Diagnostic and Prognostic Performance of N-Terminal ProBNP in Primary Care Patients With Suspected Heart Failure

Association between vitamin D levels and left ventricular function and NT-proBNP levels among thalassemia major children with iron overload

BACKGROUND

Heart disease is the major cause of death in thalassemia patients. Repeated blood transfusions and hemolysis cause iron overload and also disrupts the hydroxylation and synthesis of vitamin D, causing vitamin D deficiency. Vitamin D deficiency is associated with cardiac dysfunction.

OBJECTIVE

The purpose of this study was to determine the association between vitamin D levels and left ventricular function and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in thalassemia major children with iron overload.

PATIENTS AND METHODS

A cross-sectional study was conducted in March-April 2015 in the thalassemia clinic, Department of Child Health, Dr. Hasan Sadikin General Hospital, Bandung, Indonesia. Thirty-four children with thalassemia were enrolled consecutively. Serum vitamin D and NT-proBNP levels were measured with electrochemiluminescence (ECLIA) method and echocardiography was performed to assess ventricular function.

RESULTS

Significant correlations were found between vitamin D levels and left ventricular ejection fraction (LVEF) (r = 0.399, P = 0.019) and fractional shortening (FS) (r = 0.394, P = 0.021). There was also significant correlation between vitamin D and NT-proBNP levels (r = -0.444, P = 0.008). Chi-square analysis also showed a relationship between vitamin D and NT-proBNP (P = 0.019) levels. There was a difference in NT-proBNP levels among thalassemia major children with iron overload (P = 0.020). Post hoc analysis showed that there was a significant difference in NT-proBNP levels between those with vitamin D deficiency and those with normal vitamin D levels (P = 0.012).

CONCLUSION

There is an association between vitamin D and left ventricular function and NT-proBNP levels in children with thalassemia major and iron overload. Vitamin D can be considered in patients with thalassemia having vitamin D deficiency.

Amino-terminal pro-brain natriuretic peptide in children with latent rheumatic heart disease

Background:

Rheumatic heart disease (RHD) is a global cause of early heart failure. Early RHD is characterized by valvar regurgitation, leading to ventricular distention and possible elaboration of amino-terminal pro-brain natriuretic peptide (NT-proBNP). We investigated the ability of NT-proBNP to distinguish cases of latent RHD detected by echocardiographic screening from the controls.

Materials and Methods:

Ugandan children (N = 44, 36% males, mean age: 12 ± 2 years) with latent RHD (cases) and siblings (controls) by echocardiography were enrolled. Cases and controls were matched for age and sex, and they had normal hemoglobin (mean: 12.8 mg/dL). Children with congenital heart disease, pregnancy, left ventricular dilation or ejection fraction (EF) below 55%, or other acute or known chronic health conditions were excluded. RHD cases were defined by the World Heart Federation (WHF) 2012 consensus guideline criteria as definite. Controls had no echocardiography (echo) evidence for RHD. At the time of echo, venous blood samples were drawn and stored as serum. NT-proBNP levels were measured using sandwich immunoassay. Paired t-tests were used to compare NT-proBNP concentrations including sex-specific analyses.

Results:

The mean NT-proBNP concentration in the cases was 105.74 ± 67.21 pg/mL while in the controls, it was 86.63 ± 55.77 pg/mL. The cases did not differ from the controls (P = 0.3). In sex-specific analyses, male cases differed significantly from the controls (158.78 ± 68.82 versus 76 ± 42.43, P = 0.008). Female cases did not differ from the controls (75.44 ± 45.03 versus 92.30 ± 62.35 respectively, P = 0.4).

Conclusion:

Serum NT-proBNP did not distinguish between latent RHD cases and the controls. Sex and within-family exposures may confound this result. More investigation into biomarker-based RHD detection is warranted.

Fatigue as Presenting Symptom and a High Burden of Premature Ventricular Contractions Are Independently Associated With Increased Ventricular Wall Stress in Patients With Normal Left Ventricular Function

Background—

High idiopathic premature ventricular contractions (PVC) burden has been associated with PVC-induced cardiomyopathy. Patients may be symptomatic before left ventricular (LV) dysfunction develops. N-terminal pro–B-type natriuretic peptide (NT-proBNP) and circumferential end-systolic wall stress (cESS) on echocardiography are markers for increased ventricular wall stress. This study aimed to evaluate the relation between presenting symptoms, PVC burden, and increased ventricular wall stress in patients with frequent PVCs and preserved LV function.

Methods and Results—

Eighty-three patients (41 men; 49±15 years) with idiopathic PVCs and normal LV function referred for PVC ablation were included. Type of symptoms (palpitations, fatigue, and [near-]syncope), PVC burden on 24-hour Holter, NT-proBNP levels, and cESS on echocardiography were assessed before and 3 months after ablation. Sustained successful ablation was defined as ≥80% PVC burden reduction during follow-up. Patients were symptomatic for 24 months (Q1–Q3, 16–60); 73% reported palpitations, 47% fatigue, and 30% (near-)syncope. Baseline PVC burden was 23±13%, median NT-proBNP 92 pg/mL (Q1–Q3 50–156), and cESS 143±35 kdyne/cm 2 . Fatigue was associated with higher baseline NT-proBNP and cESS ( P <0.001, P =0.011, respectively). After sustained successful ablation, achieved in 81%, NT-proBNP and cESS decreased significantly ( P <0.001 and P =0.036, respectively). Fatigue was independently associated with a significantly larger reduction in NT-proBNP. In patients with nonsuccessful ablation, NT-proBNP and cESS remained unchanged.

