Value of plasma B type natriuretic peptide measurement for heart disease screening in a Japanese population

Artificial Intelligence-Enabled Electrocardiography Detects B-Type Natriuretic Peptide and N-Terminal Pro-Brain Natriuretic Peptide

BACKGROUND: The B-type natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (pBNP) are predictors of cardiovascular morbidity and mortality. Since the artificial intelligence (AI)-enabled electrocardiogram (ECG) system is widely used in the management of many cardiovascular diseases (CVDs), patients requiring intensive monitoring may benefit from an AI-ECG with BNP/pBNP predictions. This study aimed to develop an AI-ECG to predict BNP/pBNP and compare their values for future mortality. METHODS: The development, tuning, internal validation, and external validation sets included 47,709, 16,249, 4001, and 6042 ECGs, respectively. Deep learning models (DLMs) were trained using a development set for estimating ECG-based BNP/pBNP (ECG-BNP/ECG-pBNP), and the tuning set was used to guide the training process. The ECGs in internal and external validation sets belonging to nonrepeating patients were used to validate the DLMs. We also followed-up all-cause mortality to explore the prognostic value. RESULTS: The DLMs accurately distinguished mild (≥500 pg/mL) and severe (≥1000 pg/mL) an abnormal BNP/pBNP with AUCs of ≥0.85 in the internal and external validation sets, which provided sensitivities of 68.0-85.0% and specificities of 77.9-86.2%. In continuous predictions, the Pearson correlation coefficient between ECG-BNP and ECG-pBNP was 0.93, and they were both associated with similar ECG features, such as the T wave axis and correct QT interval. ECG-pBNP provided a higher all-cause mortality predictive value than ECG-BNP. CONCLUSIONS: The AI-ECG can accurately estimate BNP/pBNP and may be useful for monitoring the risk of CVDs. Moreover, ECG-pBNP may be a better indicator to manage the risk of future mortality.

Biomarker Development in Cardiology: Reviewing the Past to Inform the Future

Cardiac biomarkers have become pivotal to the clinical practice of cardiology, but there remains much to discover that could benefit cardiology patients. We review the discovery of key protein biomarkers in the fields of acute coronary syndrome, heart failure, and atherosclerosis, giving an overview of the populations they were studied in and the statistics that were used to validate them. We review statistical approaches that are currently in use to assess new biomarkers and overview a framework for biomarker discovery and evaluation that could be incorporated into clinical trials to evaluate cardiovascular outcomes in the future.

Application of high-performance magnetic nanobeads to biological sensing devices

Nanomaterials have extensive applications in the life sciences and in clinical diagnosis. We have developed magnetic nanoparticles with high dispersibility and extremely low nonspecific binding to biomolecules and have demonstrated their application in chemical biology (e.g., for the screening of drug receptor proteins). Recently, the excellent properties of nanobeads have made possible the development of novel rapid immunoassay systems and high-precision technologies for exosome detection. For immunoassays, we developed a technology to encapsulate a fluorescent substance in magnetic nanobeads. The fluorescent nanobeads allow the rapid detection of a specific antigen in solution or in tissue specimens. Exosomes, which are released into the blood, are expected to become markers for several diseases, including cancer, but techniques for measuring the absolute quantity of exosomes in biological fluids are lacking. By integrating magnetic nanobead technology with an optical disc system, we developed a novel method for precisely quantifying exosomes in human serum with high sensitivity and high linearity without requiring enrichment procedures. This review focuses on the properties of our magnetic nanobeads, the development of novel biosensors using these nanobeads, and their broad practical applications.

NT-proBNP is associated with mortality and adverse cardiac events in patients with atrial fibrillation presenting to the emergency department

BACKGROUND

Atrial fibrillation (AF) is the most common cardiac arrhythmia in the emergency department. The CHA₂ DS₂ -VASc score helps to predict thromboembolic risk; however, the rate of other adverse cardiac events is more difficult to predict.

HYPOTHESIS

The biomarker N-terminal pro-brain natriuretic peptide (NT-proBNP) has prognostic value in patients presenting to the emergency department with AF.

METHODS

During a 1.5-year period, a prospective study was performed in consecutive patients presenting to the emergency department with AF on the presenting electrocardiogram. At baseline, NT-proBNP was measured. The primary endpoints were all-cause death and major adverse cardiac events (MACE: all-cause mortality, myocardial infarction, or revascularization).

RESULTS

A total of 355 patients were included (mean age, 71 years; 55% male). The median duration of follow-up was 2 years. After adjustment for baseline variables, the logNT-proBNP was independently correlated with death (hazard ratio [HR]: 1.54, 95% confidence interval [CI]: 1.18-1.99) and MACE (HR: 1.27, 95% CI: 1.03-1.58). After adjustment for baseline variables, a high NT-proBNP value (>500 pmol/L) was independently correlated with death (HR: 2.26, 95% CI: 1.19-4.28), and for MACE a trend was seen (HR: 1.67, 95% CI: 0.96-2.91) compared with a low value (<250 pmol/L).

CONCLUSIONS

In patients presenting to the emergency department with AF, higher NT-proBNP values are independently associated with an increased mortality and MACE. Therefore, this biomarker may be a useful prognostic marker in the management and treatment of these patients.

Methodology and Applications of Disease Biomarker Identification in Human Serum

Biomarkers are biomolecules that serve as indicators of biological and pathological processes, or physiological and pharmacological responses to a drug treatment. Because of the high abundance of albumin and heterogeneity of plasma lipoproteins and glycoproteins, biomarkers are difficult to identify in human serum. Due to the clinical significance the identification of disease biomarkers in serum holds great promise for personalized medicine, especially for disease diagnosis and prognosis. This review summarizes some common and emerging proteomics techniques utilized in the separation of serum samples and identification of disease signatures. The practical application of each protein separation or identification technique is analyzed using specific examples. Biomarkers of cancers of prostate, breast, ovary, and lung in human serum have been reviewed, as well as those of heart disease, arthritis, asthma, and cystic fibrosis. Despite the advancement of technology few biomarkers have been approved by the Food and Drug Administration for disease diagnosis and prognosis due to the complexity of structure and function of protein biomarkers and lack of high sensitivity, specificity, and reproducibility for those putative biomarkers. The combination of different types of technologies and statistical analysis may provide more effective methods to identify and validate new disease biomarkers in blood.

Intervention for Varicose Veins of Lower Extremities Lowers the Brain Natriuretic Peptide Values in Varicose Vein Patients

Objective: To evaluate the relationship between varicose veins and heart failure, both of which cause edema of lower extremities. Materials and Methods: We enrolled 150 patients who underwent intervention for varicose veins of lower extremities between December 2012 and October 2015, and perioperative data were retrospectively investigated. Results: Of the 150 patients, 104 (69.3%) were females. The mean age was 66.8±10.6 years (27-85 years). Eighty (53.3%) patients had varicose veins in both legs. In all patients, the postoperative (brain natriuretic peptide (BNP) value was significantly lower than the preoperative BNP value (pre : post=39.3 : 30.5 pg/dl, P<0.0001). In patients with higher BNP values (>100 pg/dl), the postoperative BNP values were significantly lower than the preoperative BNP values (pre : post=192.7 : 166.1 pg/dl, P<0.0001). Body weights of the patients decreased differently between pre- and post-operation (pre : post=61.3 : 59.4 kg, P=0.0008). Conclusion: Intervention for varicose veins of lower extremities might be considered clinically useful for the improvement of cardiac function.

