Association of B-type natriuretic Peptide levels with estimated glomerular filtration rate and congestive heart failure

Cardiac magnetic resonance defines mechanisms of sex-based differences in outcomes following cardiac resynchronization therapy

Background

Mechanisms of sex-based differences in outcomes following cardiac resynchronization therapy (CRT) are poorly understood.

Objective

To use cardiac magnetic resonance (CMR) to define mechanisms of sex-based differences in outcomes after CRT and describe distinct CMR-based phenotypes of CRT candidates based on sex and non-ischemic/ischemic cardiomyopathy type.

Materials and methods

In a prospective study, sex-based differences in three short-term CRT response measures [fractional change in left ventricular end-systolic volume index 6 months after CRT (LVESVI-FC), B-type natriuretic peptide (BNP) 6 months after CRT, change in peak VO2 6 months after CRT], and long-term survival were evaluated with respect to 39 baseline parameters from CMR, exercise testing, laboratory testing, electrocardiograms, comorbid conditions, and other sources. CMR was also used to quantify the degree of left-ventricular mechanical dyssynchrony by deriving the circumferential uniformity ratio estimate (CURE-SVD) parameter from displacement encoding with stimulated echoes (DENSE) strain imaging. Statistical methods included multivariable linear regression with evaluation of interaction effects associated with sex and cardiomyopathy type (ischemic and non-ischemic cardiomyopathy) and survival analysis.

Results

Among 200 patients, the 54 female patients (27%) pre-CRT had a smaller CMR-based LVEDVI (p = 0.04), more mechanical dyssynchrony based on the validated CMR CURE-SVD parameter (p = 0.04), a lower frequency of both late gadolinium enhancement (LGE) and ischemic cardiomyopathy (p < 0.0001), a greater RVEF (p = 0.02), and a greater frequency of LBBB (p = 0.01). After categorization of patients into four groups based on cardiomyopathy type (ischemic/non-ischemic cardiomyopathy) and sex, female patients with non-ischemic cardiomyopathy had the lowest CURE-SVD (p = 0.003), the lowest pre-CRT BNP levels (p = 0.01), the lowest post-CRT BNP levels (p = 0.05), and the most favorable LVESVI-FC (p = 0.001). Overall, female patients had better 3-year survival before adjustment for cardiomyopathy type (p = 0.007, HR = 0.45) and after adjustment for cardiomyopathy type (p = 0.009, HR = 0.67).

Conclusion

CMR identifies distinct phenotypes of female CRT patients with non-ischemic and ischemic cardiomyopathy relative to male patients stratified by cardiomyopathy type. The more favorable short-term response and long-term survival outcomes in female heart failure patients with CRT were associated with lower indexed CMR-based LV volumes, decreased presence of scar associated with prior myocardial infarction and ICM, and greater CMR-based dyssynchrony with the CURE-SVD.

Machine learning for multidimensional response and survival after cardiac resynchronization therapy using features from cardiac magnetic resonance

Background

Cardiac resynchronization therapy (CRT) response is complex, and better approaches are required to predict survival and need for advanced therapies.

Objective

The objective was to use machine learning to characterize multidimensional CRT response and its relationship with long-term survival.

Methods

Associations of 39 baseline features (including cardiac magnetic resonance [CMR] findings and clinical parameters such as glomerular filtration rate [GFR]) with a multidimensional CRT response vector (consisting of post-CRT left ventricular end-systolic volume index [LVESVI] fractional change, post-CRT B-type natriuretic peptide, and change in peak VO₂) were evaluated. Machine learning generated response clusters, and cross-validation assessed associations of clusters with 4-year survival.

