Clinical applications of N-terminal pro B-type natriuretic peptide in heart failure and other cardiovascular diseases

Risk factors for inspiratory muscle weakness in coronary heart disease

BACKGROUND

Patients with coronary heart disease (CHD) are susceptible to lung function problems caused by respiratory muscle weakness. Many CHD patients show complications of respiratory muscle weakness, but the risk factors remain unclear.

OBJECTIVE

To explore the risk factors for inspiratory muscle weakness in CHD.

METHODS

This study enrolled 249 patients with CHD who underwent maximal inspiratory pressure (MIP) measurement between April 2021 and March 2022.According to the percentage of MIP (MIP/Predicted normal value [PNV]), patients were divided into the inspiratory muscle weakness (IMW) (n = 149) (MIP/PNV<70%) and control groups (n = 100) (MIP/PNV≥70༅). Clinical information and MIP of the two groups were collected and analyzed.

RESULTS

The incidence of IMW was 59.8% (n = 149). Age (P < 0.001); history of heart failure (P < 0.001), hypertension (P = 0.04), and peripheral artery disease (PAD) (P = 0.001); left ventricular end-systolic dimension (P = 0.035); presence of segmental motion abnormality of the ventricular wall (P = 0.030); and high density lipoprotein cholesterol (P = 0.001) and N-terminal brain natriuretic peptide (NT-proBNP) levels (P < 0.001) in the IMW group were significantly higher than those in the control group. The proportion of anatomic complete revascularization (P = 0.009), left ventricular ejection fraction (P = 0.010), and alanine transaminase (P = 0.014) and triglycerides levels (P = 0.014) in the IMW group were significantly lower than those in the control group. Logistic regression analysis showed that anatomic complete revascularization (OR=0.350, 95%CI 0.157-0.781) and NT-proBNP level (OR=1.002, 95%CI 1.000-1.004) were independent risk factors for IMW.

CONCLUSION

The independent risk factors for decreased IMW in patients with CAD were anatomic incomplete revascularization and NT-proBNP level.

Contemporary clinical management of monomorphic idiopathic premature ventricular contractions: results of the European Heart Rhythm Association Survey

On behalf of the European Heart Rhythm Association, we designed a survey, whose aim was to understand the trend(s) in the clinical management of idiopathic monomorphic premature ventricular contractions (PVCs) among European cardiologists and cardiac electrophysiologists. A total of 202 participants in the survey answered 27 multiple-choice questions on the clinical presentation, diagnosis and treatment of idiopathic monomorphic PVCs. The most common symptom in patients with idiopathic monomorphic PVCs is palpitations, according to the majority of responders (87%), followed by fatigue (29%) and dizziness (18%). Complete blood cell count, renal function with electrolytes levels, and thyroid function are the blood tests requested by the majority of respondents (65%, 92%, and 93%, respectively). Coronary artery disease and structural heart disease needs to be ruled out, according to the vast majority of participants (99%). A 24-h Holter ECG is the preferred ECG modality to assess the burden of PVCs (86% of respondents). Among the different option treatments, beta-blockers and class I antiarrhythmic drugs are by far (81% of respondents) the preferred pharmacological option in comparison with calcium antagonists and class III antiarrhythmic drugs. Catheter ablation has also a good reputation: 99% of responders are keen to use it, especially in patients with high burden of PVCs and when signs of cardiomyopathy occur.

The role of acute heart failure index (AHFI) combined with emergency heart failure mortality risk grade (EHMRG) in the evaluation of clinical outcomes and prognosis in patients with acute heart failure

OBJECTIVE

To investigate clinical value for the risk model of acute heart failure index (AHFI) combined with emergency heart failure mortality risk grade (EHMRG) in evaluating clinical outcomes and prognosis of patients with acute heart failure (AHF).

