Response of Doxorubicin-induced Cardiomyopathy to the Current Management Strategy of Heart Failure

Effects of Cardioprotective Tactics on the Myocardial Perfusion and Contractile Function of the Left Ventricular Myocardium in Cancer Patients with Evidence of Doxorubicin-Induced Cardiotoxicity

Aim      To study the effect of cardioprotective tactics on parameters of left ventricular myocardial perfusion and contractility as per data from single-photon emission computed tomography in oncological patients with signs of anthracycline-induced cardiotoxicity.Material and methods  The study included patients with oncological diseases (n=61) referred to polychemotherapy (PCT). For patients with signs of anthracycline-induced cardiotoxicity, a cardioprotective tactics was used, which included changing the PCT schedule and administering beta-blockers and angiotensin-converting enzyme inhibitors. For all patients at baseline, after the first four PCH courses, after initiation of the cardioprotective tactics and the next four PTC courses, the level of N-terminal pro-brain natriuretic peptide was measured and echocardiography and perfusion single-photon emission computed tomography were performed with assessment of left ventricular (LV) perfusion heterogeneity, systolic and diastolic function.Results Following four PTC courses, signs of cardiotoxicity were detected in 13 (21.3 %) patients. On the background of the cardioprotective tactics, a further decrease in LV ejection fraction (EF) by -9±2 % (p<0.01) was observed in 4 (30.8 %) patients. In 9 (69.2 %) patients, LV EF increased by 4±2 % (p<0.01). Standard indexes of LV myocardial perfusion did not significantly change. In 7 patients, the cardioprotective tactics was associated with reduced severity of myocardial perfusion disorder, LV∆σТ = -1.37±1.29 (p<0.05), and in 4 patients, with reduced heterogeneity of myocardial perfusion, LV∆σН = -1.20±0.70 (p<0.05).Conclusion      The cardioprotective tactics prevents both further disorder of perfusion and decreases in parameters of left ventricular myocardial contractility in patients with anthracycline-induced cardiotoxicity.

A short review: Doxorubicin and its effect on cardiac proteins

Doxorubicin (DOX) is a boon for cancer-suffering patients. However, the undesirable effect on health on vital organs, especially the heart, is a limiting factor, resulting in an increased number of patients with cardiac dysfunction. The present review focuses on the contractile machinery and associated factors, which get affected due to DOX toxicity in chemo-patients for which they are kept under life-long investigation for cardiac function. DOX-induced oxidative stress disrupts the integrity of cardiac contractile muscle proteins that alter the rhythmic mechanism and oxygen consumption rate of the heart. DOX is an oxidant and it is further discussed that oxidative stress prompts the damage of contractile components and associated factors, which include Ca²⁺ load through Ca²⁺ ATPase, SERCA, ryanodine receptor-2, phospholamban, and calsequestrin, which ultimately results in left ventricular ejection and dilation. Based on data and evidence, the associated proteins can be considered as clinical markers to develop medications for patients. Even with the advancement of various diagnosing tools and modified drugs to mitigate DOX-induced cardiotoxicity, the risk could not be surmounted with survivors of cancer.

Intramuscular Diphenhydramine Does Not Affect Acute Doxorubicin Infusion-Related Arrhythmia Number or Severity in a Prospective Crossover Study in Canine Lymphoma: A Pilot Study

Background: Doxorubicin (DOX) is one of the most effective chemotherapeutics for canine high-grade lymphoma. In addition to dose-dependent chronic cardiotoxicity, DOX can trigger acute cardiac arrhythmias during drug infusion. Diphenhydramine premedication is commonly used, as histamine release is a proposed mechanism for DOX-associated arrhythmogenesis. Hypothesis/Objectives: The study objectives were to evaluate the incidence and severity of DOX infusion-related cardiac arrhythmias in dogs with high-grade lymphoma and evaluate the effect of diphenhydramine premedication on arrhythmia frequency and severity during and after DOX infusion. Animals: Twenty-two client-owned dogs with cytologically/histopathologically confirmed high-grade lymphoma were recruited, of which 19 were enrolled and 9 completed the study. Methods: Dogs were screened by echocardiogram and concurrent electrocardiogram for this randomized prospective crossover study. Group A received no premedication for DOX #1 and was premedicated with diphenhydramine for DOX #2; Group B received diphenhydramine with DOX #1 and no premedication for DOX #2. For both visits, Holter monitor data were collected for 1 h pre-DOX and 3 h post-DOX administration. Results: Nineteen dogs were enrolled and 9 dogs [Group A (5), Group B (4)] completed the protocol. There was no statistical difference between the DOX alone and DOX + diphenhydramine when evaluating the total number of ventricular premature complexes (VPCs, P = 0.34), change in VPCs/hour (P = 0.25), total number of atrial premature complexes (APCs, P = 0.5), change in APCs/hour (P = 0.06), or ventricular arrhythmia severity score (P > 0.99). Conclusions and clinical importance: This study demonstrates that in these dogs with rigorous pretreatment cardiovascular screening, DOX infusion did not induce significant arrhythmias. Furthermore, these data suggest that, with this screening approach, diphenhydramine may not alter the arrhythmia number or severity in canine DOX recipients.

