Late cardiac evaluation of children with solid tumors after anthracycline chemotherapy

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.

Protective Role of Vitamin B1 in Doxorubicin-Induced Cardiotoxicity in Rats: Focus on Hemodynamic, Redox, and Apoptotic Markers in Heart

Up until now, the specific mechanisms involved in doxorubicin (DOX)-induced cardiotoxicity have not been fully elucidated. Since thiamine deficiency is associated with myocardial dysfunction and it may lead to cardiomyopathy, we aimed to investigate whether thiamine (Vitamin B₁) treatment provides cardioprotection and modulates DOX mediated subchronic cardiotoxicity as well as to determine possible mechanisms of its effects. The study involved 48 Wistar albino rats divided into four groups: healthy non-treated rats and healthy rats treated with thiamine and DOX rats without treatment and DOX rats treated with thiamine. DOX was applied as a single i.p.injection (15mg/kg), while thiamine treatment lasted 7days (25mg/kg/dayi.p.). Before and after the treatment hemodynamic changes were monitored in vivo by echocardiography. When the protocol was completed, animals were sacrificed and rat hearts were isolated in order to evaluate parameters of cardiac oxidative stress [superoxide anion radical-O₂ ^-, hydrogen peroxide-H₂O₂, nitric oxide-NO^-, index of lipid peroxidation-thiobarbituric acid (TBA) reactive substances (TBARS), superoxide dismutase - SOD, catalase (CAT), and reduced glutathione-GSH] and apoptosis (Bax, Bcl-2, caspases). DOX treatment significantly reduced the ejection fraction, while thiamine treatment led to its minor increase in the DOX-treated group. In that sense, heart oxidative stress markers were significantly increased in DOX-treated rats, while therapeutic dose of thiamine decreased the levels of free radicals. Our study demonstrated the promising ameliorative effects of thiamine against DOX-induced cardiotoxicity through modulation of oxidative stress, suppression of apoptosis, and possibility to improve myocardial performance and morphometric structure of rats` hearts.

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.

Subclinical reduction in left ventricular function using triplane and 2D speckle tracking echocardiography after anthracycline exposure in children

Objective:

Speckle tracking echocardiography (STE) enables global and regional evaluation of the left ventricle (LV); therefore, it is the most useful method for detecting subclinical dysfunction in patients exposed to cardiotoxic agents. A novel technique triplane (3P) echocardiography also allows single beat assessment of LV global longitudinal strain values. We firstly aimed to demonstrate both two-dimensional (2D)- and 3P-STE-derived LV global longitudinal strain measurements in children after anthracycline exposure.

Methods:

This study included 23 cross-sectionally enrolled asymptomatic pediatric cancer patients who received anthracycline chemotherapy and 17 healthy controls matched by age, gender, and body surface area. All subjects underwent detailed 2D, Doppler, 2D-STE, and 3P-STE for assessment of LV function. The patients had received a median cumulative dose of 150 mg/m².

Results:

1. From “Pulsed” Doppler-based measurements, only pulmonary vein flow ratio showed a significant difference between the groups. 2. When measurements were taken from the interventricular septum, the patients’ ejection time values decreased significantly and their myocardial performance index values increased significantly; when the measurements were taken from the LV free wall, the peak systolic velocities showed a statistically significant difference. 3. Both 2D- and 3P-STE-derived longitudinal myocardial deformation values of LV were lower in the patient group. 4. 2D-STE-derived LV circumferential strain values were decreased in the patient group, whereas radial strain values were not significantly different compared with matched controls.

Conclusion:

Using Doppler and 2D- and 3P-STE methods, this study confirmed the subclinical LV dysfunction in patients after anthracycline exposure.

