Brain natriuretic peptide as a marker of cardiac involvement in hypertension

Limited usefulness of resting hemodynamic assessments in predicting exercise capacity in hypertensive patients

Reliable assessments of reduced exercise capacity based on resting tests are one of the major challenges in clinical practice. The aim of this study was to evaluate the relationship between hemodynamic parameters obtained via resting tests (echocardiography and impedance cardiography (ICG)) and objective parameters of exercise capacity assessed via cardiopulmonary exercise testing and exercise ICG in patients with controlled arterial hypertension (AH). The left ventricular ejection fraction (LVEF), global longitudinal strain (GLS), diastolic function parameters (e', E/A, E/e'), cardiac output (CO), stroke volume (SV), and systemic vascular resistance index were evaluated for any correlations with selected parameters of exercise capacity, such as peak oxygen uptake (VO₂) and peak CO in 93 people with AH (mean age 54 years, 47 women). Statistically relevant correlations occurred between indices of exercise capacity (peak VO₂; peak CO) and only the following hemodynamic parameters: diastolic blood pressure (R = 0.23, p = 0.026; R = 0.24, p = 0.021; respectively), e' (R = 0.32, p = 0.002; R = 0.24, p = 0.027), E/e' (R = 0.35, p < 0.001; ns), E/A (R = 0.23, p = 0.030; R = 0.21, p = 0.047), SV at rest (ns; R = 0.24, p = 0.019), and CO at rest (ns; R = 0.21, borderline p = 0.052). No significant correlations between the exercise capacity parameters and either LVEF or GLS were observed. No hemodynamic parameter proved to be an independent correlate of either peak VO₂ or peak CO. The association between hemodynamic parameters at rest and parameters of exercise capacity was weak and limited to selected parameters of diastolic function. Exercise capacity assessment in patients with AH based on resting tests alone is insufficiently reliable and should be supplemented with exercise tests.

Plasma N-Terminal Probrain Natriuretic Peptide, Vascular Endothelial Growth Factor, and Cardiac Troponin I as Novel Biomarkers of Hypertensive Disease and Target Organ Damage in Cats

Background

In the absence of ocular target organ damage (ocular‐TOD), diagnosis of hypertension is challenging in cats. Biomarkers would provide additional support for the diagnosis of hypertension.

Hypothesis

Vascular endothelial growth factor (VEGF), N‐terminal probrain natriuretic peptide (NT‐proBNP), cardiac troponin I (cTnI), and urine protein‐to‐creatinine ratio (UPC) are predictors of systemic hypertension, will be increased in cats with hypertension with or without ocular‐TOD, and will decrease with antihypertensive treatment.

Methods

Plasma VEGF, NT‐proBNP, and cTnI concentrations and UPC were determined in healthy geriatric cats, normotensive cats with chronic kidney disease (CKD), hypertensive cats with evidence of hypertensive retinopathy (HT‐ocular‐TOD), and hypertensive cats without hypertensive ocular‐TOD (HT‐noTOD). Comparisons among groups were performed. Multivariable binary logistic regression models were built to identify independent biomarkers of hypertension and ocular‐TOD. Receiver operator characteristic (ROC) curves were drawn to assess clinical use.

Results

Cats with HT‐ocular‐TOD had significantly higher VEGF than all other groups (P < .05) and significantly higher NT‐proBNP than healthy cats (P < .001). Healthy cats had significantly lower cTnI than all other groups (P < .05). No differences were found among groups for UPC (P = .08). Cardiac troponin I and VEGF were independent predictors of hypertension (P < .05), but none of the biomarkers were independent predictors of ocular‐TOD. N‐terminal probrain natriuretic peptide concentrations decreased with antihypertensive treatment (P < .001). The ROC curves indicated that none of the biomarkers met the criteria to function as diagnostic tests for the diagnosis of hypertension or associated ocular‐TOD.

Conclusions and Clinical Significance

Despite statistical significance and changes with ocular‐TOD, antihypertensive treatment, or both, VEGF, NT‐proBNP, and cTnI did not function as useful diagnostic tests for hypertension. Persistently increased systolic blood pressure (SBP) measurements in combination with fundoscopy remains the preferred method for diagnosis of feline hypertension.

