Natriuretic peptides in patients with diastolic dysfunction due to idiopathic dilated cardiomyopathy

The proposed role of plasma NT pro-brain natriuretic peptide in assessing cardiac remodelling in hypertensive African subjects

AIM

Although plasma NT-proBNP differentiates hypertension (HT) with or without left ventricular hypertrophy (LVH) from hypertensive heart failure (HHF), most of the published data are based on studies in Western populations. Also, most previous studies did not consider left ventricular (LV) diastolic function and right ventricular (RV) function. We therefore examined the relation between NT-proBNP on LV and RV remodelling in an African hypertensive cohort.

METHODS

Subjects were subdivided into three groups after echocardiography: hypertensives without LVH (HT) (n = 83); hypertensives with LVH (HT + LVH) (n = 50); and those with hypertensive heart failure (HHF) (n = 77).

RESULTS

Subjects with HHF had significantly higher NT-proBNP levels compared to the HT + LVH group (p < 0.0002). NT-proBNP correlated positively with right atrial area, an indirect measure of RV function.

CONCLUSIONS

NT-proBNP is proposed as a useful biomarker in differentiating hypertension with or without LVH from hypertensive heart failure in black hypertensive subjects.

Hyper-Prolactinemia in Men With Idiopathic Dilated Cardiomyopathy: Does It Have any Prognostic Implications?

Background:

Prolactin (PRL) has increasingly been recognized to play a stimulatory role in inflammatory response. Recently, studies have reported an increase in prolactin level among patients with chronic heart failure, however, there is conflicting data about its role as a prognostic factor in these patients.

Objectives:

We aimed to measure PRL level in male patients with idiopathic dilated cardiomyopathy (IDC) and its relationship with some prognostic factors.

Patients and Methods:

Serum prolactin level was assessed in 33 men with a diagnosis of IDC, left ventricle ejection fraction (LVEF) less than 35% on standard medical therapy for heart failure and New York Heart Association class II-III. Serum NT-Pro BNP (N terminal pro brain natriuretic peptide), hs-CRP (High sensitive C reactive protein) and six-minute walk test (6MWT) were also measured. Our secondary endpoints were mortality, transplantation and hospitalization due to acute heart failure and all patients were followed for one year.

Results:

The mean age was 33 ± 7 years (24-45 years) and the mean LVEF was 23% ± 6.5. The mean PRL level was 16 ± 7.7 ng/mL (95% confidence interval: 13.3-18.7 ng/mL), which was significantly higher than normal reference values (4.04-15 ng/mL) (P < 0.0001). There was no correlation between PRL levels and pro BNP, hs-CRP or 6MWT test, however, the serum PRL level was slightly higher among patients who died or were hospitalized or transplanted.

Conclusions:

Considering our study results, prognostic implication of PRL should be questioned. However, it seems that the significant increase in serum PRL in the study population needs more consideration and may have its own pathophysiologic importance. Further studies are recommended for better addressing the role of PRL in chronic heart failure patients.

Neutrophil/lymphocyte ratio is related to the severity of idiopathic dilated cardiomyopathy

OBJECTIVES

The aim of this study was to assess whether NLR levels are associated with echocardiographic parameters, New York Heart Association (NYHA) functional class, or B- type natriuretic peptide (BNP) levels in patients with idiopathic dilated cardiomyopathy (DCM).

DESIGN

Eighty-seven patients with idiopathic DCM were included prospectively from 2009 to 2014. Patients with acute decompensated heart failure and conditions that alter the total or differential white blood cell counts were excluded. Blood samples were collected before echocardiographic investigation on admission.

RESULTS

There was a statistically significant correlation between neutrophil/lymphocyte ratio (NLR) and NYHA functional class (r = 0.68, p < 0.001), BNP levels (r = 0.61, p < 0.001) and various echocardiographic parameters. NLR was significantly higher in patients in NYHA functional class III or IV (n = 39) than among those categorized as NYHA class I or II (n = 48), (3.3 ± 1.0 vs 2.1 ± 0.6; p < 0.001). The NLR cutoff value predicting severe chronic HF was 2.25 with 82% sensitivity and 65% specificity (p < 0.001). On multivariate linear regression analysis NLR (p = 0.025), left ventricular end-diastolic volume (p = 0.041) and left atrial volume index (LAVI) (p = 0.001) were found to be independent positive predictors of BNP levels.

CONCLUSION

Neutrophil/Lymphocyte ratio is associated with the severity of chronic heart failure in patients with idiopathic DCM.

Concentration of natriuretic peptides in patients suffering from idiopathic arterial hypertension and left ventricular diastolic dysfunction confirmed by echocardiography

Concentration of natriuretic peptides (NPs) in arterial hypertension (AH) patients is higher than that in healthy people. One of the first symptoms of left ventricular hypertrophy (LVH) is left ventricular diastolic dysfunction (LVDD). The aim of this study was to examine whether determination of NPs in blood can be a useful indicator of LVDD detection in idiopathic AH patients. The study was conducted on three groups of patients: group Ia, 19 patients (average age 57 ± 3) with eccentric hypertrophy; group Ib, 13 patients (59 ± 4) with concentric hypertrophy; group II, 33 patients (58 ± 4) without AH or LVH. In all groups, mitral inflow profile was evaluated with Doppler test to detect LVDD, blood flow in upper right pulmonary vein, and concentration of atrial natriuretic peptide (ANP), N-terminal ANP (N-ANP), brain natriuretic peptide (BNP), and N-terminal BNP (N-BNP). In group Ia, significant correlations were observed between the following pairs: ratio of maximum early to late mitral inflow and ANP; deceleration time of early mitral inflow speed and ANP; atrial contraction (AR) and ANP; atrial contraction (AR) and N-ANP; similarly, in group Ib, significant correlations were observed between the following: relative wall thickness and BNP; isovolumic relaxation time and BNP; AR and BNP; relative wall thickness and N-BNP; isovolumic relaxation time and N-BNP; AR and N-BNP.

