Plasma B-type natriuretic peptide reflects left ventricular hypertrophy and diastolic function in hypertension

Association between B-type natriuretic peptide and long-term mortality in patients with acute severe hypertension visiting the emergency department

B-type natriuretic peptide (BNP) is a well-established prognostic factor for cardiovascular disorders. However, the association between BNP levels and mortality in patients with acute severe hypertension remains unclear. This study aimed to investigate the association between BNP levels and long-term mortality in patients with acute severe hypertension visiting the emergency department (ED). This retrospective study included patients aged ≥ 18 years who were admitted to the ED between 2016 and 2019 with acute severe hypertension (systolic blood pressure ≥ 180 mmHg or diastolic blood pressure ≥ 100 mmHg). Patients were categorized into tertiles according to BNP levels upon admission to the ED. Of the 3099 patients with acute severe hypertension, 6.4% in the first (lowest) tertile, 24.8% in the second tertile, and 44.4% in the third (highest) tertile of BNP died within 3-years. After adjusting for clinically relevant variables, patients in the second tertile of BNP (adjusted hazard ratio [HR], 2.64; 95% confidence interval [CI], 1.96-3.55), and patients in the third tertile of BNP (adjusted HR 4.18; 95% CI, 3.09-5.64) had a significantly higher risk of 3-year all-cause mortality than those in the first tertile of BNP. Therefore, BNP may be valuable for the initial assessment to identify high-risk patients among those with acute severe hypertension.

Prognostic superiority of global longitudinal strain beyond four-tiered ventricular hypertrophy in asymptomatic individuals

BACKGROUND

This study aims to explore the clinical correlates of myocardial deformations using speckle-tracking algorithm and to determine the prognostic utility of such measures in asymptomatic ethnic Chinese population.

METHODS

Global longitudinal (GLS), circumferential strain (GCS), and torsion were analyzed using featured tissue-tracking algorithm among 4049 symptom-free ethnic Chinese population. Hypertrophy (LVH) was classified into 4 tiers: indeterminate, dilated, thick and thick/dilated, by gender-stratified partition of end-diastolic volume index (EDVi) and LV mass/EDV0.67.

RESULTS

LVH (7.3%) showed substantially lower GLS (-20.3 ± 1.82% vs. -18.9 ± 2.08%) yet higher torsion (2.20 ± 0.90 vs. 2.39 ± 1.01, p < 0.001) than non-LVH participants. Those with thick LVH (n = 123) were more obese, had higher blood pressure and increased high-sensitivity C-reactive protein (hs-CRP); with dilated/thick LVH (n = 26) group demonstrating highest pro-brain natriuretic peptide (NT-proBNP) and worse GLS compared to indeterminate-/non-LVH groups. There were independent associations among larger EDVi, higher NT-proBNP and decreased torsion, and among greater LV mass/EDV0.67, worse GLS, greater GCS/torsion and hs-CRP. Over a median of 2.3 years (IQR: 1.2-4.8), the dilated, thick, and dilated/thick LVH categorizations were associated with higher risk of composite all-cause death and heart failure (HF) compared to non-LVH (adjusted hazard ratio [HR]: 3.65, 3.72, 6.01, respectively, all p < 0.05). Per 1% GLS reduction was independently associated with higher risk (adjusted HR: 1.31, p < 0.001) and improved risk prediction (p ≤ 0.001 by integrated discrimination improvement [IDI]: 3.5%, 95% CI: 1.5%-5.6%, and continuous net reclassification improvement [NRI]: 42.3%, 95% CI: 24.0%-60.6%) over LVH.

CONCLUSION

GLS improved risk stratification of four-tiered classification of LVH in asymptomatic ethnic Chinese.

Small Molecule Compound Nerolidol attenuates Hypertension induced hypertrophy in spontaneously hypertensive rats through modulation of Mel-18-IGF-IIR signalling

BACKGROUND

Cardiovascular diseases are caused by multitudes of stress factors like hypertension and their outcomes are associated with high mortality and morbidity worldwide. Nerolidol, a naturally occurring sesquiterpene found in several plant species, embodies various pharmacological benefits against numerous health disorders. However, their effects on hypertension induced cardiac complications are not completely understood.

PURPOSE

The present study is to elucidate the efficacy of nerolidol against hypertension related cardiac hypertrophy in spontaneously hypertensive rats (SHRs).

STUDY DESIGN

For preliminary in vitro studies, H9c2 cardiomyoblasts cells were challenged with 200 nM Angiotensin-II (AngII) for 12 h and were then treated with nerolidol for 24 h. The hypertrophic effect in H9c2 cells were analyzed by actin staining and the modulations in hypertrophic protein markers and mediators were determined by Western blotting analysis. For in vivo experiments, sixteen week-old male Wistar Kyoto (WKY) and SHRs were segregated into five groups (n = 9): Control WKY, hypertensive SHRs, SHRs with low dose (75 mg/kg b.w/day) nerolidol, SHRs with high dose (150 mg/kg b.w/day) nerolidol and SHR rats treated with an anti-hypertensive drug captopril (50 mg/kg b.w/day). Nerolidol treatment was given orally for 8 weeks and were analysed through Echocardiography. After euthanasia, hematoxylin and eosin staining, Immunohistochemical analysis and Western blotting was performed on left ventricle tissue.

RESULTS

Western blotting analysis revealed that nerolidol significantly attenuates AngII induced expression of hypertrophic markers ANP and BNP in H9c2 cardiomyoblasts. In addition, actin staining further ascertained the potential of nerolidol to ameliorate AngII induced cardiac hypertrophy. Moreover, nerolidol administration suppressed the hypertrophic signalling mediators like calcineurin, GATA4, Mel-18, HSF-2 and IGFIIR in a dose-dependent fashion. In silico studies also ascertained the role of Mel-18 in the ameliorative effects of nerolidol. Further, these intriguing in vitro results were further confirmed in in vivo SHR model. Oral neraolidol in SHRs efficiently reduced blood pressure and ameliorated hypertension induced cardiac hypertrophic effects by effectively reducing the levels of proteins involved in cardiac MeL-18-HSF2-IGF-IIR signalling.

CONCLUSION

Collectively, the data reveals that the cardioprotective effect of nerolidol against hypertension induced hypertrophy involves reduction in blood pressure and regulation of the cardiac Mel-18-IGFIIR signalling cascade.