METHODS

The present prospective observational cohort study enrolled a total of 228 patients with AHF who were admitted to our hospital from January 2019 to January 2020. The AHF patients were divided into four groups: (1) the high AHFI and high EHMRG group, n = 61; (2) the low AHFI and low EHMRG group, n = 92; (3) the high AHFI and low EHMRG group, n = 34; (4) the low AHFI and high EHMRG group, n = 41. AHFI and EHMRG were used to identify the risk of death for AHF patients. Serum levels of Troponin I, B-type natriuretic peptide (BNP), and NT-pro-B-type natriuretic peptide (NT-proBNP) were detected by the ELISA method. Kaplan-Meier curve was performed for analysis of survival time and a logistic regression model was used to analyse 1-year mortality of patients. Pearson's analysis was used to determine the correlation between biomarkers and EHMRG.

RESULTS

AHFI combined with the EHMRG model was associated with cardiac function status and EHMRG score was positively related to the level of Troponin I, BNP, and NT-proBNP. AHF high-risk AHFI and high-risk EHMRG indicated that patients might have a higher incidence of MACEs during hospitalisation. In addition, AHFI and high-risk EHMRG groups had shorter survival times, and AHFI was associated with 1-year mortality and was the risk factor for 1-year mortality.

CONCLUSION

AHFI combined with a high EHMRG risk model was associated with clinical outcomes and prognosis.

Are troponin and B-type natriuretic peptides useful biomarkers for the diagnosis of systemic sclerosis heart involvement? A systematic literature review

BACKGROUND

Systemic sclerosis (SSc) heart involvement (SHI) is a leading cause of SSc-associated mortality and once clinically overt, carries a very poor prognosis. There remain no established diagnostic criteria for SHI. This study aimed to systematically review the literature regarding the role of cardiac troponin (cTn) and B-type natriuretic peptide (BNP) or N-terminal B-type natriuretic peptide (NT-proBNP) in the diagnosis of SHI.

METHODS

A comprehensive search of the MEDLINE (Ovid), EMBASE and Pubmed databases was performed to identify adult human studies of at least 10 SSc patients with a primary focus of SHI that included data on cTn and BNP or NT-proBNP results. Only cohort studies and case-controlled studies were identified and the quality of the evidence presented in each study was assessed according to the Newcastle-Ottawa Quality Assessment Scale.

RESULTS

Of the 2742 studies identified by the database search, 12 articles fulfilled the study inclusion criteria. Three out of four studies evaluating SHI using cardiac magnetic resonance imaging found no association between cardiac biomarkers and imaging changes. By comparison echocardiographic abnormalities, cardiac arrhythmias and congestive cardiac failure were more likely to be associated with elevated cardiac biomarkers. Comparison of results between studies was limited by the highly heterogenous definitions of SHI and inclusion criteria employed across studies.

CONCLUSION

There are insufficient data to draw definitive conclusions about the role of cTn and BNP / NT-proBNP in the diagnosis of SHI. Currently available literature suggests that cardiac biomarkers may have some role, in conjunction with other diagnostic modalities, in identifying SHI; however, this remains a much-needed area of clinical research.

Value of N-Terminal Pro-Brain Natriuretic Peptide in Predicting Perioperative Complications Following Spine Surgery

OBJECTIVE

The utility of preoperative biomarkers for assessing perioperative complications in patients undergoing spine surgery (SS) is unclear, and no study has assessed the ability of preoperative natriuretic peptides to predict adverse events following SS. This study aimed to evaluate the prognostic importance of N-terminal pro-brain natriuretic peptide (NT-proBNP) in patients undergoing SS.

METHODS

We prospectively followed 154 consecutive adult patients ≥50 years old hospitalized for elective SS. The outcomes of interest were length of stay in hospital and perioperative medical complications during hospitalization, defined as pneumonia, deep or organ space surgical site infection, bacteremia, prolonged mechanical ventilation >48 hours, unplanned reintubation, acute renal failure, sepsis or septic shock, venous thromboembolism (deep vein thrombosis or pulmonary embolism), cardiac arrest, stroke, myocardial infarction, return to operating room, and in-hospital mortality.

