Early prediction of anthracycline induced cardiotoxicity

Acute and early-onset cardiotoxicity in children and adolescents with cancer: a systematic review

BACKGROUND

Cardiotoxicity is among the most important adverse effects of childhood cancer treatment. Anthracyclines, mitoxantrone and radiotherapy involving the heart are its main causes. Subclinical cardiac dysfunction may over time progress to clinical heart failure. The majority of previous studies have focused on late-onset cardiotoxicity. In this systematic review, we discuss the prevalence and risk factors for acute and early-onset cardiotoxicity in children and adolescents with cancer treated with anthracyclines, mitoxantrone or radiotherapy involving the heart.

METHODS

A literature search was performed within PubMed and reference lists of relevant studies. Studies were eligible if they reported on cardiotoxicity measured by clinical, echocardiographic and biochemical parameters routinely used in clinical practice during or within one year after the start of cancer treatment in ≥ 25 children and adolescents with cancer. Information about study population, treatment, outcomes of diagnostic tests used for cardiotoxicity assessment and risk factors was extracted and risk of bias was assessed.

RESULTS

Our PubMed search yielded 3649 unique publications, 44 of which fulfilled the inclusion criteria. One additional study was identified by scanning the reference lists of relevant studies. In these 45 studies, acute and early-onset cardiotoxicity was studied in 7797 children and adolescents. Definitions of acute and early-onset cardiotoxicity prove to be highly heterogeneous. Prevalence rates varied for different cardiotoxicity definitions: systolic dysfunction (0.0-56.4%), diastolic dysfunction (30.0-100%), combinations of echocardiography and/or clinical parameters (0.0-38.1%), clinical symptoms (0.0-25.5%) and biomarker levels (0.0-37.5%). Shortening fraction and ejection fraction significantly decreased during treatment. Cumulative anthracycline dose proves to be an important risk factor.

CONCLUSIONS

Various definitions have been used to describe acute and early-onset cardiotoxicity due to childhood cancer treatment, complicating the establishment of its exact prevalence. Our findings underscore the importance of uniform international guidelines for the monitoring of cardiac function during and shortly after childhood cancer treatment.

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.

Oxidative stress and inflammation: determinants of anthracycline cardiotoxicity and possible therapeutic targets

Chemotherapy with anthracycline-based regimens remains a cornerstone of treatment of many solid and blood tumors but is associated with a significant risk of cardiotoxicity, which can manifest as asymptomatic left ventricular dysfunction or overt heart failure. These effects are typically dose-dependent and cumulative and may require appropriate screening strategies and cardioprotective therapies in order to minimize changes to anticancer regimens or even their discontinuation. Our current understanding of cardiac damage by anthracyclines includes a central role of oxidative stress and inflammation. The identification of these processes through circulating biomarkers or imaging techniques might then be helpful for early diagnosis and risk stratification. Furthermore, therapeutic strategies relieving oxidative stress and inflammation hold promise to prevent heart failure development or at least to mitigate cardiac damage, although further evidence is needed on their efficacy, either alone or as part of combination therapies with neurohormonal antagonists, which are the current adopted standard.

The Role of Biomarkers in Decreasing Risk of Cardiac Toxicity after Cancer Therapy

With the improvement of cancer therapy, survival related to malignancy has improved, but the prevalence of long-term cardiotoxicity has also increased. Cancer therapies with known cardiac toxicity include anthracyclines, biologic agents (trastuzumab), and multikinase inhibitors (sunitinib). The most frequent presentation of cardiac toxicity is dilated cardiomyopathy associated with poorest prognosis. Monitoring of cardiac toxicity is commonly performed by assessment of left ventricular (LV) ejection fraction, which requires a significant amount of myocardial damage to allow detection of cardiac toxicity. Accordingly, this creates the impetus to search for more sensitive and reproducible biomarkers of cardiac toxicity after cancer therapy. Different biomarkers have been proposed to that end, the most studied ones included troponin release resulting from cardiomyocyte damage and natriuretic peptides reflecting elevation in LV filling pressure and wall stress. Increase in the levels of troponin and natriuretic peptides have been correlated with cumulative dose of anthracycline and the degree of LV dysfunction. Troponin is recognized as a highly efficient predictor of early and chronic cardiac toxicity, but there remains some debate regarding the clinical usefulness of the measurement of natriuretic peptides because of divergent results. Preliminary data are available for other biomarkers targeting inflammation, endothelial dysfunction, myocardial ischemia, and neuregulin-1. The purpose of this article is to review the available data to determine the role of biomarkers in decreasing the risk of cardiac toxicity after cancer therapy.

