The influence of age, sex and other variables on the plasma level of N-terminal pro brain natriuretic peptide in a large sample of the general population

N-terminal proBNP: a novel biomarker for the diagnosis, risk stratification and management of congestive heart failure

Congestive heart failure is a leading cause of morbidity and mortality throughout the world and is now the leading cause of hospitalizations in adults over 65 years of age with an estimated annual expenditure in excess of USD 20 billion. In addition, it is the only cardiovascular disorder that continues to increase in both incidence and prevalence, and as the population continues to age, it is expected that the prevalence of this disease will continue to rise. Ironically, the armamentarium of medications that decrease mortality due to congestive heart failure also continues to grow; however, the relative number of eligible patients with congestive heart failure (or at risk for congestive heart failure) that receive these important therapies remains low. Thus, better tools to aid the early diagnosis and management of this disease are needed. Testing for natriuretic peptide markers, such as B-type natriuretic peptide or its amino-terminal fragment, has emerged as an important tool to assist in the optimal diagnosis and risk stratification of patients with congestive heart failure and may also play a valuable role in guiding therapy.

Amino-terminal pro-brain natriuretic peptide: a biomarker for diagnosis, prognosis and management of heart failure

There is a substantial need for a diagnostic tool to aid in the early diagnosis of heart failure and in the recognition of those at risk for its development, as well as in guidance of therapy. Testing for amino-terminal pro-brain natriuretic peptide (NT-proBNP) has been recognized to have utility in the diagnosis, prognosis and management of heart failure. In addition, numerous other applications for NT-proBNP testing are now recognized, such as evaluation of patients with heart disease in the absence of heart failure, as well as the diagnostic and prognostic evaluation of patients with acute coronary syndromes or pulmonary thromboembolism.

Management of chronic heart failure: biomarkers, monitors, and disease management programs

BACKGROUND

The management of patients with heart failure has been evolving given the complex nature of the disease and the increasing number of patients.

FINDINGS

Biomarkers, and in particular the natriuretic peptides, have been studied to assist with diagnosis, chronic management, and prognosis in patients with heart failure. Several new biomarkers are emerging and may be used individually or in combination with the natriuretic peptides. The use of cardiac monitoring devices and disease management programs is being established to assist in the care of patients with chronic heart failure. Interventions using phone calls, telemedicine devices, intracardiac pressure monitors, and implantable cardioverter defibrillators have been investigated.

CONCLUSIONS

The combination of biomarkers, monitoring devices, and disease management programs shows promise for improving care in this challenging patient population.

Prevalence and treatment of heart failure in Swedish nursing homes

Background

Since the burden of care for elderly patients with heart failure (HF) can be decreased by therapeutic measures, it is important that such patients are identified correctly. This study explores the prevalence of HF in nursing homes in Sweden, with special consideration of the risk of failure to diagnose HF in the study population. A second aim is to explore medication and the adherence to guidelines for the treatment of HF.

Methods

429 patients from 11 nursing homes were included during 2008–2011. Information about diagnoses and medications from patient records, blood samples, questionnaire responses and blood pressure measurements were collected. The baseline characteristics of the patients, their medications and one-year mortality were identified and then compared regarding HF diagnosis and B-type natriuretic peptide (BNP) levels. A BNP level of >100 ng/L was used to identify potential cases of HF.

Results

The point prevalence of HF diagnosis in the medical records in the study population was 15.4%. With the recommended cut-off value for BNP, up to 196 subjects in the study population (45.7%) qualified for further screening of potential HF.

The subjects in the HF and non-HF groups were similar with the exception of mean age, BNP levels and Mini Mental State Examination results which were higher in the HF group, and the eGFR and blood pressure, which were lower when HF. The subjects with higher BNP values were older and had lower eGFR, Hb, diastolic blood pressure and BMI. The subjects with HF diagnoses were in many cases not treated according to the guidelines. Loop diuretics were often used without concomitant ACE inhibitors or angiotensin receptor blockers. The subjects without HF diagnoses in the medical records at inclusion but with BNP values >100 ng/L had less appropriate HF medication. The one-year mortality was 52.9% in the population with HF.

Conclusions

Our study suggests that the estimated prevalence of HF in nursing homes in Sweden would increase if BNP measurements were used to select patients for further examinations. The pharmacological treatment of HF varied substantially, as did adherence to guidelines.

A comparison of risk factors as predictors of cardiovascular and non-cardiovascular mortality in the elderly people--relevance of N-terminal pro-B-type natriuretic peptide and low systolic blood pressure

BACKGROUND

Many risk factors are known to predict ischaemic events and mortality in the elderly people, but their ranking of importance remains uncertain. This study was designed to identify and compare the main predictors of total mortality (TM), cardiovascular mortality (CVM) and non-cardiovascular mortality (NCVM) in older adults.

METHODS

Nine hundred and seventy-nine community resident adults aged ≥ 65 years, free of previous heart failure and cardiovascular events, participated in the study. The univariate and multivariate (Cox regression) relationships of baseline cardiovascular risk factors, treatments and laboratory data with TM, CVM and NCVM were assessed after a median follow up of 6.7 years.

RESULTS

Overall, there were 104 deaths (30 because of CVM and 74 to NCVM). In multivariate analysis, the following factors remained independently associated with mortality: NT pro-B-type natriuretic peptide (NT-proBNP) upper quintile (≥ 237 pg/ml for men, ≥ 280 pg/ml for women): hazard ratio (HR) vs. the rest of the population (95% confidence interval) 2.34 (1.52-3.60), p < 0.001 for TM; HR 5.41 (2.32-12.65), p < 0.001 for CVM; systolic blood pressure lower quintile (≤ 130 mmHg): HR 3.06 (1.80-5.21), p < 0.001 for NCVM; diabetes: HR 2.46 (1.29-4.72), p = 0.007 for NCVM; erythrocyte sedimentation rate (ESR) upper decile (≥ 41 mm/h): HR 2.33 (1.16-4.69), p = 0.02 for NCVM; platelet count lower quintile (≤ 177 × 10(9) /l): HR 2.09 (1.20-3.64), p = 0.009 for NCVM; ever-smoker status: HR 2.08 (1.23-3.52), p = 0.007 for NCVM.

CONCLUSIONS

In elderly community dwellers, NT-proBNP was the strongest predictor of TM and CVM, while especially low systolic blood pressure, together with diabetes, ESR, reduced platelet count and ever-smoker status, were the main predictors of NCVM.

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

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

B-type natriuretic peptide: distribution in the general population and the association with major cardiovascular and coronary events--the Heinz Nixdorf Recall Study

BACKGROUND

A B-type natriuretic peptide (BNP) threshold of 100 pg/ml is used in practice for identification of heart failure, but data about the "normal" distribution of BNP in a large population in primary prevention are rare. We aimed to characterize the BNP distribution in a healthy subset of a population-based cohort and to evaluate the association of elevated BNP levels with major events.

METHODS

In a first step, we determined gender-specific distribution and 90th percentiles of BNP in participants who were at baseline free from known determinants of increased BNP, i.e. cardiovascular disease, hypertension or chronic kidney disease. Consecutively, the association of BNP levels above these 90th percentiles with subsequent cardiovascular and coronary events was assessed in the entire cohort.

RESULTS

In the BNP-normal sub-sample (n = 1,639), we defined gender-specific 90th percentile of BNP (31.3 pg/ml for men, 45.5 pg/ml for women). From overall 3,697 subjects (mean age 59.4, 52.4 % female), 194 subjects developed a major cardiovascular event and 122 myocardial infarction during a mean follow-up period of 8.0 ± 1.5 years. The 90th percentiles derived from the normal subset as threshold showed strong associations with major events in the entire cohort even after adjusting for traditional risk factors: hazard ratio (95% CI): 1.86 (1.37; 2.53), p < 0.0001 for cardiovascular, and 1.77 (1.19; 2.62), p = 0.005 for coronary events.

