Plasma brain natriuretic peptide levels, right ventricular volume overload and exercise capacity in adolescents after surgical repair of tetralogy of Fallot

Systemic Manifestations of COPD and the Impact of Dual Bronchodilation with Tiotropium/Olodaterol on Cardiac Function and Autonomic Integrity

Background: Chronic obstructive pulmonary disease (COPD) has significant systemic manifestations, including cardiovascular morbidity. The main aim of our study was to evaluate the effect of short-term COPD treatment with tiotropium/olodaterol (TIO/OLO) 5/5 μg on cardiac function and autonomic integrity. Methods: Twenty-nine patients with newly diagnosed moderate-to-severe COPD were enrolled. We performed pulmonary function tests, cardiac magnetic resonance, cardiac 123I-metaiodobenzylguanidine (123I-MIBG) imaging and analysis of blood biomarkers on our study subjects. The correlations between the tests' results were evaluated at baseline. The changes in pulmonary and cardiac parameters from baseline through 12 weeks were assessed. Results: Significant associations between pulmonary function tests' results and high-sensitivity C-reactive protein (hs-CRP), as well as interleukin-22 (IL-22), were observed at baseline. Treatment with TIO/OLO significantly improved lung function as measured by spirometry and body plethysmography. Moreover, we found that the cardiac index increased from 2.89 (interquartile range (IQR) 1.09) to 3.21 L/min/m2 (IQR 0.78) (p = 0.013; N = 18) and the late heart-to-mediastinum ratio improved from 1.88 (IQR 0.37) to 2 (IQR 0.41) (p = 0.026; N = 16) after 12 weeks of treatment. Conclusions: Treatment with TIO/OLO improves lung function and positively impacts cardiac function and autonomic integrity, suggesting that dual bronchodilation might have a potential in decreasing the risk for cardiac events in COPD. Hs-CRP and IL-22 might be beneficial in determining the intensity of systemic inflammation in COPD. Further research with a larger cohort is needed to enhance the initial results of this study.

The Interplay between Myocardial Fibrosis, Strain Imaging and Collagen Biomarkers in Adults with Repaired Tetralogy of Fallot

Background: We sought to assess the interplay between right ventricle (RV) fibrosis, biventricular dysfunction based on global longitudinal strain (GLS) analysis, and biomarkers such as Galectin-3 (Gal-3), procollagen type III (PCIII), and NTproBNP. Methods: We studied 35 adult patients with rToF. All patients underwent a cardiac magnetic resonance (CMR) scan including feature tracking for deformation imaging. Blood biomarkers were measured. Results: LGE RV was detected in all patients, mainly at surgical sites. Patients with the highest RV LGE scoring had greater RV dilatation and dysfunction whereas left ventricular (LV) function was preserved. LV GLS correlated with RV total fibrosis score (p = 0.007). A LV GLS value of −15.9% predicted LGE RV score > 8 (AUC 0.754 (p = 0.02)). Neither RV GLS nor biomarker levels were correlated with the extent of RV fibrosis. A cut-off value for NTproBNP of 145.25 pg/mL predicted LGE RV score > 8 points (AUC 0.729, (p = 0.03)). A cut-off value for Gal-3 of 7.42 ng/mL predicted PR Fraction > 20% [AUC 0.704, (p = 0.05)]. Conclusions: A significant extent of RV fibrosis was mainly detected at surgical sites of RV, affecting RV performance. CMR-FT reveals subtle LV dysfunction in rToF patients, due to decreased performance of the fibrotic RV. Impaired LV function and elevated NTproBNP in rToF reflect a dysfunctional fibrotic RV.