Prevalence of atrial fibrillation in the Malaysian communities

BACKGROUND AND AIM

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia encountered in clinical practice. The REDISCOVER (Responding to Increasing Cardiovascular disease prevalence) study is an observational longitudinal community-based study that tracks changing lifestyles, risk factors and chronic disease in urban and rural areas of Malaysia. In this study, we aim to study the prevalence of AF and its associated risk factors.

METHODS

The study was conducted between 2007 and 2014. Participants were required to complete questionnaires on cardiovascular risk factors and medical history, and undergo physical examinations, blood tests, ECG and echocardiography examinations. Demographic variables including weight, height, blood pressure, serum glucose and serum lipid were recorded. Participants with AF were identified from their baseline ECG and at 3-year follow up.

RESULTS

A total of 10 805 subjects participated in the study. Mean age was 52.6(±11.6) years and 56% were female; 4.4% of subjects had a diagnosis of ischaemic heart disease, 1.3% had a previous stroke, 16.7% had diabetes mellitus and 45.6% had hypertension. There were 53 subjects diagnosed with AF at baseline, giving a prevalence of 0.49%, and 0.54% at 3 years. AF was more prevalent in males (58.5% in the AF group compared to 43.9% in sinus rhythm (SR) subjects; p=0.03) and the older age group. Ischaemic heart disease was more prevalent in AF subjects (22.6%) compared to SR subjects (4.4%) (p<0.001). In the AF group previous stroke had occurred in 1.9% of subjects compared to 1.3% in the SR population (p=0.51), and 24.5% of subjects in the AF group had diabetes compared to 16.6% in the SR group (p=0.12). There was a significant difference in the prevalence of hypertension between the AF group (59.6%) compared to the SR subjects (45.5%) (p=0.04).

CONCLUSIONS

The prevalence of AF in the Malaysian population was low at 0.54% compared to the global average of 1%. We found that AF was associated with older age, male sex, hypertension, and ischaemic heart disease.

Plasma levels of atrial and brain natriuretic peptides in apparently healthy subjects: Effects of sex, age, and hemoglobin concentration

BACKGROUND

To examine whether the use of one value of natriuretic peptides to define "normal" is appropriate in all individuals, and to assess the influence of sex, age, and other variables on atrial and brain natriuretic peptides (ANP, BNP) levels.

METHODS AND RESULTS

A total of 1375 apparently healthy people (women:155, men:1220), aged 18-70years were enrolled. Both ANP and BNP levels were higher in women than in men (ANP: 12.50±6.82pg/mL vs 8.18±4.19pg/mL; BNP: 9.85±7.63pg/mL vs 7.03±6.97pg/mL). The subjects were divided into three age groups: group I, 18-30years; group II, 30-50years; group III, 50-70years. First, the influence of age on ANP and BNP levels was examined. In women, both ANP and BNP levels were higher in groups II and III than those in group I. In men, ANP and BNP levels increased with age. Second, sex differences in ANP and BNP levels due to age were examined. ANP level was higher in women than that in men in all age groups. BNP level was higher in women than that in men in groups I and II. Multivariate analysis indicated that both ANP and BNP levels were influenced by age, hemoglobin level, and platelet counts.

CONCLUSION

Because ANP and BNP levels in healthy subjects are influenced by sex, age, and hemoglobin levels, the use of a single value to define "normal" in all individuals is not appropriate.

Plasma BNP level combined with surgical Apgar score to predict operative major cardiac adverse events in malignant obstructive jaundice patients

Objective:

To investigate the predictive effect of major adverse cardiac events (MACE) in malignant obstructive jaundice (OJ) patients using plasma brain natriuretic peptide (BNP) level and surgical Apgar scoring (SAS) system.

Methods:

Forty one malignant OJ patients undergoing surgical treatments were studied at a single center. Pre-and postoperative plasma BNP level, total bilirubin (TBil) and data of cardiac function (HR, CVP, CI, LVEF%) were detected, the SAS was calculated during the surgery, the relationship of both plasma BNP level and SAS with MACE after surgery was analyzed.

Results:

Thirteen patients out of 41 (31.71%) experienced MACE without cardiac death. OJ patients had a higher plasma BNP level than baseline before operation (191.61±105.76 pg/ml VS 175 pg/ml, P<0.05), the cardiac function data was improved (CVP: t=4.761, p=0.000; CI: t=3.539, p=0.001; LVEF%: t=3.632, p=0.001) after the operation. Patients with lower SAS had increasing incidence of MACE after surgery.

Conclusion:

Malignant OJ patients with higher preoperative BNP level and lower surgical Apgar score were identified at high risk of MACE after surgery.

Impact of B-type natriuretic peptide (BNP) on development of atrial fibrillation in people with Type 2 diabetes

AIMS

To examine if a simple biomarker can identify people with diabetes who are at high risk of atrial fibrillation.

METHODS

A retrospective cohort study was conducted at a single centre in people with Type 2 diabetes referred to our department between January 2000 and December 2007. In 517 consecutive people without any history, signs or symptoms of atrial fibrillation at baseline, the association between baseline B-type natriuretic peptide level and future atrial fibrillation incidence was examined, with adjustments for other potentially confounding factors.

RESULTS

A total of 28 people were diagnosed with new-onset atrial fibrillation during a median 6-year follow-up. When people were categorized into three groups according to B-type natriuretic peptide clinical thresholds (20 and 100 pg/ml), hazard ratios for the development of atrial fibrillation in the middle and highest B-type natriuretic peptide groups were 2.8 and 9.4, respectively, compared with the lowest B-type natriuretic peptide group. Time-dependent receiver-operating curve analysis identified a threshold for B-type natriuretic peptide to detect atrial fibrillation development of 52.8 pg/ml (sensitivity 75.2%, specificity 68.8%). The B-type natriuretic peptide predictive value was independent of and similar to that of left atrial size and ventricular dimension.

CONCLUSION

In people with Type 2 diabetes, high baseline B-type natriuretic peptide levels were significantly associated with future atrial fibrillation development.

Recent Patient Characteristics and Medications at Admission and Discharge in Hospitalized Patients With Heart Failure

BACKGROUND

To improve the clinical outcome of heart failure (HF), it is important to evaluate the etiology and comorbidities of HF. We previously reported the baseline clinical characteristics and medications in hospitalized patients with HF in years 2000 - 2002 (group 2000) and 2007 - 2009 (group 2008).

METHODS

We conducted a retrospective study of 158 patients who were hospitalized due to HF between 2012 and 2014 (group 2013) in the Department of Cardiology, Fukuoka University Hospital. We analyzed the clinical characteristics and medications at admission and discharge, and compared the findings in group 2013 to those in group 2000 and group 2008.