N-Terminal Pro-B-Type Natriuretic Peptide in Patients with Hypertensive Heart Disease

Patients with hypertensive heart disease have elevated concentrations of N-terminal pro-B-type natriuretic peptide (NT-proBNP). The aim of our study was to evaluate NT-proBNP in patients with long-standing hypertension and in patients with signs of hypertensive cardiomyopathy. The study included three groups of 50 subjects: healthy persons (Control Group), patients with hypertension and normal left ventricular systolic function (Group 1) and patients with longstanding hypertension and signs of hyper tensive cardiomyopathy with impaired left ventricular systolic function (Group 2). Our results show a very good correlation (Pearson's test) between NT-proBNP in Group 1 and Group 2 and C-reactive protein (Group 1: r = 0.8424; Group 2: r = 0.6650), systolic blood pressure (Group 1: r = 0.7213; Group 2: r = 0.4856), diastolic blood pressure (Group 1: r = 0.4282; Group 2: r = 0.3989) and ejection fraction (Group 1: r = -0.7390; Group 2: r = 0.9111). ROC analysis revealed that the AUC between the Control Group and Group 1 for NT-proBNP (0.912) was not significantly different (p>0.05) from the AUC for systolic (0.924) and diastolic pressure (0.937). A cut-off value for NT-proBNP of 5.89 pmol/L can be used to reliably distinguish patients of Group 1 from the Control Group, and a cut-off value of 21.67 pmol/L reliably separates patients from Group 1 and Group 2 (in both cases, the AUC is 1.000). Patients in Group 2 who belonged to the II and III New York Heart Association (NYHA) class had significantly higher levels of NT-proBNP than those in NYHA class I (ANOVA test, p=0.001). These data suggest that NT-proBNP is a useful biomarker for distin guishing patients with long-standing hypertension who are at risk of heart failure, allowing optimization and proper treatment of these patients.

Serum prolactin and macroprolactin in heart failure: no relation to established laboratory or clinical parameters

Background

A few smaller studies have reported that the prolactin concentration is elevated in connection with heart failure. As heart failure is combined with disturbances of several biological systems any or all of which may also influence prolactin concentrations, we wanted to evaluate the relation of prolactin to prognosis in elderly patients.

Methods

A total of 462 elderly patients from a primary health-care centre, all with symptoms of heart failure, were included. In addition to clinical examination including echocardiography, concentrations of prolactin, macroprolactin, C-reactive protein, thyroid-stimulating hormone and N-terminal pro B-type natriuretric peptide (NT-proBNP) were measured. Patients were then followed for 10 y, and all incidents of cardiovascular mortality were registered.

Results

After excluding patients with macroprolactin, hyperprolactinaemia was found in 3.7% of the patients. There were no differences in prolactin concentrations or in the frequency of macroprolactin between patients with heart failure and those with normal cardiac function, defined as left ventricular ejection fraction of at least 50%. No significant correlation could be found between NT-proBNP and prolactin. Neither could any association be found between cardiovascular mortality and prolactin concentration during 10 y of follow-up.

Conclusions

Prolactin concentrations were not associated with cardiovascular mortality or any clinical or biochemical marker of heart failure. Macroprolactin was found in similar frequency among patients with and without heart failure, and showed no correlation with mortality risk.

Tei index correlates with tissue Doppler parameters and reflects neurohormonal activation in patients with an abnormal transmitral flow pattern

BACKGROUND

Tei index (TI) is a Doppler parameter which reflects combined systolic and diastolic function. We aimed to study the relationship between TI, both traditional and tissue Doppler imaging (TDI) echocardiographic parameters and neurohormonal profile in outpatients with diastolic dysfunction expressed by an abnormal transmitral flow pattern.

METHODS AND RESULTS

A total of 67 consecutive outpatients with diastolic dysfunction (abnormal transmitral flow pattern) were studied; all patients underwent clinical evaluation, blood sampling for B-type natriuretic peptide (BNP) plasma assaying, echocardiography for the determination of left ventricular ejection fraction (LVEF), dP/dt, left atrium (LA) dimensions, longitudinal systolic (S) and diastolic wall velocities (E'and A'), TI measured with Doppler echocardiography, and mitral regurgitation (MR) quantified on a semicontinuous scale. TI values were significantly correlated with BNP levels (r = 0.33; P < 0.01), LVEF (r =-0.56; P < 0.001), dP/dt (r =-0.52; P < 0.01), S (r =-0.45; P < 0.001), E'(r =-0.36; P < 0.01), A'(r =-0.27; P < 0.05), LA volume (r = 0.35; P < 0.01), and MR (P for trend < 0.05). In a multivariate regression analysis, TI was an independent predictor of increased BNP levels (beta= 0.32; P < 0.05), even after correction for potential confounders. ROC analysis showed as values of TI >0.59 identified subjects with combined systolic and diastolic dysfunction with a sensitivity of 73.8% and a specificity of 71.4%.

CONCLUSIONS

In outpatients with diastolic dysfunction, TI, an easy to perform parameter for global ventricular performance assessment, might be useful in identifying subjects with concomitant systolic impairment and neurohormonal activation.

N-terminal B-type natriuretic peptide levels in pediatric patients with congestive heart failure undergoing cardiac surgery

OBJECTIVES

The objectives of this study were to measure circulating N-terminal B-type natriuretic peptide levels in pediatric patients undergoing surgical repair of congenital heart lesions with left ventricular volume overload and to determine whether presurgical and immediate postoperative N-terminal B-type natriuretic peptide levels could predict patient outcomes after surgical intervention.

METHODS

Thirty-eight children aged 1 to 36 months undergoing surgical repair of cardiac lesions with left ventricular volume overload were studied. Plasma N-terminal B-type natriuretic peptide levels were measured preoperatively and at 2, 12, 24, 48, and 72 hours after surgical intervention and were assessed for their predictive value of postoperative outcomes. Plasma N-terminal B-type natriuretic peptide levels were also measured in 34 similarly aged healthy children.

RESULTS

Patient preoperative N-terminal B-type natriuretic peptide levels were significantly higher than those of healthy control subjects (3085 +/- 4046 vs 105 +/- 78 pg/mL). Preoperative N-terminal B-type natriuretic peptide levels correlated with the complexity of surgical repair, as measured by cardiopulmonary bypass time (r = 0.529, P < .001), and with postoperative measures, including fractional inhaled oxygen requirements registered at 12 hours (r = 0.443, P = .005) and duration of mechanical ventilation (r = 0.445, P = .005). Plasma N-terminal B-type natriuretic peptide levels increased 5-fold within 12 hours after cardiopulmonary bypass (14,685 +/- 14,317 pg/mL). Multivariable regression analysis showed that the preoperative N-terminal B-type natriuretic peptide level was a significant predictor of duration of intensive care unit stay (P = .02) and that the peak postoperative N-terminal B-type natriuretic peptide level was a significant predictor of the intensity of overall medical management, as assessed by using the therapeutic intervention scoring system (P = .01).