Decrease of Cardiac Base Rotation in 2D Speckle Tracking Indicates Drug-induced Cardiomyopathy After Chemotherapy in Children With Cancer

Drug-induced cardiomyopathy can be life-threatening in patients with cancer. Our objective was to explore early detection of drug-induced cardiomyopathy in children with cancer. We enrolled pediatric outpatients diagnosed with cancer between 2012 and 2013. In addition, we recruited pediatric outpatients in good general condition without cardiac disease or cancer, as controls. We measured the serum levels of biomarkers and performed chest radiography, electrocardiography, and ultrasound cardiography (UCG). We analyzed left ventricular (LV) torsion and torsion-related parameters using 2-dimensional (2D) speckle tracking on UCG. In total, 35 pediatric patients were enrolled. All patients showed negative findings for plasma troponin T, radiography, and electrocardiography. During 2D speckle tracking, 9 patients were excluded due to inappropriate dynamic echo images. We compared UCG findings between 26 patients and 16 controls. Although there was no difference in ejection fraction between patients and controls, peak LV torsion tended to be lower in patients than in controls, and the absolute basal rotation value at the timing of peak LV torsion was significantly lower in patients than in controls. In conclusion, a decrease of basal rotation in 2D speckle tracking might indicate the initial changes leading to myocardial disorder after chemotherapy.

Biomarkers for monitoring chemotherapy-induced cardiotoxicity

Cardiotoxicity, including acute and late-onset cardiotoxicity, is a well-known adverse effect of many types of antitumor agents. Early identification of patients with cardiotoxicity is important to ensure prompt treatment and minimize toxic effects. The etiology of chemotherapy-induced cardiotoxicity is multifactorial. Traditional methods for assessment of chemotherapy-induced cardiotoxicity typically involve serial measurements of cardiac function via multi-modality imaging techniques. Typically, however, significant left ventricular dysfunction has already occurred when cardiotoxicity is detected by imaging techniques. Biomarkers, most importantly cardiac natriuretic peptides and troponins, are promising markers for identifying patients potentially at risk for clinical heart failure symptoms. This review summarizes the recent progress in clinical utilization of biomarkers for early diagnosis of acute cardiotoxicity and for prediction of late-onset cardiotoxicity. We also discuss the conflicting results of different studies and the association of results with study design.

Aerobic exercise in anthracycline-induced cardiotoxicity: a systematic review of current evidence and future directions

Cancer and cardiovascular disease are major causes of morbidity and mortality worldwide. Older cancer patients often wrestle with underlying heart disease during cancer therapy, whereas childhood cancer survivors are living long enough to face long-term unintended cardiac consequences of cancer therapies, including anthracyclines. Although effective and widely used, particularly in the pediatric population, anthracycline-related side effects including dose-dependent association with cardiac dysfunction limit their usage. Currently, there is only one United States Food and Drug Administration-approved drug, dexrazoxane, available for the prevention and mitigation of cardiotoxicity related to anthracycline therapy. While aerobic exercise has been shown to reduce cardiovascular complications in multiple diseases, its role as a therapeutic approach to mitigate cardiovascular consequences of cancer therapy is in its infancy. This systematic review aims to summarize how aerobic exercise can help to alleviate unintended cardiotoxic side effects and identify gaps in need of further research. While published work supports the benefits of aerobic exercise, additional clinical investigations are warranted to determine the effects of different exercise modalities, timing, and duration to identify optimal aerobic training regimens for reducing cardiovascular complications, particularly late cardiac effects, in cancer survivors exposed to anthracyclines.

Cardioprotective effect of metformin against doxorubicin cardiotoxicity in rats

Objective:

The clinical use of doxorubicin, which is a strong antineoplastic agent, is limited due to its cardiotoxic side effects. Metformin is a drug with antihyperglycemic effects, and it has been shown to have a cardioprotective effect on left ventricular function in experimental animal models of myocardial ischemia. The present study investigated the cardioprotective effect of metformin in rats with doxorubicin cardiotoxicity.

Methods:

Wistar albino rats were used in the study. Forty male, 10-week-old Wistar albino rats were randomly divided four groups. The control group rats were intraperitoneally administered saline solution twice a week, four doses in total. The doxorubicin group rats received doxorubicin (4 mg/kg, twice a week, cumulative dose: 16 mg/kg) intraperitoneally. The metformin group rats received metformin (250 mg/kg/day, every day for 14 days) via gavage. The doxorubicin + metformin group rats received doxorubicin and metformin at the same dose. Left ventricular functions were evaluated by using M-mode echocardiography one day after the last dose of doxorubicin. Heart tissue samples were histopathologically examined. Cardiomyocyte apoptosis was detected using in situ terminal deoxynucleotide transferase assay (TUNEL). Serum brain natriuretic peptide and C-type natriuretic peptide levels were measured. Catalase, superoxide dismutase, glutathione peroxidase, and tumor necrosis factor alpha levels were analyzed in the heart tissue. The assumptions of equality of variances and normal distribution were checked for all variables (Shapiro-Wilk test and Q-Q graphics). To identify intergroup differences, one-way variant analysis or the Kruskal-Wallis test was used. A p<0.05 value was accepted as statistically significant.