CONCLUSION

The gender-specific 90th percentile of BNP (31 pg/ml for males and 45 pg/ml for females) obtained from a BNP-normal sub-sample is associated with incident major cardiovascular and coronary events, suggesting that even BNP values lower than 100 pg/ml could imply prognostic information in the general population.

Hemoglobin and B-type natriuretic peptide preoperative values but not inflammatory markers, are associated with postoperative morbidity in cardiac surgery: a prospective cohort analytic study

Introduction

Risk stratification in cardiac surgery significantly impacts outcome. This study seeks to define whether there is an independent association between the preoperative serum level of hemoglobin (Hb), leukocyte count (LEUCO), high sensitivity C-reactive protein (hsCRP), or B-type natriuretic peptide (BNP) and postoperative morbidity and mortality in cardiac surgery.

Methods

Prospective, analytic cohort study, with 554 adult patients undergoing cardiac surgery in a tertiary cardiovascular hospital and followed up for 12 months. The cohort was distributed according to preoperative values of Hb, LEUCO, hsCRP, and BNP in independent quintiles for each of these variables.

Results

After adjustment for all covariates, a significant association was found between elevated preoperative BNP and the occurrence of low postoperative cardiac output (OR 3.46, 95% CI 1.53–7.80, p = 0.003) or postoperative atrial fibrillation (OR 3.8, 95% CI 1.45–10.38). For the combined outcome (death/acute coronary syndrome/rehospitalization within 12 months), we observed an OR of 1.93 (95% CI 1.00–3.74). An interaction was found between BNP level and the presence or absence of diabetes mellitus. The OR for non-diabetics was 1.26 (95% CI 0.61–2.60) and for diabetics was 18.82 (95% CI 16.2–20.5). Preoperative Hb was also significantly and independently associated with the occurrence of postoperative low cardiac output (OR 0.33, 95% CI 0.13–0.81, p = 0.016). Both Hb and BNP were significantly associated with the lengths of intensive care unit and hospital stays and the number of transfused red blood cells (p < 0.002). Inflammatory markers, although associated with adverse outcomes, lost statistical significance when adjusted for covariates.

Conclusions

High preoperative BNP or low Hb shows an association of independent risk with postoperative outcomes, and their measurement could help to stratify surgical risk. The ability to predict the onset of atrial fibrillation or postoperative low cardiac output has important clinical implications. Our results open the possibility of designing studies that incorporate BNP measurement as a routine part of preoperative evaluation, and this strategy could improve upon the standard evaluation in terms of reducing adverse postoperative events.

What Is the Meaning of Increased Myocardial Injury Enzymes during Hemodialysis? A Tissue Doppler Imaging Study

BACKGROUND

Cardiovascular death is decreasing in the general population; however, it appears in still higher rates and even increases gradually in hemodialysis (HD) patients. This situation has led to a debate about cardiovascular adverse effects of HD which lead to significant changes in cardiac and hemodynamic events. It is known that troponins are often elevated in HD patients, and high levels of troponin are associated with increased mortality. Therefore, it is difficult to interpret the value of elevations in chronic kidney disease patients.

METHODS

Echocardiographic and biochemical parameters of 41 patients treated with HD were evaluated before and after a HD session.

RESULTS

HD led to an increased heart rate, and tissue Doppler imaging parameters such as early diastolic mitral peak velocity (E)/early diastolic myocardial peak velocity (é) and septal é decreased significantly after HD. HD caused an increase in troponin I, myoglobin and cardiac creatine kinase (CK MB) levels (p = 0.019, p < 0.001 and p = 0.018, respectively). A decrease in the left ventricular peak systolic myocardial (LV S') velocity (p = 0.011) was detected in patients with increased levels of cardiac damage markers (group 2) compared to those without increased levels of cardiac damage markers (group 1) in HD.

CONCLUSION

A decrease in LV S' velocity was found to be an independent predictor of an increase of myocardial injury enzymes in HD (odds ratio = 1.099; p = 0.039). We concluded that HD may lead to significant acute stress upon the myocardium.

Plasma B-type natriuretic peptide in predicting outcomes of elective coronary artery bypass surgery

The risks of surgery and its clinical outcome are of great importance for both patients and physicians when choosing coronary artery bypass (CABG) surgery for coronary artery disease. The purpose of the current study was to clarify the relationship between serum B-type natriuretic peptide (BNP) and patient clinical outcome. Seventy-six eligible patients who underwent CABG were enrolled into the prospective study. Venous blood samples were drawn for serum BNP and N-terminal (NT)-proBNP levels measurement on preoperative Day 1, postoperative Day 1, and postoperative Day 7. Clinical end points were: (1) intensive care unit (ICU) stay longer than 4 days postoperatively and/or hospital stay longer than 13 days postoperatively; (2) major complications and poor outcomes. Patients who had prolonged ICU stay and hospitalization had significantly higher postoperative Day 1 BNP and postoperative Day 1 NT-proBNP level (p = 0.02 and 0.005, respectively). Age was significantly older in patients with prolonged ICU stay and hospitalization than those without prolonged ICU stay and hospitalization (p = 0.03). Serum creatinine level was also significantly increased in patients with prolonged ICU stay and hospitalization (p = 0.009). However, age was the only remaining factor that correlated with prolonged ICU stay and hospitalization in the multivariate logistic regression model. These results suggest that research using BNP and NT-proBNP for predicting ICU stay and hospitalization in patients who have undergone CABG must adjust risk factors to present a more appropriate estimation of its clinical outcome.

Natriuretic peptide-guided therapy: further research required for still-unresolved issues

It has been asserted that serial measurements of natriuretic peptides (NPs), i.e., B-type natriuretic peptide (BNP) or the amino-terminal fragment of pro-B-type natriuretic peptide (NT-pro BNP), could help modulate more accurately the intensity of drug treatment in patients with chronic heart failure (CHF). Nevertheless, there are still several open questions about the presumed role of NP-guided pharmacologic adjustment as a valuable strategy in this setting. In this review, we outline the main randomized controlled trials (RCTs) carried out to date regarding NP-guided therapy in CHF patients and we focus on some of the still-unresolved issues. In particular, we discuss which NP plasma level should be assumed as the optimal target level to be attained, and we debate the possible influence exerted by different age classes on clinical end points during NP-guided therapy. The possible advantages and limitations for the cardiovascular system arising from the functional activation of NPs in CHF patients are also discussed. Although the pooling of data derived from the RCTs demonstrates an overall effect of slightly significant improvement in clinical outcomes with the NP-guided approach, we have noted that there are some relatively large studies that failed to document a significant clinical improvement in terms of mortality and morbidity using an NP-guided strategy. Thus, in our opinion, larger and better conducted trials addressing the unresolved issues of NP-guided therapy should be undertaken in the future.

Clinical utility of natriuretic peptides in left ventricular failure

Left ventricular failure (LVF) is a clinical syndrome caused by abnormal systolic or diastolic function failing to meet the metabolic requirements of the body. It is important to diagnose and manage LVF in the earliest stages to prevent mortality and morbidity. This article extensively reviews the diagnostic, therapeutic, and prognostic utility of natriuretic peptides in LVF.