Utilizing cardiac biomarkers to detect and prevent chemotherapy-induced cardiomyopathy

The success achieved in advances in cancer therapy has been marred by development of cardiotoxicity, which causes significant morbidity and mortality. This has led to the development of surveillance protocols for cardiotoxicity utilizing multimodality imaging techniques and investigation of various drugs to treat and prevent cardiotoxicity in this subset of patients. Cardiac biomarkers hold important diagnostic and prognostic value in various cardiac diseases. In this review, we discuss the use of biomarkers in patients receiving chemotherapy, highlighting data behind the use of troponin, B-type natriuretic peptide, and myeloperoxidase. We also discuss the use of dexrazoxane, angiotensin-converting enzyme inhibitors, and beta blockers in the treatment and prevention of chemotherapy-induced cardiotoxicity. Cardiac biomarkers may serve an important role in selecting patients that are at high risk of cardiotoxicity and can potentially be used to guide the administration of drugs to treat and prevent cardiotoxicity.

Exercise Prevention of Cardiovascular Disease in Breast Cancer Survivors

Thanks to increasingly effective treatment, breast cancer mortality rates have significantly declined over the past few decades. Following the increase in life expectancy of women diagnosed with breast cancer, it has been recognized that these women are at an elevated risk for cardiovascular disease due in part to the cardiotoxic side effects of treatment. This paper reviews evidence for the role of exercise in prevention of cardiovascular toxicity associated with chemotherapy used in breast cancer, and in modifying cardiovascular risk factors in breast cancer survivors. There is growing evidence indicating that the primary mechanism for this protective effect appears to be improved antioxidant capacity in the heart and vasculature and subsequent reduction of treatment-related oxidative stress in these structures. Further clinical research is needed to determine whether exercise is a feasible and effective nonpharmacological treatment to reduce cardiovascular morbidity and mortality in breast cancer survivors, to identify the cancer therapies for which it is effective, and to determine the optimal exercise dose. Safe and noninvasive measures that are sensitive to changes in cardiovascular function are required to answer these questions in patient populations. Cardiac strain, endothelial function, and cardiac biomarkers are suggested outcome measures for clinical research in this field.

Use of biomarkers for the assessment of chemotherapy-induced cardiac toxicity

OBJECTIVES

To review the evidence for the use of various biomarkers in the detection of chemotherapy associated cardiac damage.

DESIGN AND METHODS

Pubmed.gov was queried using the search words chemotherapy and cardiac biomarkers with the filters of past 10years, humans, and English language. An emphasis was placed on obtaining primary research articles looking at the utility of biomarkers for the detection of chemotherapy-mediated cardiac injury.

RESULTS

Biomarkers may help identify patients undergoing treatment who are at high risk for cardiotoxicity and may assist in identification of a low risk cohort that does not necessitate continued intensive screening. cTn assays are the best studied biomarkers in this context and may represent a promising and potentially valuable modality for detecting cardiac toxicity in patients undergoing chemotherapy. Monitoring cTnI levels may provide information regarding the development of cardiac toxicity before left ventricular dysfunction becomes apparent on echocardiography or via clinical symptoms. A host of other biomarkers have been evaluated for their utility in the field of chemotherapy related cardiac toxicity with intermittent success; further trials are necessary to determine what role they may end up playing for prediction and prognostication in this setting.

CONCLUSIONS

Biomarkers represent an exciting potential complement or replacement for echocardiographic monitoring of chemotherapy related cardiac toxicity which may allow for earlier realization of the degree of cardiac damage occurring during treatment, creating the opportunity for more timely modulation of therapy.

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.