Endothelial cell modulation of cardiomyocyte gene expression

The anatomic arrangement of microvascular endothelial cells and cardiomyocytes in vivo enables close interactions among these cells. In our in vitro co-culture system, ANP and BNP expression in the mouse atrial cardiomyocyte cell line HL-1 and subsequent ANP release were significantly upregulated when co-cultured with mouse cardiac microvascular endothelial cells or exposed to endothelial cell-conditioned medium. Endothelin-1 (ET-1) activation of endothelial cells remarkably enhanced their paracrine effect on cardiomyocyte gene expression, suggesting that ET-1 stimulation of endothelial cells affects expression of fetal genes such as ANP and BNP in adult cardiomyocytes through paracrine signalling. Exposure of HL-1 cells and murine induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) to authentic angiopoietin-2 (Ang2) caused a concentration-dependent decrease in ANP expression while ET-1-induced ANP expression was augmented by low but inhibited by high concentrations of Ang2. FK506-mediated inhibition of the calcineurin-NFAT pathway in the HL-1 cells selectively inhibited the stimulatory effect of the conditioned medium derived from ET-1-pre-stimulated endothelial cells on cardiomyocyte fetal gene expression. Combined with previous results indicating a crucial role for ANP and BNP in cardiac homeostasis, our findings provide further evidence that paracrine signalling by cardiac microvascular endothelial cells modulates cardiomyocyte function.

Premature atrial and ventricular complexes in outpatients referred from a primary care facility

Background

Premature complexes are common electrocardiographic findings in daily clinical practice that require further evaluation. Investigation may sometimes be complex and expensive. The aim of our study was to analyze variables associated with premature beats identified in outpatients referred from a primary care facility.

Materials and methods

We performed a cross-sectional study of 407 outpatients (aged 55.8±11years; 56% women) who were followed by general practitioners and were referred for resting 12-lead electrocardiograms for a routine clinical follow-up. After signing informed consent, patients answered a questionnaire and underwent physical examinations, laboratory diagnostics, transthoracic echocardiograms and 24-hour Holter monitoring to evaluate for the presence of premature complexes. After the univariate analyses, logistic regression analyses were performed with adjustment for age, sex, and cardiovascular diseases.

Results

Premature complexes distribution revealed that they were frequent but with low density. Premature atrial complexes (≥ 4/hours) were associated with age (Odds Ratio (OD) = 1.030, Confidence Interval (CI) 95% = 1.002 ─ 1.059, p = 0.029), brain natriuretic peptide (BNP) levels > 20mg/dL (OR = 4.489, 95%CI = 1.918 ─ 10.507, p = 0.0005), intraventricular blocks (OR = 4.184, 95%CI = 1.816 ─ 9.406, p = 0.0005) and left atrial diameter (OR = 1.065, 95%CI = 1.001 ─ 1.134, p = 0.046). Premature ventricular complexes (≥ 5/hour) were related to age (OR = 1.032, 95%CI = 1.010 ─ 1.054, p = 0.004), the use of calcium channel blockers (OR = 2.248, 95%CI = 1.019 ─ 4.954, p = 0.045), HDL-cholesterol levels (OR = 0.971, 95%CI = 0.951 ─ 0.992, p = 0.007), BNP levels > 20mg/dL (OR = 2.079, 95%CI = 0.991 ─ 0.998, p = 0.033), heart rate (OR = 1.019, 95%CI = 1.001 ─ 1.038, p = 0.041), left ventricular hypertrophy (OR = 2.292, 95%CI = 1.402 ─ 3.746, p = 0.001) and left ventricular ejection fraction (OR = 0.938, 95%CI = 0.900 ─ 0.978, p = 0.002).

Conclusions

Premature complexes had low density and were associated with BNP levels > 20mg/dL, lower levels of HDL-cholesterol, left atrial enlargement and ventricular hypertrophy. The identification of premature complexes on 24-hour Holter monitor recordings of outpatients in a primary public healthcare setting was associated with uncontrolled cardiovascular risk factors that may be addressed with medical advice and therapy in a primary care setting.

Molecular and histological effects of MR-guided pulsed focused ultrasound to the rat heart

BACKGROUND

Image-guided high intensity focused ultrasound has been used as an extracorporeal cardiac pacing tool and to enhance homing of stem cells to targeted tissues. However, molecular changes in the myocardium after sonication have not been widely investigated. Magnetic-resonance (MR)-guided pulsed focused ultrasound (pFUS) was targeted to the rat myocardium over a range of pressures and the microenvironmental and histological effects were evaluated over time.

METHODS

Eight-to-ten-week-old Sprague-Dawley rats received T2-weighted MR images to target pFUS to the left ventricular and septum without cardiac or respiratory gating. Rats were sonicated through the thoracic wall at peak negative pressures (PNP) from 1 to 8 MPa at a center frequency of 1 MHz, 10 ms pulse duration and 1 Hz pulse repetition frequency for 100 pulses per focal target. Following pFUS, myocardium was harvested over 24 h and subjected to imaging, proteomic, and histological measurements.

RESULTS

pFUS to the myocardium increased expression of cytokines, chemokines, and trophic factors characterized by an initial increase in tumor necrosis factor (TNF)-α followed by increases in pro- and anti-inflammatory factors that returned to baseline by 24 h. Immediately after pFUS, there was a transient (< 1 h) increase in N-terminal pro b-type natriuretic peptide (NT-proBNP) without elevation of other cardiac injury markers. A relationship between PNP and expression of TNF-α and NT-proBNP was observed with significant changes (p < 0.05 ANOVA) ≥ 4 MPa compared to untreated controls. Contrast-enhanced ex vivo T1-weighted MRI revealed vascular leakage in sonicated myocardium that was accompanied by the presence of albumin upon immunohistochemistry. Histology revealed infiltration of neutrophils and macrophages without morphological myofibril changes in sonicated tissue accompanied by pulmonary hemorrhage at PNP > 4 MPa.

CONCLUSIONS

MR-guided pFUS to myocardium induced transient proteomic and histological changes. The temporal proteomic changes in the myocardium indicate a short-lived sterile inflammatory response consistent with ischemia or contusion. Further study of myocardial function and strain is needed to determine if pFUS could be developed as an experimental model of cardiac injury and chest trauma.

Association of electrocardiographic left ventricular hypertrophy with incident cardiovascular disease in Japanese older hypertensive patients

BACKGROUND

Our aim was to assess whether electrocardiographic left ventricular hypertrophy (ECG-LVH) is associated with a higher risk of cardiovascular disease (CVD) events, independent of 24-hour blood pressure (BP) and circulating levels of norepinephrine and hemostatic factors.

METHODS

In 514 older hypertensive patients (mean age 72.3 years; 37% men), we assessed ambulatory BP values, circulating levels of norepinephrine and hemostatic factors (plasma fibrinogen, prothrombin fragment 1+2 (F1+2), von Willebrand factor (vWF), and plasminogen activator inhibitor-1 (PAI-1)), and the presence or absence of ECG-LVH (Sokolow-Lyon voltage ≥ 3.5 mV). The incidence of CVD events (i.e., myocardial infarction and stroke) was prospectively ascertained.