RESULTS

The major causes of HF were ischemic heart disease, hypertensive cardiomyopathy, valvular heart disease, and dilated cardiomyopathy. The New York Heart Association classification in group 2013 was significantly higher than those in group 2000 and group 2008. There was no difference in the level of brain natriuretic peptide at admission between group 2008 and group 2013. Tolvaptan began to be administered in group 2013. The median dose of furosemide just before the use of tolvaptan was 40 mg/day. At discharge, group 2013 showed higher rates of β-blocker and aldosterone antagonist. There was no difference in the frequency of loop diuretics. The dose of carvedilol at discharge was only 6.2 ± 4.0 mg/day. Antiarrhythmic drugs and β-blocker were used more frequently in HF with reduced ejection fraction (EF) than in HF with preserved EF.

CONCLUSIONS

We may be able to improve the clinical outcome of HF by examining the differences in the clinical characteristics and medications at admission and discharge in hospitalized patients with HF.

Biomarkers for Heart Failure in Asia

Contributions from the Asian biomedical community to knowledge of biomarkers in heart failure have grown rapidly since 2000. Japan has made world-leading contributions in the discovery and application of cardiac natriuretic peptides as biomarkers in heart failure, but there has been rapid growth in reports from China. Contributions also come from Taiwan, South Korea, Singapore, and Hong Kong. Centers in Asia have established clinical cohorts providing powerful platforms for the discovery and validation of biomarkers in heart failure. This century, Asian enquiry into biomarkers in heart failure will include peptides, cytokines, metabolites, nucleic acids, and other analytes.

Revisiting Clinical Utility of Chest Radiography and Electrocardiogram to Determine Ischemic Stroke Subtypes: Special Reference on Vascular Pedicle Width and Maximal P-Wave Duration

BACKGROUNDS

It is often difficult to diagnose stroke subtypes at admission, particularly in sinus rhythm cases. Vascular pedicle width (VPW) on chest X-ray (CXR) and maximal P-wave duration (P-max) on electrocardiogram (ECG) are again realized as useful parameters reflecting intravascular volume and atrial conduction status, respectively. We investigated the utility of VPW and P-max as a tool for differentiating ischemic stroke subtypes.

METHODS

We studied 343 acute stroke patients showing sinus rhythm on admission. Dividing the patients into cardioembolic (CE) stroke (n = 57) and non-CE (n = 286) groups, we compared clinical backgrounds including VPW on CXR, and P-max in lead II and premature atrial contraction (PAC) on 12-leads ECG. Then, we investigated the independent factors for CE.

RESULTS

Independent factors associated with CE were VPW (≥59.3 mm) (p < 0.001; odds ratio (OR), 10.12; 95% confidence interval (CI), 4.13-24.8), P-max in lead II (≥120 ms) (p < 0.001; OR, 8.61; 95% CI, 3.96-18.7), PAC (p = 0.002; OR, 7.35; 95% CI, 2.14-25.3) and D-dimer level (≥1.11 µg/ml) (p = 0.016; OR, 2.57; 95% CI, 1.20-5.51).

CONCLUSIONS

VPW, P-max, PAC and D-dimer are useful parameters for diagnosing CE stroke in patients with sinus rhythm at admission.

Prevalence, incidence, and lifetime risk of atrial fibrillation in China: new insights into the global burden of atrial fibrillation

BACKGROUND

Much of the epidemiology of atrial fibrillation (AF) is based on data from Western populations. Despite the huge population of Asia, data on the clinical epidemiology of AF in Asian countries are limited. The current study aimed to investigate the prevalence and incidence of newly diagnosed (ie, incident) AF, as well as lifetime risk, in China and to determine the clinical risk factors contributing to its development.

METHODS

Using a medical insurance database involving > 10 million individuals for the years 2001 to 2012 in the southwest of China, trends in incident AF were calculated using Kaplan-Meier analysis and Cox regression. The usefulness of the CHADS2 (congestive heart failure, hypertension, age, diabetes, stroke [doubled]) and CHA2DS2-VASc (congestive heart failure, hypertension, age ≥ 75 [doubled], diabetes, stroke [doubled], vascular disease, age 65-74, and sex category [female]) scores was tested in predicting the occurrence of incident AF.

RESULTS

A total of 471,446 individuals (aged ≥ 20 years) were studied, with 1,924,975 person-years of experience. We identified 921 patients with incident AF (62% male; mean age, 62 years). The prevalence of incident AF in subjects aged ≥ 20 years was 0.2 per 100 people, with an incidence of AF of 0.05 per 100 person-years overall. Over an 11-year period, the prevalence of AF increased 20-fold, whereas AF-related stroke increased 13-fold. The lifetime risk of AF was approximately one in five among Chinese adults, and it increased with advancing age. The CHA2DS2-VASc score was superior to the CHADS2 score in predicting the risk of incident AF in our Chinese population (DeLong test, Z = 6.621, P < .001).

CONCLUSIONS

The AF burden, as well as the risk of AF-related stroke, has increased significantly over the past 11 years in the southwest of China. The public health burden of AF and its complications are greatest in the very elderly, with major implications for health-care systems given the global burden of this common arrhythmia.

Prognostic values of highly sensitive cardiac troponin T and B-type natriuretic peptide for clinical features in hypertrophic obstructive cardiomyopathy: a cross-sectional study

OBJECTIVES

Although B-type natriuretic peptide (BNP) and highly sensitive cardiac troponin T (cTnT) are useful for the evaluation of clinical features in various cardiovascular diseases, there are comparatively few data regarding the utility of these parameters in patients with hypertrophic obstructive cardiomyopathy (HOCM). The goal of this study was to assess the association between BNP, cTnT and clinical parameters in patients with HOCM.

DESIGN

Cross-sectional survey

SETTINGS

The relationship between BNP, cTnT and clinical end points and echocardiographic data was investigated.

PARTICIPANTS

This study included 102 consecutive outpatients with HOCM who were clinically stable.

RESULTS

BNP was significantly associated with both maximum left ventricular (LV) wall thickness (r=0.28; p=0.003), and septal peak early transmitral filling velocity/peak early diastolic mitral annulus velocity (r=0.51; p=0.0001). No statistically significant associations were seen between cTnT and any echocardiographic parameters, but the presence of atrial fibrillation (AF) was associated with a high level of cTnT (p=0.01).

CONCLUSIONS

BNP is useful for monitoring clinical parameters and as a reflection of both LV systolic/diastolic function and increased LV pressure in patients with HOCM. A high level of serum cTnT is associated with the presence of AF.

Plasma B-type natriuretic peptide is a useful tool for assessing coronary heart disease risk in a Japanese general population

B-type natriuretic peptide (BNP) has been reported to be associated with cardiovascular prognosis in a community-based population. In addition, accumulation of individual cardiovascular risk factors is important in predicting an individual's risk of future cardiovascular disease. However, there have been few reports showing that BNP is a comprehensive marker of the accumulation of cardiovascular risk factors. We studied 1530 community-dwelling subjects without obvious heart diseases or renal dysfunction (mean age 62 ± 15 years; 569 men and 961 women) who participated in an annual health checkup in a rural Japanese community. Coronary heart disease (CHD) risk was estimated, and patients were placed into the following three groups based on the Framingham function: low risk, moderate risk and high risk. The prevalence of moderate- and high-risk subjects for CHD rose in both genders with increasing plasma BNP levels. The area under the receiver operating characteristic curve showed a modest ability of plasma BNP levels to detect these subjects (0.755 and 0.700 for men and women, respectively). The optimal thresholds for the identification of subjects with moderate- and high-risk disease were BNP concentrations of 12.0 and 22.0 pg ml(-1), with sensitivities of 70% and 66% and specificities of 71% and 63% for men and women, respectively. In conclusion, subjects with high plasma BNP levels were at higher risk for CHD in a population without obvious heart disease or renal dysfunction.