Relationship between glomerular filtration rate and plasma N-terminal pro B-type natriuretic peptide concentrations in dogs with chronic kidney disease

Plasma N-terminal pro B-type natriuretic peptide (NT-proBNP) concentrations increase in dogs with azotemia. However, the correlation between glomerular filtration rate (GFR) and NT-proBNP concentrations in dogs has not been evaluated. The objective of this study was to evaluate the correlation between GFR and plasma NT-proBNP concentrations in dogs with chronic kidney disease (CKD). In this retrospective cross-sectional study, plasma creatinine (Cre) and NT-proBNP concentrations, plasma iohexol clearance (PCio) values and blood pressure were measured in dogs with CKD. Dogs were classified according to PCio values into D group (dogs with decreased PCio values), and N group (dogs with normal PCio values). Dogs were further categorized on the basis of their systolic blood pressure and PCio values into NT-D group (normotensive dogs with decreased PCio values), NT-N group (normotensive dogs with normal PCio values), HT-D group (hypertensive dogs with decreased PCio values) and HT-N group (hypertensive dogs with normal PCio values). Significant correlations were observed between plasma NT-proBNP and Cre concentrations (r=0.360, P<0.05) and PCio values (r=-0.470, P<0.01). Plasma NT-proBNP concentrations were significantly higher in the D group than in the N group (P<0.001). Plasma NT-proBNP concentrations were significantly higher in the HT-D group than in the other three groups (P ≤ 0.007). No differences in plasma NT-proBNP concentrations were observed between the NT-D and HT-N groups (P=0.28). Plasma NT-proBNP concentrations were significantly lower in the NT-N group than in the other three groups (P ≤ 0.043). Our findings suggest that decreased GFR might be associated with increased plasma NT-proBNP concentrations in dogs, similar to that in humans. In addition, the complication of hypertension in CKD might be associated with further increases in plasma NT-proBNP concentrations. In conclusion, the effects of GFR and blood pressure on the plasma NT-proBNP concentration were small, but it could be necessary to consider the effects when this marker is used to evaluate canine cardiac disease.

Association of serum carotenoid levels with N-terminal pro-brain-type natriuretic peptide: a cross-sectional study in Japan

BACKGROUND

Several epidemiologic studies have reported an inverse association between serum levels of carotenoids and cardiovascular disease risk. However, no studies have reported an association between serum carotenoids and N-terminal pro-brain-type natriuretic peptide (NT-proBNP) in the general population.

METHODS

In this cross-sectional study, we investigated whether serum carotenoids were associated with serum NT-proBNP in 1056 Japanese subjects (390 men, 666 women) who attended a health examination. Serum levels of carotenoids were separately determined by high-performance liquid chromatography. Serum NT-proBNP level was measured by electrochemiluminescence immunoassay.

RESULTS

Serum NT-proBNP was elevated (≥55 pg/ml) in 31.8% of men and 48.2% of women. Multivariate logistic regression analyses adjusted for confounding factors showed a significant association between the highest quartile of serum α-carotene and elevated NT-proBNP in men (odds ratio [OR] = 0.40, 95% CI = 0.19-0.82, P for trend = 0.005) and women (OR = 0.62, 95% CI = 0.39-0.99, P for trend = 0.047). In women, moreover, elevated serum NT-proBNP was significantly associated with serum canthaxanthin (OR = 0.57, 95% CI = 0.36-0.90 for highest quartile, P for trend = 0.026) and β-cryptoxanthin (OR = 0.53, 95% CI = 0.32-0.85 for highest quartile, P for trend = 0.026), after adjusting for potential confounders.

CONCLUSIONS

Higher levels of serum carotenoids were associated with lower risk of elevated serum NT-proBNP levels after adjusting for possible confounders, which suggests that a diet rich in carotenoids could help prevent cardiac overload in the Japanese population.

Perioperative application of N-terminal pro-brain natriuretic peptide in patients undergoing cardiac surgery

Background

The purpose of the research was to find out the factors which influence plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, then to assess whether preoperative plasma NT-proBNP levels could predict postoperative outcomes of cardiac surgery.

Methods

Between November 2008 and February 2010,225 patients who underwent cardiac surgery in our department were included in the study. The mean age was 61.25 ± 12.54 years, and 156 (69.3%) patients were male. NT-proBNP, CK-MB, cTnT and creatinine levels were measured preoperatively and 24 hours after operation. Postoperatively outcomes including ventilation time, length of stay in ICU and hospital, and mortality were closely monitored. The endpoints includes: 1) use of inotropic agents or intra-aortic balloon pump ≥24 h; 2) creatinine level elevated to hemodialysis; 3) cardiac events; 4) ICU stay ≥5d; 5) ventilation dependence ≥ 72 h; 6) deaths within 30 days of surgery.

Results

NT-proBNP concentrations (median [interquartile range]) increased from 728.4 pg/ml (IQR 213.5 to 2551 pg/ml) preoperatively to 1940.5 pg/ml (IQR 995.9 to 3892 pg/ml) postoperatively (P = 0.015). Preoperative atrial fibrillation, NYHA class III/IV, ejection fraction, pulmonary arterial pressure, left ventricle end-diastolic diameter (LVEDD), preoperative plasma creatinine and cTnT levels were significantly associated with preoperative NT-proBNP levels in univariate analysis. The preoperative NT-proBNP was closely related to ventilation time (P = 0.009), length of stay in ICU (P = 0.004) and length of stay in hospital (P = 0.019). Receiver operating characteristic curves demonstrated a cut-off value above 2773.5 pg/ml was the best cutoff (sensitivity of 63.6% and specificity of 80.8%) to predict the mortality within 30d of surgery.

Conclusions

Preoperative plasma NT-proBNP level presents a high individual variability in patients undergoing cardiac surgery. NYHA classification, ejection fraction, pulmonary arterial pressure, LVEDD, atrial fibrillation, preoperative plasma creatinine, and cTnT levels are significantly associated with preoperative NT-proBNP levels. Preoperative NT-proBNP is a valuable marker in predicting postoperative outcomes.

What is causing extremely elevated amino terminal brain natriuretic peptide in cancer patients?

High levels of B-type natriuretic peptide in cancer patients are poorly studied. Previously published data suggest that they are not related to fluid overload and are encountered mostly in solid cancers. The authors investigated the distribution of amino terminal pro-brain natriuretic peptide (NT-proBNP) between hematologic and solid organ malignancies and the relationship of NT-proBNP with volume status in oncologic patients. A total of 145 consecutive patients with at least one occurrence of NT-proBNP exceeding the upper normal range 10-fold were identified. The authors retrospectively reviewed their records including clinical, laboratory, and radiological data and echocardiograms. More than 70% of patients had hematologic malignancies. Patients with NT-proBNP >50,000 pg/mL had only hematologic malignancies, primarily multiple myeloma. There was no association between M-spike proteins and NT-proBNP. About 80% of patients had signs of fluid overload. The magnitude of NT-proBNP elevation was similar between those with and without heart failure or volume overload, as well as with solid cancers vs hematologic malignancies. Contrary to prior reports, it was found that very high NT-proBNP in cancer patients is usually encountered in the context of fluid overload and most often in hematologic malignancies.

The biological variation of N-terminal pro-brain natriuretic peptide in postmenopausal women with type 2 diabetes: a case control study

BACKGROUND

The incidence of heart failure in type 2 diabetes is high and it has poorer prognosis when compared with patients without diabetes. Access to echocardiography is limited and alternative methods to identify early heart failure such as the measurement of natriuretic peptides levels have been proposed. However, their wide biological variation could limit their clinical utility. Our aim was to determine if the intrinsic biological variation of one of these peptides, N-terminal proBNP, is as wide in type 2 diabetes as it is in health and to calculate the critical difference values that could be utilised in clinical practice to ensure changes observed between two samples are due to intervention rather than to its biological variability.