CONCLUSION

Plasma N-terminal B-type natriuretic peptide levels measured preoperatively and postoperatively can be a prognostic indicator in the management of the pediatric patient after surgical intervention for congenital heart repair.

Renal Dysfunction Is a Confounder for Plasma Natriuretic Peptides in Detecting Heart Dysfunction in Uremic and Idiopathic Dilated Cardiomyopathies

Background: The diagnostic value of natriuretic peptides in uremic cardiomyopathy has not been defined, nor has the effect of a hemodialysis (HD) session on peptides.

Methods: We performed an observational study of 100 white adult outpatients in New York Heart Association class I–II, with neither diabetes nor ischemic heart disease, 50 of whom had idiopathic dilated cardiomyopathy (DCM) and 50 of whom had uremic cardiomyopathy and were undergoing HD. We measured plasma N-terminal proB-type natriuretic peptide (NT-proBNP), BNP, and atrial natriuretic peptide (ANP) both before and after a dialysis session. Doppler echocardiograms were evaluated. We performed multiple regression analysis on the logarithm of peptide concentrations using clinical, laboratory, and echocardio-Doppler data as explanatory variables.

Results: Mean peptide concentrations were higher in the HD group, with an HD:DCM ratio of 25 for NT-proBNP and 5 for BNP and ANP. Peptides were correlated with each other (r &gt; 0.85). After HD, NT-proBNP significantly increased by 14%, BNP decreased by 17%, and ANP decreased by 56%. Predialysis concentrations correlated with postdialysis values (r &gt; 0.85). A multiple regression equation significantly fitted the observed peptide concentrations, both pre- and postdialysis, using the same set of 4 variables: disease group (DCM or HD), diastolic pattern, left atrial volume, and body mass index.

Conclusions: Renal dysfunction was a confounder for natriuretic peptides, which were present in higher concentrations in the uremic patients with milder cardiac dysfunction than in those with idiopathic DCM without renal dysfunction. Left diastolic function pattern and atrial volume were cardiac determinants of peptide concentrations in DCM and HD.

Individual patient meta-analyses of restrictive diastolic filling pattern and mortality in patients post acute myocardial infarction and in patients with chronic heart failure

BACKGROUND AND OBJECTIVE

Doppler echocardiographic assessment of diastolic filling provides a non-invasive estimate of left ventricular (LV) filling pressure and the most advanced diastolic filling grade, the restrictive filling pattern (RFP), has been linked to prognosis in patients post acute myocardial infarction (AMI) and with heart failure (HF). There remains some uncertainty about the prognostic role of RFP in patients with varied levels of systolic function. The objective of this collaboration is to determine whether the presence of RFP offers additional prognostic information over LV systolic function, symptoms or other clinical factors in patients post AMI or with HF.

METHODS

The Meta-analysis Research Group in Echocardiography (MeRGE) has been established in order to test this through two individual patient meta-analyses. Prospective studies that enrolled patients with either established HF or post AMI and included Doppler-echocardiography and outcome data will be merged into two large datasets (3739 AMI patients and 3540 HF patients) in order to evaluate the independent effects of RFP upon total and cardiovascular mortality using Kaplan-Meier survival analysis methods and Cox proportional hazards model for multi-variate analysis. Survival will be examined within different bands of LV systolic function based upon ejection fraction (EF).

IMPLICATIONS

This unique dataset will provide a very large cohort of patients, which will be adequately powered to provide new and prognostically important information to further aid risk stratification in these two high-risk patient groups.

N-terminal probrain natriuretic peptide predicts altered circadian variation in essential hypertension

Diminished nocturnal blood pressure fall in nondipper hypertensive patients are closely associated with poor prognosis. N-terminal probrain natriuretic peptide can also identify poor prognosis in miscellaneous heart diseases. In this study, we aimed to clarify the association between probrain natriuretic peptide levels and diminished nocturnal blood pressure fall in patients with essential hypertension. Twenty-six consecutive nondipper (age: 53+/-8 years, 14 men) (group 1), and 26 dipper hypertensive patients (age: 52+/-9 years, 16 men) (group 2), based on ambulatory blood pressure monitoring, and age and sex-matched 28 normotensive participants (age: 50+/-11 years, 16 men) (group 3) were compared with each other. Although systolic and diastolic ambulatory blood pressure values were similar in hypertensives during the day, those at night were higher in group 1 (P<0.0001). Echocardiographic findings revealed that the left ventricular mass index was higher in both group 1 (184+/-47) and group 2 (142+/-39) compared with control participants (102+/-19) (P<0.0001), but ejection fraction and relative wall thickness were similar in all groups. The transmitral E-wave velocity decreased in group 1 (0.62+/-0.15 m/s) and group 2 (0.7+/-0.14 m/sec) compared with group 3 (0.95+/-0.22 m/s) (P<0.01). The transmitral E/A ratio decreased (0.71+/-0.12, 0.81+/-0.2 and 0.79+/-0.57, respectively P<0.05), and the transmitral E-wave deceleration time increased in group 1 (208+/-46, 203+/-38 and 169+/-42 ms, respectively, P<0.05). The isovolumic relaxation time increased (112+/-23, 110+/-18 and 86+/-11 m/s, respectively, P<0.01). Although group 1 and 2 have a similar number of patients with diastolic dysfunction (23/26 and 22/26, respectively, P>0.05), there were great differences between plasma probrain natriuretic peptide levels (88+/-20, 58+/-22 and 47+/-20 pg/ml, respectively, P<0.0001). In addition, serum uric acid (6.5+/-1.4, 5.3+/-1.5 and 5.0+/-1.9, respectively P<0.001), and creatinine levels (0.88+/-0.2 and 0.78+/-0.2 vs. 0.72+/-0.3, respectively P<0.05) were higher in group 1. These observations suggest that nondipper state may be related to the increase in left ventricular mass index and probrain natriuretic peptide levels and elevation in both plasma uric acid and creatinine levels. Serum probrain natriuretic peptide levels are found to be correlated with left ventricular mass index (Pearson's correlation 469 P<0.0001); but not creatinine (Pearson's correlation 188 P>0.05).

