Correlation of plasma N-terminal pro-brain natriuretic peptide levels with left ventricle mass in children treated with anthracyclines

Novel PLGA-based nanoformulation decreases doxorubicin-induced cardiotoxicity

Nanotechnology has the potential to provide formulations of antitumor agents with increased selectivity towards cancer tissue thereby decreasing systemic toxicity. This in vivo study evaluated the potential of novel nanoformulation based on poly(lactic-co-glycolic acid) (PLGA) to reduce the cardiotoxic potential of doxorubicin (DOX). In vivo toxicity of PLGADOX was compared with clinically approved non-PEGylated, liposomal nanoformulation of DOX (LipoDOX) and conventional DOX form (ConvDOX). The study was performed using Wistar Han rats of both sexes that were treated intravenously for 28 days with 5 doses of tested substances at intervals of 5 days. Histopathological analyses of heart tissues showed the presence of myofiber necrosis, degeneration processes, myocytolysis, and hemorrhage after treatment with ConvDOX, whereas only myofiber degeneration and hemorrhage were present after the treatment with nanoformulations. All DOX formulations caused an increase in the troponin T with the greatest increase caused by convDOX. qPCR analyses revealed an increase in the expression of inflammatory markers IL-6 and IL-8 after ConvDOX and an increase in IL-8 expression after lipoDOX treatments. The mass spectra imaging (MSI) of heart tissue indicates numerous metabolic and lipidomic changes caused by ConvDOX, while less severe cardiac damages were found after treatment with nanoformulations. In the case of LipoDOX, autophagy and apoptosis were still detectable, whereas PLGADOX induced only detectable mitochondrial toxicity. Cardiotoxic effects were frequently sex-related with the greater risk of cardiotoxicity observed mostly in male rats.

Chlorogenic Acid Attenuates Doxorubicin-Induced Oxidative Stress and Markers of Apoptosis in Cardiomyocytes via Nrf2/HO-1 and Dityrosine Signaling

(1) Background: Doxorubicin (DOX) is extensively used for cancer treatments; however, its clinical application is limited because of its cardiotoxic adverse effects. A combination of DOX and agents with cardioprotective properties is an effective strategy to ameliorate DOX-related cardiotoxicity. Polyphenolic compounds are ideal for the investigation of novel cardioprotective agents. Chlorogenic acid (CGA), an essential dietary polyphenol found in plants, has been previously reported to exert antioxidant, cardioprotective, and antiapoptotic properties. The current research evaluated CGA's in vivo cardioprotective properties in DOX-induced cardiotoxicity and the probable mechanisms underlying this protection. (2) Methods: CGA's cardioprotective properties were investigated in rats that were treated with CGA (100 mg/kg, p.o.) for fourteen days. The experimental model of cardiotoxicity was induced with a single intraperitoneal (15 mg/kg i.p.) injection of DOX on the 10th day. (3) Results: Treatment with CGA significantly improved the DOX-caused altered cardiac damage markers (LDH, CK-MB, and cTn-T), and a marked improvement in cardiac histopathological features accompanied this. DOX downregulated the expression of Nrf2/HO-1 signaling pathways, and the CGA reversed this effect. Consistently, caspase-3, an apoptotic-related marker, and dityrosine expression were suppressed, while Nrf2 and HO-1 expressions were elevated in the cardiac tissues of DOX-treated rats after treatment with the CGA. Furthermore, the recovery was confirmed by the downregulation of 8-OHdG and dityrosine (DT) expressions in immunohistochemical findings. (4) Conclusions: CGA demonstrated a considerable cardioprotective effect against DOX-induced cardiotoxicity. One of the possible mechanisms for these protective properties was the upregulation of the Nrf2/HO-1-dependent pathway and the downregulation of DT, which may ameliorate oxidative stress and cardiomyocyte apoptosis. These findings suggest that CGA may be cardioprotective, particularly in patients receiving DOX-based chemotherapy.

Cardio-Oncology in Childhood: State of the Art

PURPOSE OF REVIEW

Cardio-oncology is an increasingly important field of cardiology that focuses on the detection, monitoring, and treatment of cardiovascular disease (CVD) occurring during and after oncological treatments. The survival rate for childhood cancer patients has dramatically increased thanks to new treatment protocols and cardiovascular (CV) sequelae represent the third most frequent cause of mortality in surviving patients. This study aims to provide a complete and updated review of all the main aspects of cardio-oncology in childhood and to highlight the critical issues.

RECENT FINDINGS

The problem of CV complications in childhood cancer survivors raises the need to make an early diagnosis of cardiotoxicity by the new imaging and laboratory techniques in order to intervene promptly and to implement pharmacological strategies and lifestyle changes to reduce or even to prevent cardiac injury. Furthermore, a stratification of CV risk, also including new predisposing factors such as the presence of some genetic mutations, is of paramount importance before undertaking oncological treatments. Besides, a systematic and personalized planning of long-term follow-up is fundamental to ensure a transition from pediatric to adult hospital and to avoid missed or late diagnosis of cardiomyopathy. We reviewed the main risk factors for cardiotoxicity in children, both traditional and emerging ones: the mechanisms of toxicity of both old and new antineoplastic therapies, the techniques for detecting cardiac damage, and the current evidence regarding pharmacological cardioprotection. At the end, we focused our attention on the existing guidelines and strategies about the long-term follow-up of childhood cancer survivors.

Serum Biomarkers for the Detection of Cardiac Dysfunction in Childhood Cancers Receiving Anthracycline-Based Treatment

Anthracyclines are routinely used in cancer chemotherapy in many childhood cancers. A serious adverse effect of doxorubicin chemotherapy is cardiotoxicity which may lead to congestive heart failure for long-term survivors years after treatment. Currently, echocardiography is used to control the heart function during anthracyclines therapy. B-type natriuretic peptide (BNP) and NT-proBNP as well as cardiac troponins have been proposed as clinical markers for subclinical anthracycline-induced cardiotoxicity. The BNP and pro-BNP can be easily measured in plasma and initial data indicate that the NT-proBNP could be sensitive predictor for the development of congestive heart failure.

