Relation of plasma brain and atrial natriuretic peptides to left ventricular geometric patterns in essential hypertension

Current and Emerging Classes of Pharmacological Agents for the Management of Hypertension

Cardiovascular disease accounts for more than 17 million deaths globally every year, of which complications of hypertension account for 9.4 million deaths worldwide. Early detection and management of hypertension can prevent costly interventions, including dialysis and cardiac surgery. Non-pharmacological approaches for managing hypertension commonly involve lifestyle modification, including exercise and dietary regulations such as reducing salt and fluid intake; however, a majority of patients will eventually require antihypertensive medications. In 2020, the International Society of Hypertension published worldwide guidelines in its efforts to reduce the global prevalence of raised blood pressure (BP) in adults aged 18 years or over. Currently, several classes of medications are used to control hypertension, either as mono- or combination therapy depending on the disease severity. These drug classes include those that target the renin-angiotensin-aldosterone system (RAAS) and adrenergic receptors, calcium channel blockers, diuretics and vasodilators. While some of these classes of medications have shown significant benefits in controlling BP and reducing cardiovascular mortality, the prevalence of hypertension remains high. Significant efforts have been made in developing new classes of drugs that lower BP; these medications exert their therapeutic benefits through different pathways and mechanism of actions. With several of these emerging classes in phase III clinical trials, it is hoped that the discovery of these novel therapeutic avenues will aid in reducing the global burden of hypertension.

Midregional pro-atrial natriuretic peptide, an important member of the natriuretic peptide family: potential role in diagnosis and prognosis of cardiovascular disease

Midregional pro-atrial natriuretic peptide (MR-proANP), first isolated in 1981, is a novel peptide with multiple biological functions, especially within the cardiovascular system. This peptide plays an important role in many processes, including natriuresis, diuresis, and other physiological and pathophysiological pathways in the human body. Several electronic databases (PubMed, EBSCO, Scopus, and ScienceDirect) were analyzed in the present literature review. The aim of this study was to elucidate the wide roles of MR-proANP, which can be analyzed because of the development of a new sandwich immunoassay, and to determine the possible diagnostic and prognostic implications of MR-proANP on cardiovascular disease and other disorders. The studies discussed in this literature review provide valuable data on the role of ANP in the pathogenesis, diagnostic process, prognosis, and potential therapeutic strategies for disease. Although ANP is mainly associated with cardiovascular disease, it may be used as a biomarker in diabetology, neurology, and metabolic disorders.

Cardiac Natriuretic Peptides, Hypertension and Cardiovascular Risk

Prevalence of cardiovascular (CV) disease is increasing worldwide. One of the most important risk factors for CV disease is hypertension that is very often related to obesity and metabolic syndrome. The search for key mechanisms, linking high blood pressure (BP), glucose and lipid dysmetabolism together with higher CV risk and mortality, is attracting increasing attention. Cardiac natriuretic peptides (NPs), including ANP and BNP, may play a crucial role in maintaining CV homeostasis and cardiac health, given their impact not only on BP regulation, but also on glucose and lipid metabolism. The summa of all metabolic activities of cardiac NPs, together with their CV and sodium balance effects, may be very important in decreasing the overall CV risk. Therefore, in the next future, cardiac NPs system, with its two receptors and a neutralizing enzyme, might represent one of the main targets to treat these multiple related conditions and to reduce hypertension and metabolic-related CV risk.

Brain Natriuretic Peptide and the Severity of Aortic Regurgitation: Is There Any Correlation?

We aimed to evaluate the correlation between aortic regurgitation severity and brain natriuretic (BNP) levels as a marker for left ventricular dysfunction. Sixty consecutive male patients (mean age 22 ± 3 years) with isolated chronic aortic regurgitation were enrolled in the study together with a control group of 30 age-matched healthy volunteers (group A). Patients were classified with regard to aortic regurgitation vena contracta width as follows: group B, < 3 mm, mild ( n = 16); group C, ≥ 3 and < 6 mm, moderate ( n = 26); group D, ≥ 6 mm, severe ( n = 18). BNP measurements were performed with a fluorescence immunoassay kit. BNP levels were increased in patients with aortic regurgitation, and severity of regurgitation had a significant influence on BNP levels. This effect can be explained by the volume loading effect of aortic regurgitation.

Biological, electrical and echocardiographic indices versus cardiac magnetic resonance imaging in diagnosing left ventricular hypertrophy

The aim of this study was to compare the diagnostic performance of N-terminal pro-brain natriuretic peptide (NT-proBNP), electrocardiographic (ECG) criteria and transthoracic echocardiography (TTE) versus cardiac magnetic resonance imaging in detecting left ventricular hypertrophy (LVH). The study included 42 hypertensive subjects with mean±s.d. age 48.1±12.3 years, 57.1% men, 24-h ambulatory blood pressure 144/89 mm Hg, left ventricular ejection fraction >50%, without symptoms of heart failure, and not taking any drugs that interfere with hormonal regulation. The accuracies of the methods in detecting LVH were compared at two diagnostic LVH cutoffs: low, 83 g m(-2) in men and 67 g m(-2) in women; and high, 96 g m(-2) in men and 81 g m(-2) in women. With the low and high LVH cutoffs, the areas under the receiver-operating characteristic curves and the optimal values for NT-proBNP were 0.761, 0.849, 200 and 421 pg ml(-1), respectively. An NT-proBNP level under 30 pg ml(-1) ruled out LVH with 100% sensitivity. The optimal values and literature-based values of NT-proBNP allowed a correct classification of 73-81% of the subjects. In 80-90% of the cases, the diagnostic accuracy of NT-proBNP was close to that of ECG criteria but lower than that of TTE criteria. Interestingly, combining ECG criteria and NT-proBNP level improved the diagnostic performance to be at least comparable to that of TTE: the percentages of correctly classified subjects were 73-95% vs. 67-86%, respectively. Of note, the range considers both diagnostic LVH cutoffs. The simultaneous use of ECG criteria and NT-proBNP plasma levels seemed to be powerful enough to detect LVH in most hypertensive subjects.