Cardiovascular disease and asymptomatic childhood cancer survivors: Current clinical practice

BACKGROUND

It is poorly understood how cardiovascular screening in asymptomatic childhood cancer survivors (CCS) is applied to and impacts clinical care.

OBJECTIVES

To describe the current role of cardiovascular screening in the clinical care of asymptomatic CCS.

METHODS

At 50 pediatric academic medical centers, a childhood cancer survivorship clinic director, pediatric cardiologist, and adult cardiologist with a focus on CCS were identified and invited to participate in a survey. Surveys were managed electronically. Categorical data were analyzed using nonparametric methods.

RESULTS

Of the 95 (63%) respondents, 39% were survivorship practitioners, and 61% were cardiologists. Eighty-eight percent of survivorship practitioners reported that greater than half of CCS received cardiovascular screening. CCS followed by adult cardiology were more likely to be seen by a cardio-oncologist. Those followed by pediatric cardiology were more likely to be seen by a heart failure/transplant specialist. Common reasons for referral to cardiology were abnormal cardiovascular imaging or concerns a CCS was at high risk for cardiovascular disease. Ninety-two percent of cardiologists initiated angiotensin converting enzyme inhibitor or angiotensin receptor blocker therapy for mild systolic dysfunction. Adult cardiologists initiated beta-blocker therapy for less severe systolic dysfunction compared to pediatric cardiologists (P < .001). Pediatric cardiologists initiated mineralocorticoid therapy for less severe systolic dysfunction compared to adult cardiologists (P = .025). Practitioners (93%) support a multi-institutional collaboration to standardize cardiovascular care for CCS.

CONCLUSIONS

While there is much common ground in the clinical approach to CCS, heterogeneity is evident. This highlights the need for cohesive, multi-institutional, standardized approaches to cardiovascular management in CCS.

Cardiotoxicity of Anthracyclines

Cardiotoxicity is a feared side effect that may limit the clinical use of anthracyclines. It may indeed affect the quality of life and survival of patients with cancer, regardless of oncological prognosis. This paper provides an overview of anthracycline-induced cardiotoxicity in terms of definition, classification, incidence, risk factors, possible mechanisms, diagnosis, and treatment. We also report effective strategies for preventing cardiotoxicity. In addition, we discuss limiting current approaches, the need for a new classification, and early cardiotoxicity detection and treatment. Probably, anthracycline-induced cardiotoxicity is a continuous phenomenon that starts from myocardial cell injury; it is followed by left ventricular ejection fraction (LVEF) and, if not diagnosed and cured early, progressively leads to symptomatic heart failure. Anthracycline-induced cardiotoxicity can be detected at a preclinical phase. The role of biomarkers, in particular troponins, in identifying subclinical cardiotoxicity and its therapy with angiotensin-converting enzyme inhibitors (mainly enalapril) to prevent LVEF reduction is a recognized and effective strategy. If cardiac dysfunction has already occurred, partial or complete LVEF recovery may still be obtained in case of early detection of cardiotoxicity and prompt heart failure treatment.

Effectiveness of sacubitril-valsartan in cancer patients with heart failure

AIMS

Current guidelines recommend sacubitril/valsartan for patients with heart failure and reduced left ventricular ejection fraction (LVEF), but there is lack of evidence of its efficacy and safety in cancer therapy-related cardiac dysfunction (CTRCD). Our aim was to analyse the potential benefit of sacubitril/valsartan in patients with CTRCD.