RESULTS

During an average 41 months of follow-up (1,751 person-years), 43 stroke and 3 myocardial infarction events occurred. At baseline, patients with ECG-LVH had higher mean 24-hour BP (148.8/83.8mm Hg vs. 135.7/77.2mm Hg) and circulating norepinephrine levels (404.6 pg/ml vs. 336.3 pg/ml) compared to those without ECG-LVH; the differences remained unchanged after adjustment for age, gender, smoking status, presence of diabetes, and antihypertensive medication uses at follow-up time (all P < 0.01). Cox proportional hazards models suggested that the hazard ratio (HR; 95% confidence interval (CI)) of CVD events for those with ECG-LVH was 4.4 (2.3-8.2), and the association between ECG-LVH and incident CVD events remained significant after adjustment for high 24-hour BP (≥130/80mm Hg), nocturnal SBP, circulating norepinephrine and fibrinogen levels (HRs, 3.5-4.2, all P < 0.001).

CONCLUSIONS

In older hypertensive patients, ECG-LVH was associated with a higher risk of CVD events, independent of ambulatory BP parameters and circulating norepinephrine and fibrinogen levels.

NT-proBNP predicts impaired myocardial function in newly diagnosed hypertensive patients with preserved ejection fraction

N-terminal pro-brain natriuretic peptide (NT-proBNP) is an excellent biomarker to diagnose left ventricular (LV) dysfunction. LV myocardial performance index (MPI-Tei index) is commonly used as a measure of combined systolic and diastolic function. We aimed to investigate the relationship between NT-proBNP and tissue Doppler derived MPI in newly diagnosed hypertensive patients with preserved LV ejection fraction (LVEF). We studied 236 patients with newly diagnosed HT (mean age; 52.9 ± 5.2 years). Echocardiographic examination was performed in all patients. LV mass index (LVMI) was calculated. Conventional Doppler indices (E and A waves) were recorded. The MPI value was obtained from the tissue Doppler derived ejection time, isovolumic contraction and relaxation times. The patients were divided into two groups according to the median NT-proBNP value (NT-proBNPlow group <114 pg/ml and NT-proBNPhigh group ≥114 pg/ml). Patients with NT-proBNPhigh were older and had higher levels of glucose and creatinine, lower E/A ratio and higher LVMI and MPI values than patients with NT-proBNPlow. However, LVEF were similar among the groups. Multiple linear regression analysis showed that NT-proBNP was independently associated with age, LVMI, MPI and E/A ratio. Increased NT-proBNP level was independently associated with impaired myocardial performance index in newly diagnosed hypertensive patients with preserved LVEF.

NT-proBNP, C-reactive protein and soluble uPAR in a bi-ethnic male population: the SAfrEIC study

Objective and design

This cross-sectional study aimed to investigate associations between a marker of cardiac strain, the N-terminal prohormone B-type natriuretic peptide (NT-proBNP), and inflammation as reflected by either a conventional or novel inflammatory marker in a bi-ethnic South African cohort.

Methods and subjects

We measured NT-proBNP, C-reactive protein (CRP) and plasma-soluble urokinase plasminogen activator receptor (suPAR) levels along with conventional biomarkers in black (n = 117) and white (n = 116) men.

Results

NT-proBNP, CRP and suPAR levels were higher in black compared to white men. NT-proBNP was significantly associated with both CRP (r = 0.38; p = 0.001) and suPAR (r = 0.42; p<0.001) in black men only. After full adjustment in multiple regression analyses, the above associations of NT-proBNP with CRP (β = 0.199; p = 0.018) and suPAR (β = 0.257; p<0.01) were confirmed in black men.

Conclusion

These results suggest that a low-grade inflammatory state as reflected by both a conventional and novel marker of inflammation may contribute to higher cardiovascular risk as reflected by the associations obtained with a marker of cardiac strain in black South African men.

Antihypertensive efficacy of the losartan/hydrochlorothiazide combination and its effect on plasma B-type natriuretic peptide in hypertensive patients uncontrolled by angiotensin II type 1 receptor antagonist-based therapy: a multicentre prospective observational study

BACKGROUND AND OBJECTIVES

Although strict blood pressure (BP) control is effective in the prevention of cardiovascular events, it is often insufficient in many hypertensive patients. B-type natriuretic peptide (BNP) has been shown to be associated with cardiovascular events. We investigated the effects of the losartan/hydrochlorothiazide combination on BP and plasma BNP in hypertensive patients uncontrolled by an angiotensin II type 1 receptor antagonist (angiotensin receptor blocker [ARB])-based therapy.

METHODS

In a multicentre prospective observational study, we enrolled 185 patients aged 36-79 years (mean age 63.8 years) with essential hypertension but without symptoms of heart failure who received an ARB-based therapy for ≥3 months but failed to achieve a target BP recommended by the Japanese Society of Hypertension (JSH). ARBs were switched to losartan (LOS) 50 mg/hydrochlorothiazide (HCTZ) 12.5 mg. The antihypertensive efficacy, safety, and effects of this combination on blood biochemical parameters and plasma BNP were evaluated for 12 months.

RESULTS

Mean ± SD systolic and diastolic BP decreased from 152 ± 13/87 ± 10 mmHg to 128 ± 14/74 ± 10 mmHg, respectively, after 12 months (p < 0.001). Mean ± SD plasma BNP levels decreased significantly from 46.0 ± 83.0 pg/mL to 40.8 ± 68.0 pg/mL (p < 0.05). The percentage of patients who achieved the JSH 2004 target BP was 51% after 12 months; the percentage was 63% in elderly patients aged ≥65 years without complications, and 43% in patients with concomitant diabetes mellitus or chronic kidney disease. No association was found between a decrease in plasma BNP levels and BP, age, body mass index or estimated glomerular filtration rate. There was a significant increase in serum uric acid and a decrease in serum potassium, but both were within the range of normal values. Adverse events were observed in 8.6% of the patients.

CONCLUSION

Antihypertensive treatment using two types of drugs (LOS/HCTZ) with different mechanisms yielded potent antihypertensive efficacy with safety and decreased plasma BNP levels.

NT-proBNP is associated with fibulin-1 in Africans: the SAfrEIC study

OBJECTIVES

The N-terminal prohormone B-type natriuretic peptide (NT-proBNP) is involved in the regulation of volume load and secreted when systemic cardiac overload occurs. Fibulin-1 on the other hand is a component of many extracellular matrix proteins including those present in atherosclerotic lesions, expressed in elastin-containing fibres of blood vessels, and also in the heart. Due to an alarming prevalence of hypertensive heart disease in black South Africans, we investigated the associations of NT-proBNP with fibulin-1 and markers of arterial stiffness in Africans and Caucasians.

METHODS

We included 231 Africans and 238 Caucasians from South Africa aged 22-77 years. Serum NT-proBNP and fibulin-1 levels were determined, and arterial compliance and pulse wave velocity were measured.