Results:

Our results showed that doxorubicin treatment caused significant deterioration in left ventricular functions by echocardiography, histological heart tissue damage, and increase in cardiomyocyte apoptosis. Doxorubicin + metformin group showed protection in left ventricular function, elimination of histopathologic change, and reduced of cardiomyocyte apoptosis.

Conclusion:

The present study provided evidence that metformin has cardioprotective effects against doxorubicin cardiotoxicity.

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.

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.

The late effects of anticancer therapy after childhood Wilm's tumor: the role of diastolic function and ambulatory blood pressure monitoring

OBJECTIVE

Wilms' tumor, or nephroblastoma, is the most common primary malignant renal tumor of childhood. The excellent outcome now expected for most children with this tumor is attributed to the combination of effective adjuvant chemotherapy, improved surgical and anesthetic techniques and also the radiosensitivity of the tumor. The numerous organ systems are subject to the late effects of anticancer therapy. The aim of this study was to investigate the blood pressure profile and ambulatory blood pressure monitoring, and also cardiac diastolic functions and pulmonary venous flow in 25 children with unilateral Wilms' tumor in remission.

METHODS

The patient group consists of 25 patients who successfully completed anticancer treatment for unilateral Wilms' tumor. Thirty-three age-, weight- and height-matched healthy children were considered as a control group for an echocardiographic study. Also, 20 age-, weight- and height-matched healthy children were considered as a control group for the ambulatory blood pressure monitoring study.

RESULTS

In our study, 24 h, daytime and night-time systolic blood pressure and night-time diastolic blood pressure measurements were found to be significantly increased in the patient group compared with healthy children. We detected diastolic filling pattern abnormalities. We also found increase in pulmonary venous flow (systolic and diastolic) in Wilms' tumor group.

CONCLUSIONS

We suggest the regular follow-up of survivors of Wilms' tumor for care and prevention of cardiovascular diseases.

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.

Survivor typologies predict medical surveillance participation: the childhood cancer survivor study

BACKGROUND

Adult survivors of childhood cancer adhere poorly to recommended medical surveillance. We sought to identify modifiable factors that contribute to non-adherence.

METHODS

Latent class analysis categorized survivors (ages 18-52 years) at risk of cardiac, breast, or bone late sequelae on the basis of their health-related concerns, fears, and motivation. These classifications were compared at two time points for self-reported adherence to recommended echocardiography, mammography, and bone densitometry screening.

RESULTS

Three classes (worried, collaborative, and self-controlling) characterized survivors in each of the three risk groups: cardiac (N=564; Bayesian information criterion [BIC] =10,824.66; Lo-Mendell-Rubin parametric likelihood ratio test [LRMLRT] P= .002), breast (N=584; BIC=11,779.97; LRMLRT P< .001), and bone (N=613; BIC=11,773.56; LMRLRT P= .028). Only 9% of at-risk survivors in the self-controlling class reported undergoing bone density screening in 2005, compared with 17.2% in the collaborative class (P= .034). Thirteen percent of the self-controlling, 24% of collaborative (P= .025), and 34% of worried (P= .010) classes reported undergoing bone densitometry in 2009. Whereas 73% of at-risk survivors in the worried class reported having had an echocardiogram in 2009, only 57% of the collaborative (P= .040) and 43% of self-controlling (P< .001) classes did. In 2005 and 2009, respectively, fewer survivors in the self-controlling class (37% and 53%) than in the collaborative (51%, P= .038 and 70%, P= .01) and worried (58%, P= .002 and 69%, P= .025) classes reported undergoing mammograms.

CONCLUSIONS

Modifiable intrapersonal characteristics associated with these three classes predict self-reported participation in medical surveillance. Continued observation and validation of these survivor profiles may inform tailored interventions to enhance survivors' screening participation. Copyright © 2012 John Wiley & Sons, Ltd.

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.