Evolving role for mineralocorticoid receptor antagonists in heart failure with preserved ejection fraction

PURPOSE OF REVIEW

The majority of randomized clinical trials in heart failure with preserved ejection fraction (HFpEF) have failed to show meaningful improvements in clinical outcomes. Recent randomized trials have shown benefits from mineralocorticoid receptor antagonists (MRAs) in the management of HFpEF. This review will focus on new evidence for MRA therapy in patients with HFpEF.

RECENT FINDINGS

Three randomized trials were reviewed: the Effect of spironolactone on diastolic function and exercise capacity in patients with heart failure with preserved ejection fraction: the Aldo-DHF randomized controlled trial; the Treatment of Preserved Cardiac Function Heart Failure with an Aldosterone Antagonist trial; and its echocardiography substudy. The Aldo-DHF trial showed improvements in echocardiographic measures of diastolic function. In the Treatment of Preserved Cardiac Function Heart Failure With an Aldosterone Antagonist trial, hospitalization for heart failure was significantly reduced with MRA therapy with no difference in the primary outcome of cardiovascular death or hospitalization. In patients with high risk, however, there may be a reduction in cardiovascular mortality. We will also briefly discuss finerenone, a new generation MRA associated with a lower incidence of hyperkalemia.

SUMMARY

New evidence shows that MRA therapy decreases left ventricular mass and left atrial size, reduces hospitalization, and may reduce cardiovascular mortality in patients with high risk.

Atrial and Brain Natriuretic Peptide and Endothelin-1 Concentration in Patients with Idiopathic Arterial Hypertension: The Dependence on the Selected Morphological Parameters

INTRODUCTION

The aim of the work was to study the maintenance of atrial and brain natriuretic peptide (ANP, BNP) and endothelin-1 (ET-1) in patients with idiopathic arterial hypertension and the relationships between cardiac morphological parameters and concentrations of examined peptides in group of patients with left ventricular hypertrophy (LVH).

METHODS

Seventy-six patients were enrolled in the study: 21 patients with confirmed idiopathic arterial hypertension (group 1), 18 with idiopathic hypertension and eccentric hypertrophy (group 1a), 14 with idiopathic hypertension and concentric hypertrophy (group 1b), and 23 patients without arterial hypertension, organic heart disease, or chronic respiratory tract diseases (group 2 - control group). All subjects were submitted for echocardiographic evaluation. Posterior wall thickness (PWT), interventricular septum thickness (IVST), left ventricular end-diastolic diameter (LVEDd), left atrium diameter (LAD), left ventricular mass index (LVMI), ejection fraction (EF), fractional shortening (FS), midwall shortening fraction (MWS), and relative wall thickness index (RWT) were studied. Concentrations of ANP(1-28), BNP, and ET-1 were determined with the use of radioimmunological kits (RIA). The obtained results were subjected to statistical analysis.

RESULTS

A considerable increase of ANP and BNP was observed in all patients with hypertension (group 1) in comparison to patients without hypertension (group 2). Significant increases of ANP were found in groups 1a and 1b in comparison to group 1 and 2, as well as considerably increase of BNP in group 1b compared to groups 1, 1a, and 2. In the group of patients with hypertension (group 1), a significant increase in the concentration of ET-1 compared to group 2 was found. However, the concentrations of ET-1 in groups 1 and 2 were not statistically different. Significant differences in concentrations of ET-1 between groups 1a, 1b, and 1 and 2 were seen. Significant correlations were found between concentrations of ANP, BNP, ET-1 and morphological parameters: PWT, IVST, LVMI and RWT. In group 1b, a correlation between concentrations of ANP, BNP, MWS, and LAD was found. The multiple regression analysis showed that RWT independently correlates with concentrations of ANP and BNP, and the concentration of BNP is in closer relation to RWT than ANP. In the case of ET-1, the multiple regression analysis did not show that LVMI or RWT had any independent influence on secretion of ET-1 in patients with idiopathic hypertension and LVH.