Conclusions—

In patients with frequent PVCs and preserved LV function, fatigue was associated with higher baseline NT-proBNP and cESS, and with a significantly larger reduction in NT-proBNP after sustained successful ablation. These findings support a link between fatigue and PVC-induced increased ventricular wall stress, despite preserved LV function.

Cystatin C-based CKD-EPI equations and N-terminal pro-B-type natriuretic peptide for predicting outcomes in acutely decompensated heart failure

BACKGROUND

In patients with acute decompensated heart failure (ADHF), both natriuretic peptides and renal impairment predict adverse outcomes. Our aim was to evaluate the complementary prognosis role of N-terminal pro-B-type natriuretic peptide (NT-proBNP) and the newly developed Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations based on cystatin C (CysC) for glomerular filtration rate (GFR) estimation in ADHF patients.

HYPOTHESIS

Renal impairment assessed by CysC-based CKD-EPI equations and natriuretic peptides have complementary prognostic value in ADHF patients.

METHODS

The study included 613 consecutive patients presenting with ADHF. At admission, plasma levels of NT-proBNP and CysC were determined. The GFR was estimated using CysC-based CKD-EPI equations. The primary endpoint was death from any cause and heart failure readmission.

RESULTS

During the median follow-up of 365 days (interquartile range, 227-441 days), 323 patients (0.65 %patient-year) died or were readmitted for heart failure. After multivariate adjustment, estimated GFR <60 mL/min/1.73 m(2) and NT-proBNP >3251 pg/mL were independent predictors of adverse outcomes (P < 0.01). The combination of GFR <60 mL/min/1.73 m(2) and NT-proBNP >3251 pg/mL was associated with the highest risk of adverse outcomes. Furthermore, reclassification analyses demonstrated that use of both NT-proBNP and CysC-based CKD-EPI equations resulted in improving the accuracy for adverse outcomes prediction.

CONCLUSIONS

In patients with ADHF, the combination of NT-proBNP with estimated GFR using CysC-based CKD-EPI equations better predicts outcomes than either parameter alone and adds valuable complementary prognosis information to other established risk factors.

Cardiac natriuretic peptides in plasma increase after dietary induced weight loss in obesity

Background

Cardiac natriuretic peptides are established biomarkers in heart disease, but are also affected by body mass index (BMI). The purpose of the present study was to examine the impact of weight loss and changes in body composition following dietary intervention on plasma concentrations of the prohormones to A- and B-type natriuretic peptides (proANP and proBNP) and adrenomedullin (proADM).

Results

A total of 52 healthy obese subjects, 47 women and 5 men (BMI 36.5 ± 5.6 kg/m²) were randomised to either an intensive weight reduction programme using a combination of very low calorie diet (810 kcal/day) and conventional hypo-energetic diet (1200 kcal/day) for 52 weeks, or to a control group that was offered diet-related counselling. N-terminal proBNP (NT-proBNP), mid-regional proANP (MR-proANP) and proADM (MR-proADM) and body composition using dual-energy x-ray absorptiometry (DEXA) scanning were determined at baseline and after 52 weeks. Comparisons between groups were analysed using t-tests. Changes from the baseline within the groups were analysed with paired tests. Changes in the variables, delta (∆), were calculated as 52 weeks minus the baseline.

In the intervention group, BMI decreased by almost 20% (31.6 ± 6.2 vs. 37.1 ± 6.1 kg/m²; P <0.001) with a loss of body fat of 23.5 ± 15.5% (P < 0.001). Plasma concentrations of NT-proBNP and MR-proANP increased (from 55 ± 31 to 97 ± 55 pg/ml; P < 0.001, and from 59 ± 21 to 74 ± 26 pmol/L; P < 0.001), whereas MR-proADM decreased (from 573 ± 153 to 534 ± 173 pmol/L; P <0.001). Changes (Δ) in MR-proANP correlated with Δfat mass (r = −0.359; P = 0.011) and Δglucose (r = −0.495; P <0.001), while increases in NT-proBNP were primarily associated with reduced plasma glucose (r = −0.462; P <0.001). A modest but significant weight loss of 6% (P < 0.001) was found in the control group with no changes in plasma concentrations of NT-proBNP or MR-proANP, and a minor change in MR-proADM.

Conclusions

Plasma NT-proBNP and MR-proANP concentrations increase and MR-proADM concentration decreases during weight loss, underlining the dynamic impact of BMI, body composition and glucose metabolism on these cardiovascular biomarkers.