Assessment of late cardiotoxicity of pirarubicin (THP) in children with acute lymphoblastic leukemia

BACKGROUND

Pirarubicin (tetrahydropyranyl-adriamycin: THP) is a derivative of doxorubicin with reportedly less cardiotoxicity in adults. However no studies of cardiotoxicity in children treated with THP have been reported. This study was performed to assess the THP-induced cardiotoxicity for children with acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

This study comprised 61 asymptomatic patients aged from 7.6 to 25.7 years old. Median follow-up time after completion of anthracycline treatment was 8.1 years (range: 1.7-12.5). The cumulative dose of THP ranged from 120 to 740 mg/m(2) with a median of 180 mg/m(2) . Patients underwent electrocardiogram (ECG), echocardiography, the 6-min walk test (6MWT), and measurements of serum brain natriuretic peptide (BNP) before and after exercise.

RESULTS

All subjects showed normal left ventricular function assessed by echocardiography. Ventricular premature contraction in Holter ECG and reduced exercise tolerance in the 6MWT were detected in 2/46 (3.3%) and 5/41(12.2%), respectively. Abnormal BNP levels were detected in 6/60 (10%) both before and after exercise. The cumulative dose of THP was significantly correlated with BNP levels after exercise (r = 0.27, P = 0.03), but not with any other cardiac measurements. Further analysis revealed that subjects with a high cumulative dose ≧300 mg/m(2) had significantly higher BNP levels after exercise compared with subjects with a low cumulative dose <300 mg/m(2) (P = 0.04).

CONCLUSIONS

No significant cardiac dysfunction was detected in long-term survivors who received THP treatment. The use of post-exercise BNP level to indicate high cardiotoxicity risk should be verified by further study.

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.

Review of cardiotoxicity in pediatric cancer patients: during and after therapy

With the improvement in survival from childhood cancer, late effects of therapy are becoming more apparent. Cardiac disease, one of these late effects, has a significant impact on the life of survivors of childhood cancers. Most survivors are followed by primary care doctors and adult subspecialists after they have graduated from pediatric centers. Since much of the cardiac toxicity of therapy occurs years off of therapy, it is important for these physicians to be aware of how to monitor survivors for the development of cardiac toxicities. In this paper we will discuss the incidence of cardiac disease during treatment and in survivors, what treatment modalities contribute to its development and modalities utilized to screen for cardiac disease. Recommendations for posttherapy monitoring will be emphasized.

B-type Natriuretic Peptide: Diagnostic and Therapeutic Applications in Infants and Children

The natriuretic peptide system plays an active role in the regulation of fluid balance and systemic vascular resistance. Peptides of the natriuretic system produced through recombinant DNA technology are now available for clinical use including both atrial natriuretic peptide (ANP) and brain-type natriuretic peptide (BNP). Assays of BNP are available and may be used for both diagnostic and prognostic purposes in various clinical scenarios. The basic physiology of the natriuretic peptide system is presented, applications of BNP monitoring as a diagnostic tool are reviewed, and reports regarding the use of recombinant BNP in the pediatric population are discussed.

Exacerbation of anthracycline-induced early chronic cardiomyopathy with ATRA: role of B-type natriuretic peptide as an indicator of cardiac dysfunction

Cardiac disease is a significant complication of childhood oncologic therapy. We report the case of a 14-year-old female with acute promyelocytic leukemia who developed symptomatic cardiomyopathy only 4 months into treatment with a combination of daunomycin and all-trans retinoic acid (ATRA). Despite cessation of daunomycin, she demonstrated fluctuating systolic function in relation to ATRA administration. Improvement and deterioration in systolic function on echocardiogram and serum B-natriuretic peptide levels were seen while receiving ATRA 1 week on and 1 week off, respectively, during the maintenance phase of therapy.

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.

Cardiac damage after treatment of childhood cancer: a long-term follow-up

BACKGROUND

With improved childhood cancer cure rate, long term sequelae are becoming an important factor of quality of life. Signs of cardiovascular disease are frequently found in long term survivors of cancer. Cardiac damage may be related to irradiation and chemotherapy.We have evaluated simultaneous influence of a series of independent variables on the late cardiac damage in childhood cancer survivors in Slovenia and identified groups at the highest risk.