METHODOLOGY/PRINCIPAL FINDINGS

12 postmenopausal women with diet controlled type 2 diabetes and without heart failure were compared with 11 control postmenopausal women without diabetes. N-terminal proBNP levels were measured on 10 occasions. The biological variation was calculated according to Fraser's methods. The mean NT-proBNP level was similar in both groups (mean ± standard deviation; type 2 diabetes, 10.7 pmol/L± 8.5 versus 8.49±6.0 pmol/L, p = 0.42). The biological variation was also similarly wide. The critical difference in patients with type 2 diabetes was between -70% and ±236%.

CONCLUSIONS

Type 2 diabetes does not appear to significantly influence the marked biological variation of N-terminal proBNP in postmenopausal women. The critical difference values reported in this study could be used to titrate therapy or monitor response to interventions although the change required in between samples is wide and this might limit its utility.

The impact of confounders on the test performance of natriuretic peptides for cardiac dysfunction in subjects aged 80 and older

The hypothesis that natriuretic peptides could be used to identify 'pancardiac' damage has been proposed. However, multiple factors are known to influence circulating levels of natriuretic peptides, especially in the very old. Therefore, the impact of confounders on the association between natriuretic peptide levels and cardiac dysfunction was further explored in subjects aged 80 and older. A diagnostic cross-sectional study embedded within the BELFRAIL study (n=567) was performed. Baseline BNP and NT-proBNP levels were measured and echocardiograms were performed at the subject's home. Cardiac dysfunction was defined as systolic dysfunction, valvular heart disease or isolated severe diastolic dysfunction. Several functional and structural echocardiographic parameters were independently related to circulating levels of natriuretic peptides. Cystatin C, BMI, β blockers, diabetes, heart frequency, usCRP, age and sex were identified as confounders. The prevalence of cardiac dysfunction was 17.1% in the subjects without and 30.8% in the subjects with chronic atrial fibrillation (CAF) or pacemaker (PM). Only in subjects with CAF or PM the C statistic for cardiac dysfunction improved after correcting for confounders. The post-test probability for a negative test (PTP-) ranged from 3.7% to 12.2% and the PTP+ ranged from 21.9% to 62.2% in different strata of confounders. According to these data adjusting for identified confounders does not improve the diagnostic accuracy of the natriuretic peptides for cardiac dysfunction, except in subjects with CAF or PM. Stratifying for individual confounders showed that different cut-off values could be used to optimize the diagnostic characteristics of natriuretic peptides.

Role of NT-proBNP in detection of myocardial damage in childhood leukemia survivors treated with and without anthracyclines

Background

Exposure to anthracyclines (ANT) during childhood represents a high risk for development of late cardiotoxicity. Cardiotoxicity is usually detected only when clinical symptoms or progressive cardiac dysfunction have already occurred. Early detection of cardiotoxicity may lead to better therapeutic outcome. N-terminal pro-brain natriuretic peptide (NTproBNP) has been hypothesized to reflect increased left ventricular wall stress before development of echocardiographic abnormalities. The aim of this study was to detect cardiac abnormalities using plasma NTproBNP and echocardiography in asymptomatic childhood leukemia survivors treated with or without cardiotoxic anthracycline therapy.

Methods

Serum levels of NTproBNP were determined in 69 asymptomatic survivors of childhood leukemia treated with or without anthracyclines and in 44 apparently healthy controls. The survivors were divided into two treatment groups: 36 patients after chemotherapy containing anthracyclines (ANT) and 33 patients after chemotherapy without anthracyclines (nonANT). Levels of NTproBNP were measured by using the Elecsys 2010 immunoassay analyzer (Roche Diagnostics). Echocardiography using M-mode, two-dimensional and Doppler measurements were performed on the same day as blood samples were obtained for NTproBNP analysis in survivors.

Results

Serum levels of NTproBNP were significantly higher in the ANT group than in controls (median 51.52 vs 17.37 pg/ml; p=0.0026). Survivors exposed to ANT had significantly increased levels of NTproBNP compared with patients treated without ANT (median 51.52 vs 12.24 pg/ml; p=0.0002). Female exposed and unexposed survivors had significantly higher NTproBNP levels than males. Four of the 36 survivors (11%) treated with ANT and two of the 33 patients (6%) not exposed to ANT had abnormal NTproBNP levels. Although no patient had echocardiographic abnormalities, significant differences were found in values of left ventricular ejection fraction (LVEF) and deceleration time (DT) between survivors treated with or without anthracyclines.

Conclusions

Higher levels of NTproBNP detected in childhood leukemia survivors after low anthracycline cumulative doses might reflect an initial stage of ANT cardiotoxicity before the development of echocardiographic abnormalities. Although the current studies support NTproBNP as one of the best available biochemical markers of late anthracycline cardiotoxicity, a possible strategy toward further improvement and combination with other cardiac biomarkers and novel echocardiographic methods should be explored in additional studies.

Association of cardiac and renal function with extreme N-terminal fragment pro-B-type natriuretic peptide levels in elderly patients

Background

The data are inconsistent regarding whether extreme N-terminal fragment pro-B-type natriuretic peptide (NT pro-BNP) levels are associated with impaired renal function. Furthermore, the relationship between extreme NT pro-BNP levels and cardiac and renal function in elderly patients has not been reported. The aim of the present study was to examine a hypothesis that extreme NT pro-BNP levels may be associated with impaired cardiac and renal function in elderly patients.

Methods

We retrospectively analyzed the data of demographic, clinical, and echocardiographic features on 152 consecutive elderly patients aged more than 80 years old (average age, 83.65 ± 3.58 years) with NT pro-BNP levels ≥ 3000 pg/ml. The participants were divided into two categories according to their NT pro-BNP levels: (1) 3000–10000 pg/mL and (2) >10000 pg /mL.

Results

The number of patients with impaired renal function (P = 0.019) and the mortality (P < 0.001) in the period of inpatient was higher in the group with NT pro-BNP > 10000 pg /mL. The levels of serum creatinine and creatine kinase MB (CK-MB) in the group of NT pro-BNP > 10000 pg / mL were higher than those in the group of NT pro-BNP = 3000-10000 pg/mL (P = 0.001 and P = 0.023, respectively). Furthermore, no significant difference in the distribution by NYHA class in different NT pro-BNP levels was observed. Multiple linear regression analyses demonstrated that with NT pro-BNP levels as the dependent variable, NT pro-BNP levels were positively correlated with CK-MB (β = 0.182, P = 0.024) and creatinine levels (β = 0.281, P = 0.001). The area under the receiver-operating characteristic (ROC) curve of NT pro-BNP levels and clinical diagnosis of impaired renal function was 0.596 and reached significant difference (95%CI:0.503-0.688, P = 0.044).

Conclusion

These data suggest that the extreme elevation of NT pro-BNP levels (≥3000 pg/ml) is mainly determined by impaired renal function in elderly patients above 80 years. Extreme NT pro-BNP levels may be useful for assessing the severity of impaired renal function.

The diagnosis and management of age-related veterinary cardiovascular disease

The American Veterinary Medical Association reported 81.7 million cats and 72.1 million dogs in the United States, with more than 10% over 11 years of age. Disorders of the cardiovascular system are one of the most commonly encountered disease entities in the aging pet population. This article reviews the diseases affecting older cats and dogs including how to make the diagnosis and when to treat while keeping in mind the unique aspects of comorbid conditions and polypharmacy situations encountered while managing pets with cardiovascular disease.

Serum glutathione S-transferase P1 1 in prediction of cardiac function

Background

Glutathione S-transferase P1 1 (GSTP1) belongs to the multigene isozyme family involved in cellular response to oxidative stress and apoptosis. Our initial retrospective proteomic analysis suggested that GSTP1 is associated with heart failure (HF). Although pro–B-type natriuretic peptide (proBNP) serves currently as a surrogate diagnostic and prognostic parameter in HF patients, its specificity remains uncertain. We hypothesized that GSTP1 might be a useful serum marker in the monitoring of HF patients.