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.

Biomarkers of left ventricular hypertrophy and remodeling in blacks

Left ventricular (LV) hypertrophy, a marker for adverse cardiovascular events, is more common in blacks than in non-Hispanic whites. Mechanisms leading to LV hypertrophy and mediating its clinical sequelae in blacks are not fully understood. We investigated the associations of 39 candidate biomarkers in distinct biological pathways with LV mass and geometry in blacks. Participants included 1193 blacks (63±9 years of age; 72% women; 78% hypertensive) belonging to hypertensive sibships. LV mass was measured by transthoracic echocardiography and indexed to height.(2.7) LV geometry was categorized as normal, concentric remodeling, concentric hypertrophy, and eccentric hypertrophy. Generalized estimating equations were used to assess associations of the 39 biomarkers with LV mass index after adjustment for age, sex, and conventional risk factors. After adjustment for potential confounders, log-transformed levels of the following biomarkers were independently associated with LV mass index: N-terminal pro-brain natriuretic peptide (β±SE=0.07±0.01 pg/mL; P<0.0001), mid-regional pro-atrial natriuretic peptide (β±SE=0.08±0.02 pmol/L; P<0.0001), mid-regional pro-adrenomedullin (β±SE=0.09±0.03 nmol/L; P=0.0006), C-terminal pro-endothelin (β± SE=0.05±0.02 pmol/L; P=0.0009), and osteoprotegerin (β±SE=0.07±0.02 pg/mL; P=0.0005) (β is for 1 log increase in biomarker level). The associations of these biomarkers with LV mass index were mainly due to their association with eccentric hypertrophy. Higher circulating levels of natriuretic peptides, adrenomedullin, endothelin, and osteoprotegerin were associated with increased LV mass index, providing insights into the pathophysiology of LV hypertrophy in blacks.

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.

N-terminal pro-brain natriuretic peptide in cases with metabolic syndrome and its relationship with components of metabolic syndrome and left ventricular mass index

OBJECTIVE

In this study we investigated N-terminal pro-brain natriuretic peptide (Nt-proBNP) levels in patients with metabolic syndrome (MetS) and its relationship between MetS components.

METHODS

Thirty nine recently diagnosed MetS cases and 59 control cases were included in the present study. Left ventricular mass index (LVMI) was calculated and Nt-proBNP was determined.

RESULTS

Both groups were similar in terms of age and sex. Body mass index were significantly higher in MetS than non-MetS. LVMI measurements were not different between MetS and control groups (p=0.168). Nt-proBNP levels were similar in both groups (p=0.954). There was a significant correlation between Nt-proBNP and LVMI, age, serum LDL- and HDL-cholesterol levels. Nt-proBNP was independently related with age (beta=0.357, p=0.015) and LDL-cholesterol (beta=-0.255, p=0.049) in the multivariate analysis.

CONCLUSIONS

Nt-proBNP levels don't have a significant increase in MetS. But there was a significant relationship between Nt-proBNP levels and age and LDL-cholesterol.

Plasma brain natriuretic peptide at rest and after adenosine-induced myocardial ischemia in normotensive and essential hypertensive patients with suspected coronary artery disease

This study investigated plasma brain natriuretic peptide (BNP) levels in normotensive and hypertensive patients with suspected coronary artery disease during radionuclide pharmacological stress testing. Twenty-seven normotensive patients (15 males, aged 63.0+/-4.5 years and 12 females, aged 63.0+/-4.1 years) and 38 essential hypertensive patients (25 males, aged 63.3+/-3.3 years and 13 females, aged 64.6+/-2.6 years) with chest pain and exercise stress testing inconclusive for coronary artery disease underwent myocardial perfusion single-photon emission computed tomography (SPECT) using adenosine infusion. SPECT identified patients without (16 normotensive and 22 hypertensive) and patients with (11 normotensive and 16 hypertensive) transient perfusion defects. Basal BNP levels in normotensive patients without transient myocardial ischemia (3.1+/-1.2 fmol/ml) were significantly (P<0.01) lower than those observed in normotensive patients with transient ischemia (8.2+/-1.2 fmol/ml), whereas BNP levels in hypertensive patients without transient ischemia (8.2+/-1.0 fmol/ml) did not significantly differ from those in hypertensive patients with transient ischemia (8.1+/-2.0 fmol/ml). No significant difference was found in BNP levels between males or females either in normotensive or hypertensive patients without or with ischemia. Adenosine infusion did not significantly change BNP levels in any subject group without or with myocardial perfusion defects. Our findings show that increases in BNP allow early detection of myocardial ischemia in normotensive patients, but not in hypertensive patients with suspected coronary artery disease. Adenosine-induced myocardial ischemia does not affect BNP production already activated by coronary artery disease in normotensive patients and by hemodynamic changes in hypertensive patients.