METHODS

211 long-term survivors of different childhood cancers, at least five years after treatment were included in the study. The evaluation included history, physical examination, electrocardiograpy, exercise testing and echocardiograpy. For analysis of risk factors, beside univariate analysis, multivariate classification tree analysis statistical method was used.

RESULTS AND CONCLUSION

Patients treated latest, from 1989-98 are at highest risk for any injury to the heart (73%). Among those treated earlier are at the highest risk those with Hodgkin's disease treated with irradiation above 30 Gy and those treated for sarcoma. Among specific forms of injury, patients treated with radiation to the heart area are at highest risk of injury to the valves. Patients treated with large doses of anthracyclines or concomitantly with anthracyclines and alkylating agents are at highest risk of systolic function defect and enlarged heart chambers. Those treated with anthracyclines are at highest risk of diastolic function defect. The time period of the patient's treatment is emerged as an important risk factor for injury of the heart.

Monitoring for cardiovascular disease in survivors of childhood cancer: report from the Cardiovascular Disease Task Force of the Children's Oncology Group

Curative therapy for childhood cancer has improved significantly in the last 2 decades such that, at present, approximately 80% of all children with cancer are likely to survive > or = 5 years after diagnosis. Prevention, early diagnosis, and treatment of long-term sequelae of therapy have become increasingly more significant as survival rates continue to improve. Cardiovascular disease is a well-recognized cause of increased late morbidity and mortality among survivors of childhood cancer. The Children's Oncology Group Late Effects Committee and Nursing Discipline and Patient Advocacy Committee have recently developed guidelines for follow-up of long-term survivors of pediatric cancer. A multidisciplinary task force critically reviewed the existing literature to evaluate the evidence for the cardiovascular screening recommended by the Children's Oncology Group guidelines. In this review we outline the clinical manifestations of late cardiovascular toxicities, suggest modalities and frequency of monitoring, and address some of the controversial and unresolved issues regarding cardiovascular disease in childhood cancer survivors.

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.

B-type natriuretic peptide as a marker for cardiac dysfunction in anthracycline-treated children

BACKGROUND

Anthracyclines (AC) are useful antineoplastic agents, whose utility is limited by progressive cardiotoxicity. Our purpose was to evaluate plasma B-type natriuretic peptide (BNP), as a screening test for detecting late cardiac dysfunction in AC-treated children and to determine the prevalence of late cardiac dysfunction at low cumulative AC doses.

MATERIALS AND METHODS

This was a prospective study in which patients who had completed AC therapy at least 1 year earlier, underwent a detailed echocardiogram and a simultaneous BNP level. Cardiac dysfunction was defined as any one of the following: shortening fraction (FS) <29%, rate corrected velocity of circumferential fiber shortening (VCFc) <0.9 c x sec(-1), end systolic wall stress (ESWS) >60 g x cm(-2), abnormal VCFc: ESWS ratio or decreased mitral inflow velocity (E/A) ratios, compared to age-specific norms.

RESULTS

The cohort (n = 63) included 37 males with a median age of 13.1 years (range, 6.5-26.5 years). Cardiac dysfunction was found in 26 (41%) patients and in 40% of patients who received cumulative doses <150 mg x m(-2). ESWS was the most common abnormality. Mean BNP levels in the subset with abnormal function were significantly higher than the normal group (23.4 +/- 25.3 vs. 14.2 +/- 8.9 pg x ml(-1), P = 0.02).

CONCLUSIONS

Plasma BNP was significantly elevated in AC-treated patients with late cardiac dysfunction, although there was considerable overlap of levels between groups with and without cardiac dysfunction. BNP may need further evaluation as a serial index of cardiac function in this population. Cardiac dysfunction was observed in a significant proportion of patients, even at low cumulative AC doses.

Noninvasive Evaluation of Late Anthracycline Cardiac Toxicity in Childhood Cancer Survivors

Purpose

Childhood cancer survivors treated with anthracyclines and cardiac radiation are at risk for late-onset cardiotoxicity. The purpose of this study was to delineate the relationship between clinical factors and abnormalities of noninvasive cardiac testing (NICT).

Patients and Methods

Participants were recruited from a long-term follow-up clinic. Study measures comprised physical examination, laboratory evaluation, echocardiogram, and ECG. Mean fractional shortening (FS) and afterload were compared for survivors who did (at risk [AR]) and did not (no risk [NR]) receive potentially cardiotoxic modalities, and with values expected for comparable age- and sex-matched controls.