RESULTS

Africans had significantly higher blood pressure and NT-proBNP levels than Caucasians and African men had higher fibulin-1 levels than Caucasian men. In single regression analysis, NT-proBNP was significantly associated with fibulin-1 in African men and Caucasian women. NT-proBNP correlated negatively with arterial compliance in all groups except Caucasian women. After partial adjustments, the association between NT-proBNP and fibulin-1 strengthened in African men only. After full adjustment in multiple regression analysis, the association of NT-proBNP with fibulin-1 was confirmed in African men (R(2)=0.41; β=0.26; p<0.01) and also in younger women (R(2)=0.34; β=0.251; p=0.012).

CONCLUSIONS

Only Africans indicated a significant independent association between NT-proBNP and fibulin-1, suggesting that cardiovascular alterations are already present in this relatively young African population as opposed to Caucasians.

Mass spectrometry of peptides and proteins from human blood

It is difficult to convey the accelerating rate and growing importance of mass spectrometry applications to human blood proteins and peptides. Mass spectrometry can rapidly detect and identify the ionizable peptides from the proteins in a simple mixture and reveal many of their post-translational modifications. However, blood is a complex mixture that may contain many proteins first expressed in cells and tissues. The complete analysis of blood proteins is a daunting task that will rely on a wide range of disciplines from physics, chemistry, biochemistry, genetics, electromagnetic instrumentation, mathematics and computation. Therefore the comprehensive discovery and analysis of blood proteins will rank among the great technical challenges and require the cumulative sum of many of mankind's scientific achievements together. A variety of methods have been used to fractionate, analyze and identify proteins from blood, each yielding a small piece of the whole and throwing the great size of the task into sharp relief. The approaches attempted to date clearly indicate that enumerating the proteins and peptides of blood can be accomplished. There is no doubt that the mass spectrometry of blood will be crucial to the discovery and analysis of proteins, enzyme activities, and post-translational processes that underlay the mechanisms of disease. At present both discovery and quantification of proteins from blood are commonly reaching sensitivities of ∼1 ng/mL.

Effects of statin treatment on cardiac function in patients with chronic heart failure: a meta-analysis of randomized controlled trials

BACKGROUND

Whether additional benefit can be achieved with the use of statin treatment in patients with chronic heart failure (CHF) remains undetermined.

HYPOTHESIS

Statin treatment may be effective in improving cardiac function and ameliorating ventricular remodeling in CHF patients.

METHODS

The PubMed, MEDLINE, EMBASE, and EBM Reviews databases were searched for randomized controlled trials comparing statin treatment with nonstatin treatment in patients with CHF. Two reviews independently assessed studies and extracted data. Weighted mean differences (WMD) with 95% confidence intervals (CI) were calculated using random effects models.

RESULTS

Eleven trials with 590 patients were included. Pooled analysis showed that statin treatment was associated with a significant increase in left ventricular ejection fraction (WMD: 3.35%, 95% CI: 0.80 to 5.91%, P = 0.01). The beneficial effects of statin treatment were also demonstrated by the reduction of left ventricular end-diastolic diameter (WMD: -3.77 mm, 95% CI: -6.24 to -1.31 mm, P = 0.003), left ventricular end-systolic diameter (WMD: -3.57 mm, 95% CI: -6.37 to -0.76 mm, P = 0.01), B-type natriuretic peptide (WMD: -83.17 pg/mL, 95% CI: -121.29 to -45.05 pg/mL, P < 0.0001), and New York Heart Association functional class (WMD: -0.30, 95% CI: -0.37 to -0.23, P < 0.00001). Meta-regression showed a statistically significant association between left ventricular ejection fraction improvement and follow-up duration (P = 0.03).

CONCLUSIONS

The current cumulative evidence suggests that use of statin treatment in CHF patients may result in the improvement of cardiac function and clinical symptoms, as well as the amelioration of left ventricular remodeling.

The detection of left ventricular diastolic dysfunction in hypertensive patients: Performance of N-terminal probrain natriuretic peptide

AIM

Diastolic dysfunction (DD) results in increased cardiovascular risk in hypertensives. We studied the performance of N-terminal probrain natriuretic peptide (NT-proBNP) in detecting DD.

MATERIALS AND METHODS

241 hypertensive patients admitted to cardiology polyclinics were included in this study. They were grouped according to the presence of DD. Group 1: Essential hypertensive patients without DD (n= 119); group 2: essential hypertensive patients with DD (n= 122). All underwent trans-thoracic echocardiography for the evaluation of transvalvular flow, morphology, left ventricular wall motion abnormalities and ejection fraction. NT-proBNP levels were measured by an electrochemiluminescence immunoassay.

RESULTS

The systolic blood pressure (BP) (mean+/-SD) was 140+/-12 mmHg in group 1 and 144+/-16 mmHg in group 2 (p=0.049), the diastolic BP (mean+/-SD) was 88+/-10 mmHg in group 1 and 90+/-14 mmHg in group 2 (p=0.043). The median (1st-3rd quartile) NT-proBNP level in group 2 was significantly higher than group 1 [121.05 (61.03-207.66) and 31.17 (17.07-54.09) pg/ml, respectively (p<0.001)]. In the receiver operating characteristics analysis, the area under the curve was 0.862 (95% CI 0.816-0.908). At the cut-off of 45 pg/ml, sensitivity was 86.9%, specificity was 62.4%, and at the cut-off 65 pg/ml, sensitivity was 74.6%, specificity was 83.8%.

CONCLUSION

Plasma NT-proBNP levels may be useful for identifying patients with DD and it is conceivable to use a cut-off level 65 pg/ml as a "rule in" test.

Plasma C-terminal pro-endothelin-1 is associated with left ventricular mass index and aortic root diameter in African-American adults with hypertension

Endothelin-1 (ET-1), a circulating vasoactive peptide with potent vasoconstricting and mitogenic properties, may contribute to target-organ damage in hypertension. We investigated whether plasma levels of C-terminal pro-endothelin-1 (CT-pro-ET-1) are associated with left ventricular (LV) mass and aortic root diameter in African-American adults with hypertension. Plasma CT-pro-ET-1 was measured by an immunoluminometric assay in 1041 African Americans (65±9 years, 72% women) with hypertension. LV mass and aortic root diameter were measured according to the American Society of Echocardiography guidelines, and LV mass was indexed by height to the power 2.7 (LVMi). Multivariable regression analyses were used to assess whether plasma CT-pro-ET-1 was associated with LVMi and aortic root diameter, independent of potential confounding variables. Plasma CT-pro-ET-1 was modestly correlated with LVMi (r=0.21, P<0.0001) and aortic root diameter (r=0.09, P=0.004). In separate multivariable regression models that adjusted for age, sex, body mass index, total and high-density lipoprotein cholesterol, smoking history, diabetes, history of myocardial infarction or stroke, and blood pressure-lowering medication and statin use, log CT-pro-ET-1 was significantly associated with greater LVMi (P=0.001) and larger aortic root diameter (P=0.006). CT-pro-ET-1 is independently associated with LVMi and aortic root diameter and may be a marker of target-organ damage in African-Americans adults with hypertension.