Methods and Results

Serum GSTP1 and proBNP were prospectively measured in 193 patients subdivided based on their ejection fraction (EF) either in equal-sized quintiles or predefined EF groups >52%, 43%–52%, 33%–42%, 23%–32% and ≤22%. At a cutoff of ≥231 ng/mL, GSTP1 identified HF patients with EF ≤22% with 81% sensitivity and 83% specificity, and at a cutoff of ≥655 pg/mL, proBNP identified the same patient group with 84% sensitivity and 22% specificity. GSTP1 at a ≥126 ng/mL cutoff identified EF ≤42% with 90% sensitivity and 95% specificity, or proBNP at a ≥396 pg/mL cutoff had 97% sensitivity and 20% specificity. In regression analyses, GSTP1, but not proBNP, discriminated between EF ≤42% and EF >42% in HF patients.

Conclusions

These results suggest that GSTP1 is strongly associated with HF and could serve as a sensitive and specific marker to predict the ventricular function in HF patients.

Marked decrease in BNP levels in 2 related patients with reversible dilated cardiomyopathy

Two male patients, one in his thirties and the other in his fifties, were admitted to different hospitals for congestive heart failure (CHF). In both patients, laboratory findings indicated high plasma B-type natriuretic peptide (BNP) levels (266.0 and 902.7 pg/mL, respectively) and echocardiography showed large left ventricular diastolic dimensions (LVDd) (67 and 73 mm, respectively) and low ejection fractions (EF) (26% and 18%, respectively). Coronary arteriography revealed no organic stenosis in either patient. Following treatment, plasma BNP levels decreased to below the limit of measurement (4 pg/mL) in both patients and echocardiography revealed improved LVDd (61 and 52 mm, respectively) and EF (41% and 45%, respectively). Because these patients are related, genetic factors might have affected low plasma BNP levels. Moreover, these results suggest that marked decrease in plasma BNP during follow up may be an indicator of preserved neurohormonal and organ systems.

Evaluation of N-terminal pro-B-type natriuretic peptide as a diagnostic marker of various stages of cardiomyopathy in Doberman Pinschers

OBJECTIVE

To evaluate the diagnostic value of plasma N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentrations in Doberman Pinschers in various stages of dilated cardiomyopathy (DCM).

ANIMALS

328 Doberman Pinschers.

PROCEDURES

Staging of DCM was determined via analysis of results of physical examinations, 24-hour ambulatory ECG (Holter) recordings, and echocardiographic evaluations. Plasma samples for NT-proBNP assays were obtained at each examination. Concentrations of NT-proBNP were measured in 337 samples obtained from 196 healthy Doberman Pinschers (control dogs) and in 195 samples obtained from 132 Doberman Pinschers in various stages of DCM. These included dogs that had ventricular premature contractions (VPCs; 79 samples), echocardiographic changes (23 samples), or both (51 samples); 16 samples were from dogs with overt DCM, and 26 were from dogs that were considered normal during initial examination but developed DCM within 1.5 years after this assessment. Receiver operating characteristic curves were analyzed to determine sensitivity and specificity of NT-proBNP concentrations for detection of DCM.

RESULTS

NT-proBNP concentrations in dogs that had or developed DCM were significantly higher than those of control dogs. Sensitivity and specificity of NT-proBNP concentrations (cutoff value, > 400 pmol/L) to detect all stages of DCM were 81.1 % and 75.0%, respectively; sensitivity was 90.0% and specificity was 75.0% to predict echocardiographic changes. Specificity to detect echocardiographic changes was 90.4% at a cutoff value of 550 pmol/L.

CONCLUSIONS AND CLINICAL RELEVANCE

Plasma concentrations of NT-proBNP were increased in dogs with DCM and in apparently healthy dogs that developed DCM within 1.5 years after samples were obtained, compared with concentrations in control dogs.

NT-proBNP, NT-proANP and cTnI concentrations in dogs with pre-capillary pulmonary hypertension

OBJECTIVES

To compare [NT-proBNP], [NT-proANP] and [cTnI] between control dogs with respiratory disease without pulmonary hypertension (PH) and dogs with pre-capillary PH, and to assess the accuracy of [NT-proBNP], [NT-proANP], [cTnI] to predict Doppler-derived peak tricuspid regurgitation (TR) gradient.

ANIMALS

20 dogs. 8 control dogs with respiratory disease with no PH and 12 with pre-capillary PH.

METHODS

[NT-proBNP], [NT-proANP] and [cTnI] were compared between the 2 groups and simple linear regression analysis was used to predict peak TR gradients from various blood biomarkers.

RESULTS

Median [NT-proBNP] was higher in the dogs with PH (2011 pmol/L, 274-7713 pmol/L) compared to control dogs (744 pmol/L; 531-2710 pmol/L) (p = 0.0339). [NT-proBNP] was associated with peak TR gradient (R(2) = 0.7851, p = 0.0001). Median [NT-proANP] did not differ between dogs with PH (1747 fmol/L; 894-2884 fmol/L) and control dogs (1209 fmol/L; 976-1389 fmol/L (p = 0.058). [NT-proANP] was not associated with peak TR gradient (R(2) = 0.2780, p = 0.0781). Median [cTnI] did not differ between dogs with PH (0.2850 ng/mL; 0.19-1.13 ng/mL) and control dogs (0.2 ng/mL; 0.19-0.82 ng/mL, p = 0.3051). Median [TnI] was not associated with peak TR gradient (R(2) = 0.024, p = 0.6307).

CONCLUSIONS

[NT-proBNP] concentration is significantly higher in dogs with pre-capillary PH when compared to dogs with respiratory disease without PH, and [NT-proBNP] may be useful to predict the severity of estimated PH. Elevations in [NT-proBNP] due to pre-capillary PH may complicate the interpretation of [NT-proBNP] elevations in patients presenting with cardiorespiratory abnormalities. [NT-proANP] and [cTnI] were not elevated in dogs with pre-capillary PH.

Is there an additional benefit of serial NT-proBNP measurements in patients with stable chronic heart failure receiving individually optimized therapy?

BACKGROUND

The role of serial NT-proBNP measurements in patients suffering from chronic systolic heart failure (CHF) who already receive individually optimized pharmacotherapy is still unresolved.

METHODS

NT-proBNP was assessed at baseline and at 6 months follow-up in 504 stable CHF patients treated with individually optimized pharmacotherapy. After assessment of clinical stability at 6 months, patients were followed up for at least 1 year. The combined primary endpoint was defined as death, hospitalization due to cardiac reasons or heart transplantation in 1-year follow-up. We stratified our patients according to two principles: first, a percent change of value (CV) between the first and second measurement of NT-proBNP and secondly, the transformed logarithm of NT-proBNP measured at 6 months.

RESULTS

During the follow-up period of 1 year, 50 patients (9.9%) reached the combined primary endpoint. Stratification according to percentage CV was less accurate in predicting endpoint-free survival compared to a classification in categories of lnNT-proBNP measured at 6 months (ROC AUC = 0.615; 95% CI 0.525-0.70 vs. ROC AUC = 0.790; 95% CI 0.721-0.856, respectively). When entered into proportional hazard regression analysis, lnNT-proBNP measured at 6 months remained an independent predictor of the combined primary endpoint with an associated HR of 2.53 (95% CI 1.385-4.280).

CONCLUSION

To date, this is the largest analysis of serial NT-proBNP measurements in patients with CHF receiving individually optimized medical therapy. These data suggest that a single NT-proBNP measurement after 6 months in stable clinical conditions may have higher predictive value than stratification of change in serial measurements.