Managing chemotherapy-related cardiotoxicity in survivors of childhood cancers

In the US, children diagnosed with cancer are living longer, but not without consequences from the same drugs that cured their cancer. In these patients, cardiovascular disease is the leading cause of non-cancer-related morbidity and mortality. Although this review focuses on anthracycline-related cardiomyopathy in childhood cancer survivors, the global lifetime risk of other cardiovascular diseases such as atherosclerosis, arrhythmias and intracardiac conduction abnormalities, hypertension, and stroke also are increased. Besides anthracyclines, newer molecularly targeted agents, such as vascular endothelial growth factor receptor and tyrosine kinase inhibitors, also have been associated with acute hypertension, cardiomyopathy, and increased risk of ischemic cardiac events and arrhythmias, and are summarized here. This review also covers other risk factors for chemotherapy-related cardiotoxicity (including both modifiable and non-modifiable factors), monitoring strategies (including both blood and imaging-based biomarkers) during and following cancer treatment, and discusses the management of cardiotoxicity (including prevention strategies such as cardioprotection by use of dexrazoxane).

Cardiac complications of chemotherapy: role of biomarkers

OPINION STATEMENT

Both conventional and novel antineoplastic drugs may cause damage to the heart, ultimately affecting patients' survival and quality of life. In fact, the most frequent and typical clinical manifestation of cardiotoxicity, asymptomatic or symptomatic left ventricular dysfunction, may be induced not only by conventional cancer therapy, like anthracyclines, but also by new antitumoral targeted therapy such as trastuzumab. At present, left ventricular ejection fraction assessment represents the main standard practice for cardiac monitoring during cancer therapy, but it detects myocardial damage only when a functional impairment has already occurred, not allowing for early preventive strategies. In the last decade, a newer approach based on the measurement of cardiospecific biomarkers has been proposed, proving to have higher prognostic value than imaging modalities. In particular, cardiac troponin elevation during chemotherapy allows us to identify patients who are more prone to develop myocardial dysfunction and cardiac events during follow up. In these patients, the use of an angiotensin-converting enzyme inhibitor, such as enalapril, has shown to be effective in improving clinical outcome, giving the chance for a cardioprotective strategy in a selected population.

Biomarkers for the early detection of anthracycline-induced cardiotoxicity: current status

BACKGROUND

Cardiotoxicity is a well-known and potentially serious complication of anticancer therapy. Anthracycline-based chemotherapy represents the greatest risk. Early detection of cardiotoxicity is crucial for applying preventive and supportive therapeutic strategies.

METHODS AND RESULTS

Various methods have been recommended for monitoring of cardiotoxicity. In our conditions, echocardiography and electrocardiography are routinely used. However, this approach shows low sensitivity for the early prediction of cardiomyopathy when the possibilities of appropriate management could still improve the patient's outcome. Recently, biomarkers of cardiac injury have been investigated in the assessment of chemotherapy-induced cardiotoxicity. Cardiospecific biomarkers, such as cardiac troponins, show high diagnostic efficacy in the early subclinical phase of the disease before the clinical onset of cardiomyopathy. Increase in their concentrations correlates with disease severity. As for natriuretic peptides, some studies, including ours, have shown promising results. Definitive evidence of their diagnostic and prognostic role in this context is still lacking and natriuretic peptides have not been routinely used for monitoring of cardiotoxicity in clinical practice. Other perspective biomarkers of cardiotoxicity in oncology are under study, especially heart-type fatty acid-binding protein (H-FABP) and glycogen phosphorylase BB (GPBB). Our studies using GPBB have provided encouraging results. However, the available data are limited and their practical use in this context cannot be recommended until their clinical efficacy is clearly defined.

CONCLUSIONS

This review covers the current status of biomarkers for the early detection of anthracycline-induced cardiotoxicity. The authors present in brief, their own experience with multiple biomarkers in the detection of cardiotoxicity.