Results

Among 200 patients (median age 67.4 years, 27.0% women) with CRT and CMR, associations with more than 1 response parameter were noted for the CMR CURE-SVD dyssynchrony parameter (associated with post-CRT brain natriuretic peptide [BNP] and LVESVI fractional change) and GFR (associated with peak VO₂ and post-CRT BNP). Machine learning defined 3 response clusters: cluster 1 (n = 123, 90.2% survival [best]), cluster 2 (n = 45, 60.0% survival [intermediate]), and cluster 3 (n = 32, 34.4% survival [worst]). Adding the 6-month response cluster to baseline features improved the area under the receiver operating characteristic curve for 4-year survival from 0.78 to 0.86 (P = .02). A web-based application was developed for cluster determination in future patients.

Conclusion

Machine learning characterizes distinct CRT response clusters influenced by CMR features, kidney function, and other factors. These clusters have a strong and additive influence on long-term survival relative to baseline features.

Psychosocial characteristics of patients evaluated for kidney transplant and associations with functional and frailty metrics at a veterans affairs hospital

BACKGROUND

The effect of psychosocial problems on listing outcomes and potential interactions with functional metrics is not well-characterized among Veteran transplant candidates.

METHODS

The results from psychosocial evaluations, frailty metrics, and biochemical markers were collected on 375 consecutive Veteran kidney transplant candidates. Psychosocial diagnoses were compared between patients listed or denied for transplant. Functional abilities were compared among patients with or without psychosocial diagnoses and then evaluated based on reason for denial.

RESULTS

Eighty-four percent of patients had a psychosocial diagnosis. Common issues included substance or alcohol abuse (62%), psychiatric diagnoses (50%), and poor adherence (25%). Patients with psychiatric diagnoses, cognitive impairments, and poor adherence were more likely to be denied for transplant (P < .05). Patients with depression, PTSD, and anxiety did not have worse functional ability, but experienced more exhaustion than patients without these problems. Patients denied for medical but not purely psychosocial reasons had worse troponin and functional metrics compared with listed patients.

CONCLUSION

Over 80% of patients with a psychosocial diagnosis were listed; however, poor adherence was a particularly important reason for denial for purely psychosocial reasons. Patients with psychosocial diagnoses generally were not more functionally limited than their counterparts without psychosocial diagnoses or those listed for transplant.

Serum NGAL, BNP, PTH, and albumin do not improve glomerular filtration rate estimating formulas in children

Glomerular filtration rate (GFR) is difficult to measure, and estimating formulas are notorious for lacking precision. This study aims to assess if the inclusion of additional biomarkers improves the performance of eGFR formulas. A hundred and sixteen children with renal diseases were enrolled. Data for age, weight, height, inulin clearance (iGFR), serum creatinine, cystatin C, neutrophil gelatinase-associated lipocalin (NGAL), parathyroid hormone (PTH), albumin, and brain natriuretic peptide (BNP) were collected. These variables were added to the revised and combined (serum creatinine and cystatin C) Schwartz formulas, and the quadratic and combined quadratic formulas. We calculated the adjusted r-square (r²) in relation to iGFR and tested the improvement in variance explained by means of the likelihood ratio test. The combined Schwartz and the combined quadratic formulas yielded best results with an r² of 0.676 and 0.730, respectively. The addition of BNP and PTH to the combined Schwartz and quadratic formulas improved the variance slightly. NGAL and albumin failed to improve the prediction of GFR further. These study results also confirm that the addition of cystatin C improves the performance of estimating GFR formulas, in particular the Schwartz formula.Conclusion: The addition of serum NGAL, BNP, PTH, and albumin to the combined Schwartz and quadratic formulas for estimating GFR did not improve GFR prediction in our population. What is Known: • Estimating glomerular filtration rate (GFR) formulas include serum creatinine and/or cystatin C but lack precision when compared to measured GFR. • The serum concentrations of some biological parameters such as neutrophil gelatinase-associated lipocalin (NGAL), parathyroid hormone (PTH), albumin, and brain natriuretic peptide (BNP) vary with the level of renal function. What is New: • The addition of BNP and PTH to the combined quadratic formula improved its performance only slightly. NGAL and albumin failed to improve the prediction of GFR further.