Extremely high brain natriuretic peptide does not reflect the severity of heart failure

Brain natriuretic peptide (BNP) is important in the diagnosis and management of heart failure (HF). Sometimes, very high BNP levels encountered in clinical settings seem to be out of proportion to the severity of HF. The authors retrospectively identified 113 patients with 129 admissions with a BNP value >3000 pg/mL regardless of diagnosis. The data set was analyzed using the Student t test and bivariate analysis. Fewer than half of patients were admitted for HF. In 14 patients (10.9%), no signs of HF were found. The BNP level of those with and without HF was similar. There was no difference in BNP level in patients with and without systolic dysfunction or renal dysfunction and between different age groups. Extreme values of BNP do not necessarily correlate with the presence of HF, cardiomyopathy, or kidney dysfunction. When the magnitude of BNP elevation is very high, its clinical significance is limited.

N-terminal-pro-brain natriuretic peptide is decreased in insulin dependent gestational diabetes mellitus: a prospective cohort trial

Background

N-terminal-pro-brain natriuretic peptide (NT-proBNP) is elevated in gestational hypertension and preeclampsia. This trial aimed to generate data for gestational diabetes mellitus patients, who are at risk to develop these complications.

Methods

We have measured NT-proBNP in 223 otherwise healthy women between gestational week 24 and 32 referred to the outpatient diabetes unit in a cross-sectional study.

Results

88 control subjects, 45 patients with indication for medical nutrition therapy (MNT) alone and 90 patients who required insulin therapy were included. Groups of women were comparable regarding gestational week. Body mass index before pregnancy and at blood draw was significantly higher in subjects with insulin dependent gestational diabetes mellitus compared to MNT controlled gestational diabetes mellitus. NT-proBNP was significantly lower in patients with insulin dependent gestational diabetes mellitus (35 ± 25 pg/ml) compared to controls (53 ± 43 pg/ml, p = 0.012).

Conclusions

NT-proBNP is within the reference range of normal subjects in women with gestational diabetes mellitus. Differences in body mass index, changes in glomerular filtration rate and haemodynamics may explain lower NT-proBNP concentrations in insulin dependent gestational diabetes mellitus. A false negative interpretation needs to be considered in these women.

Pro-B-type natriuretic peptide(1-108) circulates in the general community: plasma determinants and detection of left ventricular dysfunction

OBJECTIVES

The purpose of this study was to investigate circulating pro-B-type natriuretic peptide (proBNP(1-108)) in the general community and evaluate its ability to detect left ventricular (LV) dysfunction.

BACKGROUND

The current concept for cardiac endocrine function is that, in response to cardiac stress, the heart secretes B-type natriuretic peptide (BNP(1-32)) and amino-terminal pro-B-type natriuretic peptide (NT-proBNP(1-76)) after intracardiac cleavage of their molecular precursor, proBNP(1-108). We hypothesized that proBNP(1-108) circulates in normal human subjects and that it is a useful biomarker for LV dysfunction.

METHODS

Our population-based study included a cohort of 1,939 adults (age ≥45 years) from Olmsted County, Minnesota, with 672 participants defined as healthy. Subjects underwent in-depth clinical characterization, detailed echocardiography, and measurement of proBNP(1-108). Independent factors associated with proBNP(1-108) and test characteristics for the detection of LV dysfunction were determined.

RESULTS

ProBNP(1-108) in normal humans was strongly influenced by sex, age, heart rate, and body mass index. The median concentration was 20 ng/l with a mean proBNP(1-108) to NT-proBNP(1-76) ratio of 0.366, which decreased with heart failure stage. ProBNP(1-108) was a sensitive (78.8%) and specific (86.1%) biomarker for detecting LV systolic dysfunction, which was comparable to BNP(1-32), but less than NT-proBNP(1-76), in several subsets of the population.

CONCLUSIONS

ProBNP(1-108) circulates in the majority of healthy humans in the general population and is a sensitive and specific biomarker for the detection of systolic dysfunction. The proBNP(1-108) to NT-proBNP(1-76) ratio may provide insights into altered proBNP(1-108) processing during heart failure progression. Thus, this highly specific assay for proBNP(1-108) provides important new insights into the biology of the BNP system.

Effect of NT-proBNP testing on diagnostic certainty in patients admitted to the emergency department with possible heart failure

Background

Difficulty in distinguishing congestive heart failure (HF) from other causes of dyspnoea in the emergency department (ED) may result in delay in appropriate treatment and referral. Although the diagnostic value of serum amino-terminal pro-B-type natriuretic peptide (NT-proBNP) is well documented, the impact on diagnostic certainty of providing these results to ED physicians is not well studied. We sought to determine the effect of providing NT-proBNP results on diagnostic certainty of physicians managing patients presenting to the ED with suspected HF.

Methods

A randomized controlled study was conducted in 68 patients presenting to the ED with dyspnoea. ED clinicians initially rated the probability of HF as the cause of dyspnoea without the knowledge of the result. A scale of 1–7 was used, with 1 representing a high degree of certainty of a diagnosis other than HF and 7 representing a high degree of certainty of HF being the cause of dyspnoea. In 38 patients, the ED physician then reassessed the probability of HF as the cause of dyspnoea after receiving the NT-proBNP result. A cardiologist blinded to the NT-proBNP result determined the final diagnosis after review of medical records and investigations.

Results

Providing the NT-proBNP result reduced diagnostic uncertainty, defined as a test score of 3–5, from 66% of cases to 18% of cases ( P < 0.0001) and improved diagnostic accuracy from 53% to 71% ( P = 0.016).

Conclusion

Measurement of NT-proBNP concentrations reduces diagnostic uncertainty and improves diagnostic accuracy in patients presenting to the ED with dyspnoea and possible HF.

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.

Relationship between obesity and N-terminal brain natriuretic Peptide level as a prognostic value after acute myocardial infarction

Background and Objectives

Recently, the prognostic value of N-terminal brain natriuretic peptide (NT-proBNP) in acute coronary syndrome has been demonstrated in many studies. However, NT-proBNP levels are influenced by various factors such as sex, age, renal function, heart failure severity, and obesity. NT-proBNP concentrations tend to decrease with higher body mass index (BMI). The aim of this study was to examine the influence of obesity on NT-proBNP as a predictive prognostic factor in acute myocardial infarction (AMI) patients.

Subjects and Methods

Using data from the Korea Acute Myocardial Infarction Registry (January 2005 to September 2008), 2,736 AMI patients were included in this study. These patients were divided into men (n=1,972, 70%) and women (n=764, 30%), and were grouped according to their BMIs. Major adverse cardiac events (MACE) during 1 year clinical follow-up were evaluated.

Results

NT-proBNP was significantly higher in lower BMI (p<0.001). Mean NT-proBNP levels of each obesity group were 2,393±4,022 pg/mL in the lean group (n=875), 1,506±3,074 pg/mL in the overweight group (n=724) and 1,100±1,137 pg/mL in the obese group (n=1,137) (p<0.01). NT-proBNP was an independent prognostic factor of AMI in obese patients by multivariative analysis of independent risk factors of MACE (p=0.01).

Conclusion

NT-proBNP is lower in obese AMI patients than in non-obese AMI patients, but NT-proBNP is still of independent prognostic value in obese AMI patients.

Diagnostic accuracy of plasma NT-proBNP levels for excluding cardiac abnormalities in the very elderly

Background

In the elderly the diagnosis of chronic heart failure is often challenging and the availability of echocardiography can be limited. Plasma levels of NT-proBNP are valuable tools to diagnose patients with heart failure. However, the performance of this biomarker to detect cardiac abnormalities in the very elderly remains unclear. The aims of this study were to investigate the relation between NT-proBNP and cardiac abnormalities and to evaluate the use of NT-proBNP to exclude structural and functional cardiac abnormalities in a community-based sample of "well-functioning" nonagenarians.