Heart failure in adult congenital heart disease: tetralogy of Fallot

The number of rTOF patients who survive into adulthood is steadily rising, with currently more than 90% reaching the third decade of life. However, rTOF patients are not cured, but rather have a lifelong increased risk for cardiac and non-cardiac complications. Heart failure is recognized as a significant complication. Its occurrence is strongly associated with adverse outcome. Unfortunately, conventional concepts of heart failure may not be directly applicable in this patient group. This article presents a review of the current knowledge on HF in rTOF patients, including incidence and prevalence, the most common mechanisms of heart failure, i.e., valvular pathologies, shunt lesions, left atrial hypertension, primary left heart and right heart failure, arrhythmias, and coronary artery disease. In addition, we will review information regarding extracardiac complications, risk factors for the development of heart failure, clinical impact and prognosis, and assessment possibilities, particularly of the right ventricle, as well as management strategies. We explore potential future concepts that may stimulate further research into this field.

Serum N-Terminal Pro-B-Type Natriuretic Peptide as a Biomarker of Critical Pulmonary Stenosis in Neonates

Objectives: To determine the efficacy of serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels in predicting critical pulmonary stenosis (CPS) in neonates. Methods: All neonates with pulmonary stenosis (PS) admitted to the neonatal intensive care unit of Xinhua Hospital from October 2014 to December 2020 were retrospectively reviewed. Infants with serum NT-proBNP levels measured within 48 h after birth were enrolled and divided into CPS and non-CPS groups. Serum NT-proBNP levels and cardiac Doppler indices were compared between the two groups. Correlations were determined using the Spearman's rank correlation coefficient. Receiver operator characteristic curve analysis was used to explore the predictive value of NT-proBNP for identifying neonatal CPS. Results: Among 96 infants diagnosed with PS by echocardiography, 46 were enrolled (21 and 25 in the non-CPS and CPS groups, respectively). Serum NT-proBNP levels were significantly higher in the CPS group than in the non-CPS group [3,600 (2,040-8,251) vs. 1,280 (953-2,386) pg/ml, P = 0.003]. Spearman's analysis suggested a positive correlation between Ln(NT-proBNP) levels and the transvalvular pulmonary gradient (r = 0.311, P = 0.038), as well as between Ln(NT-proBNP) levels and pulmonary artery velocity (r = 0.308, P = 0.040). Receiver operating characteristic curve analysis showed that a cutoff serum NT-proBNP level of 2,395 pg/ml yielded a 66.7 and 78.9% sensitivity and specificity for identifying CPS, respectively. The area under the curve was 0.784 (95% CI, 0.637-0.931). A positive correlation was found between Ln(NT-proBNP) and length of hospital stay (r = 0.312, P < 0.05). Conclusion: Serum NT-proBNP level was positively correlated with PS severity and could be used as a biomarker to identify CPS in neonates.

NT-proBNP as Marker of Ventricular Dilatation and Pulmonary Regurgitation After Surgical Correction of Tetralogy of Fallot: A MRI Validation Study

The goal of this study is to evaluate whether NT-proBNP plasma levels may help as a screening biomarker for monitoring right ventricular dilatation, pulmonary regurgitation and the onset of heart failure in patients with repaired Tetralogy of Fallot. Our single-centre observational prospective study involved 43 patients (15.1 years, SD = 8) with corrected Tetralogy of Fallot. Data collection included: clinical parameters (electrocardiogram, chest X-ray, NYHA scale, time since last surgery), biochemistry (NT-proBNP levels) and MRI values (ventricular volumetry, pulmonary flow assessment). Mean time since last surgery was 13.5 years (SD = 7.8). There was a statistically significant correlation between the NT-proBNP levels (187.4 pg/ml, SD = 154.9) and right ventricular dilatation for both the right ventricular end-diastolic volume (124.9 ml/m², SD = 31.2) (Pearson = 0.19, p < 0.01) and end-systolic volume (56.1 ml/m², SD = 18.8) (Pearson = 0.21, p < 0.01) and also with the pulmonary regurgitation fraction (36.5%, SD = 16, Pearson = 0.12, p < 0.01). No significant correlation was found between NT-proBNP and right ventricular ejection fraction (54.6%, SD = 10.6, Pearson = -0.07), left ventricular ejection fraction (59.9%, SD = 7.1, Pearson = -0.18) or any clinical parameters. The receiver operating curve analysis evidenced that a NT-proBNP cut-off value above 133.2 pg/ml predicted the presence of dilated right ventricular end-diastolic and end-systolic volumes over centile 95 (sensitivity 82 and 83% and specificity 93 and 79%, respectively). In conclusion, in patients with surgically corrected Tetralogy of Fallot, NT-proBNP levels correlate with right ventricular dilatation and the degree of pulmonary regurgitation. Ambulatory determination of NT-proBNP might be an easy, readily available and cost-effective alternative for MRI follow-up evaluation of these patients.