Associations Between the Cyclic Guanosine Monophosphate Pathway and Cardiovascular Risk Factors: MESA

Background

cGMP mediates numerous cardioprotective functions and is a potential therapeutic target for cardiovascular disease. Preclinical studies suggest that plasma cGMP is reflective of natriuretic peptide stimulation. Epidemiologic associations between cGMP and natriuretic peptide, as well as cardiovascular disease risk factors, are unknown.

Methods and Results

We measured plasma cGMP in 542 men and 496 women free of cardiovascular disease and heart failure in MESA (Multi‐Ethnic Study of Atherosclerosis). Cross‐sectional associations of N‐terminal pro‐B type natriuretic peptide, sex hormones, and cardiovascular disease/heart failure risk factors with log(cGMP) were analyzed using multivariable linear regression models. Mean (SD) cGMP was 4.7 (2.6) pmol/mL, with no difference between the sexes. After adjusting for cardiovascular risk factors, N‐terminal pro‐B type natriuretic peptide was significantly positively associated with cGMP (P<0.05). Higher blood pressure and lower estimated glomerular filtration rate were associated with higher cGMP (P<0.05). Triglyceride levels, total/high‐density lipoprotein cholesterol ratio, presence of diabetes mellitus, and the homeostatic model assessment of insulin resistance were inversely associated with cGMP (P<0.05). Among women, free testosterone and dehydroepiandrosterone were inversely associated with cGMP, while sex hormone binding globulin was positively associated (P<0.05).

Conclusions

In a community‐cohort, plasma cGMP was associated with natriuretic peptide signaling. Higher blood pressure and greater renal dysfunction were positively associated with cGMP, while adverse metabolic risk factors were inversely associated. Increased androgenicity in postmenopausal women was inversely associated with cGMP. These novel associations further our understanding of the role of cGMP in a general population.

N-Terminal Pro B-Type Natriuretic Peptide and High-Sensitivity Cardiac Troponin T Levels Are Related to the Extent of Hibernating Myocardium in Patients With Ischemic Heart Failure

BACKGROUND

Increased N-terminal pro b-type natriuretic peptide (NT-proBNP) and high-sensitivity cardiac troponin T (hs-cTnT) can identify patients with heart failure (HF) who are at increased risk of cardiac events. The relationship of these biomarkers to the extent of hibernating myocardium and scar has not been previously characterized in patients with ischemic left ventricular dysfunction and HF.

METHODS

Patients with ischemic HF meeting recruitment criteria and undergoing perfusion and fluorodeoxyglucose-positron emission tomography to define myocardial hibernation and scar were included in the study. A total of 39 patients (mean age 67 ± 8 years) with New York Heart Association class II-IV HF and ischemic cardiomyopathy (ejection fraction [EF], 27.9% ± 8.5%) were enrolled in the study.

RESULTS

Serum NT-proBNP and hs-cTnT levels were elevated in patients with ≥ 10% hibernating myocardium compared with those with < 10% (NT-pro-BNP, 7419.10 ± 7169.5 pg/mL vs 2894.6 ± 2967.4 pg/mL; hs-cTnT, 789.3 ± 1835.3 pg/mL vs 44.8 ± 78.9 pg/mL; P < 0.05). The overall receiver operating characteristic under the curve value for NT-proBNP and hs-cTnT to predict hibernating myocardium was 0.76 and 0.78, respectively (P < 0.05). The NT-proBNP (P = 0.02) and hs-cTnT (P < 0.0001) levels also correlated with hibernation, particularly in patients with ≥ 10% scar, independent of EF, age, and estimated glomerular filtration rate. No differences were noted in biomarker levels for patients with vs those without ≥ 10% scar.

CONCLUSIONS

NT-proBNP and hs-cTnT levels are elevated in patients with ischemic HF hibernation and are correlated with the degree of hibernation but not with the presence or extent of scar. Taken together, these data support the novel concept that NT-proBNP and hs-cTnT release in patients with ischemic HF reflects the presence and extent of hibernating myocardium.