The prognostic significance of restrictive diastolic filling associated with heart failure: A meta-analysis

BACKGROUND

Several studies have reported that the presence of a restrictive filling pattern (RFP) is associated with poor outcome in patients with heart failure (HF). These studies, of variable sample size, have involved different HF patient groups with variable associated mortality rates and follow-up times, and while powered for effects on combined end-points such as death or hospital admission, many were underpowered to reliably determine the overall effect of the RFP on total mortality. Consequently, we performed a meta-analysis to determine the mortality associated with RFP in patients with HF.

METHODS

We searched several online medical databases for prospective studies of patients with HF. All authors were requested to confirm their data. All-cause mortality was compared between RFP and non-restrictive filling patterns (Non-RFP). Review Manager version 4.2.7 software was used for the analysis.

RESULTS

3024 patients in 27 studies were identified (379 idiopathic cardiomyopathy, 2645 mixed aetiology HF). Average follow-up was between 3 months and 5 years. 1284 (42%) patients had RFP at baseline. 688 deaths occurred and the overall odds ratio for death was 4.36 (CI 3.60, 5.04); idiopathic group: 6.65 (CI 3.86, 11.47); mixed aetiology group: 4.10 (CI 3.34, 5.04). The overall odds ratio for death/transplantation was 4.87 (CI 4.04, 5.86); idiopathic group: 7.62 (CI 4.50, 12.92); mixed aetiology group: 4.56 (CI 3.74, 5.56).

CONCLUSIONS

Restrictive filling pattern is associated with a four-fold increase in mortality in patients with HF and thus should be an important part of the echocardiographic assessment of such patients.

N-terminal Pro B-type Natriuretic Peptide Levels: Correlation with Echocardiographically Determined Left Ventricular Diastolic Function in an Ambulatory Cohort

OBJECTIVES

To investigate the correlations of plasma N-terminal pro B-type natriuretic peptide (NT-proBNP) levels with echocardiographic measurements of left ventricular (LV) systolic and/or diastolic function.

BACKGROUND

Plasma levels of NT-proBNP are increased in heart failure. The extent to which NT-proBNP levels increase in LV diastolic dysfunction has not been well characterized.

METHODS

Plasma NT-proBNP levels were measured in 191 consecutive, clinically stable, ambulatory patients. Echocardiography was used to determine LV systolic (LV ejection fraction [LVEF]) and diastolic function by mitral E wave to Doppler tissue early diastolic lateral annulus velocity ratio (E/Em). Patients with a history, physical findings, and/or echocardiographic evidence of cardiovascular disease (n = 148) were grouped as: (1) normal LV systolic function (LVEF > or = 55%, n = 81); and (2) LV systolic dysfunction (LVEF < 55%, n = 67). They were compared to a group of healthy control subjects (n = 43). Multivariate regression analyses were used to determine significant correlations with plasma NT-proBNP levels.

RESULTS

NT-proBNP levels correlated negatively with LVEF (P < .001) and positively with E/Em (P = .001). Multivariate regression analysis demonstrated a significant correlation of NT-proBNP levels with LVEF (P < .001) and E/Em (P = .03).

CONCLUSIONS

In this clinically stable, ambulatory cohort of patients with cardiovascular disease and healthy control subjects, plasma NT-proBNP levels were significantly higher in those with LV systolic dysfunction and/or elevated filling pressures, independent of the effects of LV mass, renal function, and age. These results suggest that NT-proBNP levels may be a useful adjunct in the characterization of patients presenting with history and/or symptoms compatible with LV systolic and/or diastolic dysfunction.

Factors associated with decreased cerebral blood flow in congestive heart failure secondary to idiopathic dilated cardiomyopathy

Cerebral blood flow (CBF) is decreased and cognitive dysfunction develops in the advanced stages of heart failure. However, few data are available regarding the factors associated with decreased CBF. Fifty-two patients with advanced congestive heart failure (CHF) secondary to idiopathic dilated cardiomyopathy (ejection fraction <or=35%) and 10 healthy volunteers were included in this study. Echocardiography and symptom-limited bicycle exercise testing were performed. Global CBF was measured by radionuclide angiography. Global CBF was 19% less in patients with CHF than in controls (p <0.01). Such reduced CBF became normalized in 4 patients with CHF who underwent cardiac transplantation. In a univariate linear regression analysis, global CBF was significantly associated with New York Heart Association functional class, disease duration, atrial fibrillation, serum B-type natriuretic peptide level, the early mitral velocity/early diastolic annular velocity ratio, and pulmonary artery systolic pressure. Global CBF was not found to be associated with the ejection fraction, peak oxygen consumption, or anaerobic threshold. In a stepwise multivariate linear regression analysis, serum B-type natriuretic peptide level (p = 0.047) and New York Heart Association functional class (p = 0.003) were significantly related to global CBF (global CBF = 48.373 - 0.05 x serum B-type natriuretic peptide level - 3.283 x New York Heart Association functional class; r(2) = 0.401). In conclusion, CBF is decreased in patients with CHF, which may be used to predict disease severity and chronicity.

Utility of brain natriuretic peptide (BNP) measurement in cardiovascular disease

Cardiac failure is a prevalent and costly condition in Western society. The ageing of the population, together with current medical options which improve, rather than eradicate heart failure, lead to the projection that this problem will increase substantially in the foreseeable future. The availability of a simple test to assist the diagnosis and effective management of heart failure would greatly assist the clinical approach to this problem. This review examines the physiological basis for the measurement of natriuretic peptides as markers of the presence or risk of heart failure. It considers its use in the hospital and non-hospital setting and examines the cost-effectiveness of current assays. It is possible that in future natriuretic peptides may offer a form of treatment for heart failure, but this is beyond the scope of this review. Nevertheless, the review highlights the potential benefits of this group of tests in the management of heart failure.