Left Atrial Size by Planimetry is Superior to M-mode Diameter: Biochemical Calibration by Atrial and Brain Natriuretic Peptide

BACKGROUND

Left atrial (LA) size is routinely assessed by M-mode on echocardiography. Recently, a superiority of apical measures of LA size has been suggested, but no biochemical calibration has been attempted yet. The aim of the current study was to compare echocardiographic parameters of LA size through biochemical calibration with the natriuretic peptides atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP).

METHODS

A total of 610 middle-aged (50-67 years) subjects from a population-based sample (MONICA Augsburg, Germany) were characterized with respect to LA area and volume from the apical two-chamber (2C) and four-chamber (4C) views in addition to M-mode echocardiography. ANP and BNP concentrations were determined by radioimmunoassay.

RESULTS

A significant correlation to ANP and BNP was present with all measures on LA size. The univariate correlation was lowest with M-mode diameter (r = 0.11 with ANP; r = 0.09 with BNP, both P < .03), whereas 2C volume displayed the closest correlation (r = 0.20 with ANP and r = 0.28 with BNP, both P < .001) and even slightly exceeded 2C area, 4C volume, and 4C area. 2C volume further displaced LV systolic function, mass index, and heart rate as statistically significant predictors of ANP (P < .001) and BNP (P < .001) on adjusted regression analysis, whereas M-mode diameter was displaced as a significant predictor of ANP and BNP (P = not significant).

CONCLUSIONS

The current population-based echocardiographic study allows new insight into the value of different measures of LA size. The closer association between natriuretic peptide concentrations and parameters derived from planimetry and volumetry suggests a superiority of these parameters LA diameter. LA volumetry should be included in routine echocardiography for optimized assessment of LA size.

Early Detection of Left Ventricular Dysfunction by Doppler Tissue Imaging and N-terminal Pro-B-type Natriuretic Peptide in Patients with Symptomatic Severe Aortic Stenosis

BACKGROUND

Patients with severe aortic stenosis (AS) require valve replacement before development of irreversible left ventricular (LV) dysfunction. It has been postulated that Doppler tissue imaging (DTI) parameters are more sensitive to detect subtle LV dysfunction compared with conventional echocardiographic parameters.

OBJECTIVE

We sought to assess early LV dysfunction with DTI-derived echocardiographic parameters and N-terminal pro-B-type natriuretic peptide (NT-proBNP) in patients with severe AS and normal LV ejection fraction.

METHODS

A total of 29 patients (mean age 65 +/- 12 years, 15 male) with symptomatic severe AS and 17 control subjects were included in the study. DTI was performed at the level of the mitral lateral (m(lat)) and septal (m(sep)) annulus. Systolic (Sm), early (Em), and late (Am) diastolic velocities were measured, and E/Em ratio was calculated. NT-proBNP was determined by an electrochemiluminescence immunoassay.

RESULTS

Baseline characteristics between patients and control subjects were similar regarding LV ejection fraction and mitral inflow E/A ratio. However, patients with AS had significantly lower DTI values (Sm, Em, Am) compared with control subjects. Moreover, LV filling pressures, expressed by the E/Em ratio, were significantly higher in patients. Correlation analysis showed a relationship between the natural logarithm of NT-proBNP and aortic valve area, Sm(lat), and E/Em((sep)) ratio. Using stepwise multiple linear regression, Sm(lat) was found to be independently related to NT-proBNP.

CONCLUSIONS

In patients with severe AS and normal LV ejection fraction, DTI showed LV systolic and diastolic dysfunction compared with control subjects. DTI-derived variables, and especially Sm(lat), were correlated with NT-proBNP levels.

Atrial natriuretic peptide gene promoter polymorphism is associated with left ventricular hypertrophy in hypertension

Recent studies suggest that the ANP (atrial natriuretic peptide)/NPRA (type A natriuretic peptide receptor) system modulates ventricular remodelling and cardiac hypertrophy in hypertension in Western populations. In the present study, we tested for any association between two SNPs (single nucleotide polymorphisms) in the ANP gene (one in the promoter and one exonic) with cardiac hypertrophy. We tested the hypothesis in 2118 hypertensive patients, including 945 with LVH [LV (left ventricular) hypertrophy] and 1173 without LVH, as well as 816 healthy control subjects. All subjects were genotyped for the -A2843G and A188G polymorphisms. We found that the GG genotype at position -2843 conferred a 2.2-fold risk for LVH compared with the AA or AG genotypes, including septal wall thickness (11.8+/-1.4 mm for GG compared with 10.9+/-1.4 and 10.7+/-1.3 mm for AA and AG respectively; P<0.01), posterior wall thickness (11.8+/-2.8 mm for GG compared with 10.6+/-1.2 and 10.6+/-1.4 mm for AA and AG respectively; P<0.01), LV mass index (62.7+/-13.6 g/m(2.7) for GG compared with 57.9+/-8.6 and 57.8+/-8.4 g/m(2.7) for AA and AG respectively; P<0.05) and relative wall thickness (50.7+/-10.8% for GG compared with 44.3+/-7.3 and 43.5+/-6.8% for AA and AG respectively; P<0.05). Plasma levels of ANP were significantly lower in the hypertensive patients with LVH carrying the GG genotypes compared with those carrying the AA or AG genotypes (P<0.01). No association of GG genotype with echocardiographic variables and plasma ANP levels was identified in hypertensive patients without LVH and in control subjects (P>0.05). No significant association between the A188G genotype and echocardiographic variables was found in either hypertensive patients or controls (P>0.05). In conclusion, our findings indicate that the -A2843G polymorphism in the ANP gene promoter might be a genetic risk factor for the development of LVH in patients with hypertension.