Results

The 278 study participants (mean age, 18.1 years; median age, 16.8 years; range, 7.5 to 39.7 years) included 223 survivors AR for cardiotoxicity after treatment with anthracyclines (median dose ± standard deviation [SD], 202 ± 109 mg/m2) and/or cardiac radiation. Mean FS (± SD) was lower for AR (0.33 ± 0.06) compared with NR survivors (0.36 ± 0.05; P = .004) and normative controls (0.36 ± 0.04; P < .001). Mean afterload (± SD) was higher for AR (58 ± 21 g/cm2) compared with NR survivors (46 ± 15 g/cm2; P < .001) and normative controls (48 ± 13 g/cm2; P < .001). The distribution of FS and afterload among NR survivors did not differ from that of controls. After adjustment for age group at diagnosis and time since completion of therapy, anthracycline dose predicted decline in distribution of FS (P < .001) and increase in distribution of afterload (P < .001). Treatment with anthracycline doses ≥ 100 mg/m2 increased the risk of abnormal NICT; survivors who received ≥ 270 mg/m2 had a 4.5-fold excess risk of abnormal NICT (95% CI, 2.1 to 9.6) compared with controls.

Conclusion

Childhood cancer survivors treated with anthracycline doses ≥ 270 mg/m2 are at greatest risk for abnormalities of FS and afterload.

Use of cardiac markers to assess the toxic effects of anthracyclines given to children with cancer: a systematic review

AIM

To evaluate the effectiveness of cardiac markers to quantify anthracycline-induced cardiotoxicity in children with cancer.

METHODS

Systematic review using a priori methods.

RESULTS

Seven studies, all with methodological limitations, were identified. One RCT suggests that cardiac troponin can be used to assess the effectiveness of the cardio-protective agent dexrazoxane. Cohort studies suggest that atrial natriuretic peptide and brain (B-type) natriuretic peptide are elevated in some subgroups of patients compared with healthy children; NT-pro-BNP levels are significantly elevated in children with cardiac dysfunction compared with those without; serum lipid peroxide is higher in children who have received doxorubicin compared with children not receiving doxorubicin; there are no differences in carnitine levels between children treated with doxorubicin and a healthy control group.

CONCLUSIONS

The limited evidence makes conclusions difficult. Research is needed to fill this important evidence gap and link short-term changes in cardiac markers to longer-term cardiac damage.

Cardiac assessment of patients for haematopoietic stem cell transplantation

The expanding role of haematopoietic stem-cell transplantation (HSCT) renders the previous policy of avoiding transplantation in high-risk cardiac patients obsolete. Patients with amyloid, autoimmune conditions, sickle-cell disease, or thalassaemia, and patients over the age of 60 years are increasingly being offered HSCT. It is evident that the policy of avoiding transplantation in patients with impaired systolic function fails to identify all high-risk patients in such groups, and will deprive some patients of the benefits of HSCT unnecessarily. The development of an appropriate algorithm for cardiac pre-assessment and peri-transplant management is hampered by an inadequate understanding of the predictive value of various tests of cardiovascular function, the rapid evolution of advanced management strategies for cardiac dysfunction, and the development of non-cardiotoxic conditioning regimens. To meet this need we propose that an algorithm based on evidence from other clinical situations - already been found to be successful in the management of HSCT in patients with systemic sclerosis - should be used uniformly, and registry studies should be undertaken to distinguish those aspects of the algorithm that positively help to expand the remit of HSCT from those that add little of value.

American Society of Clinical Oncology clinical evidence review on the ongoing care of adult cancer survivors: cardiac and pulmonary late effects

PURPOSE

To review the evidence on the incidence of long-term cardiac or pulmonary toxicity secondary to chemotherapy, radiotherapy, or trastuzumab in symptomatic and asymptomatic cancer survivors.

METHODS

An American Society of Clinical Oncology Panel reviewed pertinent information from the literature through February 2006.