BNP as a marker of diastolic dysfunction in the general population: Importance of left ventricular hypertrophy

BNP is a marker of systolic left ventricular dysfunction (LVSD) and heart failure. To assess BNP for the detection of diastolic dysfunction in the general population, we examined 1678 subjects within an age- and sex-stratified survey (MONICA Augsburg). BNP was measured using a commercially available RIA (Shionogi). BNP increased in subjects with diastolic dysfunction (mean 20.3+/-4.7 pg/ml vs. control 9.6+/-0.5 pg/ml, p<0.001), but to a lesser extent than in subjects with LV hypertrophy (LVH, mean 37.3+/-49.1 pg/ml, p<0.001 vs. control) or LVSD (mean 76.2+/-23.2 pg/ml, p<0.001 vs. control). Individuals with sole diastolic abnormality displayed BNP concentrations at the control level (mean 9.7+/-1.7 pg/ml). In univariate analysis, age, BMI, systolic blood pressure, left atrial size, LV mass index, diastolic dysfunction and EF displayed a significant correlation with BNP (p<0.001). However, LV mass index displaced diastolic dysfunction as a significant predictor of BNP in multivariate analysis. Upon ROC analysis, sensitivity and specificity for the detection of diastolic dysfunction by BNP were only 61% and 55%, respectively. Nevertheless, a normal BNP test virtually excluded the presence of diastolic dysfunction and concomitant LVH (NPV 99.9%). Increased BNP concentrations in subjects with diastolic dysfunction are strongly related to LVH. Population-wide screening for diastolic dysfunction with BNP cannot be recommended although a normal BNP test usually excludes diastolic dysfunction and LV hypertrophy.

Natriuretic peptides as markers of mild forms of left ventricular dysfunction: effects of assays on diagnostic performance of markers

BACKGROUND

We compared the performance of different natriuretic peptides to diagnose mild forms of left ventricular dysfunction (LVD) and investigated the influence of measuring B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) with different assays on the diagnostic performance of these markers.

METHODS

We measured BNP (Triage BNP), NT-proBNP (Biomedica), and N-terminal pro-A-type natriuretic peptide (NT-proANP; Biomedica) in 130 consecutive patients (age range, 28-83 years) with clinically suspected mild LVD. In patients with sufficient sample volume, we measured BNP and NT-proBNP with additional assays (Shionoria and Roche, respectively).

RESULTS

For identifying patients with mild systolic LVD, BNP and NT-proBNP were the best markers, with mean (95% confidence interval) areas under the curves (AUC) of 0.78 (0.63-0.89) and 0.75 (0.58-0.87), respectively. However, the diagnostic performance of NT-proANP [AUC, 0.64 (0.48-0.77)] was significantly worse than that of BNP (P = 0.014). Both BNP assays (Triage and Shionoria) and both NT-proBNP assays (Biomedica and Roche) performed equally well for the diagnosis of systolic LVD despite the poor agreement between NT-proBNP assays. In patients with isolated diastolic LVD, the diagnostic performance of the Triage BNP [AUC, 0.70 (0.56-0.81)] was significantly better (P = 0.006) than that of Biomedica NT-proBNP [0.49 (0.34-0.65)]. Furthermore, the performance of the Biomedica NT-proBNP assay was significantly worse (P = 0.03) than that of the Roche NT-proBNP assay for diagnosis of isolated diastolic LVD.

CONCLUSIONS

The performance of BNP for the diagnosis of systolic or diastolic LVD is not affected by the assay used, whereas the performance of NT-proBNP for the diagnosis of isolated diastolic LVD is assay dependent.

Plasma B-type natriuretic peptide levels in systolic heart failure

OBJECTIVES

This study was designed to characterize the importance of echocardiographic indexes, including newer indexes of diastolic function, as determinants of plasma B-type natriuretic peptide (BNP) levels in patients with systolic heart failure (SHF).

BACKGROUND

Plasma BNP levels have utility for diagnosing and managing heart failure. However, there is significant heterogeneity in BNP levels that is not explained by left ventricular size and function alone.

METHODS

In 106 patients with symptomatic SHF (left ventricular ejection fraction [LVEF] <0.35), we measured plasma BNP levels and performed comprehensive echocardiography with assessment of left ventricular diastolic function, including color M-mode (CMM) and tissue Doppler imaging (TDI), and of right ventricular (RV) function.

RESULTS

Median plasma BNP levels were elevated and increased with greater severity of diastolic dysfunction. We found significant correlations (p < 0.001 for all) between BNP and indexes of myocardial relaxation (early diastolic velocity: r = -0.26), compliance (deceleration time: r = -0.55), and filling pressure (early transmitral to early annular diastolic velocity ratio: r = 0.51; early transmitral flow to the velocity of early left ventricular flow propagation ratio: r = 0.41). In multivariate analysis, overall diastolic stage, LVEF, RV systolic dysfunction, mitral regurgitation (MR) severity, age and creatinine clearance were independent predictors of BNP levels (model fit r = 0.8, p < 0.001).

CONCLUSIONS

Plasma BNP levels are significantly related to newer diastolic indexes measured from TDI and CMM in SHF. Heterogeneity of BNP levels in patients with SHF reflects the severity of diastolic abnormality, RV dysfunction, and MR in addition to LVEF, age, and renal function. These findings may explain the powerful relationship of BNP to symptoms and prognosis in SHF.

In patients with severe systolic dysfunction, only brain natriuretic peptide is related to diastolic restrictive pattern

BACKGROUND

In patients with severe systolic dysfunction the relationship between diastolic dysfunction and plasma levels of atrial and brain natriuretic peptide (ANP, BNP), catecholamines, renin, and aldosterone in patients with chronic heart failure (CHF) has never been investigated.

OBJECTIVES

The aim of this study was to evaluate in clinically stable patients with severe systolic dysfunction whether the presence of diastolic restrictive pattern modifies neurohormonal plasma levels.

METHODS

Of 82 consecutive patients with stable CHF, 36 were in sinus rhythm, had an adequate ultrasound window and an ejection fraction <30%, and gave their written consent. Plasma levels of ANP, BNP, aldosterone, renin, epinephrine, and norepinephrine were assessed, and the diastolic function was evaluated by Doppler transmitral flow velocity curves.

RESULTS

Except for aldosterone, plasma levels of the other hormones were above normal range in most patients. Patients with restrictive pattern (22%) had BNP plasma levels significantly higher than patients with nonrestrictive pattern (78%): 251 +/- 196 versus 44 +/- 35 ng/L (P=.02). A BNP value of 72.6 ng/L had a sensitivity of 88%, with a specificity of 89% for detecting restrictive pattern in our population.

CONCLUSION

In clinically stable patients with CHF and severe systolic dysfunction, BNP is the only neurohormone sensitive to the concomitant presence of a restrictive pattern.