METHODS AND RESULTS

We performed a retrospective multicentre registry (HF-COH) in six Spanish hospitals with cardio-oncology clinics including all patients treated with sacubitril/valsartan. Demographic and clinical characteristics and laboratory and echocardiographic data were collected. Median follow-up was 4.6 [1; 11] months. Sixty-seven patients were included (median age was 63 ± 14 years; 64% were female, 87% had at least one cardiovascular risk factor). Median time from anti-cancer therapy to CTRD was 41 [10; 141] months. Breast cancer (45%) and lymphoma (39%) were the most frequent neoplasm, 31% had metastatic disease, and all patients were treated with combination antitumor therapy (70% with anthracyclines). Thirty-nine per cent of patients had received thoracic radiotherapy. Baseline median LVEF was 33 [27; 37], and 21% had atrial fibrillation. Eighty-five per cent were on beta-blocker therapy and 76% on mineralocorticoid receptor antagonists; 90% of the patients were symptomatic NYHA functional class ≥II. Maximal sacubitril/valsartan titration dose was achieved in 8% of patients (50 mg b.i.d.: 60%; 100 mg b.i.d.: 32%). Sacubitril/valsartan was discontinued in four patients (6%). Baseline N-terminal pro-B-type natriuretic peptide levels (1552 pg/mL [692; 3624] vs. 776 [339; 1458]), functional class (2.2 ± 0.6 vs. 1.6 ± 0.6), and LVEF (33% [27; 37] vs. 42 [35; 50]) improved at the end of follow-up (all P values ≤0.01). No significant statistical differences were found in creatinine (0.9 mg/dL [0.7; 1.1] vs. 0.9 [0.7; 1.1]; P = 0.055) or potassium serum levels (4.5 mg/dL [4.1; 4.8] vs. 4.5 [4.2; 4.8]; P = 0.5). Clinical, echocardiographic, and biochemical improvements were found regardless of the achieved sacubitril-valsartan dose (low or medium/high doses).

CONCLUSIONS

Our experience suggests that sacubitril/valsartan is well tolerated and improves echocardiographic functional and structural parameters, N-terminal pro-B-type natriuretic peptide levels, and symptomatic status in patients with CTRCD.

Regional practice norms for the care of childhood cancer survivors at risk for cardiomyopathy: A Delphi study

BACKGROUND

Treatment-associated cardiomyopathy is a leading cause of morbidity and mortality for childhood cancer survivors (CCS). As evidence is not available to guide the management of CCS at risk for cardiomyopathy, we aim to describe the collective opinion of regional experts for the care of these patients using a consensus-based Delphi methodology.

PROCEDURE

Nineteen physicians from the New England region who care for CCS treated with cardiotoxic therapy (anthracyclines, thoracic radiation) participated in a Delphi panel querying their management approach, using three rounds of anonymous questionnaires formatted as five clinical scenarios. Consensus ≥ 89% agreement.

RESULTS

The response rate was 100% for the first round and 95% for subsequent rounds. Panelists reached consensus on screening asymptomatic CCS with serial echocardiograms (94%) and electrocardiograms (89%), with some disagreement on frequency during pregnancy (83%). All panelists agreed with exercise promotion, with no restrictions on weight training. Consensus was reached on indications for referrals; cardiology for asymptomatic left ventricular dysfunction (ALVD) (100%) and maternal-fetal medicine for pregnancy (94%). In the scenario of ALVD, there was disagreement on the benefit of additional cardiac testing (50% cardiologists recommended cardiac MRI), and although all panelists endorsed treating with angiotension-converting enzyme (ACE) inhibitors, most adult cardiologists (75%) also recommended therapy with beta blockers, compared with none of the pediatric cardiologists or primary-care physicians.

CONCLUSIONS

Despite a lack of evidence to guide the management of CCS at risk for cardiomyopathy, a panel of regional physicians reached consensus on managing most clinical scenarios. A controversial area requiring further study is the medical management of ALVD.

Resveratrol solid lipid nanoparticles to trigger credible inhibition of doxorubicin cardiotoxicity

Background: Doxorubicin (DOX), a broad-spectrum chemotherapy drug, is clinically employed to treat cancers especially for breast cancer and lung cancer. But its clinical applications are limited by the dose-dependent cardiac toxicity. Resveratrol (Res), a polyphenolic antitoxin, has been proved to be capable of improving the cardiomyocyte calcium cycling by up-regulating SIRT-1-mediated deacetylation to inhibit DOX-induced cardiotoxicity.

Purpose: The objective of this study was to develop a solid lipid nanoparticle (SLN) loaded with Res to trigger inhibition of DOX-induced cardiotoxicity.

Methods: Res-SLN was prepared by emulsification-diffusion method followed by sonication and optimized using central composite design/response surface method. The Res-SLN was further evaluated by dynamic light scattering, transmission electron microscopy for morphology and high performance liquid chromatography for drug loading and release profile. And the Res distribution in vivo was determined on rats while the effect of inhibit DOX-induced cardiotoxicity was investigated on mice.

