinically stable patients (71.4% men; mean age 65.7+/-9.6 years) with symptomatic heart failure, recruited from an outpatient cardiology practice. Twenty deaths were registered during the 24-month period of data collection, all from cardiac causes. Results indicated that social isolation was a significant predictor of mortality (relative risk, 1.50, confidence interval (CI), 1.00 to 2.19; P<.038), controlling for depressive symptoms, heart failure severity, and functional status and age. Perceived intimate network support was marginally significantly associated with increased risk of mortality in this population of CHF patients (relative risk, 0.60, CI, 0.35-1.02; P<.06). However, the sample is small and caution in drawing conclusions should be exercised. Further research is required in order to either deny or confirm these findings, and to illuminate the mechanisms behind the relationships between social isolation and mortality.

Effects of dilated cardiomyopathy on the renin-angiotensin-aldosterone system, atrial natriuretic peptide activity, and thyroid hormone concentrations in dogs

OBJECTIVE

To evaluate the effect of dilated cardiomyopathy (DCM) on activity of the renin-angiotensin-aldosterone system (RAAS), the N-terminal fragment of proatrial natriuretic peptide (NT-proANP), and thyroid hormone concentrations in dogs.

ANIMALS

15 dogs with clinical signs of DCM, 15 dogs without clinical signs of DCM, and 15 age-, breed-, and sex-matched control dogs.

PROCEDURE

Physical examinations, thoracic radiography, ECG, and echocardiography were performed on all dogs, and blood and urine samples were collected.

RESULTS

Plasma renin activity (PRA), plasma aldosterone concentration (PAC), urine aldosterone-to-creatinine ratio, and NT-proANP concentrations were significantly increased in dogs with clinical signs of DCM, compared with dogs without clinical signs and control dogs. Thyroid-stimulating hormone and total thyroxine concentrations did not differ significantly among groups; however, free thyroxine (FT4) concentrations were significantly decreased in dogs with clinical signs of DCM, compared with control dogs and DCM-dogs without clinical signs. Concentrations of PRA, PAC, FT4, and urine aldosterone-to-creatinine ratio were significantly correlated, whereas plasma concentrations of NT-proANP only correlated with FT4 concentration.

CONCLUSION AND CLINICAL RELEVANCE

In dogs with clinical signs of DCM, increased concentrations of components of the RAAS were associated with increased concentrations of NT-proANP Analysis of the neurohormonal system may aid in identification of clinical stages of DCM for groups of dogs, but the range is too great and there are too many dogs that have neurohormonal concentrations within reference ranges to assess dogs on an individual basis.

Natriuretic peptide levels in atrial fibrillation: a prospective hormonal and Doppler-echocardiographic study

OBJECTIVES

The objective was to determine the independent association between atrial fibrillation (A-Fib) and activation of natriuretic peptides.

BACKGROUND

The association of A-Fib with activation of N-terminal atrial and brain natriuretic peptides (N-ANPs and BNPs, respectively) is uncertain but of great importance for the diagnostic utilization of natriuretic peptides. This uncertainty is related to the lack of appropriate controls, with left ventricular (LV) and atrial overload similar to A-Fib.

METHODS

We prospectively measured N-terminal atrial and BNPs and endothelin-1 levels in 100 patients and 14 age- and gender-matched control subjects. The 32 patients with A-Fib were compared with 68 patients in sinus rhythm and similar LV and atrial overload (due to mitral regurgitation or LV dysfunction) measured simultaneously with hormonal levels with comprehensive Doppler echocardiography.

RESULTS

Patients with A-Fib compared with those in sinus rhythm had similar symptoms, comorbid conditions, cardioactive medications, pulmonary pressure, left atrial volume, and LV ejection fraction and filling characteristics but demonstrated higher N-ANP levels (2,613 +/- 1,681 vs. 1,654 +/- 1,323 pg/ml, p = 0.007) even after adjustment for the underlying cardiac disease (p < 0.0001). Conversely, BNP levels were similar in both groups (165 +/- 163 vs. 160 +/- 269 pg/ml, p = 0.9). In multivariate analysis, a higher N-ANP level was associated with A-Fib (p = 0.0003), symptom class (p < 0.0001) and endothelin-1 level (p = 0.032) independently of left atrial volume and LV ejection fraction. Conversely, BNP showed no independent association with and was most strongly associated with LV ejection fraction (p < 0.0001).

CONCLUSIONS

Atrial fibrillation is an independent determinant of higher N-ANP levels and blurs its association with LV dysfunction. Conversely, the BNP is not independently associated with A-Fib and is strongly determined by LV dysfunction, for which it is an independent marker.

Depressed mood and subjective health symptoms as predictors of mortality in patients with congestive heart failure: a two-years follow-up study

OBJECTIVE

The present study was undertaken in order to evaluate the relationship between depressed mood (depression, emotional distress) and disease-specific subjective health symptoms upon mortality risk among patients with congestive heart failure (CHF).

METHODS AND RESULTS

Proportional hazard models were used to evaluate the effects of selected biomedical, subjective health and psychological variables on mortality among 119 clinically stable patients (71.4% men; mean age 65.7 years +/- 9.6) with symptomatic heart failure, recruited from an outpatient cardiology practice. Twenty deaths were registered during the twenty-four-month period of data collection, all from cardiac causes. Results indicated that depressed mood was a significant predictor of mortality with a hazard ratio of 1.9, p .002. In contrast, subjective health was not a significant predictor of mortality in a Cox regression model that included depressed mood. The hazard ratio for a 1-point increase in Zung Depression Scale score was equal to 1.08 based on the multivariate model.

CONCLUSIONS

Results indicate that depressed mood is significantly related to increased mortality risk among heart failure patients. This finding is of concern to clinicians and should have implications for treatment of patients with congestive heart failure.