Divergent Cardiac Effects of Angiotensin II and Isoproterenol Following Juvenile Exposure to Doxorubicin

Hypertension is the most significant risk factor for heart failure in doxorubicin (DOX)-treated childhood cancer survivors. We previously developed a two-hit mouse model of juvenile DOX-induced latent cardiotoxicity that is exacerbated by adult-onset angiotensin II (ANGII)-induced hypertension. It is still not known how juvenile DOX-induced latent cardiotoxicity would predispose the heart to pathologic stimuli that do not cause hypertension. Our main objective is to determine the cardiac effects of ANGII (a hypertensive pathologic stimulus) and isoproterenol (ISO, a non-hypertensive pathologic stimulus) in adult mice pre-exposed to DOX as juveniles. Five-week-old male C57BL/6N mice were administered DOX (4 mg/kg/week) or saline for 3 weeks and then allowed to recover for 5 weeks. Thereafter, mice were administered either ANGII (1.4 mg/kg/day) or ISO (10 mg/kg/day) for 14 days. Juvenile exposure to DOX abrogated the hypertrophic response to both ANGII and ISO, while it failed to correct ANGII- and ISO-induced upregulation in the hypertrophic markers, ANP and BNP. ANGII, but not ISO, worsened cardiac function and exacerbated cardiac fibrosis in DOX-exposed mice as measured by echocardiography and histopathology, respectively. The adverse cardiac remodeling in the DOX/ANGII group was associated with a marked upregulation in several inflammatory and fibrotic markers and altered expression of Ace, a critical enzyme in the RAAS. In conclusion, juvenile exposure to DOX causes latent cardiotoxicity that predisposes the heart to a hypertensive pathologic stimulus (ANGII) more than a non-hypertensive stimulus (ISO), mirroring the clinical scenario of worse cardiovascular outcome in hypertensive childhood cancer survivors.

Cardiovascular Function and Exercise Capacity in Childhood Cancer Survivors

Introduction: Childhood cancer survivors (CCS) might be at high risk of additional chronic diseases due to cardiotoxic side effects. The aim of this study was to analyze long-term side effects of cancer therapy on vascular structure/function, cardiac biomarkers and on physical activity. Methods: In total, 68 asymptomatic patients aged 16–30 years with childhood cancer (diagnosed 10.6 ± 3.9 years ago) were examined from 2015–2020. (Central) blood pressure and pulse wave velocity were registered via the oscillometric method, while carotid intima-media thickness (cIMT) was measured non-invasively by ultrasound. cIMT values of patients were compared to healthy controls (n = 68; aged 22.3 ± 3.5 years). Patients’ exercise capacity was recorded. The plasma N-terminal pro-brain natriuretic protein (NTproBNP) and troponin levels were measured as cardiac biomarkers. CCS were categorized in groups with low, moderate and high anthracyclines. Results: No differences were found in cIMT between patients and controls as well as between patients with various anthracycline dosage. Patients with high dose anthracyclines showed a significant lower performance versus patients with moderate dose anthracyclines (84.4% of predicted VO₂peak; p = 0.017). A total of 11.6% of CCS had abnormal NTproBNP values which correlated with received anthracycline dosage (p = 0.024; r = 0.343). Conclusion: NTproBNP levels and exercise capacity might be early markers for cardiovascular dysfunction in CCS and should be included in a follow-up protocol, while cIMT and troponin seem not to be adequate parameters.

Juvenile exposure to doxorubicin alters the cardiovascular response to adult-onset psychosocial stress in mice

Childhood cancer survivors have a high risk for premature cardiovascular diseases, mainly due to cardiotoxic cancer treatments such as doxorubicin (DOX). Psychosocial stress is a significant cardiovascular risk factor and an enormous burden in childhood cancer survivors. Although observational studies suggest that psychosocial stress is associated with cardiovascular complications in cancer survivors, there is no translationally relevant animal model to study this interaction. We established a "two-hit" model in which juvenile mice were administered DOX (4 mg/kg/week for 3 weeks), paired to a validated model of chronic subordination stress (CSS) 5 weeks later upon reaching adulthood. Blood pressure, heart rate, and activity were monitored by radio-telemetry. At the end of CSS experiment, cardiac function was assessed by echocardiography. Cardiac fibrosis and inflammation were assessed by histopathologic analysis. Gene expressions of inflammatory and fibrotic markers were determined by PCR. Juvenile exposure to DOX followed by adult-onset CSS caused cardiac fibrosis and inflammation as evident by histopathologic findings and upregulated gene expression of multiple inflammatory and fibrotic markers. Intriguingly, juvenile exposure to DOX blunted CSS-induced hypertension but not CSS-induced tachycardia. There were no significant differences in cardiac function parameters among all groups, but juvenile exposure to DOX abrogated the hypertrophic response to CSS. In conclusion, we established a translationally relevant mouse model of juvenile DOX-induced cardiotoxicity that predisposes to adult-onset stress-induced adverse cardiac remodeling. Psychosocial stress should be taken into consideration in cardiovascular risk stratification of DOX-treated childhood cancer survivors.

Glycosaminoglycans: Carriers and Targets for Tailored Anti-Cancer Therapy

The tumor microenvironment (TME) is composed of cancerous, non-cancerous, stromal, and immune cells that are surrounded by the components of the extracellular matrix (ECM). Glycosaminoglycans (GAGs), natural biomacromolecules, essential ECM, and cell membrane components are extensively altered in cancer tissues. During disease progression, the GAG fine structure changes in a manner associated with disease evolution. Thus, changes in the GAG sulfation pattern are immediately correlated to malignant transformation. Their molecular weight, distribution, composition, and fine modifications, including sulfation, exhibit distinct alterations during cancer development. GAGs and GAG-based molecules, due to their unique properties, are suggested as promising effectors for anticancer therapy. Considering their participation in tumorigenesis, their utilization in drug development has been the focus of both industry and academic research efforts. These efforts have been developing in two main directions; (i) utilizing GAGs as targets of therapeutic strategies and (ii) employing GAGs specificity and excellent physicochemical properties for targeted delivery of cancer therapeutics. This review will comprehensively discuss recent developments and the broad potential of GAG utilization for cancer therapy.