Performance of BNP and NT-proBNP for diagnosis of heart failure in primary care patients: a systematic review

National and international guidelines have been published recommending the use of natriuretic peptides as an aid to the diagnosis of heart failure (HF) in acute settings; however, few specific recommendations exist for governing the use of these peptides in primary care populations. To summarize the available data relevant to the diagnosis of HF in primary care patient population, we systematically reviewed the literature to identify original articles that investigated the diagnostic accuracy of B-type natriuretic peptide (BNP) and N-terminal proBNP (NT-proBNP) in primary care settings. The search yielded 25,864 articles in total: 12 investigating BNP and 20 investigating NT-proBNP were relevant to our objective and included in the review. QUADAS-2 and GRADE were used to assess the quality of the included articles. Diagnostic data were pooled based on three cutpoints: lowest and optimal, as chosen by study authors, and manufacturers' suggested. The effect of various determinants (e.g., age, gender, BMI, and renal function) on diagnostic performance was also investigated. Pooled sensitivity and specificity of BNP and NT-proBNP using the lowest [0.85 (sensitivity) and 0.54 (specificity)], optimal (0.80 and 0.61), and manufacturers' (0.74 and 0.67) cutpoints showed good performance for diagnosing HF. Similar performance was seen for NT-proBNP: lowest (0.90 and 0.50), optimal (0.86 and 0.58), and manufacturers' (0.82 and 0.58) cutpoints. Overall, we rated the strength of evidence as high because further studies will be unlikely to change the estimates diagnostic performance.

Racial/Ethnic differences in B-type natriuretic peptide levels and their association with care and outcomes among patients hospitalized with heart failure: findings from Get With The Guidelines-Heart Failure

OBJECTIVES

This study sought to determine if there were differences in B-type natriuretic peptide (BNP) levels across racial/ethnic groups and in their association with quality of care and in-hospital outcomes among patients with heart failure (HF).

BACKGROUND

It remains unclear whether BNP levels and their associations with quality of care and prognosis vary by race/ethnicity among patients hospitalized with HF.

METHODS

Using Get With The Guidelines-Heart Failure (GWTG-HF), patient characteristics and BNP levels at admission were compared among 4 racial/ethnic populations: white, black, Hispanic, and Asian. The associations between BNP, quality of care, in-hospital mortality, and length of stay (LOS) across these groups were analyzed.

RESULTS

A total of 92,072 patients (65,037 white, 19,092 black, 6,747 Hispanic, and 1,196 Asian) from 264 hospitals were included. Median BNP levels were higher in Asian (1,066 pg/ml) and black (866 pg/ml) patients than in white (776 pg/ml) and Hispanic (737 pg/ml) patients, and race/ethnicity was independently associated with BNP levels (p < 0.0001). Irrespective of race/ethnicity, patients in higher BNP quartiles (Q3, Q4) were more likely to be older and male and have lower body mass index, reduced ejection fraction, and renal insufficiency, whereas those in the lowest quartile (Q1) were more likely to have diabetes. With some exceptions, there were no significant racial/ethnic differences in the association of BNP levels with performance measure adherence. In multivariate analysis, elevated BNP levels remained associated with longer LOS and increased mortality in all racial/ethnic groups.

CONCLUSIONS

Asian and black patients with HF had higher BNP levels at admission compared with white and Hispanic patients. BNP levels at admission provided prognostic value for in-hospital mortality and hospital LOS irrespective of race/ethnicity.

[Utility of B-type natriuretic peptide measurement in outpatients with heart failure with preserved ejection fraction]

INTRODUCTION

Heart failure with preserved ejection fraction (HFPEF) is a highly prevalent syndrome that is difficult to diagnose in outpatients. The measurement of B-type natriuretic peptide (BNP) may be useful in the diagnosis of HFPEF, but with a different cutoff from that used in the emergency room. The aim of this study was to identify the BNP cutoff for a diagnosis of HFPEF in outpatients.

METHODS AND RESULTS

This prospective, observational study enrolled 161 outpatients (aged 68.1±11.5 years, 72% female) with suspected HFPEF. Patients underwent ECG, tissue Doppler imaging, and plasma BNP measurement, and were classified in accordance with algorithms for the diagnosis of HFPEF. HFPEF was confirmed in 49 patients, who presented higher BNP values (mean 144.4pg/ml, median 113pg/ml, vs. mean 27.6pg/ml, median 16.7pg/ml, p<0.0001). The results showed a significant correlation between BNP levels and left atrial volume index (r=0.554, p<0.0001), age (r=0.452; p<0.0001) and E/E' ratio (r=0.345, p<0.0001). The area under the ROC curve for BNP to detect HFPEF was 0.92 (95% confidence interval: 0.87-0.96; p<0.001), and 51pg/ml was identified as the best cutoff to detect HFPEF, with sensitivity of 86%, specificity of 86% and accuracy of 86%.

CONCLUSIONS

BNP levels in outpatients with HFPEF are significantly higher than in those without. A cutoff value of 51pg/ml had the best diagnostic accuracy in outpatients.

Cardiotoxicity After Anthracycline Treatment in Survivors of Adult Cancers: Monitoring by USCOM, Echocardiography and Serum Biomarkers

Background

Anthracyclines are agents with a well known documented anti-tumoral activity. Cardiac side effects are the principal toxicity. Here we evaluate and monitor the onset of late anthracycline-induced cardiotoxicity with real-time CW-Doppler ultrasound cardiac output monitoring (USCOM®) and echocardiography in combination with serum biomarkers.

Methods

Fifty-two patients without cardiac disease who had received an anthracycline-based regimen for various cancer types were included in this study. Patients’ hemodynamic parameters as stroke volume (SV USCOM (mL)) and ejection fraction (EF ECHOCARDIOGRAPHY (%)) were measured with USCOM and echocardiography and correlated to serum biomarkers (NT-pro-BNP and cTnT).