The Utility of Brain Natriuretic Peptide in Pediatric Cardiology: A Review

OBJECTIVE

The aim of this article is to evaluate the clinical utility of brain natriuretic peptide in pediatric patients, examining the diagnostic value, management, and prognostic relevance, by critical assessment of the literature.

DATA SOURCES

In December 2015, a literature search was performed (PubMed access to MEDLINE citations; http://www.ncbi.nlm.nih.gov/PubMed/) and included these Medical Subject Headings and text terms for the key words: "brain natriuretic peptide," "amino-terminal pro-brain natriuretic peptide," "children," "neonate/s," "newborn/s," "infant/s," and "echocardiography."

STUDY SELECTION

Each article title and abstract was screened to identify relevant studies. The search strategy was limited to published studies in English language concerning brain natriuretic peptide/amino-terminal pro-brain natriuretic peptide in pediatric patients.

DATA EXTRACTION

Data on age, gender, type of clinical condition, brain natriuretic peptide assay method, cardiac function variables evaluated by echocardiography, and prognosis were extracted.

DATA SYNTHESIS

Brain natriuretic peptide reference values in healthy newborns, infants, and children are presented. Brain natriuretic peptide diagnostic accuracy in newborns, infants, and children suspected to have congenital heart defects is discussed, and brain natriuretic peptide prognostic value reviewed. The data suggest that the determination of brain natriuretic peptide levels improves the diagnostic accuracy in the assessment of heart disease in the pediatric population. Brain natriuretic peptide assay may increase the accuracy of neonatal screening programs for diagnosing congenital heart defects. Echocardiographic variables correlated to brain natriuretic peptide levels. Additionally, brain natriuretic peptide levels predicted adverse outcomes in the postoperative period.

CONCLUSIONS

Brain natriuretic peptide assessment is a reliable test to diagnose significant structural or functional cardiovascular disease in children. In the integrated follow-up of these cases, several physiologic and clinical variables must be considered; brain natriuretic peptide may be an additional helpful marker. Nevertheless, larger prospective studies are warranted to elucidate the true prognostic value of brain natriuretic peptide in pediatric patients.

Comparison of the Degree of Exercise Tolerance in Children After Surgical Treatment of Complex Cardiac Defects, Assessed Using Ergospirometry and the Level of Brain Natriuretic Peptide

Children who underwent surgery for complex congenital heart defects present worse exercise capacity than their healthy peers. In adults and adolescents, heart failure is assessed on the basis of clinical symptoms using the New York Heart Association (NYHA) score, while in an infant Ross scale; heart failure can also be evaluated by other parameters. The purpose of this study was to compare the degree of exercise tolerance in children after surgery for complex heart defects, assessed by the ratio of maximum oxygen uptake (VO2max) and the brain natriuretic peptide (N-terminal fragment of the prohormone brain-type natriuretic peptide [NT-proBNP]) concentration.The study group consisted of 42 children, ages 9 to 17 years (mean 14.00 ± 2.72). Among them there were 22 children with tetralogy of Fallot (ToF) after total correction, 18 children with transposition of the great arteries (d-TGA) after the arterial switch operation, and 2 children with single ventricle (SV) after the Fontan operation. All but 1 child were in NYHA class I. The control group consisted of 20 healthy children. Outcomes of interest were the ratio of VO2max, determined during ergospirometry, and the level of NT-proBNP. The statistical analysis was performed and the groups were considered significantly different for P < 0.05.There was no statistically significant correlation between NT-proBNP and maximum oxygen uptake (VO2) kg min in the study group compared with the control group.The VO2max in the test group had a mean value less (34.6 ± 8.0) than controls (38.4 ± 7.7), and the differences were statistically significant (P = 0.041). In contrast, the average concentration of NT-proBNP in the study group was higher than controls (117.9 ± 74.3 vs 18.0 ± 24.5), and these differences were statistically significant (P < 0.001).After operations for complex heart defects (ToF, TGA, and SV), children have worse heart function parameters and exercise capacity than the healthy population. To control this, we recommend postoperative ergospirometry and determination of NT-proBNP concentrations.