Optimizing Cardiovascular Health in Patients With Cancer: A Practical Review of Risk Assessment, Monitoring, and Prevention of Cancer Treatment-Related Cardiovascular Toxicity

Advances in cancer screening and improved treatment approaches have led to an increase in survivorship and, consequently, recognition of an association between cancer treatments and the development of cardiovascular complications. In addition, as the population becomes proportionally older, comorbid cardiovascular risk factors are more prevalent in the population and compound the risk of developing cancer treatment-related cardiovascular toxicity. Cardio-oncology has emerged as a new subspecialty of medicine that provides a multidisciplinary approach, bringing together oncologists, cardiologists, and allied health care providers who are tasked with optimizing the cardiovascular health of patients exposed to potentially cardiotoxic cancer therapy. Using a case-based approach, practical advice on how to identify, monitor, and treat patients with cancer who are at risk for developing cancer treatment-related cardiovascular dysfunction is discussed. Cardiovascular risk factors (e.g., age, hypertension, diabetes) and cancer therapies (chemotherapy, targeted therapy, radiation) associated with cardiovascular toxicity are presented. Current cardiac monitoring strategies such as two- and three-dimensional echocardiography, cardiac MRI, and biomarkers (troponin and brain natriuretic peptide [BNP]) are discussed. Last, the current literature on pharmacologic (e.g., angiotensin-converting enzyme inhibitors, β-blockers, statins) and lifestyle (diet and exercise) strategies to mitigate cardiovascular toxicity during and following completion of cancer therapy are reviewed.

Childhood cancer survivors: The integral role of the cardiologist and cardiovascular imaging

IMPORTANCE

With 80% of childhood cancer survivors (CCS) alive 30 years after diagnosis, preventable causes of death, such as cardiovascular disease resulting from initial cancer therapy, becomes an important metric. This leads to a more pronounced role for cardiologists in the care of CCS.

OBSERVATIONS

While routine cardiovascular screening has been traditionally performed by the hematologist/oncologist or primary care provider, our understanding of cardiovascular disease in CCS has advanced. The measurement of left ventricular ejection fraction (LVEF) can now be complemented with additional assessments of strain, LV mass, right ventricular function, diastolic function, valve function, the pericardium, coronary perfusion, and biomarkers. Risk factor modification, prophylaxis, and timing of treatment are also critical.

CONCLUSIONS AND RELEVANCE

Early cardiovascular screening and treatment in asymptomatic CCS can be nuanced and complex. As a result, there is a renewed opportunity for the cardiologist to play an integral role in the care of CCS.

KEY POINTS

Question/Purpose: Review cardiovascular disease and the role of the cardiologist in the care of asymptomatic childhood cancer survivors (CCS).

FINDINGS

Cardiovascular care in CCS benefits from a multi-faceted approach that does not overly rely on LVEF. Meaning: Adequate screening and treatment of cardiovascular disease in asymptomatic CCS may often be optimized by the involvement of a cardiologist.

Troponins and Natriuretic Peptides in Cardio-Oncology Patients-Data From the ECoR Registry

BACKGROUND

The long-term survival of cancer patients has significantly improved over the past years. Despite their therapeutic efficacy, various cancer therapies are associated with cardiotoxicity. Therefore, timely detection of cardiotoxic adverse events is crucial. However, the clinical assessment of myocardial damage caused by cancer therapy remains difficult.

METHODS

This retrospective study was performed to evaluate the diagnostic value of cardiac troponin I (cTnI) and N-terminal pro-B-type natriuretic peptide (NT-proBNP) for monitoring cancer therapy-induced cardiomyopathy. A total of 485 cancer patients referred to our cardio-oncology unit between July 2018 and January 2020 were selected from our Essen Cardio-oncology Registry (ECoR). We included patients with all types of cancer. Plasma concentrations of cTnI and NT-proBNP were measured by radioimmunoassay, and two-dimensional left ventricular ejection fraction (2D-LVEF), diastolic function, and global longitudinal strain (GLS) were measured by transthoracic echocardiography. In 116 patients, assessment was conducted before the induction of cancer therapy and during a short-term follow-up period; n = 42 of these were treated for malignant melanoma, and n = 42 with serial measurements were under treatment for breast cancer.

RESULTS

In cross-sectional data, elevated NT-proBNP was associated with reduced LVEF and pathological GLS in the total cohort. A total of 116 patients had serial LVEF and biomarker measurements, and changes in NT-proBNP and troponin correlated with changes in LVEF during follow-up investigations. Similar to the total cohort, a subgroup of patients treated for malignant melanoma showed a correlation between the change in cTnI and the change in LVEF. In a subgroup analysis of patients undergoing breast cancer therapy, a correlation between the change in NT-proBNP and the change in LVEF could be detected. Thirty patients presented with chemotherapy-induced cardiomyopathy, defined as a significant LVEF decrease (> 10%) to a value below 50%. The number of patients with increased cTnI and NT-proBNP was significantly higher in patients with chemotherapy-induced cardiomyopathy than in patients without cardiotoxicity. Patients with positive cTnI and NT-proBNP were more likely to have a history of coronary heart disease, atrial fibrillation, and arterial hypertension.

CONCLUSION

Our data suggest that cardiac biomarkers play an important role in the detection of cancer therapy-induced cardiotoxicity. Larger systematic assessment in prospective cohorts is mandatory.

Growth-differentiation Factor-15 and Tissue Doppler Imaging in Detection of Anthracycline-induced Cardiomyopathy During Therapy of Childhood Cancers

OBJECTIVES

The aim of this study was to evaluate the importance of growth-differentiation factor-15 (GDF-15) levels and tissue Doppler imaging (TDI) in the early detection of anthracycline-induced cardiomyopathy during the treatment of childhood cancers.

PATIENTS AND METHODS

Twenty patients (13 males and 7 females) newly diagnosed with childhood cancer whose treatment protocol included anthracycline were included in the study. Echocardiography, including M-mode, pulse Doppler, and TDI, was performed after the first anthracycline treatment at cumulative doses of 100, 200, and 300 mg/m and at least 6 months after the last treatment. GDF-15 and troponin-I were also measured at these time points.

RESULTS

The median age of the patients was 14 years (range, 3 to 18 y). The median cumulative anthracycline dose was 220 mg/m (range, 60 to 400 mg/m). Conventional pulse wave and pulse wave tissue Doppler methods revealed significant differences in the right ventricular myocardial performance indices of the patients who received cumulative anthracycline doses of 300 mg/m compared with their indices at least 6 months after the last treatment. The serum GDF-15 levels after the cumulative anthracycline dose of 200 mg/m were also higher than the patients' pretreatment levels.