Results

Eighteen patients (34.6%) developed cardiac disease (NYHA I-III). An increasing cumulative anthracycline dose was associated with a decrease of the EF determined by echocardiography as well the SV by USCOM and with a higher NYHA class. Those patients who experienced cardiac disease showed a reduction of the EF and SV and increased serum biomarkers.

Conclusions

Real-time CW-Doppler USCOM, is a fast and reliable method to monitor late hemodynamic changes as a symptom of anthracycline-induced cardiotoxicity comparable to the findings by echocardiography and serum biomarkers.

Applicability of current diagnostic algorithms in geriatric patients suspected of new, slow onset heart failure

BACKGROUND

referral for echocardiography for all geriatric outpatients suspected of heart failure (HF) is not feasible. Diagnostic algorithms could be helpful.

OBJECTIVE

to investigate whether available diagnostic algorithms accurately identify (older) patients (aged 70 years or over) eligible for echocardiography, with acceptable numbers of false-negatives.

METHODS

algorithms (European Society of Cardiology (ESC)) guideline, National Institute for Health and Clinical Excellence (NICE) guideline, multidisciplinary guideline the Netherlands (NL) and algorithm by Mant et al. were validated in 203 geriatric patients (mean age 82 ± 6 years, 30% men) suspected of new, slow onset HF. HF was adjudicated by an outcome panel. Applicability of algorithms was evaluated by calculating proportion of patients (i) referred for echocardiography, (ii) with HF among referred patients and (iii) without HF in the non-referred.

RESULTS

ninety-two (45%) patients had HF. Applying algorithms resulted in referral for echocardiography in 52% (normal NT-proBNP; ESC), 72% (normal ECG; ESC), 56% (NICE), 93% (NL) and 70% (Mant) of all patients, diagnosing HF in 78, 56, 76, 49 and 62% of those referred, respectively. In patients not referred for echocardiography HF was absent in 90, 82, 93, 100 and 95%, respectively.

CONCLUSION

the ESC NT-proBNP (<400 pg/ml)-based algorithm combines the lowest number of referrals for echocardiography (of whom 78% has HF) with a limited number (10%) of false negatives in the non-referred.

Rapid point-of-care NT-proBNP optimal cut-off point for heart failure diagnosis in primary care

INTRODUCTION AND OBJECTIVES

Measurement of natriuretic peptides may be recommended prior to echocardiography in patients with suspected heart failure. Cut-off point for heart failure diagnosis in primary care is not well established. We aimed to assess the optimal diagnostic cut-off value of N-terminal pro-B-type natriuretic peptide on a community population attended in primary care.

METHODS

Prospective diagnostic accuracy study of a rapid point-of-care N-terminal pro-B-type natriuretic peptide test in a primary healthcare centre. Consecutive patients referred by their general practitioners to echocardiography due to suspected heart failure were included. Clinical history and physical examination based on Framingham criteria, electrocardiogram, chest X-ray, N-terminal pro-B-type natriuretic peptide measurement and echocardiogram were performed. Heart failure diagnosis was made by a cardiologist blinded to N-terminal pro-B-type natriuretic peptide value, using the European Society of Cardiology diagnosis criteria (clinical and echocardiographic data).

RESULTS

Of 220 patients evaluated (65.5% women; median 74 years [interquartile range 67-81]). Heart failure diagnosis was confirmed in 52 patients (23.6%), 16 (30.8%) with left ventricular ejection fraction <50% (39.6 [5.1]%). Median values of N-terminal pro-B-type natriuretic peptide were 715 pg/mL [interquartile range 510.5-1575] and 77.5 pg/mL [interquartile range 58-179.75] for patients with and without heart failure respectively. The best cut-off point was 280 pg/mL, with a receiver operating characteristic curve of 0.94 (95% confidence interval, 0.91-0.97). Six patients with heart failure diagnosis (11.5%) had N-terminal pro-B-type natriuretic peptide values <400 pg/mL. Measurement of natriuretic peptides would avoid 67% of requested echocardiograms.

CONCLUSIONS

In a community population attended in primary care, the best cut-off point of N-terminal pro-B-type natriuretic peptide to rule out heart failure was 280 pg/mL. N-terminal pro-B-type natriuretic peptide measurement improve work-out diagnoses and could be cost-effectiveness.

Anthracycline-induced cardiotoxicity: cardiac monitoring by continuous wave-Doppler ultrasound cardiac output monitoring and correlation to echocardiography

BACKGROUND

Anthracyclines are agents with a wellknown cardiotoxicity. The study sought to evaluate the hemodynamic response to an anthracycline using realtime continuous-wave (CW)-Doppler ultrasound cardiac output monitoring (USCOM) and echocardiography in combination with serum biomarkers.

METHODS

50 patients (26 male, 24 female, median age 59 years) suffering from various types of cancer received an anthracycline-based regimen. Patients' responses were measured at different time points (T0 prior to infusion, T1 6 h post infusion, T2 after 1 day, T3 after 7 days, and T4 after 3 months) with CW-Doppler ultrasound (T0-T4) and echocardiography (T1, T4) for hemodynamic parameters such as stroke volume (SV; SVUSCOM ml) and ejection fraction (EF; EFechocardiography%) and with NT-pro-BNP and hs-Troponin T (T0-T4).