Precipitation and selective extraction of human serum endogenous peptides with analysis by quadrupole time-of-flight mass spectrometry reveals posttranslational modifications and low-abundance peptides

The endogenous peptides of human serum may have regulatory functions, have been associated with physiological states, and their modifications may reveal some mechanisms of disease. In order to correlate levels of specific peptides with disease alongside internal standards, the polypeptides must first be reliably extracted and identified. Endogenous blood peptides can be effectively enriched by precipitation of the serum with organic solvents followed by selective extraction of peptides using aqueous solutions modified with organic solvents. Polypeptides on filter paper were assayed with Coomasie brilliant blue binding. The polypeptides were resolved by detergent tricine polyacrylamide electrophoresis and visualized by diamine silver staining. Peptides in the extracts were collected by C18 and analyzed by matrix-assisted laser desorption/ionization and liquid chromatography-electrospray ionization-tandem mass spectrometry (MS/MS) quadrupole time-of-flight MS/MS. Peptides were resolved as multiple isotopic peaks in MS mode with mass deviation of 0.1 Da or less and similar accuracy for fragments. The sensitivity of MS and MS/MS analysis was estimated to be in the picomolar range or less. The peptide composition of the extracts was dependent on solvent formulation. Multiple peptides from apolipoproteins, complement proteins, coagulation factors, and many others were identified by X!Tandem with high mass accuracy of peptide ions and fragments from collision-induced dissociation. Many previously unreported posttranslational modifications of peptides including phosphorylations, oxidations, glycosylations, and others were detected with high mass accuracy and may be of clinical importance. About 4,630 redundant peptides were identified with 99% confidence separately, and together some 1,251 distinct proteins were identified with 99% confidence or greater using the Paragon algorithm.

Impact of systemic hypertension on the diagnostic performance of B-type natriuretic peptide in patients with acute dyspnea

Hypertension may affect the diagnostic performance of B-type natriuretic peptide (BNP). The objective of the present study was to assess the impact of a history of hypertension or blood pressure elevation on admission on the diagnostic performance of BNP in the diagnosis of heart failure (HF) in patients with acute dyspnea. BNP levels were measured using a rapid point-of-care device in 1,586 patients with acute dyspnea. In patients with HF, BNP levels did not differ between those with and without histories of hypertension. Conversely, in patients without HF, a history of hypertension was associated with higher median BNP levels (38 pg/ml [interquartile range 13 to 119] vs 21 pg/ml [interquartile range 7 to 64], p <0.001). The areas under the receiver-operating characteristic curves were 0.88 and 0.93 for those with and without histories of hypertension, respectively (p <0.001). Blood pressure elevation on admission did not affect the diagnostic accuracy of BNP (areas under the curve 0.90 in the 2 groups). In conclusion, although a history of hypertension is associated with higher BNP levels in patients with acute dyspnea without HF, the impact on the overall diagnostic performance of BNP is modest. Accordingly, BNP performs well as an indicator of HF in patients presenting in emergency departments regardless of a history of hypertension or elevated blood pressure on admission.

Elevated NT-pro-BNP levels are associated with comorbidities among HIV-infected women

HIV infection is associated with left ventricular (LV) dysfunction and accelerated atherosclerosis. These conditions result in elevation of plasma natriuretic peptide (NP) levels. The present study compares N-terminal-pro-BNP (NT-pro-BNP) levels in HIV-infected and -uninfected women and identifies factors influencing NT-pro-BNP levels in HIV-infected women. A total of 454 HIV-infected and 200 HIV-uninfected participants from the Women's Interagency HIV Study (WIHS) had NT-pro-BNP determination. Elevated NT-pro-BNP level was defined using previously determined age stratified cut-off values of >164 ng/liter (age <60 years) and >225 (age > or = 60 years). HIV-infected women were older (41.6 +/- 8.9 vs. 38.9 +/- 10.5 years, p < 0.01) and were more likely to have anemia, hepatitis C virus (HCV) antibodies, and kidney dysfunction than HIV-uninfected women. HIV-infected women had significantly higher NT-pro-BNP levels (142.4 +/- 524.8 vs. 73.6 +/- 115.1 ng/liter, p = 0.01) and a higher prevalence of elevated NT-pro-BNP (12.1% vs. 7.5%; p = 0.08). In univariate analyses, elevated NT-pro-BNP was significantly associated with age, systolic BP, hypertension, anemia, triglyceride levels, kidney disease, and HCV seropositivity, but not HIV infection. In multivariate analysis, elevated NT-pro-BNP levels were significantly associated with anemia and kidney function, and had a borderline association with the presence of HCV antibodies. Among HIV-infected women, NT-pro-BNP levels were not independently associated with measures of severity of infection or with HAART use. Although HIV-infected women have higher NT-pro-BNP levels than HIV-uninfected women, the differences are due to non-HIV factors such as anemia, kidney disease, and HCV coinfection. These findings suggest that natriuretic peptide levels are a global marker of comorbidity in the setting of HIV infection.

Utility of B-natriuretic peptide in the evaluation of left ventricular diastolic function and diastolic heart failure

PURPOSE OF REVIEW

Heart failure with preserved ejection fraction or diastolic heart failure is an increasingly prevalent disease process today. Natriuretic peptides have been shown to provide diagnostic and prognostic utility in patients with systolic heart failure. Here we review current publications exploring the relationship between B-natriuretic peptide (BNP) and diastolic dysfunction.

RECENT FINDINGS

Investigators have found significant correlations between echocardiographic parameters for diastolic dysfunction and serum BNP levels in diagnosing diastolic heart failure. This relationship is linear with respect to severity of left ventricular dysfunction. Newer echocardiographic modalities like tissue Doppler imaging provide measures of elevated left ventricular filling pressures, which are associated with higher plasma BNP levels. Admission and predischarge BNP levels in patients with decompensated diastolic heart failure have been prognostic with respect to in-hospital mortality, short-term mortality, and hospital readmission.

SUMMARY

Review of current literature shows that BNP can be useful in providing diagnostic and prognostic data in patients with symptomatic and asymptomatic diastolic dysfunction. These data, combined with other values such as echocardiographic indices and cardiovascular risk factors, can augment the sensitivity and specificity of BNP.