Magnetically Promoted Rapid Immunoreactions Using Functionalized Fluorescent Magnetic Beads: A Proof of Principle

BACKGROUND

Accurate detection and monitoring of disease-related biomarkers is important in understanding pathophysiology. We devised a rapid immunoreaction system that uses submicrometer polymer-coated fluorescent ferrite (FF) beads containing both ferrites (magnetic iron oxide) and fluorescent europium complexes.

METHODS

FF beads were prepared by encapsulation of hydrophobic europium complexes into the polymer layers of affinity magnetic beads using organic solvent. A sandwich immunoassay using magnetic collection of antibody-coated FF beads to a specific place was performed. Brain natriuretic peptide and prostate-specific antigen were selected as target detection antigens to demonstrate the feasibility of this approach. An immunohistochemical staining using magnetic collection of antibody-coated FF beads onto carcinoma cell samples was also performed.

RESULTS

The sandwich immunoassays, taking advantage of the magnetic collection of antibody-coated FF beads, detected target antigens within 5 min of sample addition. Without magnetic collection, the sandwich immunoassay using antibody-coated FF beads required long times, similar to conventional immunoassays. Using the magnetic collection of antibody-coated FF beads, immunohistochemical staining enabled discrimination of carcinoma cells within 20 min.

CONCLUSIONS

This proof of principle system demonstrates that immunoreactions involving the magnetic collection of antibody-coated FF beads allow acceleration of the antigen–antibody reaction. The simple magnetic collection of antibody-coated FF beads to a specific space enables rapid detection of disease-related biomarkers and identification of carcinoma cells.

Plasma B-type natriuretic peptide as a predictor of cardiovascular events in subjects with atrial fibrillation: a community-based study

Objectives

Atrial fibrillation (AF) is a significant public health issue due to its high prevalence in the general population, and is associated with an increased risk of cardiovascular (CV) events including systemic thrombo-embolism, heart failure, and coronary artery disease. The relationship between plasma B-type natriuretic peptide (BNP) and CV risk in real world AF subjects remains unknown.

Methods

The subject of the study (n = 228; mean age = 69 years) was unselected individuals with AF in a community-based population (n = 15,394; AF prevalence rate = 1.5%). The CV event free rate within each BNP tertile was estimated, and Cox regression analysis was performed to examine the relative risk of the onset of CV events among the tertiles. The prognostic ability of BNP was compared to an established risk score for embolic events (CHADS2 score). In addition, to determine the usefulness of BNP as a predictor in addition to CHADS2 score, we calculated Net Reclassification Improvement (NRI) and Integrated Discrimination Improvement (IDI) indices.

Results

During the follow-up period 58 subjects experienced CV events (52 per 1,000 person-years). The event-free ratio was significantly lower in the highest tertile (p < 0.02). After adjustment for established CV risk factors, the hazard ratio (HR) of the highest tertile was significantly higher than that of the lowest tertile (HR = 2.38; p < 0.02). The predictive abilities of plasma BNP in terms of sensitivity and specificity for general CV events were comparable to those of CHADS2 score. Adding BNP to the CHADS2 score only model improved the NRI (0.319; p < 0.05) and the IDI (0.046; p < 0.05).

Conclusion

Plasma BNP is a valuable biomarker both singly or in combination with an established scoring system for assessing general CV risk including stroke, heart failure and acute coronary syndrome in real-world AF subjects.

Soluble Fms-like tyrosine kinase 1 is a novel predictor of brain natriuretic peptide elevation

Soluble fms-like tyrosine kinase 1 (sFlt-1) is an endogenous inhibitor of vascular endothelial growth factor, which is involved in cardiovascular remodeling and atherosclerosis development. To examine the predictive role of sFlt-1 levels in patients with asymptomatic heart failure, we measured circulating sFlt-1 in patients with or without coronary artery disease (CAD). We analyzed 88 Japanese patients with CAD or patients at high risk for atherosclerosis and who were undergoing total risk management for cardiovascular disease prevention. Circulating sFlt-1 levels correlated with the increase in plasma brain natriuretic peptide levels (ΔBNP) from baseline to the observed levels 5 years later in CAD patients, patients with previous myocardial infarction, and men. ΔBNP levels correlated with sFlt-1 levels in the high-sFlt-1 patients with CAD (r = 0.511, P < 0.01). In all patients, end-systolic volume index (ΔESVI) increased in correlation with a decrease in left ventricular ejection fraction (ΔEF) in the long-term observation, independent of their history of myocardial infarction (ΔESVI = 2.5 mL/m(2) increase/year). Baseline level of sFlt-1 was independent of ΔESVI or ΔEF. The present 5-year observational study demonstrated that high sFlt-1 levels predicted moderate increases in BNP levels in CAD patients. Moreover, ΔBNP was correlated with ΔESVI/year in CAD patients with high-sFlt-1 levels. These data suggest that high sFlt-1 levels may be an effective biomarker to predict the progression of heart failure in patients with CAD.

The global burden of atrial fibrillation and stroke: a systematic review of the epidemiology of atrial fibrillation in regions outside North America and Europe

BACKGROUND

Although atrial fibrillation (AF) is accepted as the most common sustained cardiac arrhythmia, most published epidemiologic studies focus on predominantly white populations in North America or Europe, and information on AF in nonwhite populations is scarce. The objective of this study was to undertake a systematic review of the published literature on the epidemiology of AF in other regions.

METHODS

Systematic literature searches (MEDLINE; 1990-2010) identified epidemiologic studies reporting on the prevalence or incidence of AF, stroke in AF, risk factors for AF, or the use of antithrombotic therapy in countries outside North America and Europe. This report presents a descriptive analysis of the data; no meta-analysis was planned.

RESULTS

Many of the 38 articles identified were from the Far East, although Australia, New Zealand, the Middle East, and South America were also represented. The reported prevalence of AF varied among countries, with different ranges in community- and hospital-based studies (0.1%-4% and 2.8%-14%, respectively). The use of anticoagulant therapy varied widely among countries and studies, as did the reported prevalence of stroke in patients with AF (2.8%-24.2%).

CONCLUSIONS

High-quality epidemiologic studies are clearly required to improve understanding of the worldwide burden of AF and stroke in AF. Major improvements in the provision of thromboprophylaxis are also needed in many countries, given the high proportion of untreated patients who are, hence, at risk of stroke.

Review on natriuretic peptides: where we are, where we are going

BACKGROUND

Tremendous advances have been made in our understanding of the pathophysiology and treatment of congestive heart failure. However, diagnosis of the disease still remains difficult, even with a comprehensive physical examination. Symptoms such as dyspnea are nonspecific and insensitive indicators for heart failure, which can go largely undetected. Several studies have suggested the need for new diagnostic capabilities, especially with the increasing prevalence of heart failure in the US. The discovery of natriuretic peptides as diagnostic biomarkers has been one of the most critical advances for the management of heart failure. Both B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide have the potential to diagnose heart failure, assess prognostic risk of rehospitalization and mortality, and even help guide treatment. Their relative cost-effectiveness and availability have also facilitated their acceptance into many emergency departments, clinics and in-patient units as standard care when evaluating patients with suspected heart failure. Our understanding of the natriuretic peptide system is still in its infancy, but natriuretic peptides have emerged as important diagnostic and prognostic tools that have generated interest in finding broader applications for their use.