RESULTS

During the 3-month observation period, the relative decrease in the EF determined by echocardiography was -2.1% (▵T0-T4, T0 71 ± 7.8%, T4 69.5 ± 7%, p = 0.04), whereas the decrease in SV observed using CW-Doppler was -6.5% (▵T0-T4, T0 54 ± 19.2 ml, T4 50.5 ± 20.6 ml, p = 0.14). The kinetics for serum biomarkers were inversely correlated.

CONCLUSIONS

Combining real-time CW-Doppler USCOM and serum biomarkers is feasible for monitoring the immediate and chronic hemodynamic changes during an anthracycline-based regimen; the results obtained were comparable to those from echocardiography.

Practical use of natriuretic peptide measurement: questionnaire results from general practitioners and cardiologists

AIMS

To elucidate the knowledge regarding B-type natriuretic peptide (BNP)/N-terminal proBNP (NT-proBNP) measurement among doctors using this biomarker.

MATERIALS & METHODS

We performed a questionnaire-based study on the use of BNP/NT-proBNP measurement among doctors; 21 general practitioners and 23 randomly chosen doctors at cardiology departments were interviewed.

RESULTS

12 general practitioners (57%) answered 'yes', eight (38%) answered 'no' and one (5%) was 'undecided' for use of BNP/NT-proBNP measurement to exclude a diagnosis of heart failure. Among cardiologists, 11 (48%) answered 'yes', ten (43%) answered 'no' and two (9%) were 'undecided' (no difference between groups, p = 0.56). The majority of doctors were familiar with BNP/NT-proBNP being affected by age but were unaware of the impact of gender and obesity.

CONCLUSION

We propose that BNP/NT-proBNP measurement results should be supplied with age- and gender-related cut-off values, along with a notion of the negative predictive value and other parameters affecting the concentration in plasma.

Natriuretic Peptide testing in primary care

The incidence, as well as the morbidity and mortality associated with heart failure (HF) continue to rise despite advances in diagnostics and therapeutics. A recent advance in the diagnostic and therapeutic approach to HF is the use of natriuretic peptide (NP) testing, including both B-type natriuretic peptide (BNP) and its amino terminal cleavage equivalent (NT-proBNP). NPs may be elevated at an early stage among those with symptoms as well among those without. The optimal approach for applying NP testing in general populations is to select the target population and optimal cut off values carefully. Superior diagnostic performance is observed among those with higher baseline risk (such as hypertensives or diabetics). As well, unlike for acute HF, the cut off value for outpatient testing for BNP is 20-40 pg/mL and for NTproBNP it is 100-150 ng/L. In symptomatic primary care patients, both BNP and NT-proBNP serve as excellent tools for excluding HF based on their excellent negative predictive values and their use may be cost effective. Among those with established HF, it is logical to assume that titration of treatment to achieve lower NPs levels may be advantageous. There are several ongoing trials looking at that prospect.

The Relationship between Serum NT- Pro-BNP Levels and Prognosis in Patients with Systolic Heart Failure

INTRODUCTION

Most studies reported using N-terminal pro-brain natriuretic peptide (NT-proBNP) in diagnosis of heart failure but there is controversy about use of these tests in determining prognosis and classification of severity of heart failure. The objective of this study was to determine the value of plasma NT-proBNP levels assessment in evaluation of mortality and morbidity of patients with systolic left ventricular dysfunction.

METHODS

A cohort study was performed in 150 patients with heart failure since September 2009 until February 2010. The patients were followed for 6 months to assess their prognosis. Patients were divided into two good and bad prognosis groups according to severity of heart failure in New York Heart Association (NYHA) class and frequency of hospital admission and mortality due to cardiac causes. Patients with good prognosis had ≥1 admission or no mortality or NYHA class ≥2 and patients that had one of this criteria considered as bad prognosis groups. Pro-BNP levels were measured at baseline and left ventricular ejection fraction (LVEF) was estimated with echocardiography. Data was analyzed with using Chi-square, t-test, ANOVA, Kruskal-Wallis tests.

RESULTS

In patients with heart failure that enrolled in this clinical study, ten patients were lost during follow-up. The mean of NT-proBNP is significantly correlated with ejection fraction (p=0.003) and NYHA class (p<0.001). In our study among 140 patients who were follow-up for 6 months, 11(9.7%) of individuals died with mean NT-proBNP of 8994.8±8375 pg/ml, in survived patients mean NT-proBNP was 3756.8±5645.6 pg/ml that was statistically significant (P=0.02). Mean NT-proBNP in the group with good prognosis was 2723.8±4845.2 pg/ml and in the group with bad prognosis was 5420.3±6681 pg/ml, difference was statistically significant (P=0.0001).

CONCLUSION

Our study in consistent with other studies confirms that NT-proBNP is significantly correlated with mortality and morbidity. This could be predicting adverse out come and stratification in patients with heart failure. It is recommended that more research be performed in Iran.

Diagnostic accuracy of point-of-care testing for acute coronary syndromes, heart failure and thromboembolic events in primary care: a cluster-randomised controlled trial

Background

Evidence of the clinical benefit of 3-in-1 point-of-care testing (POCT) for cardiac troponin T (cTnT), N-terminal pro-brain natriuretic peptide (NT-proBNP) and D-dimer in cardiovascular risk stratification at primary care level for diagnosing acute coronary syndromes (ACS), heart failure (HF) and thromboembolic events (TE) is very limited. The aim of this study is to analyse the diagnostic accuracy of POCT in primary care.