Independent value of echocardiography and N-terminal pro-natriuretic Peptide for the prediction of major outcomes in patients with suspected heart failure

N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) and echocardiography have been shown to have diagnostic and prognostic value for the assessment of heart failure (HF) in the community. This study evaluated whether echocardiography and serum NT-pro-BNP estimation have independent value for the prediction of major outcome in patients with suspected HF from the community. Accordingly, 137 patients with suspected HF referred from the community were followed up after undergoing clinical assessment, electrocardiography, NT-pro-BNP estimation, and echocardiography. Abnormal echocardiogram was defined as visual left ventricular ejection fraction </=45% or left atrial volume index >26 ml/m(2) or presence of left ventricular hypertrophy or significant valvular heart disease. Data were obtained in 132 patients (96%) over a mean follow-up period of 26 +/- 7 months during which 19 (14%) developed major cardiac events (14 deaths and 5 HF admissions). Univariate predictors for major cardiac event were age (p = 0.05), male gender (p = 0.007), presence of clinical signs of HF (p = 0.02), NT-pro-BNP level >/=50 pmol/L (p <0.001), abnormal electrocardiogram (p = 0.02), and abnormal echocardiogram (p = 0.004). However, the only independent predictors were male gender (odds ratio 3.09, 95% confidence interval 1.01 to 9.46, p = 0.05), NT-pro-BNP level >/=50 pmol/L (odds ratio 5.78, 95% confidence interval 1.63 to 20.5, p = 0.007), and abnormal echocardiogram (odds ratio 11.1, 95% confidence interval 1.43 to 85.6, p = 0.02). In conclusion, NT-pro-BNP and abnormal echocardiogram provided independent information for predicting adverse outcome in patients with suspected HF referred from the community.

Effects of an aging vascular model on healthy and diseased hearts

The vitamin D(3) and nicotine (VDN) model is a model of isolated systolic hypertension (ISH) due to arterial calcification raising arterial stiffness and vascular impedance similar to an aged and stiffened arterial tree. We therefore analyzed the impact of this aging model on normal and diseased hearts with myocardial infarction (MI). Wistar rats were treated with VDN (n = 9), subjected to MI by coronary ligation (n = 10), or subjected to a combination of both MI and VDN treatment (VDN/MI, n = 14). A sham-treated group served as control (Ctrl, n = 10). Transthoracic echocardiography was performed every 2 wk, whereas invasive indexes were obtained at week 8 before death. Calcium, collagen, and protein contents were measured in the heart and the aorta. Systolic blood pressure, pulse pressure, thoracic aortic calcium, and end-systolic elastance as an index of myocardial contractility were highest in the aging model group compared with MI and Ctrl groups (P(VDN) < 0.05, 2-way ANOVA). Left ventricular wall stress and brain natriuretic peptide (P(VDNxMI) = not significant) were highest, while ejection fraction, stroke volume, and cardiac output were lowest in the combined group versus all other groups (P(VDNxMI) < 0.05). The combination of ISH due to this aging model and MI demonstrates significant alterations in cardiac function. This model mimics several clinical phenomena of cardiovascular aging and may thus serve to further study novel therapies.

Plasma N terminal pro-brain natriuretic peptide levels and its determinants in a multi-ethnic population

This study documents the determinants and plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) among hypertensive and normotensive subjects in a multi-ethnic population in the United Arab Emirates (UAE). We obtained demographic, anthropometric and clinical data, together with fasting NT-proBNP and biochemical indices from 128 hypertensive patients and 138 normotensive subjects matched for age, gender and ethnicity. Plasma NT-proBNP levels were significantly (P<0.001), and several-fold higher among hypertensives (median 5.92, inter quartile range (IQR): 1.79-18.48 pmol/l) than normotensives (median 1.78, IQR: 0.59-4.32 pmol/l) in the total study population, and the same was true for the ethnic groups separately. Similarly, plasma levels of glucose, blood urea nitrogen (BUN) and creatinine, but not insulin, were significantly (P<0.05) higher among hypertensives than normotensives. For all subjects combined, log NT-proBNP correlated positively and significantly with age (P<0.01), log glucose (P<0.05), systolic blood pressure (SBP, P<0.001), log BUN (P<0.001) and log creatinine (P<0.001). Multivariate regression analysis showed that NT-proBNP levels were independently and positively correlated with SBP, age, gender, log BUN, Emirati and South East Asian ethnic groups and inversely associated with current exercise. In conclusion, we found circulating levels of NT-proBNP to be significantly increased in hypertensive versus normotensive subjects in the UAE and independently related to SBP, age, gender, indices of renal function and possibly exercise. Our results further suggest a possible modulating effect of ethnicity on NT-proBNP levels.

Diagnostic, prognostic, and therapeutic implications of brain natriuretic peptide in dialysis and nondialysis-dependent chronic renal failure

Premature cardiovascular disease is the leading cause of morbidity and mortality in patients with end-stage renal failure. Natriuretic peptides, specifically brain natriuretic peptide, are released from the heart in response to chamber distension and thus increased in the presence of volume expansion and cardiac overload. Their physiological role is to cause vasodilatation and promote natriuresis to maintain volume homeostasis. Increasingly serum levels of brain natriuretic peptide are used to both diagnose and manage cardiovascular disorders. Furthermore, augmenting the beneficial hemodynamic actions of brain natriuretic peptide may have a therapeutic role in decompensated heart failure. However, the diagnostic role of serum brain natriuretic peptide levels in patients with advanced renal dysfunction remains to be defined. These patients have a high prevalence of left ventricular disorders, specifically left ventricular hypertrophy, which may reduce the diagnostic utility of brain natriuretic peptide. In addition, ventricular stretch may be determined by intravascular volume status rather than by cardiac dysfunction. Nonetheless, as the prognosis of patients with end-stage renal failure and co-existing heart failure is so poor, the availability of a further marker of cardiac ''distress'' may in the future become a useful diagnostic tool and in due course may become a primary goal for titration and tailoring of therapy.

Perindopril-based blood pressure-lowering therapy reduces amino-terminal-pro-B-type natriuretic peptide in individuals with cerebrovascular disease

OBJECTIVE

The plasma amino-terminal-pro-B-type natriuretic peptide (NT-proBNP) level predicted congestive heart failure, myocardial infarction, and ischaemic stroke in participants of the Perindopril Protection Against Recurrent Stroke Study (PROGRESS), a placebo-controlled study of the effects of blood pressure lowering on cardiovascular events among individuals with cerebrovascular disease. Active treatment comprised a flexible regimen based on perindopril, with the addition of indapamide at the discretion of treating physicians. Active treatment reduced cardiovascular events, and we therefore investigated whether active treatment modified NT-proBNP and other cardiovascular risk factors.

METHODS

We measured NT-proBNP and other cardiovascular risk factors at randomization and after 13 months of therapy in a subset of 357 PROGRESS participants.

RESULTS

Baseline systolic and pulse pressures were higher in individuals with elevated baseline NT-proBNP levels. In comparison with placebo, active treatment reduced the blood pressure and NT-proBNP levels, and increased renin levels. Reduction of NT-proBNP levels by active treatment was most evident in individuals with baseline NT-proBNP levels in the highest quarter (> 26 pmol/l), with a median reduction of 16 pmol/l (interquartile range 0-51 pmol/l, P = 0.004), corresponding to a median decrease of 39% (interquartile range 0-69%). Active treatment reduced blood pressure similarly for individuals in each of the four quarters of baseline NT-proBNP. Active therapy had no effect on plasma lipid, C-reactive protein, homocysteine, or soluble vascular cell adhesion molecule 1 levels.