Cardiac Troponin T and NT-proBNP as Biomarkers of Early Myocardial Damage in Amitriptyline-Induced Cardiovascular Toxicity in Rats

The main objective of this study was to investigate whether cardiac troponin (cTn) and N-terminal, protein B-type natriuretic peptide (NT-proBNP) can be useful as indicators for amitriptyline cardiotoxicity which is a known drug having sublethal toxic cardiac effects. At the same time, this study looked at detecting potential histopathological changes specific to irreversible cardiac injuries in a rat model of amitriptyline cardiotoxicity. Male Wistar rats were randomly divided into 2 groups, control (saline) group and amitriptyline group (100 mg/kg body weight intraperitoneally, equivalent for lethal dose at 50%). Blood was collected 30 minutes after the administration. The cTn was measured using 3 different methods (2 methods designed for human use and a sandwich enzyme immunoassay specific for rat cTnT). The brain natriuretic peptide was measured by 2 different methods (1 for human and 1 specific for rats). Electrocardiography showed that the QRS complex ( P < .0001) and the QT interval ( P = .002) were significantly prolonged for amitriptyline-treated animals. Troponin T and NT-proBNP had significantly increased levels in all the rats but showed positive results only when using rat-specific quantitative measurement. In certain rats, the histopathological examination identified a few small foci of acute myocardial necrosis. In conclusion, elevation of cTnT and NT-proBNP are early indicators of cardiotoxicity, yet the significance of irreversible myocardial damage in amitriptyline cardiotoxicity needs to be further understood.

Using cardiac biomarkers and treating cardiotoxicity in cancer

Cardiotoxicity is a frequent and serious adverse effect of both conventional and novel anticancer treatments, affecting patient survival and quality of life. The current standard for cardiac monitoring during cancer therapy, mainly based on left ventricular ejection fraction assessment, detects myocardial damage only when a functional impairment has already occurred, not allowing for early preventive strategies. Measurement of cardiospecific biomarkers has proven to have higher prognostic value than imaging modalities. In particular, cardiac troponin elevation during chemotherapy allows the identification of patients who are more prone to develop myocardial dysfunction and cardiac events during follow-up. In these patients, the use of an angiotensin-converting enzyme inhibitor such as enalapril has shown to be effective in improving clinical outcome, giving the chance for a cardioprotective strategy in a selected population. Once left ventricular dysfunction occurs, heart failure therapies currently used for other forms of left ventricular dysfunction, particularly angiotensin-converting enzyme inhibitors and β-blockers, seem to be effective. However, their use in cancer patients is still undervalued.

Acceptable cardiac safety profile of neoadjuvant 5-fluorouracil, epirubicin, cyclophosphamide and celecoxib (FEC-C) for breast cancer: a subanalysis of biomarkers for cardiac injury

PURPOSES

This substudy aimed to examine the changes in biomarkers for cardiac injury in patients who received neoadjuvant 5-fluorouracil, epirubicin, cyclophosphamide with concurrent celecoxib (FEC-C).

METHODS

Thirty-four female patients with histologically confirmed locally advanced breast cancer preoperatively received 3 cycles of FEC-C (500 mg/m², 75 mg/m², 500 mg/m²) with concurrent celecoxib (400 mg bid). Blood samples were drawn from patients on day (D) 0, D3, D21, D42, and D63 (end of therapy), and the serum levels of lactate dehydrogenase (LDH) and plasma levels of cardiac troponin I (cTnI) and N-terminal prohormone brain-type natriuretic peptide (NT-proBNP) were measured with commercially available test kits.

RESULTS

All patients tolerated this regimen well. Neither life-threatening toxicity nor clinical symptoms of cardiac damage were observed. Serum LDH increased significantly from baseline after 3 cycles of FEC-C (p<0.0001), but the change was possibly brought about by chemotherapy-induced liver derangement. However, NT-proBNP decreased significantly (p=0.009), while cTnI increased nonsignificantly (p=0.078) after 3 cycles of FEC-C compared to baseline, although this increase was still regarded as normal.

CONCLUSIONS

Short-term use of the FEC-C regimen has proven to be effective in locally advanced breast cancer, with an acceptable cardiac safety profile.