RESULTS

In 21 (13.6%) patients, 32 episodes of medical adverse events occurred. Older patients and patients with more comorbid conditions, such as heart failure, diabetes, cerebrovascular disease, coronary artery disease, and chronic obstructive pulmonary disease, tended to have a higher rate of adverse events. Patients with adverse events had higher NT-proBNP and troponin levels on admission compared with patients without adverse events. Multivariate analysis showed that NT-proBNP >242 pg/ml (odds ratio 2.374; 95% confidence interval, 1.000-2.958; P = 0.001) and presence of diabetes (odds ratio 2.16; 95% confidence interval, 1.86-7.89; P = 0.008) were significant and independent predictors of perioperative adverse events.

CONCLUSIONS

This study demonstrates that preoperative NT-proBNP level in patients undergoing SS could be a valuable prognostic marker for several postoperative complications.

Velocity vector imaging echocardiography and NT-proBNP study of fetal cardiac function in pregnancy-induced maternal hypertension

PURPOSE

To investigate whether acute and transient pressure overload in patients with pregnancy-induced hypertension affects cardiac function in fetuses.

METHODS

We enrolled 104 singleton pregnant women with gestational ages ranging 30 to 33 weeks, visiting for prenatal care. Among them, 34 had gestational hypertension (GH), 32 had preeclampsia (PE), and 38 were healthy and formed the control group. Conventional echocardiographic and velocity vector imaging (VVI) variables were prospectively collected. Blood levels of N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured from cord blood drawn at birth.

RESULTS

The fetuses of mothers with preeclampsia had significantly lower left (LV) and right ventricle (RV) diastolic strain rate (SRd) and RV strain (S) and systolic strain rate (SRs) than controls. LV and RV S, SRd, and SRS were not different in fetuses of mothers with GH and controls. The NT-proBNP levels were higher in fetuses of patients with PE than in GH and controls.

CONCLUSIONS

In the third trimester of pregnancy, fetal biventricular function and NT-proBNP levels are not significantly influenced by GH. Fetuses of mothers with PE present signs of LV and RV diastolic dysfunction, right ventricular systolic dysfunction, and elevated NT-pro-BNP levels. VVI echocardiography appears more sensitive than conventional echocardiography to evaluate fetal cardiac function.

N-terminal pro-brain natriuretic peptide levels had an independent and added ability in the evaluation of all-cause mortality in older Chinese patients with atrial fibrillation

BACKGROUND

Atrial fibrillation (AF) is the most common arrhythmia and has increased prevalence in older patients, leading to poor prognosis for these patients. There is a need for a biomarker or a model of prognostic evaluation in older patients with AF, especially in China. CHADS₂ and CHA₂DS₂VASc scores have been applied to evaluate their prognosis in patients with AF. This analysis was designed to examine whether N-terminal pro-brain natriuretic peptide (NT-proBNP) levels significantly improved the evaluation of all-cause mortality in older Chinese patients with AF when added to CHADS₂ and CHA₂DS₂VASc scores.

METHODS

There were 219 older patients with AF, and follow-up was 100% complete over an average of 1.11 years. Cox regression analysis was applied to determine the variables independently associated with all-cause mortality.