CONCLUSION

We conclude that plasma NT-proBNP level, in addition to predicting cardiovascular risk, may provide a measure of risk reduction by blood pressure-lowering therapy.

B-type natriuretic peptide (BNP) levels in female systemic lupus erythematosus patients: what is the clinical significance?

Cardiovascular disease is a major cause of death in patients with systemic lupus erythematosus (SLE) especially during the late phase of the disease. This study was conducted to evaluate B-type natriuretic peptide (BNP) levels in female SLE patients without cardiac symptoms and to investigate whether BNP levels correlated with echocardiographic findings. We studied 59 women with SLE and 33 healthy women. SLE patients with history of cardiac disease, diabetes mellitus, hypertension, and other inflammatory diseases were excluded from the study. All subjects had a complete history and physical examination. Overall disease activity assessment in SLE patients at the time of the study were derived by calculation of SLE disease activity index (SLEDAI). BNP levels were determined, and transthoracic echocardiography were performed in all subjects. There was no difference between SLE patients and controls in terms of age, blood pressure, smoking status, plasma glucose, creatinine levels, and lipid profiles. Nine patients had SLEDAI score greater than 5. All subjects had an EF greater than 55%. Diastolic dysfunction was more frequent in lupus patients than in controls (15 [25.4%] vs. 2 [6%]; p = 0.022). BNP levels of SLE patients were significantly higher than controls (median 17.9 range [5-211] pg/ml vs. median 14.7 range [5-39.7] pg/ml; p = 0.033). Twenty-seven of the SLE patients (46%) and seven of the controls (21%) had BNP levels greater than or equal to 20 pg/ml (p = 0.019). There were no differences in BNP levels of SLE patients with and without diastolic dysfunction (median 17.8 range [5-117] pg/ml vs. median 18.5 range [5-211] pg/mL; p = NS). BNP levels were positively correlated with left atrium diameter (r (2) = 0.39, p = 0.001). BNP levels did not correlate with erythrocyte sedimentation rate/C-reactive protein levels, SLEDAI scores, total steroid dosage used, or other echocardigraphic parameters. BNP levels were increased in female SLE patients without cardiac symptoms as compared to healthy controls. Although none of the SLE patients in our study had clinical signs of ischemic heart disease, increased levels of BNP in SLE patients might be a reflection of a ischemic myocardial tissue.

Utility of plasma apelin and other indices of cardiac dysfunction in the clinical assessment of patients with dilated cardiomyopathy

Apelin is a recently discovered peptide ligand reported to be involved in the regulation of cardiovascular homeostasis. The exact role of apelin in the pathophysiology of congestive heart failure has remained obscure, and the reported circulating levels of apelin in patients with heart failure have been contradictory. To establish the role of apelin in the assessment of cardiac dysfunction we measured plasma apelin levels in 65 patients with congestive heart failure caused by idiopathic dilated cardiomyopathy (IDC) and 14 healthy volunteers by specific radioimmunoassay. IDC patients were carefully examined including echocardiography, both-sided cardiac catheterization and cardiopulmonary exercise test. In addition, plasma levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), N-terminal pro-atrial natriuretic peptide (NT-proANP), interleukin (IL)-6, tumor necrosis factor alpha (TNF-alpha), epinephrine and norepinephrine were determined. Plasma apelin levels were similar in IDC patients (median 26.5 pg/ml, range<3.40-97.6 pg/ml) and in control subjects (median 24.1 pg/ml, range 19.0-28.7 pg/ml; p=NS). Unlike the levels of NT-proBNP, IL-6, TNF-alpha, and norepinephrine, plasma apelin levels did not reflect the severity of heart failure. Our study demonstrates that although disturbed apelin-APJ signalling in heart may play a role in the pathophysiology of heart failure, circulating apelin levels cannot be applied in the clinical assessment of patients with chronic left ventricular dysfunction.

The interplay between haemodynamic load, brain natriuretic peptide and left atrial size in the early stages of essential hypertension

OBJECTIVE

Left atrial (LA) enlargement is an index of adverse cardiovascular events. We sought to investigate any possible correlation between haemodynamic load, neurohumoral factors and LA size in the early stages of essential hypertension.

METHODS

We studied 94 consecutive middle-aged subjects, with newly diagnosed stage I-II essential hypertension without left ventricular (LV) hypertrophy and 34 age and sex-matched normotensive individuals. Ambulatory blood pressure (BP) monitoring, plasma levels of brain natriuretic peptide (BNP), metabolic profile and left atrial volume index (LAVI), an echocardiographic measurement of LA volume indexed for the body surface area, constituted the work-up of all subjects.

RESULTS

Hypertensive compared with normotensive subjects had significantly increased office and ambulatory systolic and diastolic BP (P < 0.0001 for all cases) as well as body mass index and waist-to-hip ratio (P < 0.05 for both cases). BNP levels were greater in hypertensive compared with normotensive subjects but were not statistically significant (20.4 versus 17.1 pg/ml, P = NS). Hypertensive compared with normotensive subjects also had significantly increased LV mass index (105 versus 84 g/m, P < 0.0001), LA diameter (39 versus 36 mm, P < 0.0001), and LAVI (22 versus 19 ml/m, P < 0.05). In the hypertensive population, LAVI exhibited significant positive relationships with office systolic BP, ambulatory pulse pressure, LV mass index and BNP. In multiple linear regression analysis only LV mass index and BNP were significantly associated with LAVI (beta = 0.298, P = 0.030 and beta = 0.322, P = 0.009, respectively).

CONCLUSIONS

Increased LAVI, closely associated with LV mass index and BNP, was still found in the early stages of essential hypertension. However, the clinical significance of these findings remains to be elucidated in future studies.

Mechanism of Angiotensin II Type 1 Receptor Blocker Action in the Regression of Left Ventricular Hypertrophy

Left ventricular hypertrophy refers to a pathologic increase in left ventricular mass and is associated with an increased risk of subsequent cardiovascular morbidity and mortality from any cause. In the development of left ventricular hypertrophy there is growth of cardiomyocytes and accumulation of extracellular matrix and fibrosis. The actions are partly induced by angiotensin II, the principal effector of the renin-angiotensin-aldosterone system, binding to the AT1 receptor. Biochemical markers, some implicated in inflammatory changes, correlate with changes in left ventricular mass. The reduction in left ventricular mass brought about with angiotensin-converting enzyme inhibitor or angiotensin receptor blocker (ARB) therapy correlates with a reduction in these inflammatory changes, monitored by brain natriuretic peptide. Recent studies incorporating trials of ARBs have found ARBs to be more effective in reducing left ventricular mass than beta blockers and possibly more effective than calcium antagonists. Initial studies suggest that ARBs and angiotensin-converting enzyme inhibitors may have similar effects in terms of reducing left ventricular hypertrophy, and the combination of angiotensin-converting enzyme inhibitors and ARBs is thought to be synergistic due to a more complete inhibition of the renin-angiotensin-aldosterone system. In conclusion, these agents are efficacious in antihypertensive therapy and can play an important role in the prevention or regression of left ventricular hypertrophy due to hypertension.