Methods

Prospective multicentre controlled trial cluster-randomised to POCT-assisted diagnosis and conventional diagnosis (controls). Men and women presenting in 68 primary care practices in Zurich County (Switzerland) with chest pain or symptoms of dyspnoea or TE were consecutively included after baseline consultation and working diagnosis. A follow-up visit including confirmed diagnosis was performed to determine the accuracy of the working diagnosis, and comparison of working diagnosis accuracy between the two groups.

Results

The 218 POCT patients and 151 conventional diagnosis controls were mostly similar in characteristics, symptoms and pre-existing diagnoses, but differed in working diagnosis frequencies. However, the follow-up visit showed no statistical intergroup difference in confirmed diagnosis frequencies. Working diagnoses overall were significantly more correct in the POCT group (75.7% vs 59.6%, p = 0.002), as were the working diagnoses of ACS/HF/TE (69.8% vs 45.2%, p = 0.002). All three biomarker tests showed good sensitivity and specificity.

Conclusion

POCT confers substantial benefit in primary care by correctly diagnosing significantly more patients.

Trial registration

DRKS: DRKS00000709

Serum N-terminal pro-B-type natriuretic peptide levels at the time of hospital admission predict of microvascular obstructions after primary percutaneous coronary intervention for acute ST-segment elevation myocardial infarction

BACKGROUND

Significant microvascular obstruction (MVO) during primary percutaneous coronary intervention (PCI) may suggest severe myocardial damage. The predictive value of N-terminal pro-B-type natriuretic peptide levels (NT-proBNP) for MVO has not been previously evaluated.

HYPOTHESIS

The purpose of the study was to determine whether NT-proBNP levels measured upon hospital admission of ST-segment elevation myocardial infarction (STEMI) patients receiving primary PCI have predictive value for MVO.

METHODS

NT-proBNP levels were obtained upon admission to the emergency department, for 41 acute STEMI patients. Cardiac contrast-enhanced magnetic resonance imaging (CE-MRI) was performed within 4 days after PCI. The optimal cut-off value to predict grade 3 MVO was determined using a receiver operating characteristic (ROC) curve. Multivariate regression analysis was performed to determine predictors for grade 3 MVO.

RESULTS

MVO grade correlated with left ventricular ejection fraction (LVEF; r =-0.383, P = 0.013), peak serum creatine kinase MB iso-enzyme (CK-MB; r = 0.470, P = 0.002), and NT-proBNP levels (r = 0.357, P = 0.022). The optimal cut-off value to predict grade 3 MVO was an NT-proBNP level of ≥80 pg/mL. Multivariate regression analysis, including LVEF, peak CK-MB, and an NT-proBNP ≥80 pg/mL revealed that only an NT-proBNP ≥80 pg/mL was an independent factor related to grade 3 MVO.

CONCLUSION

NT-proBNP levels upon hospital admission have a predictive value for MVOs. Further study is needed to determine if protective treatment strategies are warranted in STEMI patients with high NT-proBNP levels at presentation.

Value of brain natriuretic peptides in primary care patients with the clinical diagnosis of chronic heart failure

INTRODUCTION

Brain natriuretic peptide (BNP) and N-Terminal pro natriuretic peptide (NT-proBNP) are widely accepted to diagnose congestive heart failure (CHF) in the emergency room. The aim of this study was to evaluate the value of BNP and NT-proBNP to diagnose CHF in primary care.

METHODS

Clinical and Doppler-echocardiographic assessment of patients referred by their general practitioner (GP) with the diagnosis of CHF. Receiver operating curves were used to evaluate the accuracy of BNP and NT-proBNP for echocardiographically confirmed systolic and/or diastolic heart failure.

RESULTS

Three hundred and eighty four patients (mean age of 65) were included. One hundred and ninety three (50%) patients had systolic heart failure and 31 (8%) had isolated diastolic heart failure. Using currently recommended cut-off values of BNP (less than 100 pg/ml) and NT-proBNP (less than 125 pg/ml) for exclusion of CHF, BNP was false negative in 25% and NT-proBNP in 10% of the patients. The area under the curve was better for NT-proBNP than for BNP (0.742 vs. 0.691).

CONCLUSION

In this population with a high prevalence of CHF, BNP and NT-proBNP failed to adequately rule out CHF. GP's should be cautious when using BNP and NT-proBNP in primary care. An echocardiography remains compulsory in unexplained dyspnea.

N-terminal Pro brain natriuretic peptide is a reliable biomarker of reduced myocardial contractility in patients with lamin A/C gene mutations

BACKGROUND

Recently, concerns have been raised about a possible lack of sensitivity of biomarkers to detect left ventricular (LV) dysfunction in patients with myopathies. We examined the ability of the N-terminal brain natriuretic peptide (NT-proBNP) to detect LV or right ventricular (RV) dysfunction in patients with lamin A/C (LMNA) gene mutations.

METHODS

We prospectively measured plasma NT-proBNP in consecutive patients with documented LMNA mutations and age-sex matched controls. All patients underwent standard echocardiography implemented by pulsed tissue-Doppler echocardiography (TDE).