Results: Res-SLN with homogeneous particle size of 271.13 nm was successfully formulated and optimized. The prepared Res-SLN showed stable under storage and sustained release profile, improving the poor solubility of Res. Heart rate, ejection fractions and fractional shortening of Res-SLN treating mice were found higher than those on mice with cardiac toxicity induced by single high-dose intraperitoneal injection of DOX. And the degree of myocardial ultrastructural lesions on mice was also observed.

Conclusion: Res-SLN has a certain therapeutic effect for protecting the myocardium and reducing DOX-induced cardiotoxicity in mice.

Trends in the prevalence of malignancy among patients admitted with acute heart failure and associated outcomes: a nationwide population-based study

Cancer is the second leading cause of death in the USA, and cardiovascular disease is the second leading cause of morbidity and mortality among cancer survivors. Cancer survivors share common risk factors for cardiovascular disease with non-cancer patients. With improved survival, cancer patients become susceptible to treatment-related toxicity often involving the heart. The impact of concurrent malignancy on outcomes particularly among heart failure patients is an area of active research. We studied the trends in the prevalence of a concurrent diagnosis of breast, prostate, colorectal, and lung cancer among admissions for acute heart failure and the associated trends for in-hospital mortality. Patients aged ≥ 18 years who were admitted with a primary diagnosis of "congestive heart failure" (CCS codes 99 and 108) from years 2003 to 2014 were included. We analyzed the rate of admission and in-hospital mortality among patients who had a concurrent diagnosis for either lung cancer, colorectal cancer, breast cancer (among females), or prostate cancer (among males). We performed a multivariate analysis to assess the role of a concurrent diagnosis of any cancer in predicting in-hospital mortality among HF admissions. From 2003 to 2014 across over 12 million HF admissions, ≈ 7% had a concurrent diagnosis of either lung, breast, colorectal, or prostate cancer. The prevalence was highest for breast cancer (2.3%) followed by prostate cancer (2.1%) and colorectal cancer (1.5%) and lowest with lung cancer (1.1%). The prevalence of cancer increased over the duration of study among all four cancer types with the largest increase in prevalence of breast cancer. Baseline comorbidities including hypertension, diabetes, smoking, chronic kidney disease, and coronary artery disease increased over time among patients with and without cancer. In-hospital mortality was higher among those with a diagnosis of lung cancer (5.9%) followed by colorectal cancer (4.0%), prostate cancer (3.5%), no diagnosis of cancer (3.3%), and breast cancer (3.2%). In-hospital mortality declined across HF admissions with and without a cancer diagnosis from 2003 to 2014. Decline in such mortality among heart failure was highest for patients with lung cancer (8.1 to 4.6% from 2003 to 2014; p < 0.001). Multivariate analysis showed that a concurrent diagnosis of cancer was associated with a marginally lower hospital mortality compared with controls (adjusted odds ratio 0.95, 95% confidence interval 0.94-0.96; p < 0.001). Among HF admissions, the prevalence of a concurrent cancer diagnosis increased over time for breast, lung, colorectal, and prostate cancer. Baseline in-hospital mortality was higher among HF admissions with either lung cancer, colorectal cancer, or prostate cancer and lower with breast cancer compared with controls without a cancer diagnosis. Adjusted analysis revealed no evidence for higher hospital mortality among HF admissions with any accompanying cancer diagnosis.

Protecting the heart in cancer therapy

Recent advances in cancer prevention and management have led to an exponential increase of cancer survivors worldwide. Regrettably, cardiovascular disease has risen in the aftermath as one of the most devastating consequences of cancer therapies. In this work, we define cancer therapeutics-induced cardiotoxicity as the direct or indirect cardiovascular injury or injurious effect caused by cancer therapies. We describe four progressive stages of this condition and four corresponding levels of prevention, each having a specific goal, focus, and means of action. We subsequently unfold this didactic framework, surveying mechanisms of cardiotoxicity, risk factors, cardioprotectants, biomarkers, and diagnostic imaging modalities. Finally, we outline the most current evidence-based recommendations in this area according to multidisciplinary expert consensus guidelines.