N-terminal pro-B-type natriuretic peptide and B-type natriuretic peptide for identifying coronary artery disease and left ventricular hypertrophy in ambulatory chronic kidney disease patients

Elevated natriuretic peptide levels are common in patients with chronic kidney disease (CKD), as is the presence of coronary artery disease (CAD) and left ventricular hypertrophy (LVH). It was hypothesized that N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) and B-type natriuretic peptide (BNP) levels could identify CAD and LVH in asymptomatic patients with CKD. Clinical, laboratory, and echocardiographic data were collected prospectively in 54 ambulatory patients with CKD not requiring dialysis. CAD was defined by previous myocardial infarction or coronary revascularization. The median age was 70 years (interquartile range [IQR] 57 to 76). Fourteen patients (26%) had CAD, and 30 (56%) had LVH. Median NT-pro-BNP was 724 pg/ml (IQR 168 to 2,950), median BNP was 137 pg/ml (IQR 31 to 391), and the median glomerular filtration rate (GFR) was 31 ml/min/1.73 m2 (IQR 21 to 42). A strong correlation was found between NT-pro-BNP and BNP levels (R = 0.74, p <0.0001), but only moderate correlations were found between NT-pro-BNP and GFR (R = -0.45, p = 0.0006) and between BNP and GFR (R = -0.38, p = 0.005). There was no trend of an increase in the prevalence of LVH or CAD with decreasing GFR. However, across progressive NT-pro-BNP and BNP quartiles, the prevalences of LVH and CAD increased significantly. Receiver-operating characteristic curves showed that these 2 markers are similar and significant predictors for indicating LVH (area under the curve [AUC] 0.72, p = 0.005 for NT-pro-BNP; AUC 0.72, p = 0.007 for BNP) and CAD (AUC 0.80, p = 0.001 for NT-pro-BNP; AUC 0.82, p = 0.0004 for BNP; p = 0.45 for NT-pro-BNP vs BNP). In conclusion, NT-pro-BNP and BNP levels are significant and equivalent indicators of CAD and LVH in asymptomatic patients with CKD.

Amino-terminal pro-B-type natriuretic peptide and B-type natriuretic peptide in the general community: determinants and detection of left ventricular dysfunction

OBJECTIVES

This study sought to characterize factors influencing amino-terminal pro-B-type natriuretic peptide (NT-proBNP) and to evaluate the ability of NT-proBNP to detect left ventricular (LV) dysfunction in a large community sample.

BACKGROUND

Secretion of BNP increases in cardiac disease, making BNP an attractive biomarker. Amino-terminal proBNP, a fragment of the BNP prohormone, is a new biomarker. We evaluated factors influencing NT-proBNP in normal patients and compared the ability of NT-proBNP and BNP to detect LV dysfunction in a large community sample.

METHODS

Amino-terminal pro-BNP was determined in plasma samples of a previously reported and clinically and echocardiographically characterized random sample (n = 1,869, age > or =45 years) of Olmsted County, Minnesota.

RESULTS

In normal patients (n = 746), female gender and older age were the strongest independent predictors of higher NT-proBNP. Test characteristics for detecting an LV ejection fraction < or =40% or < or =50% were determined in the total sample with receiver operating characteristic curves. Amino-terminal pro-BNP had significantly higher areas under the curve for detecting an LV ejection fraction < or =40% or < or =50% than BNP in the total population and in several male and age subgroups, whereas areas were equivalent in female subgroups. Age- and gender-adjusted cutpoints improved test characteristics of NT-proBNP. Both assays detected patients with systolic and/or moderate to severe diastolic dysfunction to a similar degree, which was less robust than the detection of LV systolic dysfunction alone.

CONCLUSIONS

Amino-terminal pro-BNP in normal patients is affected primarily by gender and age, which should be considered when interpreting values. Importantly, in the entire population sample NT-proBNP performed at least equivalently to BNP in detecting LV dysfunction and was superior in some subgroups in detecting LV systolic dysfunction.

Capability of B-Type Natriuretic Peptide (BNP) and Amino-Terminal proBNP as Indicators of Cardiac Structural Disease in Asymptomatic Patients with Systemic Arterial Hypertension

Background: The aim of the present study was to prospectively evaluate the diagnostic utility of B-type natriuretic peptide (BNP) and amino-terminal proBNP (NT-proBNP) measurements for the detection of cardiac structural disease in asymptomatic patients with systemic arterial hypertension and to test the hypothesis that the 2 analytes are equally useful in this clinical setting.

Methods: We studied a consecutive series of 149 asymptomatic patients referred for echocardiographic evaluation of the cardiac effects of systemic arterial hypertension. Diagnosis of cardiac structural disease was based on the presence of systolic or diastolic dysfunction, left atrial dilatation, left ventricular dilatation or hypertrophy, pulmonary hypertension, and wall motion or valvular abnormalities. Blood concentrations of BNP and NT-proBNP were measured by 2 commercially available assays (Abbott AxSYM and Roche Elecsys, respectively). Diagnostic accuracies of BNP and NT-proBNP were assessed by ROC curve analysis. Areas under the curves were compared by analysis of equivalency.

Results: In distinguishing between hypertensive patients with cardiac structural disease (n = 118) and hypertensive patients without (n = 31), areas under the curves were 0.740 (95% confidence interval, 0.662–0.808) for BNP and 0.762 (0.685–0.828) for NT-proBNP and were significantly equivalent (P = 0.015). Cutoff values with a 90% sensitivity for cardiac structural disease were 17 ng/L for BNP and 39 ng/L for NT-proBNP, with 29% and 32% specificity, respectively.

Conclusions: BNP and NT-proBNP have similar capabilities for detecting cardiac structural disease in asymptomatic patients with systemic arterial hypertension. However, in the setting evaluated, a screening strategy relying on measurement of BNP or NT-proBNP may be of limited value because of the low specificity at the selected cutoff values.

Hypertensive heart disease

Left ventricular hypertrophy (LVH) and diastolic dysfunction (CHF-D) are the early manifestations of cardiovascular target organ damage in patients with arterial hypertension and signify hypertensive heart disease. Identification of hypertensive heart disease is critical, as these individuals are more prone to congestive heart failure, arrhythmias, myocardial infarction and sudden cardiac death. Regression of left ventricular (LV) mass with antihypertensive therapy decreases the risk of future cardiovascular events. The goal of antihypertensive therapy is to both lower blood pressure (BP) and interrupt BP-independent pathophysiologic processes that promote LVH and CHF-D. The purpose of this review is to summarize current and emerging approaches to the pathophysiology and treatment of hypertensive heart disease.