RESULTS

Twenty-three patients were included (10 males, mean age 39.2 ± 18.9 years);10 had previous atrial arrhythmias, 8 had been implanted with cardioverter defibrillator for primary prevention of sudden death, 5 patients were of NYHA class II and 18 of NHYA class I. Sinus rhythm was recorded in all. NT-proBNP was increased in LMNA patients versus controls (123 ± 229 versus 26 ± 78 pg/ml, p=0.0004); 7 patients had depressed LV and/or RV contractility. Patients with reduced LV or RV contractility had increased mean NT-proBNP (341 ± 1032 pg/ml versus 80 ± 79 pg/ml in patients with normal myocardial contractility, p=0.004). Receiver-operating-characteristics analysis shows that NT-proBNP reliably detected depressed contractility (area under the curve 0.889 [0.697-1.000]). Sensitivity and specificity were 88% and 83% respectively, applying manufacturer's recommended cut-off concentration of 125 pg/ml.

CONCLUSION

NT-proBNP reliably detected the presence of reduced LV/RV contractility in LMNA patients.

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.

Usefulness of natriuretic peptides in primary health care: an exploratory study in elderly patients

OBJECTIVE

To explore the negative predictive value (NPV), positive predictive value (PPV), sensitivity, and specificity of natriuretic peptides, cut-off levels, and the impact of gender and age in elderly patients with systolic heart failure (HF).

DESIGN

Cross-sectional exploratory study.

SETTING

One primary healthcare centre.

PATIENTS

A total of 109 patients with symptoms of HF were referred for echocardiographic examination with a cardiovascular consultation. Systolic HF was diagnosed (ESC guidelines) in 48 patients (46% men, 54% women, mean age 79 years) while 61 patients (21% men, 79% women, mean age 76 years) had no HF.

MAIN OUTCOME MEASURES

NPV, PPV, sensitivity, specificity, and cut-off levels.

RESULTS

Including all 109 patients, NPV was 88% for NT-proBNP (200 ng/L) and 87% for BNP (20 pg/ml). PPV was 81% for NT-proBNP (500 ng/L) and 68% for BNP (50 pg/ml). Sensitivity was 96% for NT-proBNP (100 ng/L) and 96% for BNP (10-20 pg/ml). Specificity was 87% for NT-proBNP (500 ng/L) and 71% for BNP (50 pg/ml). Nt-proBNP (beta = 0.035; p < 0.001) and BNP (beta = 0.030; p < 0.001) were associated with age, but not with gender. In a multivariate analysis age (beta = 0.036; p < 0.001) and male gender (beta = 0.270; p = 0.014) were associated with NT-proBNP, but only age for BNP (beta = 0.030; p < 0.001).

CONCLUSION

Natriuretic peptides in an elderly population showed high NPVs, but not as high as in younger patients with HF in other studies. Age and male gender were associated with higher levels of NT-proBNP while only age was related to elevated BNP levels.

Clinically relevant diagnostic research in primary care: the example of B-type natriuretic peptides in the detection of heart failure

With the emergence of novel diagnostic tests, e.g. point-of-care tests, clinically relevant empirical evidence is needed to assess whether such a test should be used in daily practice. With the example of the value of B-type natriuretic peptides (BNP) in the diagnostic assessment of suspected heart failure, we will discuss the major methodological issues crucial in diagnostic research; most notably the choice of the study population and the data analysis with a multivariable approach. BNP have been studied extensively in the emergency care setting, and also several studies in the primary care are available. The usefulness of this test when applied in combination with other readily available tests is still not adequately addressed in the relevant patient domain, i.e. those who are clinically suspected of heart failure by their GP. Future diagnostic research in primary care should be targeted much more at answering the clinically relevant question 'Is it useful to add this (new) test to the other tests I usually perform, including history taking and physical examination, in patients I suspect of having a certain disease'.

Prognostic threshold levels of NT-proBNP testing in primary care

AIMS

Chronic heart failure (HF) is a common condition with a poor prognosis. As delayed diagnosis and treatment of HF patients in primary care can be detrimental, risk-stratified waiting lists for echocardiography might optimize resource utilization. We investigated whether a prognostic threshold level of the cardiac peptide, NT-proBNP, could be identified.

METHODS AND RESULTS

From 2003-2005, 5875 primary care patients with suspected HF (median age 73 years) had NT-proBNP analysed in the Copenhagen area. Eighteen percent died and 20% had a cardiovascular (CV) hospitalization (median follow-up time: 1127 and 1038 days, respectively). In Cox proportional hazards regression models regarding NT-proBNP levels, the fourth decile (range: 83-118 pg/mL) was associated with a 90% (95% CI: 30-190, P < 0.01) increased risk for CV hospitalization and the seventh decile (range: 229-363 pg/mL) was associated with an 80% (95% CI: 20-190, P = 0.01) increased mortality risk after adjustment for age, sex, previous hospitalization, CV diseases, and chronic diseases.

CONCLUSION

We identified prognostic threshold levels for mortality and CV hospitalization for NT-proBNP in primary care patients suspected of HF. Our results have the potential to be used to risk-stratify waiting lists for echocardiography.