OBJECTIVE

The purpose of this review is to discuss the clinical approaches and future applications of natriuretic peptides in diagnosing and managing treatment of congestive heart failure.

METHOD

A comprehensive review of studies to assess the utility of natriuretic peptides for diagnosis and prognosis of heart failure and other conditions.

CONCLUSION

Natriuretic peptides are powerful tools to aid the physician in the diagnosis, prognosis and management of heart failure in both in-patient and out-patient settings. However, natriuretic peptides should be used as an adjunct test as many circumstances can also influence changes in natriuretic peptide levels.

Brain natriuretic peptide is related to carotid plaques and predicts atherosclerosis in pre-dialysis patients with chronic kidney disease

BACKGROUND

Although brain natriuretic peptide (BNP) concentration has been associated with atherosclerosis and ischemic cardiovascular diseases (CVD) in the general population, less is known about this relationship in pre-dialysis chronic kidney disease (CKD) patients.

METHODS

We prospectively analyzed 227 pre-dialysis patients with CKD [median estimated glomerular filtration rate (eGFR): 28.82 (11.65-48.20) ml/min/1.73 m(2)]. At enrollment, BNP concentrations, biochemical and echocardiographic parameters were measured, and carotid artery ultrasound was performed. Patients were prospectively followed for a mean 31.8 months (range 0.5-57.0 months). Ischemic CV events and patient outcomes were recorded.

RESULTS

Median BNP concentration at enrollment was significantly higher in the CKD patients than in a control group [53.9 (16.2-181.0) pg/ml vs. 9.4 (7.0-15.3) pg/ml, P<0.01]. BNP concentration was positively related with the carotid intima-media thickness of the common carotid artery (CCA-IMT) and left ventricular mass index (LVMI) and was significantly higher in patients with than without carotid plaques (P<0.01). Logistic regression analysis confirmed that lgBNP concentration was independently correlated with carotid plaques. Thirty-two patients experienced ischemic cardiovascular (ICV) events during follow-up. Kaplan-Meier analysis showed that cumulative survival without new ICV events was better in patients with lower than with higher BNP concentrations (P<0.01). Cox regression analysis showed that BNP was an independent risk factor for ICV events (HR=3.167, 95%CI=1.398-7.171, P<0.01).

CONCLUSIONS

Similar to findings in the general population, elevated BNP level is related to atherosclerosis and an increased risk of ICV events in pre-dialytic CKD patients.

Hyperinsulinemia correlates with low levels of plasma B-type natriuretic peptide in Japanese men irrespective of fat distribution

BACKGROUND

B-type natriuretic peptide (BNP), a member of the natriuretic peptide family, is a cardiac-derived secretory hormone with natriuretic, diuretic, and vasorelaxant activities. Intraabdominal fat accumulation is associated with atherosclerotic cardiovascular diseases and cardiac dysfunction. Circulating BNP levels are relatively low (within the normal limits) in obesity and the metabolic syndrome. However, the relationship between plasma BNP levels and visceral fat accumulation in general population has not been reported. The present study analyzed the relationships between plasma BNP levels and various clinical variables, including insulin, visceral and subcutaneous fat area (VFA and SFA, respectively), in normal Japanese men.

METHODS

The study (Victor-J study) subjects were consecutive 500 Japanese male workers, who underwent a health checkup and were measured VFA and SFA by computed tomography.

RESULTS

Age-adjusted simple linear regression analysis showed that log-BNP correlated positively with HDL-cholesterol, and negatively with VFA, log-immunoreactive insulin (IRI), log-triglyceride, and LDL-cholesterol, but not body mass index or SFA. Stepwise multiple regression analysis identified log-IRI and HDL-cholesterol as significant determinants of log-BNP. Subjects with IRI ≥5.5 μIU/mL had lower plasma BNP levels than those with IRI < 5.5 μIU/mL, irrespective of obesity (body mass index, cutoff value 25 kg/m2), visceral fat accumulation (VFA, cutoff value 100 cm2) and subcutaneous fat accumulation (SFA, cutoff value 128 cm2).

CONCLUSIONS

Our study showed that hyperinsulinemia correlated with low levels of plasma BNP in general men, irrespective of fat distribution.

TRIAL REGISTRATION

UMIN 000004318.

Heart rate recovery: a practical clinical indicator of abnormal cardiac autonomic function

The autonomic nervous system (ANS) and cardiovascular function are intricately and closely related. One of the most frequently used diagnostic and prognostic tools for evaluating cardiovascular function is the exercise stress test. Exercise is associated with increased sympathetic and decreased parasympathetic activity and the period of recovery after maximum exercise is characterized by a combination of sympathetic withdrawal and parasympathetic reactivation, which are the two main arms of the ANS. Heart rate recovery after graded exercise is one of the commonly used techniques that reflects autonomic activity and predicts cardiovascular events and mortality, not only in cardiovascular system disorders, but also in various systemic disorders. In this article, the definition, applications and protocols of heart rate recovery and its value in various diseases, in addition to exercise physiology, the ANS and their relationship, will be discussed.

Chronic heart failure: we are fighting the battle, but are we winning the war?

Heart failure represents an end-stage phenotype of a number of cardiovascular diseases and is generally associated with a poor prognosis. A number of organized battles fought over the last two to three decades have resulted in considerable advances in treatment including the use of drugs that interfere with neurohormonal activation and device-based therapies such as implantable cardioverter defibrillators and cardiac resynchronization therapy. Despite this, the prevalence of heart failure continues to rise related to both the aging population and better survival in patients with cardiovascular disease. Registries have identified treatment gaps and variation in the application of evidenced-based practice, including the use of echocardiography and prescribing of disease-modifying drugs. Quality initiatives often coupled with multidisciplinary, heart failure disease management promote self-care and minimize variation in the application of evidenced-based practice leading to better long-term clinical outcomes. However, to address the rising prevalence of heart failure and win the war, we must also turn our attention to disease prevention. A combined approach is required that includes public health measures applied at a population level and screening strategies to identify individuals at high risk of developing heart failure in the future.