RESULTS

Few studies directly addressing the benefits of screening for long-term cardiac or pulmonary toxicity in asymptomatic cancer survivors who received chemotherapy, radiotherapy, or trastuzumab were identified. The reviewed literature included primarily retrospective and cross-sectional studies describing the incidence of cardiac and pulmonary late effects. Anatomic and/or functional abnormalities have been associated with use of all currently available anthracyclines and their derivatives. Trastuzumab-related cardiac dysfunction rarely causes death, and in most cases is reversible with improvement in cardiac function on drug discontinuation and/or treatment with cardiac medications. The estimated aggregate incidence of radiation-induced cardiac disease is 10% to 30% by 5 to 10 years post-treatment, although the incidence may be lower with modern techniques. Radiation pneumonitis is reported in 5% to 15% of lung cancer patients receiving definitive external-beam radiation therapy. A minority of patients may develop progressive pulmonary fibrosis; late complications include cor pulmonale and respiratory failure. Bleomycin-induced pneumonitis is an acute rather than late effect of treatment. Late pulmonary complications in bone marrow or stem cell transplantation patients who develop interstitial pneumonitis include idiopathic pneumonia syndrome and bronchiolitis obliterans.

CONCLUSION

An increased incidence of cardiac and/or pulmonary dysfunction is observed in cancer survivors. Research is needed to identify high-risk patients, and to determine the optimal screening strategies and subsequent treatment.

Cardiac safety profile of pegylated liposomal doxorubicin reaching or exceeding lifetime cumulative doses of 550 mg/m2 in patients with recurrent ovarian and peritoneal cancer

The objective of this study is to evaluate the cardiac safety of pegylated liposomal doxorubicin (PLD) reaching or exceeding a cumulative dose of 550 mg/m(2) in patients with recurrent ovarian and peritoneal cancer. A total of 14 patients (11 ovarian cancer, 3 primary peritoneal cancer) who received PLD in our center between February 2004 and October 2006 met inclusion criteria of the study. PLD was administered at doses of 30 mg/m(2) together with carboplatin or 50 mg/m(2) as a single agent every 3-6 weeks. Left ventricular ejection fraction (LVEF) estimations performed by M Mode ultrasound (General Electric Vivid-3, Milwaukee, Wisconsin) and clinical cardiac status were used to detect PLD-related cardiotoxicity. The median cumulative dose of PLD was 685.5 mg/m(2) (range 552-1015 mg/m(2)) and the median number of PLD courses was 9.5 (range 7-17). One patient had also been previously treated with conventional doxorubicin. LVEF scans were obtained on 10 of the 14 patients at the beginning of the therapy and on all patients at the end of therapy. No clinical evidence (symptoms or physical findings) of cardiac dysfunction had been observed in these patients either during active treatment or follow-up period. Despite small number of patients and lack of control group, our study suggests that the cumulative doses in excess of 550 mg/m(2) of PLD seem to not carry a significant risk of cardiomyopathy as judged by LVEF and clinical follow-up.

QT prolongation and Torsades de Pointes in patients previously treated with anthracyclines

Anthracyclines reduce myocardial repolarization reserve and might increase the risk for Torsades de Pointes a long time after treatment. We studied all the publications concerning Torsades de Pointes in patients previously treated with anthracyclines to investigate the clinical circumstances leading to this rare life-threatening complication. Our literature search yielded nine reports of 11 patients who had developed Torsades de Pointes anywhere from weeks to years following treatment with anthracyclines. One of the patients was hospitalized in our medical center. Risk factors and triggers for Torsades de Pointes, among other clinical aspects, were analyzed in each report. Most patients (n=10; 90.9%) were previously treated with anthracyclines owing to acute leukemias: acute myelogenous leukemia (n=5), acute lymphocytic leukemia (n=3) and acute promyelocytic leukemia (n=2). One patient was previously treated with anthracyclines owing to Hodgkin's lymphoma. Most patients were women (n=9; 81.8%). The most prevalent triggers for Torsades de Pointes were the administration of a QT-prolonging agent (n=10; 90.9%) and hypokalemia (n=9; 81.8%). Azole derivatives were the most prevalent of the QT-prolonging agents that triggered Torsades de Pointes (n=5; 45.5%). Although four patients suffered from anthracycline-induced left ventricular dysfunction and five other patients had only one or two questionable triggers for Torsades de Pointes, in only two of these cases the authors considered previous treatment with anthracyclines as a risk factor for Torsades de Pointes. Previous treatment with anthracycline is an underestimated risk factor for Torsades de Pointes. Possible triggers includes azole derivatives, other QT-prolonging agents and hypokalemia. Women patients are particularly at risk.