Cardiovascular Disease and Breast Cancer: Where These Entities Intersect: A Scientific Statement From the American Heart Association

Cardiovascular disease (CVD) remains the leading cause of mortality in women, yet many people perceive breast cancer to be the number one threat to women's health. CVD and breast cancer have several overlapping risk factors, such as obesity and smoking. Additionally, current breast cancer treatments can have a negative impact on cardiovascular health (eg, left ventricular dysfunction, accelerated CVD), and for women with pre-existing CVD, this might influence cancer treatment decisions by both the patient and the provider. Improvements in early detection and treatment of breast cancer have led to an increasing number of breast cancer survivors who are at risk of long-term cardiac complications from cancer treatments. For older women, CVD poses a greater mortality threat than breast cancer itself. This is the first scientific statement from the American Heart Association on CVD and breast cancer. This document will provide a comprehensive overview of the prevalence of these diseases, shared risk factors, the cardiotoxic effects of therapy, and the prevention and treatment of CVD in breast cancer patients.

Attenuation of doxorubicin-induced cardiotoxicity and genotoxicity by an indole-based natural compound 3,3'-diindolylmethane (DIM) through activation of Nrf2/ARE signaling pathways and inhibiting apoptosis

The most crucial complication related to doxorubicin (DOX) therapy is nonspecific cytotoxic effect on healthy normal cells. The clinical use of this broad-spectrum chemotherapeutic agent is restricted due to development of severe form of cardiotoxicity, myelosuppression, and genotoxicity which interfere with therapeutic schedule, compromise treatment outcome and may lead to secondary malignancy. 3,3'-diindolylmethane (DIM) is a naturally occurring plant alkaloid formed by the hydrolysis of indolylmethyl glucosinolate (glucobrassicin). Therefore, the present study was undertaken to investigate the protective role of DIM against DOX-induced toxicity in mice. DOX was administered (5 mg/kg b.w., i.p.) and DIM was administered (25 mg/kg b.w., p.o.) in concomitant and 15 days pretreatment schedule. Results showed that DIM significantly attenuated DOX-induced oxidative stress in the cardiac tissues by reducing the levels of free radicals and lipid peroxidation, and by enhancing the level of glutathione (reduced) and the activity of antioxidant enzymes. The chemoprotective potential of DIM was confirmed by histopathological evaluation of heart and bone marrow niche. Moreover, DIM considerably mitigated DOX-induced clastogenicity, DNA damage, apoptosis, and myeloid hyperplasia in bone marrow niche. In addition, oral administration of DIM significantly (p < .05) stimulated the Nrf2-mediated activation of antioxidant response element (ARE) pathway and promoted expression of ARE-driven cytoprotective proteins, HO-1, NQO1, and glutathione-S-transferase (GST). In connection with that, DIM significantly attenuated DOX-induced apoptosis by upregulation of Bcl-2 expression and downregulation of Bax and caspase-3 expression. Thus, this study suggests that DIM has promising chemoprotective efficacy against DOX-induced toxicity and indicates its future use as an adjuvant in chemotherapy.

Management of Heart Failure in Cancer Patients and Cancer Survivors

The number of cancer survivors increases annually, because of advances in detection and treatment, and the aging and growth of the population. This increase has brought a concomitant increase in morbidity and mortality from other conditions related to the adverse effects of cancer treatments. Cardiovascular diseases, and in particular left ventricular dysfunction and heart failure, are among the most significant of these. There are no unified and universally accepted evidence-based practice guidelines on the management of heartfailure in this population. This article discusses the epidemiologic impact of cancer therapeutics-related cardiac dysfunction, and reviews its most significant mediators and provides a condensed but comprehensive synopsis on its evaluation and management.

Prevention and Monitoring of Cardiac Dysfunction in Survivors of Adult Cancers: American Society of Clinical Oncology Clinical Practice Guideline

Purpose

Cardiac dysfunction is a serious adverse effect of certain cancer-directed therapies that can interfere with the efficacy of treatment, decrease quality of life, or impact the actual survival of the patient with cancer. The purpose of this effort was to develop recommendations for prevention and monitoring of cardiac dysfunction in survivors of adult-onset cancers.

Methods

Recommendations were developed by an expert panel with multidisciplinary representation using a systematic review (1996 to 2016) of meta-analyses, randomized clinical trials, observational studies, and clinical experience. Study quality was assessed using established methods, per study design. The guideline recommendations were crafted in part using the Guidelines Into Decision Support methodology.

Results

A total of 104 studies met eligibility criteria and compose the evidentiary basis for the recommendations. The strength of the recommendations in these guidelines is based on the quality, amount, and consistency of the evidence and the balance between benefits and harms.