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.

The role of N terminal pro-brain natriuretic peptide in the evaluation of left ventricular diastolic dysfunction: correlation with echocardiographic indexes in hypertensive patients

The utility of N-Terminal pro Brain Natriuretic Peptide (NT-proBNP) and Brain Natriuretic Peptide (BNP) for detecting left ventricular (LV) diastolic dysfunction in hypertensive patients without heart failure symptoms is unclear. In this study, we investigated the relation between NT-proBNP plasma levels and LV diastolic dysfunction in hypertensive patients without systolic dysfunction.

METHOD

We studied 40 ambulatory patients (26 women, mean age 52 +/- 5) with controlled hypertension. LV diastolic function was assessed with conventional Doppler, by means of mitral inflow and with tissue Doppler echocardiography by means of mitral annulus. The ratio of early diastolic transmitral E wave velocities to tissue Doppler mitral annulus early diastolic E' wave velocities (E/E'), was used to detect LV filling pressures. Patients were divided in three groups according to E/E' ratios < 10 (group I), E/E' ratios ''between'' 10 and 15 (group II) and E/E' ratios > 15 (group III). Plasma concentrations of NT-proBNP were measured by electro chemiluminescence's immunoassay.

RESULTS

The NT-proBNP blood levels were positively correlated significantly with E/E' ratio (r = 0.80, P < 0.0001). Patients with elevated LV end diastolic pressure (LVEDP), defined as E/E' > 15 (n = 8) had highest NT-proBNP (203 +/- 75 pg/ml) levels. E/E' 10 to 15 group (n = 16) had a mean NT-proBNP level of 71 +/- 26 pg/ml, and those with E/E' < 10 (n = 16) had 39 +/- 20 pg/ml. A NT-proBNP value of 119 pg/ml had a sensitivity of 87%, a specificity of 100% for predicting E/E' > 15.

CONCLUSION

The assessment of the blood concentration of NT-proBNP is of potential value for identification of those patients with hypertension to detect early cardiovascular changes, especially LV diastolic dysfunction.

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).

Combined effects of low-dose spironolactone and captopril therapy in a rat model of genetic hypertrophic cardiomyopathy

For several years, the severe side effects associated with the use of high doses of the aldosterone antagonist, spironolactone, limited its clinical use. Studies have recently shown efficacy and minimal side effects of low-dose spironolactone combined with standard therapy in the treatment of heart failure and hypertensive patients. The authors evaluated the effects of low-dose spironolactone alone or in combination with angiotensin-converting enzyme (ACE) inhibitors on the progression of left ventricular dysfunction and remodeling in a congenic rat model of hypertrophic cardiomyopathy. The congenic SS-16/Mcwi rats developed severe cardiac hypertrophy despite being normotensive even on high-salt diet. SS-16/Mcwi and SS/Mcwi rats were fed a low-salt (0.4% NaCl) diet and were treated with vehicle (CON), spironolactone (20 mg/kg/d subcutaneously), captopril (100 mg/kg/d drinking water), or both spironolactone and captopril for 4 weeks. Blood pressure, plasma peptides, cardiac fibrosis, and echocardiography measurements were evaluated. Spironolactone at a low dose had no effect on blood pressure, cardiac hypertrophy, and fibrosis in either strain. However, in combination with captopril, spironolactone decreased the cardiac hypertrophy more than captopril treatment alone. In the SS-16/Mcwi rats, the combined therapy significantly preserved the cardiac index when compared with control. These data indicate that the addition of low-dose spironolactone to captopril treatment was more effective in preventing the progression of heart hypertrophy and ventricular dysfunction in the SS-16/Mcwi than captopril alone. This study suggests that combined spironolactone and captopril therapy may be useful in the treatment of hypertrophic cardiomyopathy.

Patterns of left ventricular hypertrophy in essential hypertension: should echocardiography guide the pharmacological treatment?

The experimental design of clinical studies, on the pharmacological treatment of essential hypertension, has ignored a fundamental issue: Hypertensive patients are not a homogenous population. The adaptation of the cardiovascular system to hypertension is structurally and functionally heterogeneous. Recent clinical investigations suggest that this heterogeneity can be minimized by echocardiography. Thus, when the hemodynamic and neurohormonal profiles of untreated hypertensive patients are considered, in the particular context of the cardiac morphologic adaptation to high blood pressure, distinct common denominators emerge. Concentric and eccentric hypertrophy, the two most common patterns of ventricular hypertrophy, are at the extremes of the geometric spectrum. Concentric hypertrophy is characterized by an elliptic left ventricle, normal stroke volume and high peripheral vascular resistance. Its predominant neurohormonal profile includes elevated plasma renin and natriuretic peptide levels. Conversely, most patients with eccentric hypertrophy have a spheric left ventricle, increased stroke volume and low peripheral vascular resistance. Its corresponding neurohormonal profile shows low serum renin and enhanced sympathetic nervous activity. The therapeutic response, to angiotensin II antagonists and to beta-adrenergic blockers, of these two geometric patterns is also different. Concentric hypertrophy is substantially reversed by losartan, whereas, eccentric hypertrophy is refractory to both, losartan and atenolol. These facts raise a relevant question: Should ventricular geometry be considered when deciding which antihypertensive drug is to be prescribed?