Sex-specific threshold levels of plasma B-type natriuretic peptide for prediction of cardiovascular event risk in a Japanese population initially free of cardiovascular disease

Elevated plasma B-type natriuretic peptide (BNP) levels have been reported to be related to a high risk for cardiovascular (CV) disease in the general population. However, there has been no accurate determination of the threshold levels of plasma BNP that indicate an increased potential for the development of general CV events (i.e., heart failure, stroke, and myocardial infarction) and the validity of these levels for predicting CV events compared to classic risk markers. To establish gender-specific thresholds of plasma BNP levels associated with increased risk for CV disease in the general population, baseline BNP levels were determined in community-dwelling adults (n = 13,209, mean age 62 ± 10 years,) and CV events in the cohort were captured prospectively. The cohort was divided by deciles of plasma BNP level in each gender. A Cox proportional-hazards model was used to determine the relative hazard ratios among the deciles. In addition, to compare the utility of plasma BNP to the Framingham 10-year risk score for predicting general CV events, receiver-operating characteristic analysis was performed. During follow-up, CV events were identified in 429 patients in the cohort. Compared to the reference decile level (first to fourth), the hazard ratio was significantly increased from the ninth decile in men (greater than approximately 37 pg/ml) and the highest decile in women (greater than approximately 55 pg/ml). The area under the curve generated on receiver-operating characteristic analysis of plasma BNP testing was comparable to that for the Framingham risk scoring system (0.67 vs 0.68 in men, 0.63 vs 0.68 in women; p = NS for both). In conclusion, within a community-based general population with no CV history, plasma BNP levels higher than defined thresholds show increased risk for general CV events, and the predictive ability for CV events occurring within several years may be comparable to that of an established long-standing risk score.

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-B-type Natriuretic Peptide Levels in the Korean General Population

Background and Objectives

B-type natriuretic peptide (BNP) or N-terminal pro-BNP (NT-proBNP) levels may serve as a useful marker of cardiovascular risk for screening of the general population. We evaluated reference levels and distribution of NT-proBNP in the Korean general population based on a large cohort study.

Subjects and Methods

We included 1,518 adult subjects (ages 40-69) of a community-based cohort from the Korea Rural Genomic Cohort (KRGC) Study. Thorough biochemical and clinical data were recorded for all subjects. Levels of NT-proBNP from all participants were determined. In order to determine normal reference levels, subjects with factors known to influence NT-proBNP levels were excluded.

Results

The characteristics of the cohort are described below; subjects were 41.2% male, and the mean age was 54.8±8.4 years. The distribution of risk factors for cardiovascular disease in the cohort included hypertension (25%), left ventricular hypertrophy by electrocardiography (ECG-LVH) (15%), hypercholestolemia (4.5%), smoking (32%), diabetes (10.9%), history of coronary heart disease (4.9%), history of heart failure (0.9%), symptoms of heart failure (6.1%), elevated serum creatinine (≥1.5, 3.7%), and severe obesity (body mass index >30 kg/m², 4.6%). The levels of NT-proBNP of all subjects are shown below; the mean was 60.1±42.1, and the median was 36.5 pg/mL. In addition, the levels of NT-proBNP of normal subjects (which did not have any risk factors, n=224) are shown below; the mean was 40.8, and the median was 32.1 pg/mL. In normal subjects, the NT-proBNP level was slightly higher in females (25.7±24.8 vs. 46.9±35.4, p<0.001). NT-proBNP level increased with age in both the normal population and the total population. There were no significant differences in NT-proBNP levels in subjects who smoked, or had diabetes mellitus, hypertension or ECG-LVH. However, in subjects with a history of congestive heart failure (CHF) (58.5±103.29 vs. 213.8±258.8, p<0.005), elevated serum creatinine levels (≥1.5 mg/dL, 146.2±98.2 vs. 54.3±38.1, p<0.001), or who were older (≥60, 48.4 vs. 84.2±139.5 pg/mL, p<0.05), the BNP level was higher. In addition, patients with more than 3 risk factors for CHF had higher BNP levels (risk 0: 40.8±34.0, 1-2: 57.4±93.2, ≥3: 85.0±152.9 pg/mL). NT-proBNP levels were also related with age, sex, urine albumin, serum Cr, and high sensitivity C-reactive protein (p<0.05).

Conclusion

We determined the reference value and distribution of NT-proBNP in the Korean adult general population. We also found that adjustments for the independent effects of age, sex and renal function appear necessary when determining cardiac risk based on proBNP levels.

Relation of smoking status to serum levels of N-terminal pro-brain natriuretic peptide in middle-aged men without overt cardiovascular disease

Cigarette smoking impairs arterial function and promotes atherosclerosis. However, whether smoking status is associated with cardiac overload has not yet been fully examined, particularly from an epidemiologic viewpoint. The present study examined the relation of smoking status to serum levels of N-terminal pro-brain natriuretic peptide (NT-pro-BNP), a marker of cardiac overload, in middle-aged men without overt cardiovascular disease. Serum NT-pro-BNP levels were measured in a work-site based population of 969 men (mean age 44 ± 6 years) who did not have any history or presence of cardiovascular disease. Smoking status was evaluated by self-reported questionnaire. Four hundred fifty-nine, 222, and 288 subjects were never, former, and current smokers, respectively. NT-pro-BNP levels were significantly higher in current smokers (21.7 ± 2.3 pg/ml) than in never smokers (17.9 ± 2.1 pg/ml, p <0.001). This significant difference was maintained even after adjusting for age, obesity, heart rate, hypertension, dyslipidemia, impaired fasting glucose/diabetes mellitus, left ventricular hypertrophy, estimated glomerular filtration rate, high-sensitivity C-reactive protein, alcohol consumption, and regular exercise. Current smokers had an increased odds ratio (3.04, 95% confidence interval 1.64 to 5.61, p <0.001) for elevated NT-pro-BNP (>54.5 pg/ml) compared to never smokers, even after adjusting for the studied variables. In contrast, former smokers did not show a significantly increased odds ratio for elevated NT-pro-BNP. NT-pro-BNP levels showed a weak, but significant negative correlation with duration of smoking cessation (partial r = -0.15, p = 0.034) in former smokers. In conclusion, these results suggest that cigarette smoking increases cardiac overload, whereas smoking cessation ameliorates these conditions.

N-terminal pro-brain natriuretic peptide and tumor necrosis factor-alpha both are increased in patients with Hepatitis C

Many patients with hepatitis C chronic infection (HCV+ patients) experience symptoms (fatigue, dyspnea) not proportional to the liver involvement and resemble symptoms of heart failure (HF). To our knowledge, no study evaluated at the same time serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) and tumor necrosis factor alpha (TNF-alpha) in HCV+ patients. Circulating NT-proBNP and TNF-alpha were assayed in 60 HCV+ patients, and in 60 sex- and age-matched controls. HCV+ patients showed significantly higher mean NT-proBNP and TNF-alpha levels than controls (P < 0.003). By defining high NT-proBNP level as a value higher than 125 pg/mL (the single cutoff point for outpatients under 75 years of age), 28% of HCV+ and 7% controls had high NT-proBNP (chi-square; P < 0.002). With a cutoff point of 900 pg/mL (that should be used for ruling in HF in patients age 50-75; such as the patients in our study), 3% HCV+ and 0 controls had high NT-proBNP. In conclusion, the study demonstrates high levels of circulating NT-proBNP and TNF-alpha in HCV+ patients. The increase of NT-proBNP may indicate the presence of a subclinical cardiac dysfunction. Further prospective studies quantifying symptoms and correlating these with echocardiographic parameters are needed to confirm this association.

Comparison between immunoradiometric and fluorimetric brain natriuretic peptide determination in patients with congestive heart failure

This study compared two different methods, namely the immunoradiometric (IRMA) and fluorimetric (FIA), in order to determine plasma brain natriuretic peptide (BNP) in congestive heart failure (CHF) patients.

METHODS

CHF in-patients underwent echocardiography and plasma BNP determination using both two methods. The echocardiograms analysed left ventricular end-systolic (LVESV) and end-diastolic (LVEDV) volumes and systolic dysfunction [left ventricular ejection fraction (LVEF) <50%].