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

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

Use and misuse of serum troponin assays in pediatric practice

Cardiac troponin (cTn) is instrumental in screening and diagnosing myocardial ischemia in adults. However, the role of cTn screening in the pediatric population is less clear. The purpose of this study was to evaluate the current clinical practice, diagnostic and prognostic value, and resource utilization associated with cTn assays in the pediatric population. A multicenter, retrospective review of all cTn assays performed on patients aged ≤18 years from January 2003 to December 2010 in the Intermountain Healthcare system was conducted. Data collected included patient demographics, location, presenting symptoms, provisional and discharge diagnoses, additional tests, clinical outcomes (hospitalization days, ventilation, and death), and patient charges. During the study period, cTn assays were performed on 3,497 pediatric patients. The most common presenting diagnoses were chest pain (40%), trauma (11%), and poisoning or drug overdose (9%). Irrespective of diagnosis, elevated cTn was associated with an increased rate of hospitalization, ventilation, and death. Overall, 12% of patients had elevated cTn. Of the patients with chest pain, 4% had elevated cTn, 53% of whom were diagnosed with myopericarditis. In the myopericarditis group, 66% presented with fever, and 98% had abnormal electrocardiographic findings. For patients presenting with chest pain, approximately $162,000 was spent per positive result. In conclusion, cTn screening has strong prognostic value in pediatric patients, even in noncardiac diagnoses such as trauma or drug overdose. However, cTn screening in pediatric patients with chest pain provides minimal benefits and is associated with increased resource utilization, unless patients have constitutional symptoms, such as fever and/or electrocardiographic abnormalities.

Assessment of cardiotoxicity with cardiac biomarkers in cancer patients

Cardiotoxicity remains a major limitation of chemotherapy, strongly affecting the quality of life and the overall survival of cancer patients, regardless of their oncologic prognosis. The time elapsed from the end of cancer therapy to the beginning of heart failure therapy for chemotherapy-induced cardiac dysfunction is an important determinant of the extent of recovery. This highlights the need for a real-time diagnosis of cardiac injury. The current standard for monitoring cardiac function detects cardiotoxicity only when a functional impairment has already occurred, precluding any chance of preventing its development. In the last decade, early identification, assessment, and monitoring of cardiotoxicity, by measurement of serum cardiospecific biomarkers, have been proposed as an effective alternative. In particular, the role of troponin I in identifying patients at risk for cardiotoxicity and of angiotensin-converting enzyme inhibitors in preventing left ventricular ejection fraction reduction and cardiac events has clearly proved to be an effective strategy for this complication. In addition, novel biomarkers for the identification of cardiotoxicity are emerging. The use of a multimarker approach may provide a unique opportunity for advancement in this field, allowing for better stratification of the cardiac risk in cancer patients treated with anticancer drugs.

Role of biomarkers in cardioncology

Cardiotoxicity is a serious adverse effect of anticancer drugs, impacting on quality of life and overall survival of cancer patients. According to the current standard for monitoring cardiac function, cardiotoxicity is usually detected only when a functional impairment has already occurred, precluding any chance of preventing its development. Over the last decade, however, a new approach, based on the use of cardiac biomarkers, has emerged, and has proven to be an effective alternative strategy for early detection of subclinical cardiac injury. In particular, the role of troponin I in identifying patients at risk of cardiotoxicity and of angiotensin-converting enzyme inhibitors in preventing left ventricular ejection fraction reduction and late cardiac events represent an effective tool for the prevention of this complication.

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.

Cardiac troponin T for early detection of cardiotoxicity in breast cancer patients treated with epirubicin

The aim of the study was to investigate the role of cTnT for the prediction of long term cardiac dysfunction after epirubicin-containing adjuvant chemotherapy for breast cancer. The study group comprised of 45 patients (all female; mean age 48 ±8 years), treated with epirubicin-containing adjuvant chemotherapy for stage 2 and stage 3 breast cancer. Patients received either 4 cycles of cyclophosphamide plus epirubicin (90 mg/m2) (n=23; stage 2 breast cancer) or 6 cycles of cyclophosphamide plus epirubicin (75 mg/m2) plus fluorouracil (n=18; stage 3 breast cancer). Venous blood samples were drawn, before and 72 hours after, every cycle of chemotherapy for the measurement of cTnT. Cardiac assessment was carried out at baseline and 1 year after chemotherapy by clinical evaluation, electrocardiography, radio-nuclide ventriculography (RNV) and transthoracic echocardiography. All patients remained free of clinical heart failure during the study period. In 26 patients (63%), cTnT was elevated after chemotherapy. Mean left ventricular ejection fraction, assessed by RNV at baseline and one year after chemotherapy, were 61±8% and 56±7% (p<0.0001). The sensitivity and specifity of cTnT for the detection of left ventricular systolic dysfunction at one year were 69% and 39% respectively. Echocardiographic examinations at baseline and one year after chemotherapy revealed a significant decrease in E/A ratio from 1.15±0.3 to 0.9±0.2 in cTnT positive patients, suggesting diastolic dysfunction. In conclusion, elevated serum cTnT levels after epirubicin-containing adjuvant chemotherapy for stage 2 and stage 3 breast cancer, predict future cardiac dysfunction with moderate sensitivity and poor specificity.