CONCLUSIONS

Increased concentration of ANP in patients with idiopathic hypertension may point to the coexistence of complications with type of LVH. High concentration of BNP may specifically suggest concentric LVH. This is important - especially if there are difficulties in interpretations of results of other clinical examinations. However, increased concentrations of ET-1 in the plasma of patients with hypertension and LVH should not be treated as an indicator of LVH degree.

Clinical significance of brain natriuretic peptide in patients with postmyocardial infarction

BACKGROUND

Risk stratification after acute myocardial infarction (AMI) includes the evaluation of left ventricular (LV) function. Natriuretic peptides, and particularly brain natriuretic peptide (BNP), emerged as a potential marker of ventricular function and prognosis after AMI.

HYPOTHESIS

Brain natriuretic peptide levels are related to ventricular function, either systolic or isolated diastolic, and can give prognostic information in patients surviving AMI.

METHODS

In all, 101 patients were enrolled. An echocardiographic (M-mode, two-dimensional, and pulsed Doppler) evaluation was performed and blood samples for BNP measurement were obtained. Clinical events were recorded during 12 months of follow-up.

RESULTS

A negative correlation between BNP and LV ejection fraction was observed (r = -0.38; p < 0.001). The BNP levels were higher among patients with LV systolic dysfunction than in patients with isolated diastolic dysfunction (339.1 +/- 249.9 vs. 168.0 +/- 110.5 pg/ml, p = 0.001). The latter had higher levels of BNP than those with normal LV function (68.3 +/- 72.6 pg/ml, p < 0.001). The BNP accuracy to detect LV systolic dysfunction was good (area under the ROC curve [AUC] = 0.83) and increased when isolated diastolic dysfunction was also considered (AUC = 0.87). Brain natriuretic peptide had a very good accuracy in the prediction of death (AUC = 0.95) and the development of heart failure (AUC = 0.90).

CONCLUSION

These results extend previous evidence relating BNP to systolic function after AMI. Furthermore, a relationship between BNP levels and diastolic function was found. Brain natriuretic peptide had a very good performance in detecting the occurrence of an adverse event. We conclude that BNP can detect high-risk patients and help select patients for more aggressive approaches.

Evidence for the use of B-type natriuretic peptides for screening asymptomatic populations and for diagnosis in primary care

OBJECTIVES

To determine the screening and diagnostic properties of BNP and NT-proBNP for heart failure in primary care.

DESIGN AND METHODS

We conducted a systematic review of randomized control trials and observational (cohort or case-control) studies of heart failure detection using B-type natriuretic peptides published in English from January 1989 to February 2005. We extracted or calculated sensitivity, specificity, positive and negative likelihood ratios, area under the receiver-operator characteristic curve and diagnostic odds ratio (DOR).

RESULTS

We included 17 studies (7 screening, 9 diagnosis in primary care or specialised clinic, 1 both). There was considerable heterogeneity within the study populations, reference standard for diagnosis, and B-type natriuretic peptide decision point. Sensitivity ranged from 26% to 98%; and specificity from 44% to 88%. For screening, the Diagnostic Odds Ratio (DOR) ranged from 2.7 to 29, and for diagnosis from 2.8 to 137.

CONCLUSIONS

The performance characteristics of B-type natriuretic peptides measurement are not suitable for screening asymptomatic patients. For diagnosis in primary care, low B-type natriuretic peptide values may be used to rule-out heart failure but, due to poor specificity, high values cannot be used to rule-in the condition.

Systolic and diastolic heart failure are associated with different plasma levels of B-type natriuretic peptide

Previous studies have found that plasma B-type natriuretic peptide (BNP) is elevated during left ventricular systolic or diastolic dysfunction. It is unclear whether the ventricular systolic and diastolic function is associated with different levels of plasma BNP. Plasma BNP was measured in 149 heart failure patients by a rapid point-of-care assay. The patients were divided into left ventricular diastolic dysfunction (n = 48), left ventricular systolic dysfunction (n = 62) and right ventricular systolic dysfunction group (n = 39). The mean BNP level in the left ventricular diastolic dysfunction, left ventricular systolic dysfunction and right ventricular systolic dysfunction was 115 +/- 80 pg/ml, 516 +/- 445 pg/ml and 345 +/- 184 pg/ml, respectively (p < 0.05). We concluded that ventricular systolic and diastolic dysfunction increases plasma BNP levels to a different extent. Left and right ventricular systolic dysfunction is associated with a higher level of plasma BNP than left ventricular diastolic dysfunction.