Left ventricular geometric patterns in the Jackson cohort of the Atherosclerotic Risk in Communities (ARIC) Study: clinical correlates and influences on systolic and diastolic dysfunction

BACKGROUND

The distribution and determinants of left ventricular (LV) geometric patterns and their relation to LV function in African Americans is not well described despite higher rates of LV hypertrophy and cardiovascular mortality reported in this group.

PURPOSE

This study investigates the distribution and clinical correlates of LV geometric patterns and how these patterns relate to function in a population-based African American cohort.

METHODS

The study population included participants in the Jackson cohort of ARIC, who underwent echocardiograms between 1993 and 1995. We defined 4 geometric patterns (normal geometry, concentric remodeling [CR], eccentric hypertrophy [EH], and concentric hypertrophy [CH]) according to LV mass index and relative wall thickness. Multiple logistic regression was used to assess the association of geometric patterns to systolic dysfunction and diastolic dysfunction, adjusting for traditional coronary risk factors.

RESULTS

There were 1849 participants in the study population (mean age 59 years, 65% women). Concentric remodeling and CH were highly prevalent. Concentric hypertrophy and EH groups had the highest rates of hypertension, obesity, and diabetes mellitus. Compared to the normal geometric pattern, EH was related to systolic dysfunction (OR 24.27, CI 6.71-87.80), and CH was related to diastolic dysfunction 1.58 (1.04-2.39). Concentric remodeling was not related to systolic or diastolic dysfunction.

CONCLUSION

In this large middle-aged African American cohort, CR and CH are prevalent. Hypertension, diabetes mellitus, and obesity are associated with both CH and EH. Concentric hypertrophy is strongly associated with diastolic dysfunction; EH is strongly associated with systolic dysfunction. Concentric remodeling, however, is not related to either systolic or diastolic dysfunction.

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.

Myocardial stiffness is an important determinant of the plasma brain natriuretic peptide concentration in patients with both diastolic and systolic heart failure

AIMS

Plasma brain natriuretic peptide (BNP) concentration increases in proportion to heart failure (HF) severity. Although plasma BNP decreases to a certain level by optimal treatment, there is significant heterogeneity in the baseline value among individuals. The underlying mechanism of the steady-state plasma BNP levels remains still controversial. We investigated the hypothesis that myocardial stiffness (K(m)) is a major determinant of the plasma BNP level.

METHODS AND RESULTS

In 19 patients with diastolic HF [DHF; left ventricular ejection fraction (LVEF) > or =4 5%], 18 with systolic HF (SHF; LVEF < 45%), and 12 controls, left ventricular (LV) performance variables and the results of the stress-strain analyses were obtained by the combined simultaneous measurement of echocardiographic and haemodynamic data, and compared with the plasma BNP level. In DHF, a significant correlation was observed between plasma BNP and fractional shortening (P = 0.010), pulmonary capillary wedge pressure (P = 0.030), end-diastolic pressure (P = 0.006), time constant of the LV isovolumic-pressure decline (P = 0.049), end-diastolic stress (P = 0.012), and K(m) (P = 0.004), respectively. In SHF, a significant correlation was observed between plasma BNP and end-diastolic stress (P = 0.036), chamber stiffness (P = 0.048), and K(m) (P = 0.003), respectively.

CONCLUSION

In stable conditions, K(m) may be the most important determinant of the plasma BNP production in patients with both DHF and SHF.

Increased plasma concentrations of N-terminal pro-brain natriuretic peptide reflect the presence of mildly reduced left ventricular diastolic function in hypertension

BACKGROUND

The potential use of assays of N-terminal pro-brain natriuretic peptide for detection of diastolic abnormalities associated with alterations in blood pressure has not been elucidated. This study was designed to determine whether increased plasma concentrations of N-terminal pro-brain natriuretic peptide sensitively reflect abnormal diastolic function associated with hypertension.

METHODS

Concentrations of N-terminal pro-brain natriuretic peptide in plasma were assayed in 40 previously untreated hypertensive patients without overt congestive heart failure and in 20 age and sex-matched controls. Hypertensive patients were studied with the use of pulsed Doppler and color M-mode Doppler echocardiography for the evaluation of left ventricular diastolic function.

RESULTS

Concentrations of N-terminal pro-brain natriuretic peptide were elevated in hypertensive patients [75.1+/-75.2 (SD) pg/ml compared with 37.9+/-38.5 in controls, P<0.05]. In hypertensive patients, concentrations of N-terminal pro-brain natriuretic peptide were negatively correlated with the ratio of color M-mode flow propagation velocity to transmitral E velocity consistent with the view that increased concentrations of N-terminal pro-brain natriuretic peptide are indicative of alterations in diastolic function. Hypertensive patients with N-terminal pro-brain natriuretic peptide values above the mean value in the control group exhibited significantly increased brachial intimal-medial thickness and reduced wall stress, consistent with the view that increased N-terminal pro-brain natriuretic peptide was associated with favorable peripheral arterial remodeling.