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.

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.

Amino-terminal pro-B-type natriuretic peptide testing for the diagnosis or exclusion of heart failure in patients with acute symptoms

When used for the evaluation of patients with acute symptoms in the emergency department setting, amino-terminal pro-B-type natriuretic peptide (NT-proBNP) testing is highly sensitive and specific for the diagnosis or exclusion of acute destabilized heart failure (HF), with results comparable to those reported for B-type natriuretic peptide (BNP) testing. When used for the diagnostic evaluation of the patient with possible HF, NT-proBNP testing returns information that may be superior to clinical judgment. However, the optimal application of NT-proBNP is in concert with history and physical examination, adjunctive testing, and with the knowledge of the differential diagnosis of an elevated NT-proBNP level. Studies indicate a dual use for NT-proBNP, both to exclude acute HF (where NT-proBNP concentrations <300 ng/L have a 98% negative predictive value), as well as to identify the diagnosis. To identify acute HF in patients with dyspnea, an age-independent NT-proBNP cut point of 900 ng/L has a similar value as that reported for a BNP value of 100 ng/L. However, age stratification of NT-proBNP using cut points of 450, 900, and 1,800 ng/L (for age groups of <50, 50-75, and >75 years) reduces false-negative findings in younger patients, reduces false-positive findings in older patients, and improves the overall positive predictive value of the marker without a change in overall sensitivity or specificity. Clinically validated, cost-effective algorithms for the use of NT-proBNP testing exist. Therefore, the logical use of NT-proBNP for the evaluation of the patient with suspected acute HF is useful, cost-effective, and may reduce adverse outcomes compared with standard clinical evaluation without natriuretic peptide testing.

Cardiac troponin is the most effective translational safety biomarker for myocardial injury in cardiotoxicity

There is an overwhelming weight of evidence that certifies cardiac troponin (cTn) as the preferred, defacto, translational, safety biomarker for myocardial injury in cardiotoxicity. As well as being the gold standard for cardiac injury in man, it has been widely used for clinical assessment and monitoring of cardiac toxicity in humans being treated for cancer. Furthermore, several dozen preclinical published studies have directly confirmed its effectiveness in laboratory animals for assessment of cardiotoxicity. It is gradually being reverse translated from human into animal use as a safety biomarker. Its use is especially merited whenever there is any safety signal indicating potential cardiotoxicity and its required inclusion as a routine biomarker in preclinical safety studies seems on the horizon. There are some considerations that are unique to use of cTn assays in animals. Lack of awareness of these has, historically, significantly inhibited the introduction of cTn as a safety biomarker in preclinical toxicology. Firstly, cross-species reactivity is usually but not always high. Secondly, there is a background of cardiac injury that needs to be controlled for, including spontaneous cardiomyopathy in Sprague Dawley rats, and inappropriate blood collection methods. Also, there are faster kinetics of clearance in rats than for humans. Also, coincident muscle injury is frequent with cardiotoxicity and requires a skeletal muscle biomarker. Because cTn assays were developed for detection of gross cardiac necrosis, such as occurs with myocardial infarct, the more sensitive assays should be used for preclinical studies. However, analytic sensitivity is higher for standard preclinical studies than for clinical diagnostic testing because of use of concurrent controls and use of batch analysis that eliminates interassay variability. No other biomarker of myocardial injury comes close to cTn in effectiveness, including CK-MB, LDH-1 and 2, myoglobin, and FABP3. In addition to the use of cTn for monitoring active myocardial degeneration, there is growing evidence that measurements of brain natriuretic peptide (BNP) may be effective for monitoring drug-induced left ventricular dysfunction.