The Tei index identifies a differential effect on left and right ventricular function with low-dose anthracycline chemotherapy

OBJECTIVE

We sought to study the relative effect on left ventricular (LV) and right ventricular (RV) function of low-dose anthracycline-containing chemotherapy regimes.

METHODS

A total of 23 patients (mean age 48 +/- 20 years) underwent echocardiographic examinations before any anthracycline had been administered and then after low-dose anthracycline (doxorubicin 50-125 mg/m2). The Tei index was used to compare the relative effects on RV and LV function.

RESULTS

Anthracycline administration was significantly associated with an increase in the LV Tei index (0.38 +/- 0.12 vs 0.46 +/- 0.16, P = .02). There was no significant change in the RV Tei index (0.19 +/- 0.10 vs 0.20 +/- 0.10, P = .72). Comparing the relative effect on global LV and RV function the change in LV Tei was significantly greater than the change in RV Tei (0.07 +/- 0.13 vs 0.01 +/- 0.09, P = .044).

CONCLUSIONS

Low-dose anthracycline administration has a significant negative impact on LV function but does not affect RV function.

Treatment of stage I, IIA, IIIA1 pediatric Hodgkin disease with doxorubicin, bleomycin, vincristine and etoposide (DBVE) and radiation: a Pediatric Oncology Group (POG) study

PURPOSE

The objectives of this study were to evaluate the feasibility of reducing therapy, while maintaining treatment efficacy, in the context of a cooperative group clinical trial that allowed for clinical staging in early stage Hodgkin disease (HD).

PATIENTS AND METHODS

Between August 1992 and December 1993, 51 eligible children < or =21 years of age, 31 male and 20 female, were enrolled in this study which was designed for low stage (IA, IIA, IIIA1) HD. Laparotomy and surgical staging was optional. Five postpubertal patients with Stage IA and IIA disease received only involved-field radiation therapy. The other 46 patients, who form the basis of this report, received combined modality therapy consisting of four courses of doxorubicin, bleomycin, vincristine, and etoposide (DBVE) followed by 2,550 cGy involved-field irradiation.

RESULTS

With a median follow-up of 8.4 years, the 6-year overall and event-free survival rates for the 46 patients treated with combination therapy were 98 +/- 2% and 91 +/- 5%, respectively. All patients achieved remission after completion of therapy. There have been four recurrences and a remission death due to gunshot wound. Combined modality therapy was well tolerated. Predominant side effects were gastrointestinal and hemopoietic. There have been no clinically significant cardio-pulmonary side effects so far.

CONCLUSION

In clinically staged children with early-stage HD, DBVE and low-dose involved-field irradiation was effective therapy with tolerable side effects and reduced potential for long-term adverse events.

Evaluation of anthracycline-induced early left ventricular dysfunction in children with cancer: a comparative study with echocardiography and multigated radionuclide angiography

The study aimed to compare diastolic and systolic dysfunctions detected by echocardiography (ECHO) and multigated radionuclide angiography (MUGA) in patients with cancer in the first 3 months after anthracycline-comprising chemotherapy. Children with leukemia and solid tumors who had anthracycline-comprising chemotherapy were enrolled in the study. ECHO and MUGA were performed in all patients before the first chemotherapy course and in the first 3 month of completing anthracycline-comprising chemotherapy. Cumulative anthracycline doses per body surface were calculated. Left ventricular systolic and diastolic functions were measured by both techniques. Twenty-one patients with a median age of 6.9 +/- 3.6 years were enrolled in the study. Mean cumulative anthracycline doses were equivalent to 276 +/- 83 mg/m2 doxorubicin. After anthracycline chemotherapy, cardiac dysfunction was detected in 14 and 48% of the patients by ECHO and MUGA, respectively. All dysfunctions detected by ECHO were systolic, whereas 29% of the patients had diastolic and 38% of the patients had systolic dysfunction in MUGA study. Although the study group is small, MUGA seems more sensitive in detecting anthracycline-induced systolic and diastolic cardiac dysfunctions compared to ECHO.