Spectrum bias--why clinicians need to be cautious when applying diagnostic test studies

When applying study results to their practice, the clinician is constrained by a number of factors, perhaps none more important than spectrum bias, which describes the effect a change in patient case mix may have on the performance of a test. Although the literature contains notable examples of spectrum bias, the emphasis has been to demonstrate its existence and its implications on study design rather than how it affects the clinician. Here a definition is proposed before considering it from a GP's perspective. As a patient's probability of disease is in part determined by the test's result, having reliable estimates of a test's performance is imperative to making good decisions on patient management. Knowing how the test performs on a patient usually means knowing its performance within a particular subgroup. Unfortunately, studies tend to report weighted average estimates of performance across broad populations. Such estimates may be inaccurate at an individual level and at a population level with the overall performance of the test in practice varying significantly from the average estimate reported, owing to differing case mixes. To avert such problems, investigators should design studies to evaluate tests over all relevant subgroups, and where this is not possible, to be explicit about the case mix in the study sample. Furthermore, GPs should endeavour to know both individual patients and practice populations as a whole in terms of demographics and co-morbidities before applying study results to their patients.

Validity of N-terminal propeptide of the brain natriuretic peptide in predicting left ventricular diastolic dysfunction diagnosed by tissue Doppler imaging in patients with chronic liver disease

BACKGROUND AND AIMS

Left ventricular diastolic dysfunction has been reported in patients with liver cirrhosis. Although conventional Doppler echocardiography has been used to assess diastolic filling dynamics, this technique is limited in diagnosing left ventricular diastolic dysfunction. The aim of the study was to validate the N-terminal propeptide of the brain natriuretic peptide (NT-proBNP) in predicting left ventricular diastolic dysfunction diagnosed by tissue Doppler imaging in patients with chronic liver disease.

METHODS

In 64 patients, left ventricular diastolic dysfunction was classified using tissue Doppler imaging and serum levels of NT-proBNP were measured.

RESULTS

Left ventricular diastolic dysfunction was found in 25 of 31 (80.6%) patients with severe liver fibrosis/cirrhosis versus 2 of 8 (25.0%) patients with moderate and 6 of 25 (24.0%) patients with mild liver fibrosis (P<0.001). Mean NT-proBNP levels were 407.1+/-553.4 pg/ml in patients with severe fibrosis/cirrhosis as compared with 60.8+/-54.9 pg/ml and 55.4+/-41.4 pg/ml in patients with mild and moderate fibrosis (P=0.001). NT-proBNP was most accurate in predicting advanced left ventricular diastolic dysfunction with an area under the receiver-operating characteristic curve of 0.90 (95% confidence interval, 0.77-1.0; P<0.001). A cutoff value of greater than 290 pg/ml was highly predictive of advanced left ventricular diastolic dysfunction.

CONCLUSION

NT-proBNP is a useful marker in detecting advanced left ventricular diastolic dysfunction in patients with chronic liver disease. Patients with severe liver fibrosis/cirrhosis and NT-proBNP levels exceeding 290 pg/ml should undergo further cardiac evaluation.

Natriuretic peptide vs. clinical information for diagnosis of left ventricular systolic dysfunction in primary care

BACKGROUND

Screening of primary care patients at risk for left ventricular systolic dysfunction by a simple blood-test might reduce referral rates for echocardiography. Whether or not natriuretic peptide testing is a useful and cost-effective diagnostic instrument in primary care settings, however, is still a matter of debate.

METHODS

N-terminal pro-brain natriuretic peptide (NT-proBNP) levels, clinical information, and echocardiographic data of left ventricular systolic function were collected in 542 family practice patients with at least one cardiovascular risk factor. We determined the diagnostic power of the NT-proBNP assessment in ruling out left ventricular systolic dysfunction and compared it to a risk score derived from a logistic regression model of easily acquired clinical information.

RESULTS

23 of 542 patients showed left ventricular systolic dysfunction. Both NT-proBNP and the clinical risk score consisting of dyspnea at exertion and ankle swelling, coronary artery disease and diuretic treatment showed excellent diagnostic power for ruling out left ventricular systolic dysfunction. AUC of NT-proBNP was 0.83 (95% CI, 0.75 to 0.92) with a sensitivity of 0.91 (95% CI, 0.71 to 0.98) and a specificity of 0.46 (95% CI, 0.41 to 0.50). AUC of the clinical risk score was 0.85 (95% CI, 0.79 to 0.91) with a sensitivity of 0.91 (95% CI, 0.71 to 0.98) and a specificity of 0.64 (95% CI, 0.59 to 0.67). 148 misclassifications using NT-proBNP and 55 using the clinical risk score revealed a significant difference (McNemar test; p < 0.001) that was based on the higher specificity of the clinical risk score.

CONCLUSION

The evaluation of clinical information is at least as effective as NT-proBNP testing in ruling out left ventricular systolic dysfunction in family practice patients at risk. If these results are confirmed in larger cohorts and in different samples, family physicians should be encouraged to rely on the diagnostic power of the clinical information from their patients.

Amino-terminal pro-B-type natriuretic peptide testing to assist the diagnostic evaluation of heart failure in symptomatic primary care patients

When used for the evaluation of symptomatic patients in general practice, amino-terminal pro-B-type natriuretic peptide (NT-proBNP) testing is highly sensitive, with an excellent negative predictive value for cost-effective exclusion of the diagnosis of heart failure (HF). Importantly (similar to other NP assays), lower values for NT-proBNP are expected among patients with HF in the primary care setting compared with patients with acute dyspnea. Among primary care patients with dyspnea, a noncardiac source of dyspnea is most likely in patients with findings below the recommended age-stratified NT-proBNP cut points. Conversely, an NT-proBNP result above the age-stratified primary care cut points does not absolutely indicate the presence of HF; a more directed cardiovascular workup is indicated.