Recommendations

It is important for health care providers to initiate the discussion regarding the potential for cardiac dysfunction in individuals in whom the risk is sufficiently high before beginning therapy. Certain higher risk populations of survivors of cancer may benefit from prevention and screening strategies implemented during cancer-directed therapies. Clinical suspicion for cardiac disease should be high and threshold for cardiac evaluation should be low in any survivor who has received potentially cardiotoxic therapy. For certain higher risk survivors of cancer, routine surveillance with cardiac imaging may be warranted after completion of cancer-directed therapy, so that appropriate interventions can be initiated to halt or even reverse the progression of cardiac dysfunction.

Management of Potential Long-Term Toxicities in Breast Cancer Patients

Breast cancer is the most common non-cutaneous malignancy among women, and there are over 3 million breast cancer survivors living in the United States today. Excellent cure rates with modern therapies are associated with substantial toxicities for many women; it is important that health care providers attend to the resulting symptoms and issues to optimize quality of life in this population. In this article, we review management options for potential long term toxicities in breast cancer survivors, with a particular focus on bone health, fertility preservation, premature menopause, cardiac dysfunction, and cognitive impairment.

Medical interventions for treating anthracycline-induced symptomatic and asymptomatic cardiotoxicity during and after treatment for childhood cancer

BACKGROUND

Anthracyclines are frequently used chemotherapeutic agents for childhood cancer that can cause cardiotoxicity during and after treatment. Although several medical interventions in adults with symptomatic or asymptomatic cardiac dysfunction due to other causes are beneficial, it is not known if the same treatments are effective for childhood cancer patients and survivors with anthracycline-induced cardiotoxicity. This review is an update of a previously published Cochrane review.

OBJECTIVES

To compare the effect of medical interventions on anthracycline-induced cardiotoxicity in childhood cancer patients or survivors with the effect of placebo, other medical interventions, or no treatment.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2015, Issue 8), MEDLINE/PubMed (1949 to September 2015), and EMBASE/Ovid (1980 to September 2015) for potentially relevant articles. In addition, we searched reference lists of relevant articles, conference proceedings of the International Society for Paediatric Oncology (SIOP), the American Society of Clinical Oncology (ASCO), the American Society of Hematology (ASH), the International Conference on Long-Term Complications of Treatment of Children & Adolescents for Cancer, and the European Symposium on Late Complications from Childhood Cancer (from 2005 to 2015), and ongoing trial databases (the ISRCTN Register, the National Institutes of Health (NIH) Register, and the trials register of the World Health Organization (WHO); all searched in September 2015).

SELECTION CRITERIA

Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) comparing the effectiveness of medical interventions to treat anthracycline-induced cardiotoxicity with either placebo, other medical interventions, or no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. One review author performed the data extraction and 'Risk of bias' assessments, which another review author checked. We performed analyses according to the guidelines in the Cochrane Handbook for Systematic Reviews of Interventions.

MAIN RESULTS

In the original version of the review we identified two RCTs; in this update we identified no additional studies. One trial (135 participants) compared enalapril with placebo in childhood cancer survivors with asymptomatic anthracycline-induced cardiac dysfunction. The other trial (68 participants) compared a two-week treatment of phosphocreatine with a control treatment (vitamin C, adenosine triphosphate, vitamin E, oral coenzyme Q10) in leukaemia patients with anthracycline-induced cardiotoxicity. Both studies had methodological limitations.The RCT on enalapril showed no statistically significant differences in overall survival, mortality due to heart failure, development of clinical heart failure, and quality of life between treatment and control groups. A post-hoc analysis showed a decrease (that is improvement) in one measure of cardiac function (left ventricular end-systolic wall stress (LVESWS): -8.62% change) compared with placebo (+1.66% change) in the first year of treatment (P = 0.036), but not afterwards. Participants treated with enalapril had a higher risk of dizziness or hypotension (risk ratio 7.17, 95% confidence interval 1.71 to 30.17) and fatigue (Fisher's exact test, P = 0.013).The RCT on phosphocreatine found no differences in overall survival, mortality due to heart failure, echocardiographic cardiac function, and adverse events between treatment and control groups.

AUTHORS' CONCLUSIONS

Only one trial evaluated the effect of enalapril in childhood cancer survivors with asymptomatic cardiac dysfunction. Although there is some evidence that enalapril temporarily improves one parameter of cardiac function (LVESWS), it is unclear whether it improves clinical outcomes. Enalapril was associated with a higher risk of dizziness or hypotension and fatigue. Clinicians should weigh the possible benefits with the known side effects of enalapril in childhood cancer survivors with asymptomatic anthracycline-induced cardiotoxicity.Only one trial evaluated the effect of phosphocreatine in childhood cancer patients with anthracycline-induced cardiotoxicity. Limited data with a high risk of bias showed no significant difference between phosphocreatine and control treatments on echocardiographic function and clinical outcomes.We did not identify any RCTs or CCTs studying other medical interventions for symptomatic or asymptomatic cardiotoxicity in childhood cancer patients or survivors.High-quality studies should be performed.