CONCLUSIONS

Elevated concentrations of N-terminal pro-brain natriuretic peptide in plasma reflect the presence of left ventricular diastolic abnormalities and peripheral arterial remodeling in asymptomatic patients with hypertension.

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.

Dilated cardiomyopathy relieved as a result of beta-blocker therapy: a case report--key points in assessment of prognosis based on MIBG myocardial scintigraphy and BNP levels

A 48-year-old male patient was admitted to our hospital with dyspnea accompanied by orthopnea. Chest x-rays showed a cardiothoracic ratio of 68% and pulmonary congestion. He was diagnosed with dilated cardiomyopathy. Beta-Blocker (carvedilol) therapy was initiated on Day 22 of the disease using a small initial dose. He was followed up based on BNP levels and MIBG scintigraphy. The H/M ratio and MIBG washout rate were 1.98 and 33.4%, respectively, on Day 20 and 2.15 and 28.1%, respectively, on Day 72. The patient was discharged on Day 72 when congestive heart failure improved. Relatively high BNP levels were observed for 1 month after starting treatment with a beta-blocker. Plasma BNP levels were still as high when his heart failure was improved. BNP is useful as a convenient indicator for the severity of cardiac diseases. MIBG scintigraphy may be used thereafter to evaluate the severity in greater detail and more precisely determine the prognosis.

The natriuretic peptides and their role in disorders of right heart dysfunction and pulmonary hypertension

Atrial natriuretic peptide (ANP) and B-type natriuretic peptide (BNP) are increased in conditions with cardiac ventricular volume and pressure overload. The general physiological and potential therapeutic roles of natriuretic peptides in respiratory disease, right ventricular (RV) dysfunction, and pulmonary arterial hypertension (PAH) are reviewed. BNP levels can be used to differentiate between dyspneic patients with a pure respiratory defect and those with RV dysfunction. BNP levels also correlate with mean pulmonary arterial pressure (mPAP) and pulmonary vascular resistance (PVR) in patients with PAH (atrial septal defect, chronic thromboembolic disease, and scleroderma). BNP is a predictor of mortality in patients with primary pulmonary hypertension (PPH). These are important clinical implications in that a noninvasive blood test may be used to identify high-risk patients for more invasive procedures such as cardiac catheterization. BNP or NT-proBNP measurements may also be used to guide therapy (e.g., pulmonary vasorelaxants) in PAH since upregulation of the natriuretic peptide pathway has been shown to reduce cardiac hypertrophy and PAH. Additionally, there may be therapeutic potential via recombinant BNP or neutral endopeptidase inhibitors in RV dysfunction and PAH.

Usefulness of B-type Natriuretic Peptide (BNP) as a screen for left ventricular abnormalities in diabetes mellitus

Cardiovascular disease is the leading cause of morbidity and mortality in diabetic subjects. Diabetes, independently of the mechanism, is associated with an increased risk of left ventricular hypertrophy, left ventricular dysfunction and coronary artery disease. B-type natriuretic peptide (BNP) is a cardiac neurohormone predominantly released from the cardiac ventricles in response to left ventricular volume expansion and pressure overload. Numerous studies have shown that BNP levels are elevated in asymptomatic or symptomatic left ventricular dysfunction, hypertrophy and coronary artery disease. BNP testing plays an important role in the screening and diagnosis of left ventricular dysfunction by improving the performance of non-specialist physicians in diagnosing heart failure. In clinical practice, BNP testing is best used as a 'rule out' test targeted to patients at high risk for left-ventricular dysfunction, such as those with diabetes. Studies are needed to establish if this promising biological tool, in the next future, would assist the management of diabetic patients.

Natriuretic peptides as markers of preclinical cardiac disease in obesity

BACKGROUND

Aim of the study was to evaluate the role of atrial (ANP) and brain natriuretic peptides (BNP) as markers of preclinical cardiac disease in obesity.

METHODS

We selected 26 obese (BMI > 29 kg m(-2)) never-treated hypertensives (24-h BP > 140 and/or 90 mmHg), 26 obese normotensives (24-h BP < 130/80 mmHg) and 25 lean (BMI < or = 25 kg m(-2)) never-treated hypertensives. Each subject underwent measurements of ANP and BNP plasma levels, 24-h ambulatory blood pressure (BP) monitoring, digitized M-mode and Doppler echocardiography.

RESULTS

Mean values of ANP and BNP were similar among the three groups. All the subjects had normal left ventricular (LV) systolic function. Within each group ANP levels were higher in patients with LV diastolic dysfunction than in patients with normal diastolic function, and BNP levels were higher in patients with LV hypertrophy and in patients with LV diastolic dysfunction. Within each group, ANP levels were inversely correlated with LV diastolic indices, whereas BNP levels were directly correlated with LV mass index and inversely correlated with LV diastolic indices. ANP and BNP levels were not correlated with other echocardiographic parameters, age, BMI or 24-h BP values.

CONCLUSION

In normotensive and hypertensive obese subjects the relationships of ANP and BNP levels with LV morpho-functional characteristics follow the same trend as in lean hypertensives, with ANP mainly influenced by diastolic dysfunction and BNP influenced by both LV hypertrophy and LV diastolic dysfunction. Therefore ANP and BNP can be considered useful markers of preclinical cardiac disease in obesity.