Brain natriuretic peptide and severity of disease in non-alcoholic cirrhotic patients

BACKGROUND

Cirrhotic patients have a hyperdynamic systemic circulation. They have insidious cardiac problems besides well-known complications. Brain natriuretic peptide (BNP) relaxes vascular smooth muscle and has a portal hypotensive action. The relations between BNP levels and severity of disease, cardiac dysfunction and esophageal varices were studied in non-alcoholic cirrhotic patients.

METHODS

Fifty-two non-alcoholic cirrhotic patients were evaluated for decompensation component of cirrhosis. The BNP concentration of echocardiographically examined patients was determined.

RESULTS

The BNP levels were significantly higher in ascites, spontaneous bacterial peritonitis and hepatic encephalopathy history group (P = 0.033, P < 0.001, P = 0.014, respectively), but no significant difference were observed for presence of esophageal varices and bleeding history (P = 0.267, P = 0.429). A significant correlation was observed between BNP concentration and Child score (r = 0.427, P = 0.012), interventricular septal thickness (r = 0.497, P < 0.001) and left ventricular posterior wall thickness (r = 0.526, P < 0.001). According to Child-Pugh classification there were no significant difference between groups for echocardiographic measurements and blood pressure (P > 0.05), but plasma BNP levels were significantly higher in Child class B and C patients compared with class A patients (P < 0.05).

CONCLUSION

Increased levels of BNP are more likely related to the severity of disease in non-alcoholic cirrhotic patients. The advanced cirrhosis is associated with more advanced cardiac dysfunction and BNP has prognostic value in progression of cirrhosis.

Bedside tests of B-type natriuretic peptide in the diagnosis of left ventricular diastolic dysfunction in hypertensive patients

AIMS

To investigate the value of B-type natriuretic peptide (BNP) in diagnosing left ventricular diastolic dysfunction in patients with hypertension.

METHODS

The left ventricular diastolic function and plasma BNP levels were assessed prospectively in 135 hypertensive patients.

RESULTS

The plasma BNP in patients with (n=61) and without (n=74) diastolic dysfunction was 122+/-105 and 18+/-16 pg/ml, respectively (p<0.001). Increased BNP levels were associated with systolic blood pressure (p<0.05), left ventricular mass index (p<0.001), the E/A ratio of transmitral flow (p<0.01) and the isovolumic relaxation time (p<0.01). A receiver-operator characteristic curve showing the sensitivity and specificity of BNP against the echocardiography diagnosis of diastolic dysfunction revealed an area under the curve (accuracy) of 0.904 (p<0.01). Using a cut-off value of >40 pg/ml, the sensitivity and specificity of plasma BNP in diagnosing left ventricular diastolic dysfunction were 79% and 92%, respectively.

CONCLUSIONS

The plasma BNP levels in patients with hypertension are closely related to left ventricular hypertrophy and filling impairment. Plasma BNP may be used to facilitate the diagnosis of left ventricular diastolic dysfunction.

Early brain natriuretic peptide increase reflects acute myocardial ischemia in patients with ongoing chest pain

BACKGROUND

Plasma brain natriuretic peptide levels increase during acute ischemic events. In this study we tested the diagnostic performance of brain natriuretic peptide measurements in the detection of acute myocardial ischemia.

METHODS

Blood brain natriuretic peptide was measured in 101 patients with ongoing chest pain but no heart failure or an ST-segment elevation myocardial infarction on arrival at the emergency department (baseline) and at 2 and 6 h later. After diagnostic testing and 1-month follow-up for ischemia, patients were classified as either ischemic or non-ischemic.