CONCLUSIONS

Doppler/TDI and GDF-15 levels may be used in the early determination of anthracycline-induced cardiomyopathy during the treatment of childhood cancers.

Protective effect of cilostazol against doxorubicin-induced cardiomyopathy in mice

Doxorubicin (Dox) is an effective anti-cancer drug, but its use is limited because of its adverse effect of inducing irreversible dilated cardiomyopathy. Cilostazol (Cilo), a potent phosphodiesterase III inhibitor, has been reported to have an anti-inflammatory effect. Here, we investigated whether Cilo has a protective effect against Dox-induced cardiomyopathy (DIC). Mice were randomly divided into four groups: saline control, Dox (15 mg/kg), Dox (15 mg/kg) plus Cilo (50mg/kg), and Cilo (50mg/kg). The results showed that the coadministration of Dox and Cilo significantly enhanced left-ventricular systolic function compared with Dox alone. In addition, Cilo treatment significantly reduced Dox-induced perivascular fibrosis, collagen concentration, and connective growth factor expression in the heart. Also, Cilo administration markedly reduced Dox-induced levels of serum B-type natriuretic peptide, dysferlin, high-mobility group protein B1, Toll-like receptor 4, nuclear factor-κB p65, and cyclooxygenase-2. Furthermore, Cilo treatment significantly reduced Dox-induced oxidative stress by lowering the translocation of Nrf2 into the nucleus and the expression of NQO1, heme oxygenase 1, and superoxide dismutase-1. Our results suggest that Cilo may be a potential antifibrotic, antioxidative, and anti-inflammatory drug for DIC.

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.

Anthracycline-dependent cardiotoxicity and extracellular matrix remodeling

The mechanisms of anthracycline-dependent cardiotoxicity have been studied widely, with the suggested principal mechanism of anthracycline damage being the generation of reactive oxygen species by iron-anthracycline complexes, leading to lipid peroxidation and membrane damage. An increasing number of researchers studying cardiovascular events associated with anthracycline-based chemotherapy are addressing cardiac extracellular matrix (ECM) remodeling. The heart is an efficient muscular pump, with the cardiomyocytes and intramural coronary vasculature of the heart tethered in an ECM consisting of a network of fibrillar, structural proteins, mostly collagens. Increasing evidence suggests that the ECM plays a complex and diverse role in the processes initiated by anthracycline-class drugs that lead to cardiac damage. This review discusses adverse myocardial remodeling induced by anthracyclines and focuses on their mechanisms of action.

Bedside biomarkers in pediatric cardio renal injuries in emergency

Point of care testing (POCT) using biomarkers in the emergency department reduces turnaround time for clinical decision making. An ideal biomarker should be accurate, reliable and easy to measure with a standard assay, non-invasive, sensitive and specific with defined cutoff values. Conventional biomarkers for renal injuries include rise in serum creatinine and fluid overload. Recently, neutrophil gelatinase associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), cystatin C, interleukin-18 (IL-18) and liver fatty acid binding protein (L-FABP) have been studied extensively for their role in acute kidney injury associated with various clinical entities. Biochemical markers of ischaemic cardiac damage commonly used are plasma creatine kinase and cardiac troponins (cTn). Clinically valuable cardiac markers for myocardial injury in research at present comprise BNP/NT-proBNP and to a lesser extent, CRP, which are independent predictors of adverse events including death and heart failure. Current status of point of care biomarkers for diagnosis and prognostication of renal and cardiac injuries in pediatric emergency care is appraised in this review.

Serum biomarkers for the detection of cardiac toxicity after chemotherapy and radiation therapy in breast cancer patients

Multi-modality cancer treatments that include chemotherapy, radiation therapy, and targeted agents are highly effective therapies. Their use, especially in combination, is limited by the risk of significant cardiac toxicity. The current paradigm for minimizing cardiac morbidity, based on serial cardiac function monitoring, is suboptimal. An alternative approach based on biomarker testing, has emerged as a promising adjunct and a potential substitute to routine echocardiography. Biomarkers, most prominently cardiac troponins and natriuretic peptides, have been evaluated for their ability to describe the risk of potential cardiac dysfunction in clinically asymptomatic patients. Early rises in cardiac troponin concentrations have consistently predicted the risk and severity of significant cardiac events in patients treated with anthracycline-based chemotherapy. Biomarkers represent a novel, efficient, and robust clinical decision tool for the management of cancer therapy-induced cardiotoxicity. This article aims to review the clinical evidence that supports the use of established biomarkers such as cardiac troponins and natriuretic peptides, as well as emerging data on proposed biomarkers.

Screening for cardiac dysfunction in anthracycline-exposed childhood cancer survivors

PURPOSE

To examine the utility and reliability of obtaining early echocardiographic measurements of left ventricular (LV) remodeling as well as blood biomarkers of cardiac injury in asymptomatic childhood cancer survivors at risk for LV dysfunction and congestive heart failure due to past exposure to anthracycline chemotherapy.

EXPERIMENTAL DESIGN

Using a cross-sectional design, anthracycline-exposed childhood cancer survivors with preserved ejection fraction (EF; ≥50%) were evaluated using early echocardiographic indices and blood biomarkers of LV dysfunction. Survivors treated with ≥300 mg/m(2) anthracyclines [high risk (HR): n = 100] were compared with those treated with <300 mg/m(2) anthracyclines [low risk (LR): n = 50] and matched healthy controls (HC: n = 50). All echocardiograms were interpreted by an institutional cardiologist and a study cardiologist blinded to risk status.

RESULTS

Time from diagnosis was comparable for HR (12.0 years) and LR (13.2 years, P = 0.8) survivors. Echocardiograms: HR had lower LV thickness-dimension ratio (Z-score: HR: -0.62, LR: -0.03, HC: -0.02; P < 0.001), increased LV wall stress (HR: 66.7 g/cm(2), LR: 56.6 g/cm(2), HC: 54.2 g/cm(2); P < 0.01), and higher myocardial performance index (HR: 0.51, LR: 0.46, HC: 0.46; P < 0.01). Interobserver correlation (clinical/blinded reading) for all echocardiographic indices was excellent (range: R = 0.76-0.97, P < 0.001). Blood biomarkers: With the exception of NT-proBNP (r = 0.28, P < 0.01), there was no correlation between blood biomarkers (B-type natriuretic peptide, Troponin-T, ST-2, Galectin-3) and LV dysfunction.