Impact of early changes in left ventricular filling pattern on long-term outcome after acute myocardial infarction

BACKGROUND

In patients with heart failure due to chronic ischemic heart disease improvement of diastolic function indicates improved survival and a reduced morbidity, but whether this is also the case after acute myocardial infarction is not known.

METHODS

To assess the prognostic importance of changes in left ventricular filling pattern, assessed with mitral deceleration time and colour M-mode flow propagation velocity, on cardiac death and readmission due to heart failure serial Doppler echocardiography was carried out in 103 patients with a first myocardial infarction. Based on echocardiography on hospital admission and after 1 month, patients were divided into three groups: group A (n=29) comprised patients with normal filling at either examination, group B (n=29) comprised patients with improvement of initially abnormal filling, and group C (n=45) patients with deterioration or no change of an abnormal filling pattern.

RESULTS

One-year survival free of cardiac death or hospitalisation for heart failure was 97% in group A, 86% in group B and 64% in group C (P<0.0001). In Cox analysis persistence of abnormal filling or deterioration of left ventricular filling was still a predictor of the combined endpoint (risk ratio 4.4, 95% CI 1.8-12.0, P=0.003) after adjustment of LV filling on admission, left ventricular systolic function and clinical variables. Serial analyses of left ventricular systolic function demonstrated a significant improvement after 1 year in ejection fraction in groups A and B, whereas ejection fraction remained unchanged in group C.

CONCLUSION

Patients with a persistently abnormal or a deterioration of left ventricular filling pattern as opposed to improved or normal filling are at increased risk of cardiac death and readmission due to heart failure after acute myocardial infarction.

Cardiac hormones as diagnostic tools in heart failure

In patients with heart failure, plasma levels of atrial natriuretic peptide (ANP), B-type natriuretic peptide (BNP), and the N-terminal fragments of their prohormones (N-ANP and N-BNP) are elevated, because the cardiac hormonal system is activated by increased wall stretch due to increased volume and pressure overload. Patients suspected of having heart failure can be selected for further investigations on the basis of having an elevated plasma concentration of N-ANP, BNP, and N-BNP. High levels of cardiac hormones identify those at greatest risk for future serious cardiovascular events. Moreover, adjusting heart failure treatment to reduce plasma levels of N-BNP may improve outcome. Cardiac hormones are most useful clinically as a rule-out test. In acutely symptomatic patients, a very high negative predictive value is coupled with a relatively high positive predictive value. Measurement of cardiac hormones in patients with heart failure may reduce the need for hospitalizations and for more expensive investigations such as echocardiography. However, there have also been conflicting reports on the diagnostic value of cardiac hormones, they are not specific for any disease, and the magnitude of the effects of age and gender on BNP in the normal subgroup suggests that these parameters need to be considered when interpreting cardiac hormone levels.

Unusual left ventricular dilatation without functional or biochemical impairment in normotensive extremely overweight Japanese professional sumo wrestlers

To explore the physiologic limit of left ventricular (LV) enlargement, we performed echocardiography and air displacement plethysmography to respectively assess LV dimension and function and the body composition of Japanese professional sumo wrestlers. After excluding subjects with cardiovascular disease, hypertension, plasma brain natriuretic peptide (BNP) > or =17.9 pg/ml, diabetes mellitus, or asthma, 331 subjects (mean +/- SD age, 21.6 +/- 3.7 years; height 179.2 +/- 5.3 cm; weight 1,17.9 +/- 21.5 kg; percent fat, 29.6 +/- 6.6%) were analyzed. LV end-diastolic dimension averaged 58.4 +/- 3.7 mm and was within the generally regarded normal limit (< or =54 mm) in 14.5% of subjects, but was > or =60 mm in 41.1% of subjects. LV septal and posterior wall thicknesses were 10.3 +/- 0.9 and 10.2 +/- 0.9 mm, respectively. Peak E- and A-wave velocities, E/A ratio, LV fractional shortening, and BNP were 96 +/- 16 and 51 +/- 13 cm/s, 2.0 +/- 0.7, 33.5 +/- 4.5%, and 3.1 +/- 3.7 pg/ml, respectively. LV end-diastolic dimension was not correlated with these indexes of LV function or with plasma BNP levels, but was significantly correlated with height, weight, body surface area, fat-free mass, and fat mass. These results show that among very large, highly trained, professional athletes, LV end-diastolic dimension frequently exceeds the traditionally accepted upper limit of normal for the general population. This increase in LV end-diastolic dimension may thus represent an extreme example of the physiologic adaptation of the athlete's heart.

Natriuretic peptides in the diagnosis of heart disease--first amongst equals?

The natriuretic peptides and their role in neurohumoral regulation of the cardiovascular system have become the focus of considerable interest from the scientific and clinical community in recent years. BNP in particular has been shown to be an important diagnostic and prognostic marker of use in a wide range of applications. As measurement techniques develop and are refined, routine evaluation of serum levels of these markers is expected to become more widespread. We have reviewed the biochemistry of the natriuretic peptide family, their role in cardiovascular pathophysiology and the evidence supporting their use in the clinical setting.

Reliability of N-terminal pro-brain natriuretic peptide assay in diagnosis of heart failure: cohort study in representative and high risk community populations

OBJECTIVE

To investigate the performance of a novel assay for N-terminal pro-brain natriuretic peptide (NT-proBNP) in diagnosing heart failure in various randomly selected general and high risk community populations.

DESIGN

Community cohort study (substudy of the echocardiographic heart of England screening study).

SETTING

Four randomly selected general practices in the West Midlands of England.

PARTICIPANTS

591 randomly sampled patients over the age of 45, stratified for age and socioeconomic status and falling into four cohorts (general population, patients with an existing clinical label of heart failure, patients prescribed diuretics, and patients deemed at high risk of heart failure).

MAIN OUTCOME MEASURE

Sensitivity, specificity, positive and negative predictive values, likelihood ratios, and area under receiver operating characteristic curve for NT-proBNP assay in the diagnosis of heart failure.

RESULTS

For NT-proBNP in the diagnosis of heart failure in the general population (population screen), a level of >36 pmol/l had a sensitivity of 100%, a specificity of 70%, a positive predictive value of 7%, a negative predictive value of 100%, and an area under the receiver operating characteristic curve of 0.92 (95% confidence interval 0.82 to 1.0). Similar negative predictive values were found for patients from the three other populations screened.