RESULTS

In the ischemic group median (25th, 75th percentiles) brain natriuretic peptide values (pg/ml) were 122 (20, 349) at baseline, 116 (36, 347) at 2 h, increasing to 148 (52, 428) at 6 h (p<0.001 vs. baseline). Non-ischemic patients had 12 (5, 32) at baseline, 9 (6, 30) at 2 h, and 13 (5, 29) at 6 h (p<0.001 vs. corresponding values of the ischemic group). Receiver operator characteristic curves were constructed for brain natriuretic peptide values at baseline 2 and 6 h and for the increase of peptide levels from baseline to 6 h. All areas under curve indicated a significant diagnostic ability for the detection of ischemia. The 6-h measurement had better diagnostic performance than baseline and 2-h measurements. The subgroup of ischemic patients without myocardial necrosis also had higher brain natriuretic peptide values and could thus be discriminated from non-ischemic subjects.

CONCLUSIONS

Brain natriuretic peptide values may detect acute myocardial ischemia in patients with ongoing chest pain but without ST-segment elevation, and distinguish ischemic patients from those with pain of non-ischemic origin.

Plasma amino-terminal pro-brain natriuretic peptide and accuracy of heart-failure diagnosis in primary care: a randomized, controlled trial

OBJECTIVES

The purpose of this study was to determine the effect of amino-terminal pro-brain natriuretic peptide (N-BNP) on the diagnostic accuracy of heart failure (HF) in primary care.

BACKGROUND

The accurate diagnosis of patients with suspected HF presenting in primary care is difficult. Amino-terminal pro-brain natriuretic peptide is present in high levels in cardiac dysfunction and may improve the diagnostic accuracy of HF in primary care.

METHODS

The Natriuretic Peptides in the Community Study was a prospective, randomized controlled trial of the effect of N-BNP on the accuracy of HF diagnosis. Patients presenting to their general practitioner (GP) with symptoms of dyspnea and/or peripheral edema were included. The GPs formulated an initial diagnosis based on clinical assessment. All patients underwent a full cardiologic assessment that included echocardiography and N-BNP. Each patient was randomized to the BNP group (GP received the N-BNP result) or the control group (GP did not receive the N-BNP result). Patients were then reviewed by their GP, and their diagnosis was reviewed. The primary end point was the accuracy of the GPs' diagnoses compared with the panel standard.

RESULTS

A total of 305 patients were included; mean age was 72 years, 65% were female. Seventy-seven patients met the panel criteria for HF. The diagnostic accuracy improved 21% in the BNP group and 8% in the control group (p = 0.002). The main impact of N-BNP measurement on diagnostic accuracy was the GPs' correctly ruling out HF. The number needed to diagnose by N-BNP measurement was seven patients.

CONCLUSION

This study demonstrates that N-BNP measurement significantly improves the diagnostic accuracy of HF by GPs over and above customary clinical review.

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.

Natriuretic peptide measurement as a screening test for overt and subclinical heart failure

The prevalence of heart failure will increase in a number of industrialized countries as the proportion of elderly within the population increases. Despite recent advances in medical and surgical intervention, the prognosis for this disorder has not improved significantly. To make a major impact on the prognosis for heart failure, it would be important to be able to recognize various forms of heart disease before severe heart failure has developed. Chest X-radiography, ECG and echocardiography may not be adequate screening tools for heart failure in large populations. Natriuretic peptides are secreted from the heart in response to various cardiac abnormalities including ventricular dysfunction, volume overload, hypertrophy, and myocardial ischemia. Circulating levels of natriuretic peptides are elevated in various forms of structural cardiac disease regardless of etiology and the degree of ventricular systolic dysfunction. Natriuretic peptides, specifically B-type natriuretic peptide, are practically stable and can be measured without an extraction procedure. We have reviewed the recent status of plasma natriuretic peptide measurement for identification of patients with congestive heart failure, left ventricular dysfunction, and high risk of heart failure, especially in mass screening settings.

Utility of the amino-terminal fragment of pro-brain natriuretic peptide in plasma for the evaluation of cardiac dysfunction in elderly patients in primary health care

BACKGROUND

The aims of this study were to measure the N-terminal fragment of pro-brain natriuretic peptide (proBNP) in plasma in medical conditions commonly found in primary care and to evaluate the utility of these measurements in identifying impaired cardiac function in elderly patients with symptoms associated with heart failure.