CONCLUSION

Childhood cancer survivors with preserved EF 10+ years from anthracycline exposure had dose-dependent changes in echocardiographic markers of LV dysfunction.

Cardiotoxicity in rabbits after a low-level exposure to diazinon, propoxur, and chlorpyrifos

Lethal cardiac complications leading to death and various arrhythmias have been reported after organophosphate and/or carbamate poisonings. The present study focuses on the long-term effects of repeated low-level exposure to diazinon, propoxur, and chlorpyrifos (CPF) on cardiac function in rabbits. The yearly based experimental scheme of exposure consisted of two oral administration periods, lasting 3 months and 1 month each, interrupted by an 8-month washout period (total duration 12 months). At the end of the experimental scheme, the rabbits underwent an echocardiographic evaluation under sedation, after which they were killed and the tissue and serum samples were collected. A mild localized cardiotoxic effect was established by echocardiography for the three pesticides tested. Severe histological alterations were identified, especially in the diazinon-treated animals in agreement with increased persistence of this pesticide established in the cardiac tissue. In addition, all pesticides tested increased the oxidative stress and oxidative modifications in the genomic DNA content of the cardiac tissues, each one following a distinct mechanism.

Educational paper: decreasing the burden of cardiovascular disease in childhood cancer survivors: an update for the pediatrician

The cardiovascular impact of cancer therapies on the heart is one of the major concerns in the long-term follow-up of childhood cancer survivors (CCSs). Long-term cardiovascular effects include the development of left ventricular dysfunction resulting in congestive heart failure and ischemic heart disease, as well as valvular and pericardial disease. This is mainly ascribed to the cardiotoxic side effects of chemotherapeutic agents (especially anthracyclines) and radiotherapy, but other factors such as radiation and inflammation play a role in the effect of childhood cancer on the cardiovascular health. The most concerning effect is the high incidence of symptomatic heart failure in CCS patients treated with anthracyclines. More than 50 % of CCSs treated with anthracyclines develop asymptomatic left ventricular dysfunction after cancer therapy, with approximately 5 % developing clinical signs of heart failure during long-term follow-up. Once CCS patients develop congestive heart failure, prognosis is poor and is not influenced by current medical treatment strategies. To reduce the long-term burden of cardiovascular disease in pediatric cancer patients, a diversified approach will be necessary. In the acute phase, prevention of cardiac damage through the use of cardioprotective agents (e.g., dexrazoxane) or by administering less cardiotoxic chemotherapeutic agents is to be considered. A recent randomized trial suggested that the use of dexrazoxane reduced cardiac toxicity without affecting cancer outcomes. Especially patients requiring high doses of chemotherapeutic agents could benefit from this approach. Recent data suggest that genetic testing might identify patients at higher risk for cardiotoxicity. This seems mainly related to genes involved in drug metabolism. This would allow personalized approach adjusting chemotherapy based on cardiovascular risk profiling. This could be combined with newer monitoring strategies in the acute phase using newer echocardiographic techniques and biomarker screening to identify patients with early damage to the myocardium. For the long-term CCS cohort, early detection and treatment of early dysfunction prior to the development of congestive heart failure could potentially improve long-term outcomes. Promoting healthy lifestyles and controlling additional cardiovascular risk factors (e.g., obesity, diabetes, arterial hypertension) is an important task for every physician involved in the care of this growing cohort.

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

Background

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

Methods

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

Results

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

Conclusions

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

Detection and prevention of cardiac complications of cancer chemotherapy

Despite continuous improvements in management of patients with cancer, cardiac side-effects still account for a substantial limitation of chemotherapy. Evaluation of cardiac toxicity in patients includes consideration of biomarkers such as cardiac troponins and B-type natriuretic peptides, together with non-invasive imaging in the form of 2D-, 3D-, or strain-echocardiography, multiple gated radionuclide angiography, quantitative gated blood-pool SPECT, (123)I-metaiodobenzylguanidine scintigraphy, or cardiac magnetic resonance imaging. These approaches differ from each other with regards to availability, accuracy, sensitivity to detect early stages of cardiac injury, individual reliability, ease of use in a longitudinal follow-up perspective, and to related cost-effectiveness. Improving prevention of these cardiac side-effects depends on several, currently unresolved issues. Early detection and quantification of cardiac damage is required to adapt chemotherapy in progress for optimal management of patients. Whether increased availability of myocardial strain imaging and repeat blood biomarkers determinations will reliably and consistently achieve these goals remain to be confirmed. Also, protective approaches to reduce cardiac toxicity of anticancer drugs should be reconsidered according to the recently restricted approval for use of dexrazoxane. Anthracycline-based regimens, encapsulated anthracyclines and non-anthracycline regimens should be revisited with regards to antitumour efficacy and cardiac toxicity. Cardiovascular drugs that proved effective in prevention of anthracycline-induced cardiac toxicity in experimental models should be investigated in clinical trials. Finally, the efficacy of cardiovascular drugs that have already been tested in clinical settings should be confirmed and compared with each other in patients in increased numbers.

Cardiotoxicity of childhood cancer treatment: update and current knowledge on long-term follow-up

Therapeutic advances in paediatric oncology allowed increasing numbers of children to survive until adulthood. However, chemotherapy and radiotherapy are potentially cardiotoxic and contribute to a significant morbidity and mortality, cardiovascular events remaining the leading cause of death among survivors. This review summarizes the physiopathology of treatment-related cardiovascular diseases, their incidence, and the risk factors associated with each specific therapy. Few studies have investigated the cardiac outcomes of adult surviving from childhood cancers but all demonstrated a substantial risk for late cardiac effects. Cardiovascular monitoring, prevention, and early detection of cardiac dysfunction are, therefore, the keystones of an improved long-term outcome.

Cardiovascular status of childhood cancer survivors exposed and unexposed to cardiotoxic therapy

PURPOSE

To determine whether cardiovascular abnormalities in childhood cancer survivors are restricted to patients exposed to cardiotoxic anthracyclines and cardiac irradiation and how risk factors for atherosclerotic disease and systemic inflammation contribute to global cardiovascular status.