RESULTS

Median age was 85 years, and all-cause mortality was 24.2% (53 patients). Plasma NT-proBNP levels were significantly associated with all-cause mortality in univariate [hazard ratio (HR): 1.842; 95% confidence interval (CI): 1.530-2.218] and multivariate (HR: 1.377; 95% CI: 1.063-1.785) Cox regression analyses and had significantly higher c-statistic (0.771; 95% CI: 0.698-0.845) than CHADS₂ (0.639; 95% CI: 0.552-0.726) and CHA₂DS₂VASc (0.633; 95% CI: 0.546-0.720) scores (P < 0.05 for all). The addition of NT-proBNP levels to CHADS₂ (0.783; 95% CI: 0.713-0.854) and CHA₂DS₂VASc (0.775; 95% CI: 0.704-0.846) scores significantly increased their c-statistics (P < 0.001 for all). Model based on NT-proBNP levels including age, hemoglobin, fasting blood glucose, glomerular filtration rate and NT-proBNP levels had a significantly higher c-statistic (0.890; 95% CI: 0.841-0.938) than CHADS₂ and CHA₂DS₂VASc scores (P < 0.001 for all). Model based on NT-proBNP levels had significantly higher c-statistic than the addition of NT-proBNP levels to CHADS₂ and CHA₂DS₂VASc scores (P < 0.05).

CONCLUSION

NT-proBNP levels were an independent biomarker associated with an increased all-cause mortality in older Chinese patients with AF, and had an independent and added ability to evaluate their all-cause mortality compared with CHADS₂ and CHA₂DS₂VASc scores.

Pro-BDNF Contributes to Hypoxia/Reoxygenation Injury in Myocardial Microvascular Endothelial Cells: Roles of Receptors p75NTR and Sortilin and Activation of JNK and Caspase 3

The aim of this study was to identify the role of the precursor of the brain-derived neurotrophic factor (pro-BDNF) in myocardial hypoxia/reoxygenation injury (H/R) and to address the underlying mechanisms. For this purpose, myocardial microvascular endothelial cells (MMECs) exposed to a high concentration of glucose (30 mM) for 48 h were subjected to 4 h of hypoxia followed by 2 h of reoxygenation. Terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) staining and flow-cytometric analysis were performed to detect apoptosis. Cell scratch and capillary-like-structure formation assays were employed to evaluate cell function. The levels of apoptosis-related proteins were evaluated by Western blotting and immunofluorescence assays. Our results showed that H/R resulted in MMEC injury, as indicated by significant increases in TUNEL-positive cell numbers and a reduction in MMEC migration and in capillary-like-structure formation coupled with increased pro-BDNF protein expression. In addition, overexpression of pro-BDNF in MMECs via a viral vector led to increased pro-BDNF expression, and this upregulation induced apoptosis. Mechanistic experiments revealed that H/R did not influence BDNF, JNK, and caspase 3 expression, but upregulated pro-BDNF, p75^NTR, sortilin, phospho-JNK, and cleaved caspase 3 protein levels. In contrast, neutralization of endogenous pro-BDNF with an antibody significantly attenuated H/R-induced upregulation of pro-BDNF, p75^NTR, sortilin, p-JNK, and cleaved caspase 3 protein levels, indicating that p75^NTR-sortilin signaling and activation of JNK and caspase 3 may be involved in these effects. In conclusion, H/R-induced injury may be mediated by pro-BDNF, at least in part through the regulation of p75^NTR-sortilin signaling and activation of JNK and caspase 3.

Isorhamnetin protects against hypoxia/reoxygenation-induced injure by attenuating apoptosis and oxidative stress in H9c2 cardiomyocytes