CONCLUSIONS

This NT-proBNP assay seems to have value in the diagnosis of heart failure in the community. High negative predictive values indicate that the assay's chief use would be to rule out heart failure in patients with suspected heart failure with normal concentrations of NT-proBNP. Positive results may identify patients who need cardiac imaging.

BNP in hormone-guided treatment of heart failure

The pharmacotherapy of heart failure has become complex. Angiotensin-converting enzyme inhibitors (or angiotensin II receptor blockers), beta-blockers, spironolactone, diuretics and digoxin can be prescribed concurrently. Endothelin antagonists and combined inhibitors of converting enzyme and neutral endopeptidase are under investigation. Optimal dosing will become increasingly difficult to judge. Plasma brain natriuretic peptide (BNP) indicates the severity of left ventricular dysfunction. The C-terminal bioactive peptide and N-terminal BNP (N-BNP) circulate at concentrations related to cardiac status. We proposed that plasma levels of N-BNP would provide an index to guide drug treatment in established heart failure. Sixty-nine patients were randomized to treatment adjusted according to clinical criteria or plasma N-BNP. Hormone-guided therapy resulted in fewer clinical end points than did clinical management. This encourages further exploration of hormone guidance of anti-heart failure therapy, which could be extended to patients with preserved ejection fraction, in addition to those with established systolic dysfunction.

Natriuretic peptides during the development of doxorubicin-induced left ventricular diastolic dysfunction

OBJECTIVES

To investigate changes in plasma atrial natriuretic peptide (ANP), N-terminal pro-atrial natriuretic peptide (NT-pro-ANP) and brain natriuretic peptide (BNP) during the development of doxorubicin-induced left ventricular systolic and diastolic dysfunction as measured by echocardiography (ECHO).

DESIGN

Prospective study.

SETTING

University hospital.

SUBJECTS

Twenty-eight adult patients with non-Hodgkin's lymphoma, who received doxorubicin to the cumulative dose of 400-500 mg m(-2).

MAIN OUTCOME MEASURES

The relationship between plasma natriuretic peptides and systolic and diastolic ECHO indices after the cumulative doxorubicin doses of 200, 400 and 500 mg m(-2).

RESULTS

Left ventricular ejection fraction (LVEF, by 2D ECHO) decreased from 58 +/- 1.7 to 52.5 +/- 1.3% (P=0.036) and fractional shortening (FS) from 34.6 +/- 1.4 to 27.8 +/- 0.9% (P=0.002). Peak E wave velocity decreased from 63.3 +/- 3.2 to 51.3 +/- 2.6 cm s(-1) (P=0.008) resulting in a statistically nonsignificant decrease in E/A ratio from 1.08 +/- 0.01 to 0.85 +/- 0.07. A significant decrease was observed in the percentage of left ventricular filling during the 1/3 of diastole (1/3FF) from 42.2 +/- 1.7 to 36.5 +/- 2.0% (P < 0.001). LV end systolic diameter increased from 32 +/- 1 to 38 +/- 1 mm (P=0.011), whereas left atrial (LA) diameter remained unchanged. Peak filling rate decreased from 4.4 +/- 0.2 to 4.0 +/- 0.2 stroke volume s(-1) (SV s(-1)) (ns). Plasma levels of ANP increased from 16.4 +/- 1.3 to 22.7 +/- 2.4 pmol L(-1) (P=0.002), NT-pro-ANP from 288 +/- 22 to 380 +/- 42 pmol L(-1) (P=0.019) and BNP from 3.3 +/- 0.4 to 8.5 +/- 2.0 pmol L(-1) (P=0.020). There was a significant inverse correlation between the decrease in FS and the increases in plasma NT-pro-ANP (r= -0.524, P=0.018) and plasma BNP (r=0.462, P=0.04) and between the decrease in PFR and the increases in plasma ANP (r= -0.457, P=0.043) and plasma NT-pro-ANP (r= -0.478, P=0.033). Furthermore, after doxorubicin therapy, significant inverse correlations were observed between E/A ratio and plasma ANP (r= -0.535, P=0.008), between E/A ratio and plasma NT-pro-ANP (r= -0.432, P=0.04) and between E/A ratio and plasma BNP (r= -0.557, P=0.006) as well as between 1/3FF and plasma BNP (r= -0.493, P=0.017). There was also a trend for correlation between LA diameter and plasma BNP (r=0.395, P=0.062) and peak E wave velocity and plasma BNP (r= -0.414, P=0.05), respectively. However, no significant correlations were observed between any of the systolic parameters and natriuretic peptide levels.

CONCLUSIONS

The results of this prospective study show that during the evolution of doxorubicin-induced LV dysfunction the secretion of natriuretic peptides is more closely associated with the impairment of left ventricular diastolic filling than with the deterioration of LV systolic function.

Genomic sequence and cardiac expression of atrial natriuretic peptide in cats

OBJECTIVE

To determine the nucleotide and amino acid sequence of atrial natriuretic peptide (ANP) in cats and its typical regions of cardiac expression.

ANIMALS

5 healthy adult mixed-breed cats.

PROCEDURE

Total RNA was extracted from samples obtained from the left and right atrium, left and right ventricle, and interventricular septum of each cat. The RNA was used to produce cDNA for sequencing and northern blot analysis. Genomic DNA was extracted from feline blood samples. Polymerase chain reaction primers designed from consensus sequences of other species were used to clone and sequence the feline ANP gene.

RESULTS

The feline ANP gene consists of 1,072 nucleotides. It consists of 3 exons (123, 327, and 12 nucleotides) separated by 2 introns (101 and 509 nucleotides). It has several typical features of eukaryotic genes and a putative steroid-response element located within the second intron. Preprohormone ANP consists of 153 amino acids. The amino acid sequence of the active form of feline ANP (ANP-30) is identical to that of equine, bovine, and ovine ANP-30 and differs from that of human, canine, and porcine ANP-28 only by 2 carboxy-terminal arginine residues. The ANP mRNA was detected only in the left and right atria.

CONCLUSIONS AND CLINICAL RELEVANCE

The genetic and protein structure and principal regions of cardiac expression of feline ANP are similar to those of other species. Results of this study should be helpful in future studies on the natriuretic response in cats to diseases that affect cardiovascular function.