Methods

A diagnostic cross-sectional study embedded within the Leiden 85-plus Study in the municipality of Leiden, the Netherlands. Plasma NT-proBNP levels were measured and 2-dimensional echocardiography was performed in a subgroup of 80 well-functioning nonagenarians. Linear regression analysis was used to explore the relation between NT-proBNP and cardiac abnormalities and ROC curve analysis was used to assess the performance of NT-proBNP to exclude cardiac abnormalities. The upper limit of the lowest tertile of NT-proBNP was used as a cut-off value.

Results

NT-proBNP levels were associated with abnormal left ventricular (LV) dimensions, LV systolic and diastolic function, left atrial enlargement and valvular heart disease. LV mass, E/A ratio and degree of aortic regurgitation were identified as independent predictors of NT-proBNP. NT-proBNP levels were higher with greater number of echocardiographic abnormalities (P < 0.001). A cut-off level of 269.5 pg/mL identified patients with abnormal LV dimensions or depressed LV systolic function (sensitivity 85%, negative predictive value (NPV) 77%, area under the curve 0.75 (95% CI 0.64-0.85)). In addition, high NPV were found for LV systolic dysfunction, left atrial enlargement, severe valvular heart disease and pulmonary hypertension. The test performance of NT-proBNP to exclude any echocardiographic abnormality showed a sensitivity of 82% and a NPV of 65%.

Conclusions

In this convenience sample of well-functioning nonagenarians NT-proBNP was related to a wide variety of functional and structural echocardiographic abnormalities. Moreover, NT-proBNP could be used to exclude echocardiographic abnormalities in well-functioning nonagenarians and might be used to indicate who needs to be referred for further cardiovascular examination.

Myocardial strain and strain rate in monitoring subclinical heart failure in asymptomatic long-term survivors of childhood cancer

We studied the role of global myocardial strain and strain rate in monitoring subclinical heart failure in a large group of asymptomatic long-term survivors of childhood cancer. Global strain (rate) parameters of survivors were compared with those in healthy controls and were related to conventional echocardiographic parameters, N-terminal-pro-natriuretic peptide (NT-pro-BNP) levels and clinical parameters. Two-dimensional (2-D) echocardiography was performed in 111 survivors and 107 healthy controls. Blood samples were taken from survivors to determine NT-pro-BNP levels. We showed that global myocardial strain, strain rate and time to peak systolic strain in asymptomatic survivors of childhood cancer were significantly lower compared with healthy controls (p values <0.0001) and were significantly related to several systolic and diastolic left ventricular parameters. Whether myocardial strain and strain rate are superior to conventional echocardiography in the early detection of subclinical heart failure needs to be explored in further longitudinal prospective studies.

Anticancer therapy induced cardiotoxicity: review of the literature

Innovative anticancer strategies have contributed to an improved survival of patients suffering from malignancies, and in some cases, have turned cancer into a chronic disease. Therefore, the early and particularly late onsets of adverse cardiovascular effects of systemic anticancer treatments are of increasing interest. Among a rapidly increasing variety of anticancer drugs, the anthracyclines and the monoclonal antibody, trastuzumab, are the agents with a well-known cardiotoxicity. The diagnostic work-up, the cardiotoxic risk of anthracyclines and trastuzumab, and additionally, cardiotoxicity as a risk factor of a multimodal therapeutic approach in breast cancer patients is discussed in this study.

Comparison of brain natriuretic peptide (BNP) and NT-proBNP in screening for pulmonary arterial hypertension in patients with systemic sclerosis

OBJECTIVE

To compare the performance of brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in screening for pulmonary arterial hypertension (PAH) in systemic sclerosis (SSc).

METHODS

Between January 2008 and March 2009, outpatients referred to our unit and satisfying LeRoy criteria for SSc were assessed for PAH. Doppler echocardiography, BNP measurement, and NT-proBNP measurement were done concomitantly for a complete clinical, instrumental, and biochemical evaluation. Right-heart catheterization was carried out in cases of suspected PAH [estimated pulmonary arterial pressure (PAP) ≥ 36 mm Hg; diffusion capacity for carbon monoxide (DLCO) ≤ 50% of predicted value; 1-year DLCO decline ≥ 20% in absence of pulmonary fibrosis; unexplained dyspnea].

RESULTS

One hundred thirty-five patients were enrolled (124 women, 11 men; 96 limited SSc, 39 diffuse SSc); precapillary PAH was found in 20 patients (15 limited SSc, 5 diffuse SSc). The estimated PAP correlated with both BNP (R = 0.3; 95% CI 0.14-0.44) and NT-proBNP (R = 0.3, 95% CI 0.14-0.45). BNP [area under the curve (AUC) 0.74, 95% CI 0.59-0.89] was slightly superior to NT-proBNP (AUC 0.63, 95% CI 0.46-0.80) in identification of PAH, with diagnosis cutoff values of 64 pg/ml (sensitivity 60%, specificity 87%) and 239.4 pg/ml (sensitivity 45%, specificity 90%), respectively. BNP (log-transformed, p = 0.032) and creatinine (p = 0.049) were independent predictors of PAH, while NT-proBNP was not (p = 0.50).

CONCLUSION

In our single-center study, the performance of BNP was slightly superior to that of NT-proBNP in PAH screening of patients with SSc, although normal levels of these markers do not exclude diagnosis. We observed that impaired renal function is associated with an increased risk of PAH in SSc. Further multicenter studies are needed to confirm our results (ClinicalTrials.gov ID NCT00617487).

Age-dependent values of N-terminal pro-B-type natriuretic peptide are superior to a single cut-point for ruling out suspected systolic dysfunction in primary care

AIMS

The study evaluated the use of age-related decision limits for N-terminal pro-B-type natriuretic peptide (NT-proBNP), for ruling out suspected systolic dysfunction in symptomatic patients in primary care, compared with the present standards.

METHODS AND RESULTS

Data were obtained from 5508 patients from 10 studies in the UK, New Zealand, Europe, and USA. All have had NT-proBNP analysis and echocardiography. The median age was 62 years (range 18-100 years) with a prevalence of reduced left ventricular systolic function (left ventricular ejection fraction < or =40%) of 18%. In a receiver operating characteristic curve analysis, overall area under the curve (AUC) was 0.89. When looking at different age groups, AUC was highest (0.95) for <50 years, intermediate (0.90) for 50-75 years, and lowest (0.82) for >75 years. Using optimized decision limits, sensitivity, specificity, and negative predictive values (NPVs) were: <50 years (50 ng/L): 99.2, 57.2, and 99.7%; 50-75 years (75 ng/L): 95.9, 51.0, and 96.8%; and >75 years (250 ng/L): 87.9, 53.7, and 92.4%, respectively. Using only a single decision value (125 ng/L for all ages) gave sensitivities of 89.1, 91.9, and 94.3%; specificities of 84.0, 69.1, and 29.3% and NPVs of 97.7, 97.6, and 93.4%. A decision value of 400 ng/L for all ages gave much lower sensitivities.

CONCLUSION

In a large population of patients in primary care, the use of age-stratified NT-proBNP decision limits considerably improves performance over current standards, with an excellent NPV for exclusion of reduced left ventricular systolic function.

Relation of natriuretic peptides and midregional proadrenomedullin to cardiac chamber volumes by computed tomography in patients without heart failure: from the ROMICAT Trial

BACKGROUND

Stress myocyte biomarkers are used prognostically in patients with cardiovascular disease. We examined associations between amino-terminal pro-B-type natriuretic peptide (NT-proBNP), midregional pro-A-type natriuretic peptide (MR-proANP), and midregional proadrenomedullin (MR-proADM) concentrations and cardiac chamber volumes in chest pain patients without heart failure by use of computed tomography (CT).