To unveil the possible protective role of isorhamnetin, an immediate 3'-O-methylated metabolite of quercetin, in cardiomyocyte under hypoxia/reoxygenation (H/R) condition and the underlying mechanisms involved, H9c2 cardiomyocytes were exposed to the vehicle or H/R for 6 h (2 h of hypoxia following by 4 h of reoxygenation) with isorhamnetin (0, 3, 6, 12, 25, 50 μM for 4 h prior to H/R exposure). Apoptosis was evaluated by TUNEL staining, flow cytometry analysis and western blot assay for cleaved caspase-3. Myocardial injure in vivo was determined by infarct size using TTC staining, histological damage using H&E staining and myocardial apoptosis. Here, we found that isorhamnetin dose-dependently protected H9c2 cardiomyocytes against H/R-induced injure, as evidenced by the reduction in lactate dehydrogenase (LDH) levels, increases in cell viability, superoxide dismutase (SOD) and catalase (CAT) activity, with the maximal effects at 25 μΜ. In addition, isorhamnetin treatment significantly inhibited apoptosis in H/R-induced H9c2 cardiomyocytes and ameliorated H/R-induced myocardial injure in vivo, concomitant with the upregulation of sirtuin 1 (SIRT1) expression. Mechanism studies demonstrated that isorhamnetin pretreatment remarkably abolished H/R-induced downregulation of Nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) expressions and upregulation of NADPH oxidase-2/4 (NOX-2/4) expressions in cardiomyocytes. However, SIRT1 inhibition (Sirtinol) not only inhibited isorhamnetin-induced Nrf2/HO-1 upregulation and NOX-2/4 downregulation, but also alleviated its anti-apoptotic effects. Taken together, these data indicate that isorhamnetin can exhibit positive effect on H/R-induced injure by attenuating apoptosis and oxidative stress in H9c2 cardiomyocytes, which is partly attributable to the upregulation of SIRT1 and Nrf2/HO-1-mediated antioxidant signaling pathway.

Blood, tissue and imaging biomarkers in calcific aortic valve stenosis: past, present and future

PURPOSE OF REVIEW

Calcific aortic valve stenosis is the most prevalent valvular heart disease in the high-income countries. To this date, no medical therapy has been proven to prevent or to stop the progression of aortic valve stenosis. The physiopathology of aortic valve stenosis is highly complex and involves several signalling pathways, as well as genetic related factors, which delay the elaboration of effective pharmacotherapies. Moreover, it is difficult to predict accurately the progression of the valve stenosis and finding the optimal timing for aortic valve replacement remains challenging. Therefore, the present review makes an inventory of the most recent and promising circulating and imaging biomarkers related to the underlying mechanisms involved in the physiopathology of aortic valve stenosis, as well as the biomarkers associated with the left ventricular (LV) remodelling and subsequent dysfunction in patients with aortic valve stenosis.

RECENT FINDINGS

Over the last decade, several blood, tissue and imaging biomarkers have been investigated in aortic valve stenosis patients. At the aortic valve level, these biomarkers are mostly associated and/or involved with processes such as lipid infiltration and oxidation, chronic inflammation and fibrocalcific remodelling of the valve. Moreover, recent findings suggest that aging and sex hormones might interact with these multiple processes. Several studies demonstrated the usefulness of circulating biomarkers such as lipoprotein(a), brain natriuretic peptides and high-sensitivity cardiac troponin, which are very close to clinical routine. Furthermore, noninvasive imaging biomarkers including positron emission tomography and cardiac magnetic resonance, which provide a detailed view of the disease activity within the aortic valve and its repercussion on the left ventricle, may help to improve the understanding of aortic valve stenosis physiopathology and enhance the risk stratification. Other biomarkers such as von Willebrand factor and microRNAs are promising but further studies are needed to prove their additive value in aortic valve stenosis.

SUMMARY

Most of the biomarkers are used in research and thus, are still being investigated. However, some biomarkers including plasma level of lipoprotein(a), F-sodium fluoride, brain natriuretic peptides and high-sensitivity cardiac troponin can be or are very close to be used for the clinical management of patients with aortic valve stenosis. Moreover, a multibiomarker approach might provide a more global view of the disease activity and improve the management strategies of these patients.

NT-proBNP as early marker of subclinical late cardiotoxicity after doxorubicin therapy and mediastinal irradiation in childhood cancer survivors

BACKGROUND

Childhood cancer survivors treated with anthracyclines and mediastinal irradiation are at risk for late onset cardiotoxicity.

AIMS OF THE STUDY

To assess the role of N-terminal pro-brain natriuretic peptide (NT-proBNP) and tissue Doppler imaging (TDI) as early predictors of late onset cardiotoxicity in asymptomatic survivors of childhood cancer treated with doxorubicin with or without mediastinal irradiation.