Is inappropriate left ventricular mass related to neurohormonal factors and/or arterial changes in hypertension? a LIFE substudy

We investigated whether inappropriately high left ventricular (LV) mass, defined as observed LV mass exceeding the level of individual LV mass predicted from gender, height, and stroke work, may be associated with an imbalance between growth-promoting and growth-inhibitory factors and/or structural vascular changes. In 53 patients with hypertension and electrocardiographic LV hypertrophy, 24-h ambulatory blood pressure (BP); echocardiographic LV mass, stroke volume and stroke work; minimal forearm vascular resistance (MFVR); and intima-media cross-sectional area in common carotid arteries (IMA) were evaluated after 2 weeks of placebo treatment. Serum insulin, plasma epinephrine, norepinephrine, endothelin, angiotensin II, aldosterone, and brain natriuretic peptide (BNP) were also measured. High observed LV mass was related to high IMA (r=0.46, P<0.001), MFVR (in men: r=0.36, P<0.05), 24-h ambulatory systolic BP (r=0.30, P=0.06), and lower plasma angiotensin II (r=-0.33, P<0.05), but not to other circulating growth factors. Stroke work was similarly related to IMA (r=0.42, P<0.01), MFVR (in men: r=0.41, P<0.05), and plasma angiotensin II (r=-0.32, P<0.05). Inappropriate LV mass, identified by the ratio between observed LV mass and the value predicted for gender, height, and stroke work, was not significantly related to any of the arterial or neurohormonal variables. In this small series of older hypertensive patients, inappropriate LV mass was not significantly related to arterial changes or to measured circulating growth factors, although weak relations cannot be excluded. Alternatively, inappropriately high LV mass might be related to unmeasured factors such as local myocardial alterations in growth factors and/or genetic predisposition to develop excessive LV hypertrophy.

NT-proANP and BNP in renovascular and in severe and mild essential hypertension

BACKGROUND/AIMS

The plasma concentrations of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) become increased in hypertension. However, it is unknown what is the effect of the etiology and the severity of hypertension on the plasma concentrations of ANP and BNP.

METHODS

We examined plasma levels of ANP (measured as N-terminal fragment of proatrial natriuretic peptide; NT-proANP) and BNP in patients having sustained hypertension of different etiology and severity: in patients with renovascular hypertension (RVHT, n = 12), severe essential hypertension (SEHT, n = 37), and mild essential hypertension (MEHT, n = 29). In addition, we studied the diagnostic value of NT-proANP and BNP to discriminate patients with RVHT from patients with essential hypertension.

RESULTS

The plasma concentrations of NT-proANP and BNP were higher in the RVHT group (593 +/- 80 and 25.0 +/- 9.3 pmol/l, respectively) than in the SEHT group (320 +/- 33 and 4.7 + 0.6 pmol/l, respectively; p < 0.001 for both), in spite of the similar blood pressure level, and also higher than in the MEHT group (356 +/- 30 and 7.0 +/- 1.0 pmol/l; p = 0.004 and p = 0.006, respectively). There was no difference in natriuretic peptide levels between the SEHT and MEHT groups. Plasma NT-proANP and BNP correlated positively with aging and serum creatinine concentration and inversely with left ventricular diastolic filling. In addition, NT-proANP correlated positively with systolic blood pressure and BNP with left ventricular mass index. The areas under receiver operating characteristic curves for plasma NT-proANP and BNP to discriminate RVHT patients from patients with essential hypertension were 0.793 and 0.782, respectively. The best cutoff value was 530 pmol/l for NT-proANP, giving a sensitivity of 67% with a specificity of 86%. The cutoff value of 9.8 pmol/l for BNP resulted in a sensitivity of 58% and a specificity of 90%.

CONCLUSIONS

Patients with RVHT have higher plasma levels of NT-proANP and BNP than patients with essential hypertension. In addition to the etiology of hypertension, also left ventricular characteristics are important determinants of NT-proANP and BNP concentrations in hypertension. Due to the low sensitivity, NT-proANP and BNP are not suitable as screening tools for RVHT.

Exercise capacity and brain natruiretic peptide in hypertension

Brain natriuretic peptide (BNP) is increased and it is also released during exercise in hypertension, but its biologic role is unclear. However, since BNP is released from the left ventricule and it is known to reduce left ventricular filling pressure, it is possible that it exerts a favorable effect on exercise performance. We studied the relationship between endogenous BNP release and exercise capacity in hypertension with reference to left ventricular hypertrophy (LVH). Cardiopulmonary exercise study was carried out in 2 groups of hypertensives, 24 [16 men, aged 50 (SD 11) years] of whom had echocardiographic LVH and 25 [16 men, aged 41 ( 12)] who did not have LVH. In multiple regression analyses, the major determinants of peak oxygen uptake (VO max) were age (-), sex (male), peak exercise systolic BP (+) and post-exercise BNP (-). For the predicted adjusted %VO max as a measure of individualised exercise capacity, the significant predictors were the exercise-induced BNP rise (-) (p = 0.0003) and peak exercise systolic BP (+) (p = 0.001). In other words, subjects with greater myocardial dysfunction had a greater rise in BNP during exercise. LVH did not however relate to exercise capacity. The baseline, post-exercise and the % rise in BNP (pmol/L) with exercise were not statistically different in those with LVH compared with those without (median values of 11.2, 14.6 and 133% versus 10.6, 11.5 and 120% respectively). Similarly, there were no significant differences in exercise capacity between the groups: exercise time, oxygen uptakes at ventilatory threshold and at peak exercise (VO max) were 10.8 (2.5) min, 15.8 (4.6) and 33.6 (7.6) ml/min/kg in the LVH group against 11.4 (2.9) min, 18.6 (5.2) and 36 (11.1) ml/min/kg in the non-LVH group respectively. The estimated VO max was not different from that predicted from age, sex, weight and height in either group suggesting preserved exercise capacity in these subjects as a whole. In Conclusion, BNP may potentially act as a homeostatic mechanism that helps to limit exercise incapacity in hypertension irrespective of LVH.