Cardiotoxicity of anticancer treatments: Epidemiology, detection, and management

Answer questions and earn CME/CNE Cancer and heart disease are the leading causes of morbidity and mortality in the industrialized world. Modern treatment strategies have led to an improvement in the chances of surviving a diagnosis of cancer; however, these gains can come at a cost. Patients may experience adverse cardiovascular events related to their cancer treatment or as a result of an exacerbation of underlying cardiovascular disease. With longer periods of survival, late effects of cancer treatment may become clinically evident years or decades after completion of therapy. Current cancer therapy incorporates multiple agents whose deleterious cardiac effects may be additive or synergistic. Cardiac dysfunction may result from agents that can result in myocyte destruction, such as with anthracycline use, or from agents that appear to transiently affect left ventricular contractility. In addition, cancer treatment may be associated with other cardiac events, such as severe treatment-induced hypertension and vasospastic and thromboembolic ischemia, as well as rhythm disturbances, including QTc prolongation, that may be rarely life-threatening. Early and late effects of chest radiation can lead to radiation-induced heart disease, including pericardial disease, myocardial fibrosis, cardiomyopathy, coronary artery disease, valvular disease, and arrhythmias, in the setting of myocardial fibrosis. The discipline of cardio-oncology has developed in response to the combined decision making necessary to optimize the care of cancer patients, whether they are receiving active treatment or are long-term survivors. Strategies to prevent or mitigate cardiovascular damage from cancer treatment are needed to provide the best cancer care. This review will focus on the common cardiovascular issues that may arise during or after cancer therapy, the detection and monitoring of cardiovascular injury, and the best management principles to protect against or minimize cardiotoxicity during the spectrum of cancer treatment strategies. CA Cancer J Clin 2016;66:309-325. © 2016 American Cancer Society.

Heart failure in chemotherapy-related cardiomyopathy: Can exercise make a difference?

Medical therapies in oncology have resulted in better survival resulting in a large population who are at risk of early and late cardiac complications of chemotherapy. Cardiotoxicity related to chemotherapy can manifest decades after treatment with a threefold higher mortality rate as compared to idiopathic dilated cardiomyopathy. The leading cause of death in cancer survivors seems to be cardiac. Early detection and intervention could prevent progression of heart failure to end stage disease requiring advanced therapies such as implantation of ventricular assist devices or cardiac transplantation. This review focuses on the role of exercise in cardioprotection in this population. The current practice of depending on ejection fraction for diagnosis of heart failure is suboptimal to detect subclinical disease. It is also important to diagnose and treat early diastolic dysfunction as this tends to lead to heart failure with preserved ejection fraction. Hence we suggest an algorithm here that is based on using strain rate and tissue Doppler imaging modalities to detect subclinical systolic and diastolic dysfunction. Further research is warranted in terms of defining exercise prescriptions in this population. Human studies with multicenter participation in randomized controlled trials should be done to elucidate the intricacies of aerobic exercise intervention in cardiotoxicity dependent heart failure. It is also necessary to assess the utility of exercise interventions in the different chemotherapeutic regimens as they impact the outcomes.

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The need for exercise prescription to prevent cardiotoxicity in chemotherapy patients

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The molecular basis of exercise as an intervention

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Summary of existing evidence

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Need for further studies on the role of exercise in different chemotherapeutic regimens

Routine Prophylactic Cardioprotective Therapy Should Not Be Given to All Recipients of Potentially Cardiotoxic Cancer Chemotherapy

With growing recognition of the associations between cancer therapy and cardiotoxicity, attention has increasingly focused on the prevention of cancer therapy-related cardiovascular disease. Various strategies for cardioprotection have been proposed, including routine administration of therapies such as inhibitors of the renin-angiotensin-aldosterone system and β-blockers. We argue this approach is unsupported by the evidence and will be associated with a high likelihood of adverse effects. We highlight alternate strategies for managing this emerging issue, which focus on a targeted approach to primary prevention driven by early identification of cardiotoxicity and selective prophylaxis of patients at increased risk for developing cardiotoxicity.