BNP and congestive heart failure

Brain natriuretic peptide (BNP), a peptide hormone secreted chiefly by ventricular myocytes, plays a key role in volume homeostasis. The plasma concentration of BNP is raised in various pathological states, especially heart failure. Many studies suggest that measurement of plasma BNP has clinical utility for excluding a diagnosis of heart failure in patients with dyspnea or fluid retention and for providing prognostic information in those with heart failure or other cardiac disease. It may also be of value in identifying patients after myocardial infarction in whom further assessment of cardiac function is likely to be worthwhile. Preliminary evidence suggests that measuring the plasma concentration of BNP may be useful in fine tuning therapy for heart failure. Artificially raising the circulating levels of BNP shows considerable promise as a treatment for heart failure. With simpler assay methods now available, it is likely that many physicians will measure plasma BNP to aid them in the diagnosis, risk stratification, and monitoring of their patients with heart failure or other cardiac dysfunction.

Brain natriuretic peptide blood levels in the differential diagnosis of dyspnea

STUDY OBJECTIVES

In dyspneic patients without left ventricular enlargement, it may be difficult to differentiate between obstructive lung disease and diastolic heart failure. Determination of plasma brain natriuretic peptide (BNP) levels, known to increase with ventricular stretch, may be of clinical relevance in this situation. We compared the discriminant power of BNP blood levels and of echocardiography in patients with either chronic obstructive lung disease or diastolic heart failure.

PATIENTS

Twenty-six New York Heart Association class III dyspneic patients with normal left ventricular systolic function were enrolled: 17 patients with chronic obstructive lung disease and 9 patients with unequivocal diastolic heart failure.

RESULTS

Echocardiographic data were unable to accurately differentiate between the two groups, whereas BNP levels were significantly and markedly higher in patients with diastolic heart failure when compared to those with obstructive lung disease (224 +/- 240 pg/mL vs 14 +/- 12 pg/mL, p < 0.0001).

CONCLUSIONS

These preliminary results warrant a prospective, large-scale evaluation of the value of BNP assay for determining diastolic dysfunction, a common cause of dyspnea in elderly patients, and differentiating it from other diagnoses such as obstructive lung disease.

Blood pressure-independent additive effects of pharmacologic blockade of the renin-angiotensin and endothelin systems on progression in a low-renin model of renal damage

Pharmacologic blockade of the renin and endothelin (ET) systems is an established strategy to interfere with progression of renal failure. In the Heyman nephritis model, additive benefits of decreases in BP with the combination of angiotensin-converting enzyme inhibitors (ACE-i) and ET(A) receptor antagonists (ET-RA) were demonstrated. To further investigate these findings and to exclude confounding effects of BP decreases, this issue was reassessed in a low-renin model of subtotal kidney resection. Subtotally nephrectomized (SNX) and sham-operated rats were left untreated or received an ACE-i, an angiotensin II subtype 1 receptor antagonist (AT1-RA), an ET-RA, or combinations thereof (ACE-i plus ET-RA or AT1-RA plus ET-RA). The parameters studied were the glomerulosclerosis index (GSI), tubulointerstitial index, vascular damage index, glomerular geometry, and albumin excretion. After 12 wk, BP values were comparable. Urinary albumin excretion rates were significantly higher for untreated SNX rats (24.3 +/- 31.3 mg/24 h), compared with untreated sham-operated rats (0.71 +/- 0.40 mg/24 h). Rates were significantly lower for all treated, compared with untreated, SNX groups. GSI values were significantly higher for untreated SNX rats than for untreated sham-operated rats. ACE-i caused significantly lower GSI in SNX rats (0.46 +/- 0.06), compared with AT1-RA (0.60 +/- 0.10) or ET-RA (0.65 +/- 0.10). GSI values were significantly decreased further with ACE-i plus ET-RA (0.29 +/- 0.09) or AT1-RA plus ET-RA (23 +/- 0.05) treatment. Changes in the tubulointerstitial index and vascular damage index proceeded in parallel. The results document BP-independent effects of the ACE-i and AT1-RA on the GSI and urinary albumin excretion and an effect of the ET-RA on the GSI. The contrasting results suggest different pathogenetic pathways for glomerulosclerosis and albuminuria. The combination of treatments provided superior effects on the GSI and tubulointerstitial index but not on urinary albumin excretion.

The impact of cardiac natriuretic peptide determination on the diagnosis and management of heart failure

The long-predicted endocrine function of the heart has been proven by the discovery of atrial natriuretic peptide (atrial natriuretic factor, A-type natriuretic peptide; ANP) 20 years ago. This subsequently led to the description of a whole family of structurally similar but genetically distinct peptides, the natriuretic peptide family, which contributes to cardiovascular homeostasis. These looped peptides promote natriuresis and diuresis, act as vasodilators, and exert antimitogenic effects on cardiovascular tissues. Two members, ANP and brain natriuretic peptide (B-type natriuretic peptide; BNP) are secreted by the heart mainly in response to myocardial stretch induced by volume load. The natriuretic peptides are synthesized as preprohormones. The C-terminal endocrinological active peptides (ANP, BNP) and their N-terminal prohormone fragments are found in plasma. The natriuretic peptide system is activated to its highest degree in ventricular dysfunction. However, natriuretic peptides are increased in all patients with edematous disorders which lead to an increase in atrial tension or central blood volume, such as renal failure or ascitic liver cirrhosis. It could be demonstrated that in chronic heart failure patients and during the subacute phase of myocardial infarction, of all tested neurohormones, the cardiac natriuretic peptides were best markers to identify heart failure and the most powerful predictors of morbidity and mortality. Natriuretic peptides are independent markers for risk assessment. In comparative studies BNP was superior to ANP and its N-terminal prohormone fragments in myocardial infarction as well as in chronic heart failure patients. Less data on N-terminal proBNP (NT-proBNP) is available, but BNP and NT-proBNP appear to be equivalent markers. For primary care physicians natriuretic peptide measurement is useful to decide which patient with suspected heart failure warrants further investigation, particularly when assessment of left ventricular function is not readily available. Natriuretic peptides have an excellent negative predictive value, particularly in high risk patients. An increase in BNP is serious enough to warrant follow-up examinations. For the cardiologists the natriuretic peptides are helpful for guidance of therapy and monitoring disease course in heart failure patients and for risk stratification in heart failure and myocardial infarction.