METHODS

We assessed echocardiographic characteristics and atherosclerotic disease risk in 201 survivors of childhood cancer with and without exposure to cardiotoxic treatments at a median of 11 years after diagnosis (range, 3 to 32 years) and in 76 sibling controls.

RESULTS

The 156 exposed survivors had below normal left ventricular (LV) mass, wall thickness, contractility, and fractional shortening and above normal LV afterload. The 45 unexposed survivors also had below normal LV mass overall, and females had below normal LV wall thickness. Exposed and unexposed survivors, compared with siblings, had higher levels of N-terminal pro-brain natriuretic peptide (81.7 and 69.0 pg/mL, respectively, v 39.4 pg/mL), higher mean fasting serum levels of non-high-density lipoprotein cholesterol (126.5 and 121.1 mg/dL, respectively, v 109.8 mg/dL), higher insulin levels (10.4 and 10.5 μU/mL, respectively, v 8.2 μU/mL), and higher levels of high-sensitivity C-reactive protein (2.7 and 3.1 mg/L, respectively, v 0.9 mg/L; P < .001 for all comparisons). Age-adjusted, predicted-to-ideal 30-year risk of myocardial infarction, stroke, or coronary death was also higher for exposed and unexposed survivors compared with siblings (2.16 and 2.12, respectively, v 1.70; P < .01 for both comparisons).

CONCLUSION

Childhood cancer survivors not receiving cardiotoxic treatments nevertheless have cardiovascular abnormalities, systemic inflammation, and an increased risk of atherosclerotic disease. Survivorship guidelines should address cardiovascular concerns, including the risk of atherosclerotic disease and systemic inflammation, in exposed and unexposed survivors.

Serial measurements of NT-proBNP are predictive of not-high-dose anthracycline cardiotoxicity in breast cancer patients

Background:

The aim of this study was to assess the value of N-terminal pro-brain natriuretic peptide (NT-proBNP) in predicting late cardiotoxicity in patients treated with not-high-dose chemotherapy (NHDC), and to compare the predictive value of NT-proBNP and cardiac troponin I (cTnI).

Methods:

In 71 patients undergoing NHDC with anthracyclines, NT-proBNP and cTnI levels were measured before and 24 h after each NHDC cycle. Left ventricular (LV) function was assessed by echocardiography at baseline, every two NHDC cycles, at the end of chemotherapy, and at 3-, 6- and 12-month follow-up.

Results:

During NHDC, only NT-proBNP showed abnormal values. According to NT-proBNP behaviour, patients were divided into two groups: group A (n=50) with normal (n=23) or transiently elevated NT-proBNP levels (n=27), and group B (n=21) with persistently elevated NT-proBNP levels. At follow-up, LV impairment was significantly worse in group B than in group A. %Δ (baseline–peak) NT-proBNP was predictive of LV impairment at 3-, 6- and 12-month follow-up, with a cutoff of 36%.

Conclusion:

Serial measurements of NT-proBNP may be a useful tool for the early detection of patients treated with NHDC at high risk of developing cardiotoxicity.

Cardiac function in survivors of acute lymphoblastic leukaemia and Hodgkin's lymphoma

AIM

The study objective was to assess plasma N-terminal-pro-brain natriuretic peptide (BNP) levels and to evaluate left ventricular mass as well as left ventricular systolic and diastolic functions in 44 children who had undergone treatment for acute lymphoblastic leukaemia and Hodgkin's lymphoma, with regard to gender, age at disease onset, time that had passed since therapy completion, cumulative dose of antracyclines and mediastinal radiotherapy applied.

METHODS

The median levels of pro-BNP were found to be higher in the whole study group as compared with the control (55.9 ± 53.1 ng/mL vs. 38.5 ± 47.7 ng/mL, P= 0.059). The pro-BNP values >80.0 ng/mL (standard deviation score (SDS)) were noted in 11/44 patients, including those exceeding 115.0 ng/mL (2 SDS) - in 6/44 patients.

RESULTS

No correlation was observed of pro-BNP levels with the accumulated dose of antracyclines (r=-0.42, P= 0.79) or mediastinal radiotherapy (r= 0.197, P= 0.2). However, negative correlation was found between pro-BNP and the time that had passed since therapy completion (r=-0.378, P= 0.009). In echocardiography, shortening and ejection fractions remained normal, whereas the indexed stroke volume was below 40 mL/m(2) in 16/44 patients. The E/A index below 1.5 was found in 6/44 cases. The left ventricular systolic mass remained within the normal range. Negative correlation was noted between isovolumetric diastolic time and pro-BNP level.

CONCLUSIONS

Increased levels of pro-BNP after anti-cancer treatment with the involvement of cardiotoxic substances may indicate the first symptoms of myocardial dysfunction, despite the lack of major echocardiographic disorders.

N-terminal pro-brain natriuretic peptide level as a screening tool for cardiac involvement in paediatric diseases of extracardiac origin

BACKGROUND

Serum concentrations of N-terminal natriuretic pro-brain natriuretic peptide (NT-proBNP) correlate well with the severity of cardiac disease in children and adults. There are also paediatric illnesses of extracardiac origin that may cause deterioration of the cardiac function in some patients (pts). A high NP level can signify a concomitant cardiac involvement in respiratory distress, or secondary to a systemic disease.

OBJECTIVE

To assess the potential of NT-proBNP as a screening tool for cardiac involvement in paediatric diseases of extracardiac origin.

METHODS

A literature search was performed in PubMed for the relevant studies with the subject brain natriuretic peptide (BNP) and NT-proBNP from 1995 to 2010 with stress on characteristics of the natriuretic peptides, paediatric reference values and systemic paediatric diseases with potential influence on the myocardial performance. The main focus has been NT-proBNP being the most stable NP and correlating well with BNP.

RESULTS

Most studies agree that a high NT-proBNP level indicates cardiac dysfunction in different systemic diseases such as thalassemia and cystic fibrosis or in pts after chemotherapy. In special clinical scenarios as sepsis or respiratory distress, NT-proBNP helps to narrow down the differential diagnosis or can be used for risk stratification.