Estimated glomerular filtration rate is associated with both arterial stiffness and N-terminal pro-brain natriuretic peptide in newly diagnosed hypertensive patients

Even a slight decrease in the glomerular filtration rate (GFR) is an independent risk factor for cardiovascular disease. Arterial stiffness, left ventricular hypertrophy and N-terminal pro-brain natriuretic peptide (NT-proBNP) are independent risk factors for cardiovascular disease, which are particularly common in end-stage renal disease. We aimed to evaluate the association between GFR with arterial stiffness, left ventricle mass (LVM) and NT-proBNP in hypertensive subjects with normal to mildly impaired renal function. The study population consisted of 285 newly diagnosed hypertensive patients (mean age; 49.9 ± 11.8 years). GFR was estimated (eGFR) by the Modification of Diet in Renal Disease formula. Pulse wave velocity (PWV) and augmentation index (AIx), which reflects arterial stiffness, were calculated using the single-point method via the Mobil-O-Graph® ARCsolver algorithm. LVM was obtained by echocardiography. Plasma NT-proBNP was measured by electrochemiluminescence. The patients were divided into two groups according to the median eGFR value (eGFRlow group <101 ml/min/1.73 m(2) and eGFRhigh group ≥ 101 ml/min/1.73 m(2)). LVM and NT-proBNP values were higher in eGFRlow group compared with eGFRhigh group (p<0.05). Pulse wave velocity and augmentation index values were higher in eGFRlow group compared with eGFRhigh group (p<0.05, for all). Multiple linear regression analysis showed that eGFR was independently associated with PWV (β=-0.422, p<0.001) and NT-proBNP (β=-0.404, p<0.001). Present study showed that eGFR was independently associated with PWV and NT-proBNP values. Importantly, these findings may explain, in part, the increase in cardiovascular risk in with slightly impaired renal function.

Myocardial dysfunction and chronic heart failure in patients with long-lasting type 1 diabetes: a 7-year prospective cohort study

The aim of the study is to evaluate the prevalence and incidence of myocardial dysfunction (MD) and heart failure (HF) in long-lasting (≥10 years) type 1 diabetes without cardiovascular disorders or with hypertension or coronary heart disease (CHD). The study included 1,685 patients with type 1 diabetes (mean baseline age, 51 years; diabetes duration, 36 years). In all patients, echocardiography was performed, NT-proBNP levels were measured, and clinical symptoms were evaluated. A 7-year follow-up was conducted to monitor systolic and diastolic manifestations of MD and HF. At the end of the follow-up period, the prevalence of HF in the entire group was 3.7 %, and the incidence was 0.02 % per year. The prevalence of MD was 14.5 % and the incidence -0.1 % per year. MD and HF were observed only in hypertensive or CHD patients. At baseline, subjects with diastolic HF constituted 85 % of the HF population and those with systolic HF the remaining 15 %. Baseline HF predictors included age, diabetes duration, HbA1c levels, CHD, systolic blood pressure >140 mmHg, and GFR <60 mL/min/1.73 m(2). In patients with type 1 diabetes, MD and HF occurred only when diabetes coexisted with cardiovascular disorders affecting myocardial function. The prevalence and incidence of HF in patients with hypertension and CHD were relatively low. While the cause of this observation remains uncertain, it could probably be explained, at least partially, by the cardioprotective effect of concomitant treatment.

[Prognostic role of NT-proBNP in emergency department in the elderly with acute heart failure]

OBJECTIVE

To determine prognostic role of NT-proBNP as predictor of 30 day-mortality and readmission in the elderly with acute heart failure (AHF) treated in Spanish Emergency Departments (EDs), and to analyse the confounding factors when the NT-proBNP value is interpreted.