Relation of circulating blood volume to left ventricular geometry in essential hypertension

To investigate whether circulating blood volume contributes to left ventricular (LV) geometry, 60 outpatients with untreated, mild to moderate essential hypertension and 45 normotensives were studied. Based on echocardiographic LV mass index and relative wall thickness, four patterns of LV geometry, i.e., normal left ventricle, concentric remodeling, eccentric hypertrophy and concentric hypertrophy, were identified. Plasma volume and blood volume were measured by the 131I labeled human serum albumin technique. LV end-diastolic volume was greater in patients with eccentric hypertrophy than in the groups of patients with normal left ventricles, concentric remodeling, or concentric hypertrophy or in normotensive subjects. No differences were found in systolic function among the five groups. Both plasma volume and blood volume were decreased in the concentric remodeling group as compared with the other four groups. However, there were no differences in plasma volume or blood volume among the normal left ventricle, eccentric hypertrophy and concentric hypertrophy groups. These data indicate that a small LV chamber in cases of "concentric remodeling" may be related to decreased plasma and blood volumes, but an enlarged LV chamber in cases of "eccentric hypertrophy" is not likely to be related to either plasma or blood volume levels in mild to moderate untreated essential hypertension.

Increased plasma brain natriuretic peptide level as a guide for silent myocardial ischemia in patients with non-obstructive hypertrophic cardiomyopathy

OBJECTIVES

We measured plasma atrial/brain natriuretic peptide (ANP/BNP) levels at rest and during exercise and correlated the results with various clinical findings, particularly with myocardial ischemia, in asymptomatic hypertrophic cardiomyopathy (HCM).

BACKGROUND

In patients with HCM, ANP and BNP levels are elevated and exercise-induced myocardial ischemia is common. However, it has not yet been elucidated how these levels at rest and their change with dynamic exercise are related to ischemia.

METHODS

Levels of ANP and BNP were measured at rest and at peak exercise during (99m)Tc-tetrofosmin scintigraphy in 31 asymptomatic patients with non-obstructive HCM and in 10 control subjects.

RESULTS

Levels of ANP and BNP at rest and the change of ANP and BNP levels (PG/ML) from rest to exercise were significantly greater in HCM than in control subjects (ANP: rest, 53.2 +/- 31.8 vs. 11.6 +/- 6.1; exercise, 114.5 +/- 74.8 vs. 28.3 +/- 23.4. BNP: rest, 156.7 +/- 104.1 vs. 9.8 +/- 9.6; exercise, 201.6 +/- 131.5 vs. 13.2 +/- 14.5). Septal perforator compression (SPC) and exercise-induced ischemia were observed, respectively, in 20 (64.5%) and in 19 (61.3%) patients with HCM. The increment of ANP during exercise was similar between HCM subgroups with or without inducible ischemia. However, BNP levels at rest and BNP increments during exercise were significantly greater in the HCM subgroup with inducible ischemia than in the subgroup without (rest, 190.5 +/- 116.2 vs. 103.1 +/- 48.3; exercise, 250.5 +/- 142.2 vs. 124.2 +/- 58.6). Multiple logistic regression analysis revealed that SPC and BNP levels at rest were independently associated with exercise-induced ischemia.

CONCLUSIONS

Measurement of plasma BNP levels at rest may be useful in predicting silent myocardial ischemia in HCM.

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.

Leg edema, ST-T abnormalities, and high BNP values are important signs of heart failure in the elderly

This study was aimed at the mechanism of the circulatory failure characteristic of the elderly through elucidating the cause of leg edema frequently found in patients under treatment in health care facilities for physical or mental handicaps. ECG and measurement of atrial (ANP) and brain (BNP) natriuretic peptides were carried out on 156 patients (mostly females aged 84 years on average) and echocardiographic assessment was done on 44 patients. Non-specific ST-T abnormalities were frequently found in patients with moderate or severe leg edema (61 vs. 37% in those with slight or no edema). BNP levels were markedly increased in patients with either leg edema or ECG abnormalities (Group B) and with both (Group C) compared with those without either (Group A), with averages of 35.5+/-23.9, 91.3+/-80.1, and 184.3+/-139.0 pg/ml, respectively, for Group A, B, and C. UCG examination revealed marked regurgitation of cardiac valves, more frequently in patients with BNP over 50 pg/ml than in those with less (14/24 vs. 2/20), with a difference in extent of 5.7 versus 1.6 on an arbitrary scale. In addition to left ventricular hypertrophy, dilatation of the left atrium and inferior vena cava was frequently observed in patients with higher BNP levels. It is concluded that both cardiac valve regurgitation and myocardial damage represented by ST-T abnormalities on ECG result in heart failure characteristic of the elderly, and that an increase in BNP is an important sign of such heart failure.

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.