CONCLUSION

NT-proBNP can serve as a screening tool in various primarily non-cardiac paediatric diseases. Together with the clinical picture, a high level suggests further assessment by a paediatric cardiologist.

Plasma B-type natriuretic peptides in children with cardiovascular diseases

Natriuretic peptides (NP) are released from the heart in response to pressure and volume overload. The biologic properties of NPs include counterregulation of the rennin-angiotensin-aldosterone pathway and a decrease in sympathetic tone resulting in diuresis, natriuresis, and vasodilation. Natriuretic peptides help to maintain fluid balance and blood pressure in a healthy physiologic range. The B-type natriuretic peptide (BNP) and its N-terminal precursor (NTpBNP) have become important diagnostic biomarkers of cardiovascular diseases (CVDs) in adults. Although many studies suggest that BNP also is a reliable test for diagnosing significant CVDs in children, data are lacking on whether additional use of BNP increases diagnostic accuracy and predicts prognosis. This comprehensive review describes the utility of BNP and NTpBNP for various CVDs of the neonatal and pediatric age groups. Because BNP is not a stand-alone test, it should not replace history, physical examination, or clinical judgment, but it has a clear value in adding details to the whole story for children, thus enabling the front-line physicians to make a diagnosis, especially in the acute care setting.

Cardiac side-effects of cancer chemotherapy

The spectrum of cardiac side-effects of cancer chemotherapy has expanded with the development of combination, adjuvant and targeted chemotherapies. Their administration in multiple regimens has increased greatly, including in older patients and in patients with cardiovascular and/or coronary artery disease (CAD). Cardiac toxicity of anthracyclines involves oxidative stress and apoptosis. Early detection combines 2D-echocardiography and/or radionuclide angiography and recent methods such as tissue Doppler imaging, strain rate echocardiography and sampling of serial troponin and/or NT-proBNP levels. Dexrazoxane has proven effective in the prevention of dose-related toxicity in children and adults. High doses of the alkylating drugs cyclophosphamide and ifosfamide may result in a reversible heart failure and in life-threatening arrhythmias. Myocardial ischemia induced by the antimetabolites 5-fluorouracil and capecitabine impacts prognosis of patients with prior CAD. Severe arrhythmias may complicate administration of microtubule inhibitors. Targeted therapies with the antibody-based tyrosine kinases (TK) inhibitors trastuzumab and, to a lesser extent, alemtuzumab induce heart failure or asymptomatic LV dysfunction in 1-4% and 10%, respectively. Cetuximab and rituximab induce hypotension, whereas bevacizumab may promote severe hypertension and venous thromboembolism. Small molecule TK inhibitors may also elicit LV dysfunction, in only few patients treated with imatinib mesylate, but in a substantially higher proportion of those receiving the multitargeted TK inhibitor sunitinib or the recently approved drugs erlotinib, lapatinib and dasatinib. Management of patients at increased cardiovascular risk associated with advancing age, previous CAD or targeted therapies may be optimized by referral to a cardiologist in a cross-specialty teamwork.

The use of B-type natriuretic peptide in paediatric patients: a review of literature

OBJECTIVE

Plasma levels of brain natriuretic peptide (BNP) and its inactive fragment N-terminal pro-BNP are recognized as reliable markers of ventricular dysfunction in adults. We aimed to verify BNP applications in children.

METHODS

A review of the literature on this subject was carried out.

RESULTS

When dealing with paediatric patients, age and sex-related normal values must be considered. Higher BNP plasma levels are reported in children with chronic heart failure; they are related with the type of dysfunction and with prognosis. Moreover, increased BNP levels have been reported in asymptomatic children and adolescents pretreated with anthracyclines, who are at risk for ventricular dysfunction.

CONCLUSION

BNP and pro-BNP also seem to be effective markers of ventricular dysfunction in paediatric patients. Clinical use may be extended not only for the characterization of heart dysfunction, but also for monitoring asymptomatic patients at specific risk. To this purpose, wider application in clinical trials appears warranted.

Plasma natriuretic peptides levels and echocardiographic findings in late subclinical anthracycline toxicity

The purpose of this study was to evaluate late cardiac toxicity by comprehensive echocardiographic study, and to determine whether plasma atrial natriuretic peptide and brain natriuretic peptide levels might be indicators of neurohumoral activation. The study included 49 long-term survivors and 21 controls. A wide variety of echocardiographic parameters were measured or calculated. Plasma peptide levels were determined. Patients had significant changes in different echocardiographic parameters that are suggestive of LV systolic and diastolic dysfunction. Plasma peptide levels were not increased. The authors have found significant subclinic cardiotoxicity by echocardiography. Survivors seem to have normal plasma natriuretic peptide levels in long-term period.

The role of biomarkers in the early detection of anthracycline-induced cardiotoxicity in children: a review of the literature

Anthracycline-induced cardiotoxicity can cause serious health problems for an increasing number of children surviving childhood malignancies. Early detection of cardiac failure is critically important for the prevention and management of anthracycline-induced cardiotoxicity. The aim of this research was to determine the role of biomarkers in the early detection of anthracycline-induced cardiotoxicity in children. A literature review is presented of studies regarding the use of the biomarkers B-type natriuretic peptide (BNP), N-terminal pro-BNP (NT-pro-BNP), cardiac troponin T (cTnT), and cardiac troponin I (cTnI) in relation with anthracycline-induced cardiotoxicity in children. Six of 14 studies in children showed a significant relation between elevated biomarkers BNP, NT-pro-BNP, and cTnT and cardiac dysfunction. Six studies, although small, suggest that BNP, NT-pro-BNP, and cTnT might be useful markers in the early detection of anthracycline-induced cardiotoxicity.

Troponins and natriuretic peptides in the monitoring of anthracycline cardiotoxicity

Anthracycline-related cardiotoxicity has a substantial negative impact on long-term survivors of childhood cancer. The detection of cardiotoxicity is currently based on echocardiography or radionuclide angiography. However, as they depict only the final outcome of myocardial injury in terms of reduced heart contractility, heart specific biomarkers of myocardial destruction or dysfunction could be advantageous by allowing for an earlier detection of cardiotoxicity. In the present study, the usefulness of cardiac troponins and natriuretic peptides, the most commonly used biomarkers of myocardial destruction and ventricular dysfunction respectively, to detect and to predict the development of anthracycline cardiotoxicity has been reviewed.