Biomarkers in pediatric heart disease

A biomarker is a characteristic that can be used as an indicator of a biological state. A biomarker can be a clinical observation, laboratory test or an imaging parameter. In this review, we discuss the use of biomarkers in differentiating cardiac from noncardiac disease; predicting the prognosis of patients with heart failure, pulmonary hypertension and dilated cardiomyopathy; diagnosing subclinical cardiac involvement in muscular dystrophy and postchemotherapy cancer patients; detecting acute rejection following heart transplantation; diagnosing Kawasaki disease; aiding the management of postoperative cardiac patients; and managing both common (tetralogy of Fallot) and complex (single-ventricle physiology) congenital heart diseases.

Exercise capacity in children and adolescents with corrected congenital heart disease

Congenital heart disease promotes hemodynamic changes that can contribute to reduce exercise capacity. The aim of the study was to evaluate the exercise capacity of children and adolescents with cyanotic congenital heart disease and to assess respiratory muscle strength, plasma levels of B-type natriuretic peptide and ventricular ejection fraction, as well the associations between these variables. Cross-sectional study that evaluated 48 patients between 6 and 18 years-old that underwent a six-minute walk test (6MWT), respiratory muscle strength, dosage of B-type natriuretic peptide and echocardiography. The mean age was 13.3 ± 4.1 years, and the most prevalent heart disease was tetralogy of Fallot (54.2 %). The average distance walked was 452.7 ± 73.2 m, significantly below the predicted (69 %) (p < 0.001). The maximum inspiratory pressure was above the predicted result (111.4 %), average 58.2 ± 22.3 (p = 0.56), and the maximum expiratory pressure was 63.2 ± 23.3 cm H2O, significantly below the predicted (63 %) (p < 0.001). The level of B-type natriuretic peptide was elevated in all patients, with a median of 2087.17 (502.54-4,768.05). The ventricular ejection fraction showed a median of 65.9 (41-100). There was no correlation between the 6MWT, ventricular ejection fraction (r = -0.05; p = 0.72), inspiratory muscle strength (r = 0.03; p = 0.81), expiratory muscle strength (r = 0.09; p = 0.05) and B-type natriuretic peptide (r = -0.04; p = 0.77). Children and adolescents with cyanotic congenital heart disease present a lower exercise capacity and expiratory muscle strength. No associations were found between exercise capacity, respiratory muscle strength, B-type natriuretic peptide and left ventricular ejection fraction.

Association between N-terminal pro-brain natriuretic peptide and quality of life in adult patients with congenital heart disease

AIMS

Advances in medical treatment have resulted in increased life expectancy in congenital heart disease. Consequently, the focus of management has shifted from reducing mortality to reducing long-term morbidity with the goal of improving quality of life. A predictor of quality of life might be N-terminal pro-brain natriuretic peptide, a well-established marker for heart failure. We aimed to determine the association between N-terminal pro-brain natriuretic peptide and quality of life in patients with congenital heart disease.

METHODS

We collected blood samples from consecutive patients who were initially operated between 1968 and 1980 (47.8% women; mean age 40.2±5.4 years). The 36-item Short-Form Health Survey was completed to assess subjective health status as a measure of quality of life. Analysis was performed for the entire group and for subgroups defined as simple versus complex congenital heart diseases. Median N-terminal pro-brain natriuretic peptide level was 15.2 pmol/L (overall range 1.3-299.3 pmol/L). N-terminal pro-brain natriuretic peptide levels were associated with the subdomain physical functioning (β=-0.074, p=0.031). This association remained significant after adjustment for age and sex (β=-0.071, p=0.038) and after adjustment for age, sex, body mass index, left ventricular function, and renal function (β=-0.069, p=0.048). In complex congenital heart disease, the association between N-terminal pro-brain natriuretic peptide and physical functioning remained significant in multivariable analysis (β=-0.076, p=0.046). No associations were found in the simple congenital heart disease group or on the other health status subdomains.