METHODS

We studied 415 patients (221 men and 194 women; mean age, 72 years) who had contacted a primary healthcare center for dyspnea, fatigue, and/or peripheral edema. One cardiologist evaluated the patients in terms of history, physical examination, functional capacity, electrocardiography, and suspicion of heart failure. Plasma N-terminal proBNP was measured by an in-house RIA. An ejection fraction < or =40% by Doppler echocardiography was regarded as reduced cardiac function. Abnormal diastolic function was defined as an abnormal mitral inflow defined as reduced ratio of peak early diastolic filling velocity to peak filling velocity at atrial contraction (E/A ratio), or as abnormal pulmonary venous flow pattern.

RESULTS

Patients with impaired functional capacity, impaired systolic function, and/or impaired renal function had significantly increased N-terminal proBNP concentrations. By multiple regression analysis, N-terminal proBNP concentrations were also influenced by ischemic heart disease, cardiac enlargement, and certain medications but not by increased creatinine. No gender differences were observed. Patients with isolated diastolic dysfunction attributable to relaxation abnormalities had lower concentrations than those with normal cardiac function, whereas those with pseudonormal E/A ratios or restrictive filling patterns had higher concentrations.

CONCLUSIONS

Plasma N-terminal proBNP concentrations increase as a result of impaired systolic function, age, impaired renal function, cardiac ischemia and enlargement, and certain medications. Values are high in diastolic dysfunction with pseudonormal patterns, but not in patients with relaxation abnormalities. An increase in plasma N-terminal proBNP might be an earlier sign of abnormal cardiac function than abnormalities identified by currently used echocardiographic measurements.

Impaired vasodilator responses to atrial natriuretic peptide in essential hypertension

BACKGROUND

Atrial natriuretic peptide (ANP) has vasodilating and diuretic/natriuretic properties, both of which contribute to lower blood pressure. These effects are mediated by binding of ANP to a cell-surface receptor [type A guanylyl cyclase (GC-A)]. It has been demonstrated by studies in monogenetic mouse models that the ANP/GC-A system participates in the maintenance of blood pressure homeostasis.

METHODS

In male patients with essential hypertension (EH; n = 36) as the only cardiovascular risk factor and normotensive controls (n = 12), blood flow was measured in the forearm circulation in response to i.a. infusion of synthetic human ANP, acetylcholine, orciprenaline, and sodium nitroprusside by strain-gauge venous plethysmography. In blood samples, cyclic guanosine'5-monophosphate (cGMP) and ANP concentrations were measured at resting conditions and during exogenous ANP infusion. In 200 patients with EH, genomic DNA was screened for an inhibitory deletion mutation of the GC-A gene, which has been recently linked to EH in a Japanese cohort.

RESULTS

The vasodilatations in response to ANP and acetylcholine were impaired in the forearm circulation of patients with EH, whereas the responses to orciprenaline and nitroprusside were preserved. Plasma ANP and cGMP concentrations were increased in the patients with EH both at resting conditions and during ANP infusion; the resting plasma cGMP levels correlated significantly with the plasma ANP levels (r = 0.68). A specific deletion mutation of the GC-A gene did not account for the diminished relaxant effects of ANP in our study population.

CONCLUSIONS

The vascular ANP/GC-A pathway is altered in patients with EH, in addition to the known defects on the nitric oxide/cGMP pathway. Attenuation of the vasodilative responses to ANP suggests impaired receptor or postreceptor responsiveness of GC-A. It is possible that this dysfunction participates in the pathomechanism of EH.

B-type natriuretic peptide is related to left ventricular mass in hypertensive patients but not in athletes

A positive correlation has been previously documented between B-type natriuretic peptide (BNP) levels and left ventricular mass index (LVMI) in hypertensive patients. We evaluated 8 cycling athletes, 8 healthy age-matched controls; 17 hypertensive patients and 7 age-matched controls. LVMI was significantly higher in athletes and hypertensive patients than in their controls. Plasma levels of BNP in hypertensive patients were significantly higher than in athletes and their age-matched controls. No significant difference was found between athletes and their controls. Cycling athletes had significantly larger LVMI than hypertensive patients and controls, without elevated BNP levels. These results suggest that BNP levels are elevated in patients with increased LVM due to hypertension but not in physiologically increased LVM. Whether elevated BNP levels in athletes is a sign of structural heart disease merits further investigation.