Anthracycline cardiotoxicity in childhood

Over the last 40 years, a significant advance has been made in the treatment of childhood and adult cancers. However, the increase of the survival rate points out medium- and long-term adverse effects that constitute a serious limitation for the quality of life in adults survived from a childhood cancer. Cardiovascular disease is an important cause of morbidity and mortality in adults treated with chemo- and radiotherapy for childhood cancers. Although some antitumor treatments are potentially cardiotoxic, anthracycline therapy and radiotherapy are mostly responsible for long-term cardiac damage. Anthracycline toxicity is generally limited to the myocardium, while radiation can cause injury to all components of the heart. The purpose of this review is to discuss the mechanisms of action of anthracyclines, their cardiotoxicity, the feasibility of screening, and the prevention of cardiac damage after treatment in childhood.

Amino-terminal pro-B-type natriuretic peptide testing in neonatal and pediatric patients

Concentrations of amino-terminal pro-B-type natriuretic peptides (NT-proBNP) are often markedly elevated immediately after birth and typically decrease to normal concentrations after the first week of life. Despite these early life elevations (which likely reflect activity of the natriuretic peptide system to assist in mobilization of fluid in the neonatal period), NT-proBNP has been shown to be useful for the diagnosis or exclusion of heart failure (HF) in the neonate, infant, adolescent, and older child. After the resolution of the normative early-life elevations of NT-proBNP, it is reasonable to use age-adjusted cut points suggested for younger adults (<50 years), namely levels <300 ng/L to "rule out" HF, and >450 ng/L to "rule in" HF. In children with congenital heart disease with or without symptoms of HF, NT-proBNP concentrations are typically elevated and may be prognostically useful. Furthermore, NT-proBNP may be useful for the identification of patients treated with cardiotoxic chemotherapy at risk for the subsequent development of cardiomyopathy. Knowledge of expected concentrations of NT-proBNP at varying stages of life is important to optimally utilize this assay in the pediatrics setting.

The differential diagnosis of an elevated amino-terminal pro-B-type natriuretic peptide level

Although amino-terminal pro-B-type natriuretic peptides (NT-proBNP) are useful for the diagnosis or exclusion of heart failure (HF), this marker may identify a wide range of disease processes other than HF. Indeed, elevation of NT-proBNP may occur in a number of heart diseases (including heart muscle disease, valve disease, rhythm abnormalities, pulmonary hypertension, and cytotoxic injury to the heart) and in disease processes other than primary cardiac illnesses, including gram-negative sepsis. Importantly, although NT-proBNP may increase in settings other than HF, the presence and severity of such NT-proBNP release is often significantly associated with risk for adverse outcome. Accordingly, elevation of NT-proBNP in the context of non-HF situations should not be regarded as a "false-positive" finding, and elevated NT-proBNP values should not be discarded without consideration of the serious adverse outcomes associated with the elevation. Future studies will be necessary to further understand the utility of NT-proBNP testing in states other than cardiovascular disease.

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.

Longitudinal evaluation of early and late anthracycline cardiotoxicity in children with AML

BACKGROUND

Anthracyclines are effective antineoplastic drugs in acute myelogenous leukemia (AML). However, their use is limited by cardiomyopathy, which occurs in children already at cumulative doses of 300 mg/m(2) (given as daunorubicin equivalent).

PROCEDURE

To evaluate anthracycline-associated cardiomyopathy in pediatric AML-patients, the incidence of early and late (>1 year after intensive AML chemotherapy) clinical and subclinical cardiotoxicity was analyzed out of a total of 1,207 patients <18 years treated between 1993 and 2003 in trials AML-BFM93/98: 1,010 protocol patients with de novo AML, 121 with Down syndrome (DS)-AML, and 76 with secondary AML. The cumulative dose of anthracyclines was generally risk-adapted: 300-450 mg/m(2) using 1-4-hr infusions of anthracyclines with the assumed lowest cardiotoxic potential. Eight hundred eighty-five patients (73%) were eligible for the analysis of early and 547 (45%) of late cardiotoxicity (1,399 follow-up data).

RESULTS

Thirty-eight patients (4.3%), including 3 DS-AML and 1 secondary AML, suffered from early cardiomyopathy. After 5 years, four patients showed temporarily or persistently a reduced shortening fraction, which led to death in one DS-AML patient. Including these 4 patients, late cardiomyopathy was seen in 16 patients (cumulative incidence after 11 years: 5% +/- 1%). Nine patients (2.5 +/- 1%) showed clinical symptoms, five of them had persistent abnormal shortening fraction. Late subclinical cardiomyopathy occurred temporarily in seven patients. Late clinical cardiomyopathy mainly affected patients with a second anthracycline therapy (secondary malignancy) and those with early cardiotoxicity.

CONCLUSION

In spite of a highly intensive and effective treatment, the frequency of anthracycline-associated cardiomyopathy was low in the AML-BFM studies.

Anthracycline cardiotoxicity

The use of anthracyclines is limited by dose-dependent cardiotoxicity. Three forms of anthracycline cardiotoxicity are described; an immediate pericarditis-myocarditis syndrome, an early onset chronic progressive CHF developing during or shortly after therapy and late-onset cardiotoxicity presenting years following treatment. A number of risk factors have been reported, including; cumulative dose, administration schedule, mediastinal radiotherapy, old and young age, concurrent cardiovascular disease, combination therapy, gender, ethnicity and chromosomal abnormalities. Evaluation of left ventricular ejection fraction has been widely adopted as a means of monitoring and assessing anthracycline-induced cardiotoxicity. Biochemical markers and other techniques, such as endomyocardial biopsy, metaiodobenzylguanidine and indium-111-antimyosin scintigraphy are not routinely used. Methods employed to prevent cardiotoxicity include cumulative dose limitation, alteration of administration schedule, anthracycline analogues, liposomal formulations and the cardioprotective agent, dexrazoxane. With the growing number of paediatric malignancy survivors and the increasing use of anthracyclines in the adjuvant treatment of breast cancer, the cardiotoxicity associated with these agents will remain a formidable issue for physicians. Further work is required to identify patients at increased risk of cardiotoxicity and to develop novel methods of protecting and treating this adverse effect.