METHODS

A cross-sectional study on 58 asymptomatic survivors of childhood cancer who received doxorubicin in their treatment protocols and 32 asymptomatic Hodgkin's lymphoma survivors who received anthracycline and mediastinal irradiation. Levels of NT-proBNP, TDI, and conventional echocardiography were determined.

RESULTS

Thirty percent of survivors had abnormal NT-proBNP levels. It was significantly related to age at diagnosis, duration of follow-up, and cumulative dose of doxorubicin. TDI detected myocardial affection in 20% more than conventional echocardiography. Furthermore, abnormalities in TDI and NT-pro-BNP levels were more common in Hodgkin lymphoma survivors receiving both chemotherapy and radiotherapy.

CONCLUSIONS

TDI could detect early cardiac dysfunction even in those with normal conventional echocardiography. Measurement of NT-proBNP represents an interesting strategy for detecting subclinical cardiotoxicity. We recommend prospective and multicenter studies to validate the role of NT-proBNP as an early marker for late onset doxorubicin-induced cardiotoxicity.

Impaired fetal myocardial deformation in intrahepatic cholestasis of pregnancy

OBJECTIVES

To investigate changes in fetal myocardial deformation in intrahepatic cholestasis of pregnancy.

METHODS

Patients with intrahepatic cholestasis of pregnancy were divided into 2 groups according to the total maternal serum bile acid concentration: mild cholestasis (10-40 μmol/L) and severe cholestasis (>40 μmol/L). Fetal echocardiography and velocity vector imaging were performed on women with cholestasis and control patients. The left ventricular global longitudinal strain and strain rate were measured. Clinical characteristics, maternal serum bile acid levels, and N-terminal pro-brain natriuretic peptide (NT-proBNP) levels in umbilical vein blood were compared between groups. The relationships among fetal myocardial deformation, maternal total bile acids, and cord NT-proBNP were analyzed.

RESULTS

Twenty women with mild cholestasis, 20 with severe cholestasis, and 40 control patients were enrolled. There were no significant differences in maternal and gestational ages between the case and control groups. Maternal bile acids and NT-proBNP were significantly higher in fetuses of mothers with cholestasis than control fetuses. The left ventricular longitudinal strain (-10.56% ± 1.83% versus -18.36% ± 1.11%; P < .01), systolic strain rate (-1.63 ± 0.18 versus -2.04 ± 0.18 secondsz(-1); P < .01), and diastolic strain rate (1.37 ± 0.18 versus 1.83 ± 0.14 seconds(-1); P < .01) were significantly decreased in fetuses with severe cholestasis compared with control fetuses. There were positive correlations between fetal myocardial deformation and maternal total bile acids (r = 0.705, 0.643, and 0.690, respectively; P < .01) and between myocardial deformation and NT-proBNP (r = 0.672, 0.643, and 0.647; P < .01).

CONCLUSIONS

Fetal myocardial deformation is impaired in severe intrahepatic cholestasis of pregnancy. Further investigation is needed to determine whether fetal echocardiography and velocity vector imaging can help predict which fetuses of mothers with cholestasis are likely to have poor outcomes.

B-type natriuretic peptide clinical activation in aortic stenosis: impact on long-term survival

OBJECTIVES

This study was conducted to define the association between serum B-type natriuretic peptide (BNP) activation and survival after the diagnosis of aortic stenosis (AS).

BACKGROUND

In AS, the link between BNP levels and clinical outcome is in dispute. Failure to account for the normal shifting of BNP ranges with aging in men and women, not using hard endpoints (survival), and not enrolling large series of patients have contributed to the uncertainty.

METHODS

A program of prospective measurement of BNP levels with Doppler echocardiographic AS assessment during the same episode of care was conducted. BNP ratio (measured BNP/maximal normal BNP value specific to age and sex) >1 defined BNP clinical activation.