MATERIAL AND METHODS

A multicentre and multi-purpose cohort study with prospective follow-up was conducted on all patients aged 65 years or older with AHF treated in Spanish EDs. The variables recorded include demographic characteristics, comorbidity, details of episode, and NT-proBNP value. The outcome variables were 30 day-mortality and readmission. An NT-proBNP ≥ 5,180 pg/ml was adopted as the cut-off limit. The statistical package SPSS 18.0 was used to analyse the data.

RESULTS

A total of 585 patients were included, with a mean age of 80.4 (SD: 6.9) years old. The cut-off NT-proBNP ≥ 5,180 pg/ml was independently associated with a severely impaired glomerular filtration (<30 ml/h) (P < .001) and severe episode (NYHA II-IV) (P = .012). The NT-proBNP area under curve (AUC) for 30 day-mortality was 0.71 (CI 95%: 0.63-0.77; P < .001) and for 30 day-readmission, was 0.50 (CI 95%: 0.45-0.56; P = .846). A multivariable analysis showed that the cut-off NT-proBNP ≥ 5,180 pg/ml was an independent factor associated with 30 day-mortality in the elderly with AHF attended in Spanish EDs.

CONCLUSIONS

The NT-proBNP value is associated with short-term mortality in the elderly with AHF attended in the EDs independently of the presence of confounding factors, such as the severity of the episode and glomerular filtration reduction, but not with 30 day-readmission.

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.

High-sensitive troponin T and N-terminal pro-B type natriuretic peptide are associated with cardiovascular events despite the cross-sectional association with albuminuria and glomerular filtration rate

AIMS

It has been suggested that troponins and natriuretic peptides can be falsely elevated in subjects with impaired kidney function because of decreased renal clearance. The value of these biomarkers in subjects with impaired kidney function has therefore been debated. We tested in a population-based cohort study, first, whether high-sensitive troponin T (hsTnT) and N-terminal pro-B-type natriuretic peptide (NT-pro-BNP) levels are cross-sectionally associated with the estimated glomerular filtration rate (eGFR) and albuminuria, and secondly, whether these markers are associated with cardiovascular outcome, independent of eGFR, albuminuria and conventional cardiovascular risk factors.

METHODS AND RESULTS

We included 8121 subjects from the PREVEND study with both values of hsTnT and NT-pro-BNP available. High-sensitive troponin T >0.01 µg/L and NT-pro-BNP >125 ng/L were defined as elevated. We first performed linear regression analyses with hsTnT and NT-pro-BNP as dependent variables. Next, we performed Cox-regression analyses, studying the associations of hsTnT and NT-pro-BNP with incident cardiovascular events. Of our cohort, 6.7% had an elevated hsTnT and 12.2% an elevated NT-pro-BNP. Also, the estimated glomerular filtration rate, albuminuria, and ECG-assessed ischaemia and left ventricular hypertrophy were all significantly associated with hsTnT and NT-pro-BNP in the linear regression analyses. Both hsTnT and NT-pro-BNP appeared associated with cardiovascular events, and these associations remained significant after adjustment for eGFR, albuminuria, age, gender and conventional cardiovascular risk factors (P= 0.03 and P< 0.001, respectively). Only a few subjects with markedly reduced renal function were included. The results presented are therefore mainly valid for a population with mildly impaired renal function.

CONCLUSION

These data indicate that a finding of an increased hsTnT or NT-pro-BNP in subjects with chronic kidney disease stages 1/3 should be taken seriously as a prognostic marker for a worse cardiovascular outcome and not be discarded as merely a reflection of decreased renal clearance.

Biomonitors of cardiac injury and performance: B-type natriuretic peptide and troponin as monitors of hemodynamics and oxygen transport balance

Serum biomarkers, such as B-type natriuretic peptide and troponin, are frequently measured in the cardiac intensive care unit. A review of the evidence supporting monitoring of these biomarkers is presented.

DESIGN

A search of MEDLINE, PubMed, and the Cochrane Database was conducted to find literature regarding the use of B-type natriuretic peptide and troponin in the cardiac intensive care setting. Adult and pediatric data were considered.