METHODS

At the time of 64-slice CT scan, we acquired plasma and serum samples for these biomarkers from 346 patients [mean (SD) age 53 (12) years, 65% men]. Left atrial volume (LAV) and left ventricular volumes at end-diastole (LVEDV) and end-systole (LVESV) were measured and indexed to body surface area (LAVI, LVEDI, LVESI).

RESULTS

Concentrations of both natriuretic peptides were correlated with LAV and LAVI (r = 0.19-0.32, all P

CONCLUSIONS

In patients without heart failure, both NT-proBNP and MR-proANP concentrations are independently associated with LA enlargement, whereas MR-proADM concentrations are correlated with LV volumes. This may partially explain the well-recognized value of natriuretic peptides for use in risk stratification.

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Key Words Collapse

MESH Headings

• Adrenomedullin/blood
• Atrial Function, Left
• Biomarkers/blood
• Cohort Studies
• Female
• Humans
• Male
• Middle Aged
• Myocardial Infarction/diagnosis
• Natriuretic Peptide, Brain/blood
• Protein Precursors/blood
• Reproducibility of Results
• Tomography, X-Ray Computed
• Ventricular Function, Left

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Grants

• T32HL076136 NHLBI NIH HHS
• R01 HL080053 NHLBI NIH HHS
• L30 HL093806-01 NHLBI NIH HHS
• L30 HL093806 NHLBI NIH HHS
• K23 HL098370 NHLBI NIH HHS
• T32 HL076136 NHLBI NIH HHS
• L30HL093896 NHLBI NIH HHS

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Affiliation(s)

Quynh A Truong Cardiac MR PET CT Program, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
Emily Siegel
Mahir Karakas
James L Januzzi
Fabian Bamberg
Amir A Mahabadi
Selcuk Dasdemir
Thomas J Brady
Andreas Bergmann
Jan Kunde
John T Nagurney
Udo Hoffmann
Wolfgang Koenig

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NT-proBNP levels in systemic sclerosis: association with clinical and laboratory abnormalities

OBJECTIVE

To identify factors related to NT-proBNP levels in systemic sclerosis (SSc).

DESIGN AND METHODS

NT-proBNP was measured in 119 patients with SSc and 20 controls. Patients with transtricuspid gradient (TG) > or =36 mm Hg or > or =31 mmHg plus dyspnea were considered to have suspected systemic sclerosis-associated pulmonary arterial hypertension (SScPAH).

RESULTS

Increasing age, NYHA functional class, skin score, history of systemic arterial hypertension (SAH), anticentromere antibodies, diastolic dysfunction, reduced pulmonary diffusing capacity, and TG were positively associated with NT-proBNP. In multivariable linear regression, TG, age, and SAH were independently associated to NT-proBNP levels. An ROC curve analysis (with an area under the curve of 0.89, 95% CI: 0.83-0.95) suggested a cutoff of 157.8pg/mL to identify patients with suspected SScPAH, presenting a sensitivity of 100% (78.1-100) and specificity of 72.3% (62.3-80.5).

CONCLUSIONS

NT-proBNP levels are related to clinical and laboratory abnormalities in SSc. The results indicate that NT-proBNP may be a useful tool in the evaluation of SScPAH.

Diagnostic and prognostic value of brain natriuretic peptide (BNP) concentrations in very elderly heart disease patients: specific geriatric cut-off and impacts of age, gender, renal dysfunction, and nutritional status

Confirming the presence of heart failure (HF) in geriatric patients is made difficult by the overlapping symptoms with other diseases and by limited access to investigative techniques such as echography, and the clinical signs are either non-constant or difficult to interpret. In this context, BNP measurement could prove highly useful. We determined a cut-off value of BNP for diagnosing HF in geriatric patients and gauged its predictive power in terms of cardiovascular events, dependence and death within a 6-month timeframe. This clinical and biological study was performed in patients, 44 women and 20 men, age>65 years with suspected HF hospitalized in the geriatric unit at Emile-Roux hospital. Echography was performed at baseline examination. BNP concentrations were determined at baseline examination and at 2 and 6 months later. Renal function was assessed via the Cockroft-Gault formula. Nutritional status was assessed using the geriatric nutritional risk index (GNRI). Final reference diagnosis was established by both cardiologist and geriatrician. The diagnostic value of BNP was assessed by area under the ROC curve. The average age of the 64 patients was 84.3±7.4 years. The final diagnosis was HF in 26 patients (41%). A BNP<129pg/ml had a negative predictive value of 90% (accuracy 80%) for excluding the diagnosis of HF. BNP values were predictive of cardiovascular events over a 2-month timeframe in patients with HF and over a 6-month timeframe in the global population. BNP values were not predictive of mortality in patients with or without HF. BNP testing should help to differentiate pulmonary from cardiac etiologies of dyspnea, but a specific cut-off point has to be used in geriatric settings, mainly for patients presenting nutritional and renal dysfunctions.

The accuracy of plasma natriuretic peptide levels for diagnosis of cardiac dysfunction and chronic heart failure in community-dwelling elderly: a systematic review

BACKGROUND

measurement of plasma natriuretic peptide levels has been proposed as a simple, accessible test to assist the diagnosis of cardiac dysfunction and heart failure. Most studies have been hospital based and have investigated the relationship between natriuretic peptides and cardiac dysfunction or heart failure in younger populations.

OBJECTIVE

we performed a systematic review to evaluate the diagnostic accuracy of plasma natriuretic peptide measurement in elderly patients from the general population.

METHODS

electronic searches of MEDLINE and EMBASE from January 1985 to May 2008 were performed. Diagnostic cohort and cross-sectional studies on the accuracy of natriuretic peptides for diagnosis of cardiac dysfunction or chronic heart failure in people aged 75 and over in the community were included. The quality of the selected studies was assessed with the modified QUADAS tool and the data extracted by two independent reviewers.

RESULTS

five studies were included. The general quality of the studies was moderate. The extracted data could not be pooled. Negative likelihood ratios for cardiac dysfunction ranged from 0.09 to 0.29.

CONCLUSION

we found limited evidence supporting the use of plasma natriuretic peptide measurement for diagnosis of cardiac dysfunction or heart failure in the elderly of 75 years and over in the general population. Important questions about the implementation of plasma natriuretic peptide measurement in daily practice remain unresolved.

Adjusting for clinical covariates improves the ability of B-type natriuretic peptide to distinguish cardiac from non-cardiac dyspnoea: a sub-study of HEARD-IT

AIMS

We sought to create a model that adjusts B-type natriuretic peptide (BNP) for specific covariates to better distinguish cardiac from non-cardiac dyspnoea.

METHODS AND RESULTS

HEARD-IT was a multicentre, prospective study of the diagnostic utility of acoustic cardiography in the emergency department. Dyspnoeic patients more than 40 years were eligible. Two cardiologists independently adjudicated the HF outcome. Using logistic regression, a model adjusting BNP for pertinent covariates was developed (n = 740). The mean age was 66 +/- 13 years. Age, gender, ethnicity, body mass index, blood urea nitrogen, and creatinine affected BNP levels independently of HF. The model adjusting BNP for these covariates improved the area under receiver operator characteristic curve for HF compared with BNP alone (0.948, 95% CI 0.934-0.963 vs. 0.937, 95% CI 0.920-0.954; P = 0.004). Net reclassification improvement, a novel metric of model performance, was 3.5% for those without HF (P = 0.05) compared with conventional, unadjusted BNP cut-offs. Thirteen of 116 (11%) patients without HF, but with unadjusted BNP values > or =100 pg/mL, were correctly reclassified as not having HF with the adjusted BNP model.

CONCLUSION

Adjusting BNP for important covariates may improve its ability to distinguish cardiac from non-cardiac dyspnoea.