RESULTS

Seventy-three (71% males, age 67 ± 9.6 yr) patients were enrolled, 31.5% affected by valvular heart disease. The mean LVEF was 39.8 ± 14.1%; in 26 (35%) a hypertensive etiology emerged. The immunoradiometric assay (IRMA) BNP was found to be significantly lower than the FIA determination 116.5 ± 149 pg/ml vs 267.3 ± 285.6 pg/ml; p=0.0001) and the two methods were closely correlated (r=0.89; p=0.00001). Logistic regression demonstrated a significant correlation between BNP, LVEF, and LVESV/LVEDV (r=-0.45, p=0.0003; r=-0.48, p=0.00001; r=0.22 p=0.003; r=0.34 p=0.0001; r=0.13 p=0.02; r=0.28 p=0.001 IRMA and FIA, respectively). IRMA BNP and FIA BNP significantly increased according to the worsening functional class [from 34.3 ± 60.2 pg/ml in NYHA (New York Heart Association) I to 555.5 ± 273.1 pg/ml in NYHA IV; from 86.1 ± 162.1 pg/ml in NYHA I to 1070 ± 42.2 pg/ml in NYHA IV, respectively]. In severe systolic dysfunction (LVEF<30%), receiver operating characteristic analysis revealed a satisfactorily sensitivity and specificity using a cut-off point of 50.6 pg/ml with IRMA and 243 pg/ml with FIA. In mild systolic dysfunction (LVEF<50%), a good sensitivity and specificity using a cut-off point of 42 pg/ml with IRMA and 182 pg/ml with FIA emerged.

CONCLUSIONS

In CHF patients both BNP methods correlated with NYHA class, LVEF, and ventricular volumes.

Visceral fat is negatively associated with B-type natriuretic peptide levels in patients with advanced type 2 diabetes

AIMS

The association between BMI and low levels of B-type natriuretic peptide (BNP), a marker of heart failure, has been demonstrated in a large population-based cohort. We examined the effects of obesity on BNP levels in patients with diabetes that are often associated with obesity and a higher risk for heart failure.

METHODS

Plasma BNP levels, BMI, and cardiac function parameters were measured in 608 patients with type 2 diabetes. A computed tomography scan was performed to measure abdominal fat.

RESULTS

In multivariable regression analyses adjusted for age, sex, systolic blood pressure, pulse rate, serum creatinine, asynergy, left atrial dimension, percent fractional shortening, and left ventricular mass, there was an inverse relationship between BMI and BNP (p<0.001). Obese individuals with 25</=BMI<30 and 30</=BMI individuals were more likely to have lower BNP levels compared with BMI<22 individuals (multivariable-adjusted odds ratios (95% CIs): 1.61 (1.16-2.26) and 2.07 (1.35-3.22), respectively). Inverse associations were noted between BNP and visceral fat area (VFA) in both sexes (p=0.029 for men, p=0.024 for women).

CONCLUSIONS

In patients with type 2 diabetes, BNP levels are significantly lower in obese subjects after multivariable adjustments. Among various obesity parameters, visceral fat was most closely associated with BNP levels.

The relationship between heart rate recovery and brain natruretic Peptide in patients with chest discomfort: a study for relationship between heart rate recovery and pre-exercise, post-exercise levels of brain natruretic Peptide in patients with normal systolic function and chest discomfort

Background and Objectives

The correlation between brain natruretic peptide (BNP) level and cardiac autonomic function has been studied in type 2 diabetic patients. However, there is limited data from patients with normal systolic function. We evaluated the association between heart rate recovery (HRR) representing autonomic dysfunction and three plasma BNP levels: pre-exercise, post-exercise, and change during exercise in patients with normal systolic function.

Subjects and Methods

Subjects included 105 patients with chest pain and normal systolic function. HRR was defined as the difference between the peak heart rate and the rate measured two minutes after completion of a treadmill exercise test. We measured plasma BNP levels before exercise, 5 minutes after completion of exercise, and during exercise (absolute value of difference between pre- and post-exercise BNP levels).

Results

Patients with abnormal HRR values (≤24 beats for the first 2 minutes of HRR) had lower high-density lipoprotein, lower peak heart rates, and higher pre- and post-exercise BNP levels than patients with normal HRR values. The patients with coronary artery disease (CAD) had abnormal HRR. However, no significant differences were found between the two groups in terms of history of hypertension (HTN), diabetes, and peak systolic blood pressure (SBP) and diastolic blood pressure (DBP). HRR was significantly associated with pre-exercise BNP (r=-0.36, p=0.004) and post-exercise BNP (r=-0.27, p=0.006), but not BNP changes. Further, pre-exercise BNP levels showed a greater association with HRR than post-exercise BNP levels.

Conclusion

HRR is independently associated with pre-exercise and post-exercise BNP levels, even in patients with normal systolic function.

High circulating levels of N-terminal pro-brain natriuretic peptide and interleukin 6 in patients with mixed cryoglobulinemia

Many patients with mixed cryoglobulinemia and chronic HCV infection experience symptoms, such as dyspnea, which sometimes do not seem to indicate the involvement of the liver but rather the symptoms of heart failure. To our knowledge, there has been no other study evaluating the serum levels of N-terminal pro-brain natriuretic peptide (NTproBNP) and Interleukin 6 (IL-6) in such patients. Serum NTproBNP and IL-6 were assayed in 54 patients with mixed cryoglobulinemia and chronic HCV infection, and in 54 sex- and age-matched controls. Cryoglobulinemic-patients showed significantly higher mean NTproBNP and IL-6 levels than the controls (P = 0.005). By defining a high NTproBNP level as a value higher than 125 pg/ml (the single cut-off point for patients under 75 years of age), 30% of patients with mixed cryoglobulinemia and chronic HCV infection and 7% of controls had high NTproBNP (chi-square; P < 0.003). With a cut-off point of 300 pg/ml (used to rule out heart failure in patients under 75 years of age), 5/49 patients with mixed cryoglobulinemia and chronic HCV infection and 0/54 controls had high NTproBNP (chi-square; P < 0.04). With a cut-off point of 900 pg/ml (used for including heart failure in patients aged between 50 and 75, such as the patients in this study) 3/51 of patients with mixed cryoglobulinemia and chronic HCV infection and 0/54 controls had high NTproBNP (chi-square; P = 0.07). The study revealed high levels of circulating NTproBNP and IL-6 in patients with mixed cryoglobulinemia and chronic HCV infection. The increase in NTproBNP could indicate the presence of a subclinical cardiac dysfunction.

Natriuretic Peptides and Assessment of Cardiovascular Disease Risk in Asymptomatic Persons

Current tools for cardiovascular disease (CVD) risk assessment in asymptomatic individuals are imperfect. Preventive measures aimed only at individuals deemed high risk by current algorithms neglect large numbers of low-risk and intermediate-risk individuals who are destined to develop CVD and who would benefit from early and aggressive treatment. Natriuretic peptides have the potential both to identify individuals at risk for future cardiovascular events and to help detect subclinical CVD. Choosing the appropriate subpopulation to target for natriuretic peptide testing will help maximize the performance and the cost effectiveness. The combined use of multiple risk markers, including biomarkers, genetic testing, and imaging or other noninvasive measures of risk, offers promise for further refining risk assessment algorithms. Recent studies have highlighted the utility of natriuretic peptides for preoperative risk stratification; however, cost effectiveness and outcomes studies are needed to affirm this and other uses of natriuretic peptides for cardiovascular risk assessment in asymptomatic individuals.