CONCLUSION

In adults operated for congenital heart disease, N-terminal pro-brain natriuretic peptide is associated with the subdomain physical, primarily in the complex subgroup.

Associations between N-terminal pro-B-type natriuretic peptide and cardiac function in adults with corrected tetralogy of Fallot

BACKGROUND

Amino-terminal B-type natriuretic peptide (NT-proBNP) may detect early cardiac dysfunction in adults with tetralogy of Fallot (ToF) late after corrective surgery. We aimed to determine the value of NT-proBNP in adults with ToF and establish its relationship with echocardiography and exercise capacity.

METHODS AND RESULTS

NT-proBNP measurement, electrocardiography and detailed 2D-echocardiography were performed on the same day in 177 consecutive adults with ToF (mean age 34.6 ± 11.8 years, 58% male, 89% NYHA I, 29.3 ± 8.5 years after surgical correction). Thirty-eight percent of the patients also underwent a cardiopulmonary-exercise test. Median NT-proBNP was 16 [IQR 6.7-33.6] pmol/L, and was elevated in 55%. NT-proBNP correlated with right ventricular (RV) dilatation (r = 0.271, p < 0.001) and RV systolic dysfunction (r = -0.195, p = 0.022), but more strongly with LV systolic dysfunction (r=-0.367, p<0.001), which was present in 69 patients (39%). Moderate or severe pulmonary regurgitation was not associated with higher NT-proBNP. Tricuspid and pulmonary regurgitation peak velocities correlated with NT-proBNP (r = 0.305, p < 0.001 and r = 0.186, p = 0.045, respectively). LV twist was measured with speckle-tracking echocardiography in 71 patients. An abnormal LV twist (20 patients, 28%) was associated with elevated NT-proBNP (p = 0.030). No relationship between NT-proBNP and exercise capacity was found.

CONCLUSIONS

NT-proBNP levels are elevated in more than 50% of adults with corrected ToF, while they are in stable clinical condition. Higher NT-proBNP is most strongly associated with elevated pulmonary pressures, and with LV dysfunction rather than RV dysfunction. NT-proBNP has the potential to become routine examination in patients with ToF to monitor ventricular function and may be used for timely detection of clinical deterioration.

Late gadolinium enhancement (LGE) progresses with right ventricle volume in children after repair of tetralogy of fallot

Background

Fibrosis after myocardial damage can be determined by cardiac magnetic resonance (CMR) with late gadolinium enhancement (LGE). We studied whether ventricular LGE is visible in the ventricles of pediatric and adolescent TOF (tetralogy of Fallot) patients by measuring LGE and investigating whether fibrosis correlated with right ventricular volume, pulmonary regurgitation, N-terminal pro-brain natriuretic peptide (NT-proBNP) or the aminoterminal propeptide of type III procollagen (PIIINP). We also studied if the patient's age, post-operative follow-up time or surgical history would affect LGE.

Methods

A total of 40 pediatric patients who had undergone TOF repair and 43 healthy age and gender matched controls underwent a CMR study, whereby LGE was scored in the right (RV) and the left ventricle. To exclude the possible iatrogenic scarring we calculated the LGE score by excluding the right ventricular outflow tract and VSD patch region.

Results

All patients had RV LGE and in 39 of 40 it was seen also outside the surgically affected areas. The amount of LGE correlated positively with the RV end-diastolic volume (r = 0.44, P = 0.0045), pulmonary regurgitation (r = 0.40, P = 0.013), and with NT-proBNP. The presence of LGE also depended on post-operative follow-up time (r = 0.53, P = 0.006). PIIINP levels of TOF patients were significantly higher than in the control subjects but it did not correlate with LGE or with any of the studied clinical markers.