RESULTS

In 1,953 consecutive patients with at least moderate AS (aortic valve area 1.03 ± 0.26 cm(2); mean gradient 36 ± 19 mm Hg), median BNP level was 252 pg/ml (interquartile range: 98 to 592 pg/ml); BNP ratio 2.46 (interquartile range 1.03 to 5.66); ejection fraction (EF) 57% ± 15%, and symptoms present in 60% of patients. After adjustment for all survival determinants, BNP clinical activation (BNP ratio >1) independently predicted mortality after diagnosis (p < 0.0001; hazard ratio [HR]: 1.91; 95% CI: 1.55 to 2.35) and provided incremental power to the survival predictive model (p < 0.0001). Eight-year survival was 62 ± 3% with normal BNP levels, 44 ± 3% with BNP ratio of 1 to 2 (adjusted HR: 1.49; 95% CI: 1.17 to 1.90), 25 ± 4% with BNP ratio of 2 to 3 (adjusted HR: 2.12; 95% CI: 1.63 to 2.75), and 15 ± 2% with BNP ratio of ≥3 (adjusted HR: 2.43; 95% CI: 1.94 to 3.05). This strong link to survival was confirmed in asymptomatic patients with normal EF (adjusted HR: 2.35 [95% CI: 1.57 to 3.56] for BNP clinical activation and 2.10 [95% CI: 1.32 to 3.36] for BNP ratio of 1 to 2, 2.25 [95% CI: 1.31 to 3.87] for BNP ratio of 2 to 3, 3.93 [95% CI: 2.40 to 6.43] for BNP ratio of ≥3). Aortic valve replacement was associated with survival improved by a similarly high margin (p = 0.54) with BNP ratio of <2 (HR: 0.68; 95% CI: 0.52 to 0.89; p = 0.003) or BNP ratio of >2 (HR: 0.56; 95% CI: 0.47 to 0.66; p < 0.0001).

CONCLUSIONS

In this large series of patients with AS, BNP clinical activation was associated with excess long-term mortality incrementally and independently of all baseline characteristics. Higher mortality with higher BNP clinical activation, even in asymptomatic patients, emphasizes the importance of appropriate clinical interpretation of BNP levels in managing patients with AS.

Use of cardiac markers for monitoring of doxorubixin-induced cardiotoxicity in children with cancer

The aim of this study was to evaluate N-terminal probrain natriuretic peptides (NT-pro-BNP), cardiac troponin T, and creatinine kinase, MB isoenzyme (CK-MB) in the determination of subclinical left ventricular (LV) dysfunction by echocardiography in patients treated with doxorubicin. We performed a cross-sectional case study of systolic, diastolic function and tissue Doppler imaging by echocardiography in children with cancer who received a certain cumulative dose of doxorubicin. Blood levels for NT-pro-BNP, cardiac troponin T, and CK-MB were analyzed within 6 hours of the cardiac study. Of 30 patients, 5 (16.7%) had LV dysfunction with an abnormally high NT-pro-BNP level of 363 ± 78 pg/mL, whereas patients with normal LV function had an NT-pro-BNP level of 148 ± 173 pg/mL (P = 0.012). The NT-pro-BNP level not only inversely correlated with fractional shortening (r = -0.43, P = 0.017) and ejection fraction (r = - 0.45, P = 0.013) but also correlated with mitral deceleration time ( r = 0.41, P = 0.021) and a cumulative dose of doxorubicin (r = 0.44, P = 0.014). For tissue Doppler imaging, NT-pro-BNP correlated with a peak systolic velocity at the myocardial segment (Sm) (r = -0.40, P = 0.027). NT-pro-BNP is a sensitive test and has a moderate relationship with the LV systolic and diastolic function, thus making it a useful cardiac marker for the monitoring of early anthracycline cardiotoxicity.