RESULTS AND CONCLUSION

Both B-type natriuretic peptide and troponin have demonstrated utility in the intensive care setting but there is no conclusive evidence at this time that either biomarker can be used to guide inpatient management of children with cardiac disease. Although B-type natriuretic peptide and troponin concentrations can alert clinicians to myocardial stress, injury, or hemodynamic alterations, the levels can also be elevated in a variety of clinical scenarios, including sepsis. Observational studies have demonstrated that perioperative measurement of these biomarkers can predict postoperative mortality and complications.

RECOMMENDATION AND LEVEL OF EVIDENCE

(class IIb, level of evidence B): The use of B-type natriuretic peptide and/or troponin measurements in the evaluation of hemodynamics and postoperative outcome in pediatric cardiac patients may be beneficial.

Relationship of brain natriuretic peptide concentrations to left ventricular function and adverse outcomes in children with end-stage renal disease undergoing hemodialysis

B-type natriuretic peptide (BNP) is a biomarker of cardiovascular disease that is common in adults with chronic kidney disease (CKD). However, in children with CKD, the range and predictive power of BNP concentrations are not known. We aimed to determine the effect of HD on BNP, as well as the prognostic impact of BNP, in end-stage renal disease (ESRD) children undergoing hemodialysis (HD). Thirty-five children with chronic renal failure (16 boys age 12.1 ± 3.7 years) on maintenance HD were included. BNP level was measured, and Doppler echocardiography was performed 30 min before (pre-HD BNP) and 30 min after (post-HD BNP) HD in each patient. An adverse event was defined as all-cause death and heart failure hospitalization. The median pre-HD BNP, the post-HD BNP, and the change in BNP were, respectively, 240 pg/ml (72 to 3346), 318 pg/ml (79 to 3788), and 9 pg/ml (-442 to 1889). Pre-HD BNP concentration was negatively correlated with left ventricular (LV) ejection fraction (r = -0.41, P = 0.018). During a mean follow-up of 39 ± 14 months, 6 patients died, and 3 were hospitalized for heart failure. Using univariate analysis, BNP before and after HD as well as Doppler tissue imaging velocities had a strong graded relationship with adverse events. Cox proportional hazards model demonstrated that pre-HD body weight (P = 0.008), pre-HD BNP (P = 0.011), and post-HD BNP (P = 0.038) remained independent predictors of adverse outcome. Even in case of ESRD, BNP still strongly correlated with LV systolic and diastolic dysfunction and was associated with mortality in HD children.

Physical exercise with weight reduction lowers blood pressure and improves abnormal left ventricular relaxation in pharmacologically treated hypertensive patients

In spite of appropriate pharmacologic therapy, many hypertensive patients develop an abnormal left ventricular relaxation with preserved systolic function. This cardiac dysfunction increases the risk of cardiovascular complications. The authors assessed the therapeutic effects of an intervention with exercise training and weight reduction in patients with pharmacologically well-treated hypertension who had abnormal left ventricular relaxation with normal systolic function. Eighty-eight (44%) of 202 medically treated hypertensive patients had abnormal ventricular relaxation with normal ejection fraction. These patients were randomized to either a 6-month intervention program (cycle ergometer training twice a day for 5 days a week and a hypocaloric diet) or a control program (unchanged pharmacologic therapy without exercise and diet. Body weight, blood pressure, New York Heart Association class, glomerular filtration rate, and exercise capacity and workload were measured. Cardiac function was assessed by measuring N-terminal pro-B-type natriuretic peptide values, the electrocardiographic QT dispersion interval, and echocardiography (left atrial size, Doppler-derived E/A ratio, and mitral deceleration time). Physical exercise with weight reduction reduced blood pressure, decreased cardiovascular risks, and improved abnormal left ventricular relaxation. Measuring left atrial size is the best method for assessing changes in left ventricular relaxation with preserved systolic function.