Conclusions

LGE is present globally in the right ventricular muscle in children and adolescents with TOF. The longer the follow-up time the more common was the LGE in the right ventricle.

Biomarkers in congenital heart disease: do natriuretic peptides hold the key?

Congenital heart disease is the most common congenital abnormality. The long-term prognosis of these patients has changed significantly over the last half century, thanks to improvements in cardiovascular diagnosis, surgery and postoperative care. However, residual lesions are not uncommon and many of the interventions performed remain palliative rather than reparative, leading to the development of ventricular dysfunction and heart failure. Natriuretic peptides are well-established markers of disease severity and prognosis in patients with heart failure due to noncongenital (acquired) heart disease. However, the role of biomarkers in congenital heart disease is unclear. This review highlights the impact of neurohormonal activation in patients with congenital heart disease, as well as the usefulness of assessing natriuretic peptide levels in specific clinical situations.

Effects of left ventricular function on the exercise capacity in patients with repaired tetralogy of Fallot

BACKGROUND

Tissue Doppler imaging has been recently used to evaluate ventricular function. Peak oxygen uptake (V•O2peak) has been demonstrated as a predictor for death in adults with repaired tetralogy of Fallot (TOF). The aim of this study was to determine which Doppler parameters correlated with V•O2peak in patients with repaired TOF.

METHOD AND RESULTS

Doppler echocardiography, tissue Doppler imaging, and exercise test were performed in 30 patients with TOF after surgical repair. In 30 patients with repaired TOF (median age 14 years, range 9-25 years), 11 patients (37%) were female. Seven patients (median age 12 years) had normal left ventricular diastolic function, whereas the rest of the patients were classified as diastolic dysfunction grade II (median age 15 years; n=15) and III and IV (median age 18 years; n=8). The oxygen uptake at anaerobic threshold (V•O2AT) and peak exercise in patients with left ventricular diastolic dysfunction was significantly lower than that in those with normal diastolic function. Also, V•O2AT and V•O2 peak in patients with diastolic dysfunction grade III and IV were significantly lower than that in those with diastolic dysfunction grade II. Left ventricular early diastolic myocardial velocity was most closely correlated to V•O2peak (r=0.51; P=0.005). Peak early ventricular filling velocity to early diastolic myocardial velocity ratio was significantly correlated with V•O2peak (r=-0.50; P=0.006).

CONCLUSION

Left ventricular diastolic dysfunction is correlated with V•O2peak. Left ventricular diastolic function should be a routine echocardiographic assessment in patients with repaired TOF.

Diagnostic, prognostic and therapeutic relevance of B-type natriuretic hormone and related peptides in children with congenital heart diseases

The aim of this article is to review the diagnostic and prognostic relevance of measurement of brain natriuretic peptide (BNP) and N-terminal pro-brain natriuretic peptide (NT-proBNP) in pediatric patients with congenital cardiac diseases (CHD). A computerized literature search in the National Library of Medicine using the keywords "BNP assay" and "NT-proBNP assay"+neonate/s and newborn/s was performed. Next, we refined the analysis to include only the studies specifically designed to evaluate the clinical usefulness of BNP and NT-proBNP measurements in children with CHD. Several authors suggested that BNP/NT-proBNP is clinically helpful as a diagnostic and prognostic marker for children with suspected CHD. BNP values are age dependent, even in paediatric populations. Unfortunately, accurate reference values for BNP and NT-proBNP for neonatal ages have only recently become available. As a result, the lack of homogenous and accurate decisional levels in the neonatal period greatly limits the clinical impact of the BNP assay, and also contributed to the production of conflicting results. Regardless of age, there is great variability in BNP/NT-proBNP values among CHD characterized by different hemodynamic and clinical conditions. In particular, cardiac defects characterized by left ventricular volume and pressure overload usually show a higher BNP response than CHD which is characterized by right ventricular volume or pressure overload. BNP and NT-proBNP may be considered helpful markers in the integral clinical approach for patients with CHD. Measurement of BNP cannot replace cardiac imaging (including echocardiography, angiography and magnetic resonance), but provide independent, low cost and complementary information for the evaluation of cardiac function and clinical status.