Plasma B-type natriuretic peptide level and cardiovascular events in chronic kidney disease in a community-based population

BACKGROUND

Plasma B-type natriuretic peptide (BNP) levels are confounded by renal dysfunction, so this study examined whether plasma BNP might be a reliable biomarker of the onset of cardiovascular (CV) events in a population-based cohort with impaired renal function.

METHODS AND RESULTS

Baseline data, including plasma BNP, serum creatinine, and urinary protein levels, were determined in participants from a community-based population. Estimated glomerular filtration rate (eGFR) was calculated, and chronic kidney disease (CKD) was defined as either: eGFR <60 mlxmin(-1)x1.73 m(-2) and/or proteinuria (CKD definition-1) or GFR <60 mlxmin(-1)x1.73 m(-2) (CKD definition-2). The CV endpoint was surveyed prospectively. The cohorts were followed for 5,275 person-years for CKD definition-1, and for 4,350 person-years for CKD definition-2. The CV event-free survival rate in the highest BNP quartile in either CKD definition was the lowest among the quartile groups (P<0.001). In multivariate Cox regression models adjusted by traditional CV risk factors and atrial fibrillation, relative risk (RR) for CV events was significantly higher in the highest BNP quartile compared with the lowest BNP quartile (CKD definition-1, RR 3.51, P<0.01: CKD definition-2, RR 4.67, both P<0.01).

CONCLUSIONS

Plasma BNP level provides strong predictive information about the future onset of CV events in CKD subjects selected from the general population.

Association of plasma B-type natriuretic peptide levels with obesity in a general urban Japanese population: the Suita Study

The inverse association between plasma B-type natriuretic peptide (BNP) levels and body mass index (BMI) has been reported in Western populations. Here we analyzed the relationship between plasma BNP and obesity in a general urban Japanese population. We recruited 1,759 subjects without atrial fibrillation or history of ischemic heart disease aged 38-95 years (mean age +/- standard deviation 64.5 +/- 10.9 years, 56.1% women, mean BMI 22.8 +/- 3.1 kg/m(2)) from the participants in the Suita Study between August 2002 and December 2003. In multivariable regression analyses adjusted for age, systolic blood pressure, pulse rate, serum creatinine, left ventricular hypertrophy in ECG, the inverse relationships between BNP levels and BMI (kg/m(2)) was found in both sexes (both p<0.001). Multivariable-adjusted mean plasma BNP levels in the group of BMI<18.5, 18.5< or =BMI< 22, 22< or =BMI<25, and 25< or =BMI were 23.4, 17.9, 14.0 and 13.0 pg/mL, respectively (trend p<0.001). The negative association of body fat (percentage and mass), skin fold thickness, or waist circumference with BNP levels was observed the negative associations in both sexes (p<0.01). Among the obesity indices, body fat mass is most tightly associated with BNP. In conclusion, plasma BNP was inversely associated with obesity related markers such as body fat mass, skinfold thickness and waist circumferences after adjusted for relevant covariates in a Japanese population.

B-type natriuretic peptide is predictive of hospitalization in community-dwelling elderly without heart diseases

AIM

To examine prospectively the relationship between plasma B-type natriuretic peptide (BNP) levels in community-dwelling elderly and their hospitalization.

METHODS

A total number of 644 subjects aged 65 years or older were recruited from the annual community health examinations. Those with a history of stroke or neurological findings were not included. After excluding those with old myocardial infarction, left ventricular dysfunction, moderate or severe valvular disorders, atrial fibrillation, renal insufficiency, and history of hospitalization within 1 year, 602 participants (226 men, 376 women; mean age, 80.3 +/- 6.2 years) remained eligible for this study. Antihypertensive medications, activities of daily living (ADL) score and history of hospitalization were assessed by annual interview. Measurement of casual blood pressure, Mini-Mental State Examination, electrocardiography and echocardiography were performed. Plasma BNP, serum creatinine, total cholesterol, albumin and hemoglobin A1c levels were also examined. A follow-up survey was performed for the occurrence and reasons for hospitalization.

RESULTS

During a median follow up of 37 months, 112 subjects were hospitalized. After adjustment for conventional risk factors of hospitalization using the Cox proportional hazard model, each increment of 1 standard deviation in log BNP levels was associated with a 36% increase in the risk of hospitalization (P = 0.02). Plasma BNP levels were significantly higher in the hospitalized subjects due to stroke, heart diseases, dementia, pneumonia and also difficulty to live alone than those of the subjects without hospitalization.

CONCLUSION

Plasma BNP level is a very useful biochemical marker predictive of future hospitalization in community-dwelling independent elderly people without apparent heart diseases.

High circulating N-terminal pro-brain natriuretic peptide and tumor necrosis factor-α in mixed cryoglobulinemia

AIM: To evaluate serum levels of N-terminal pro-brain natriuretic peptide (NTproBNP) and tumor necrosis factor α (TNF-α) in a large series of patients with hepatitis C associated with mixed cryoglobulinemia (MC+HCV).

METHODS: Serum NTproBNP and TNF-α levels were assayed in 50 patients with MC+HCV, and in 50 sex- and age-matched controls.

RESULTS: Cryoglobulinemic patients showed significantly higher mean NTproBNP and TNF-α levels than controls (P < 0.001; Mann-Whitney U test). By defining high NTproBNP level as a value higher than 125 pg/mL (the single cut-off point for outpatients under 75 years of age), 30% of MC+HCV and 6% of controls had high NTproBNP (χ², P < 0.01). With a cut-off point of 300 pg/mL (used to rule out heart failure (HF) in patients under 75 years of age), 8% of MC+HCV and 0 controls had high NTproBNP (χ², P < 0.04). With a cut-off point of 900 pg/mL (used for ruling in HF in patients aged 50-75 years; such as the patients of our study), 6% of MC+HCV and 0 controls had high NTproBNP (χ², P = 0.08).

CONCLUSION: The study demonstrates high levels of circulating NTproBNP and TNF-α in MC+HCV patients. The increase of NTproBNP may indicate the presence of a subclinical cardiac dysfunction.

B type natriuretic peptide--a diagnostic breakthrough in peri-operative cardiac risk assessment?

The B-type natriuretic peptides; B-type natriuretic peptide and N-terminal pro-B-type natriuretic peptide, are increasing being used as biomarkers for the diagnosis, management and prognostication of cardiac failure, but their application in the peri-operative period is unclear. This review examines the current understanding of the role of B-type natriuretic peptides in both the operative and non-operative settings. Normal values, diagnostic thresholds, monitoring targets and significant prognostic levels are identified. Using this as a background, the role of B-type natriuretic peptides in the prediction of peri-operative mortality and morbidity is examined and potential confounders, such as renal failure and body mass index, which may impact significantly on the utility of the biomarkers, are discussed. Clinical recommendations with regard to its use are made and a research agenda is proposed for future peri-operative studies.