Practical application of natriuretic peptides in paediatric cardiology

It is still uncertain if cardiac natriuretic peptides are useful biomarkers in paediatric cardiology. In this review we identify four clinical scenarios in paediatric cardiology, where clinical decision-making can be difficult, and where we feel the paediatric cardiologists need additional diagnostic tools. Natriuretic peptide measurements could be that extra tool. We discuss and suggest N-terminal pro-B-type natriuretic peptide and B-type natriuretic peptide reference intervals for children without cardiovascular disease and cut-off points for the four specific paediatric heart conditions. We conclude that in premature neonates with persistent arterial ducts; in teenagers with tetralogy of Fallot and pulmonary regurgitation; and in children with heart transplants and potential allograft rejection cardiac peptides can provide the clinician with additional information, but in children with atrial septal defects the peptides are not helpful in guiding treatment or follow-up.

Evaluation of exercise capacity with cardiopulmonary exercise testing and BNP levels in adult patients with single or systemic right ventricles

INTRODUCTION

The aim of the study was to evaluate exercise capacity using cardiopulmonary exercise test (CpET) and serum B-type natriuretic peptide (BNP) levels in patients with single or systemic right ventricles.

MATERIAL AND METHODS

The study group included 40 patients (16 males) - 17 with transposition of the great arteries after Senning operation, 13 with corrected transposition of the great arteries and 10 with single ventricle after Fontan operation, aged 19-55 years (mean 28.8 ±9.5 years). The control group included 22 healthy individuals (10 males) aged 23-49 years (mean 30.6 ±6.1 years).

RESULTS

The majority of patients reported good exercise tolerance - accordingly 27 were classified in NYHA class I (67.5%), 12 (30%) in class II, and only 1 (0.5%) in class III. Cardiopulmonary exercise test revealed significantly lower exercise capacity in study patients than in control subjects. In the study vs. control group VO(2max) was 21.7 ±5.9 vs. 34.2 ±7.4 ml/kg/min (p = 0.00001), maximum heart rate at peak exercise (HRmax) 152.5 ±32.3 vs. 187.2 ±15.6 bpm (p = 0.00001), VE/VCO(2) slope 34.8 ±7.1 vs. 25.7 ±3.2 (p = 0.00001), forced vital capacity (FVC) 3.7 ±0.9l vs. 4.6 ±0.3 (p = 0.03), forced expiratory volume in 1 s (FEV(1)) 3.0 ±0.7 vs. 3.7 ±0.9l (p = 0.0002) respectively. Serum BNP concentrations were higher in study patients than in control subjects; 71.8 ±74.4 vs. 10.7 ±8.1 (pg/ml) respectively (p = 0.00001). No significant correlations between BNP levels and CpET parameters were found.

CONCLUSIONS

Patients with a morphological right ventricle serving the systemic circulation and those with common ventricle physiology after Fontan operation show markedly reduced exercise capacity. They are also characterized by higher serum BNP concentrations, which do not however correlate with CpET parameters.

Clinical relevance of measurement of brain natriuretic peptide and N-terminal pro-brain natriuretic peptide in pediatric cardiology

BACKGROUND

The aim of this review is to understand the clinical usefulness of Brain Natriuretic Peptide (BNP) and N-terminal pro-Brain Natriuretic Peptide (NT-proBNP) in pediatric cardiology.

METHODS

A computerized literature search on National Library of Medicine using the keywords "BNP assay" and "NT-proBNP assay" was performed. Then, we refined the analysis to include only the studies specifically designed to evaluate the clinical usefulness of BNP and NT-proBNP assays in patients with congenital heart disease.

RESULTS

BNP and NT-proBNP are useful marker for diagnosis of heart failure, for the assessment of clinical severity and for the follow-up of congenital and pediatric heart diseases. However, results from different studies are often partial and not always univocal. Moreover, reference intervals in pediatric population have not yet been extensively evaluated.

CONCLUSIONS

BNP and NT-proBNP may be considered helpful markers for the integrated diagnosis and management of pediatric patients, though further studies are needed to support their routine use.