Anthracycline-Induced Cardiomyopathy in Adults

Anthracyclines are one of the most commonly used antineoplastic agent classes, and a core part of the treatment in breast cancers, hematological malignancies, and sarcomas. Their benefit is decreased by their well-recognized cardiotoxicity. The purpose of this review is to outline the presentation, mechanisms, diagnosis, and treatment of anthracyclines-induced cardiotoxicity. Symptomatic heart failure occurs in 2% to 5% of patients treated with anthrayclines and may be higher in older patients or patients with cardiovascular risk factors. The mechanisms involved in anthracycline-induced cardiotoxicity involve myocyte loss by apoptosis in the presence of a limited regenerative capacity. Once symptomatic, anthracycline-induced cardiotoxicity is associated with markedly decreased survival. Left ventricular ejection fraction (LVEF), mostly determined using echocardiography, is used to monitor patients treated with anthracyclines. As more than 1/3 of patients treated with anthracyclines do not recover their baseline LVEF once it is decreased, more sensitive echocardiographic indices of LV function such as myocardial deformation or biomarkers have been studied in patients monitoring. Cardioprotective treatments such as angiotensin-converting enzyme inhibitors, beta-blockers, iron chelators, statins, and metformin are also the topic of research efforts.

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.

Resveratrol-induced autophagy promotes survival and attenuates doxorubicin-induced cardiotoxicity

Resveratrol (RSV) has many biological effects, including antitumor and antiviral activities, and vascular protection. Recent studies have suggested that RSV exerts its antitumor effects through induction of autophagy by an unknown mechanism. Doxorubicin (DOX) is a wide spectrum antitumor drug, but its clinical application is limited by its cardiotoxicity. This study evaluated whether the manipulation of autophagy could attenuate the cardiotoxic effects of DOX in vitro as well as in a rat model of DOX-induced cardiotoxicity. We found that DOX induced H9C2 cell apoptosis by inhibiting AMPK activation and promoting pro-apoptotic protein expression through p38MAPK/p53 signaling. RSV-treated H9C2 cells showed increased autophagy through the AMPK/mTOR/Ulk1 pathway. When DOX and RSV were combined, apoptosis was decreased, despite a slight increase in the autophagy ratio. The same result was observed in the rat model of DOX-induced cardiotoxicity. Injection with DOX or RSV alone, or in combination, for a week, resulted in a reduced apoptotic ratio in the combination group compared with the DOX alone group. Our results strongly indicate that this co-treatment strategy with RSV can attenuate the cardiotoxic effects of DOX. Our findings may have important clinical implications.

Modulating effect of synthetic statins against damage induced by doxorubicin in somatic cells of Drosophila melanogaster

The competitive inhibitors of HMG-CoA reductase, popularly known as statins, exert pleiotropic effects, which result from the ability of statins to inhibit the synthesis of isoprenoids, which are fundamental for the functioning of proteins responsible for intracellular signaling. Some recent studies suggest an important role associated with the use of antineoplastic atorvastatin and rosuvastatin, the statins most widely used today. In this study, the Drosophila wing spot test was used to evaluate possible protective effects of atorvastatin and rosuvastatin against damage induced by DXR. Larvae were chronically treated with negative control (ethanol 5%), positive control (DXR 0.125 mg/mL) and five different concentrations of atorvastatin and rosuvastatin. The results demonstrated absence of a mutagenic effect for the two statins tested. The analysis of the descendants co-treated with DXR and atorvastatin/rosuvastatin revealed a modulatory effect of these statins on damage induced by DXR. This effect was verified in all concentrations tested in the descendants of the ST and HB crosses treated with rosuvastatin, and only in descendants of the HB cross treated with atorvastatin. Induction of apoptosis and antioxidant activity appear to be the main mechanisms involved in reducing the frequency of mutant spots and consequent modulation of the damage induced by DXR.

Cardiomyopathy associated with cancer therapy

Chemotherapy-associated cardiomyopathy is a well known cardiotoxicity of contemporary cancer treatment and a cause of increasing concern for both cardiologists and oncologists. As cancer outcomes improve, cardiovascular disease has become a leading cause of morbidity and mortality among cancer survivors. Asymptomatic or symptomatic left ventricular systolic dysfunction in the setting of cardiotoxic chemotherapy is an important entity to recognize. Early diagnosis of cardiac injury through the use of novel blood-based biomarkers or noninvasive imaging modalities may allow for the initiation of cardioprotective medications or modification of chemotherapy regimen to minimize or prevent further damage. Several clinical trials are currently underway to determine the efficacy of cardioprotective medications for the prevention of chemotherapy-associated cardiomyopathy. Implementing a strategy that includes both early detection and prevention of cardiotoxicity will likely have a significant impact on the overall prognosis of cancer survivors. Continued coordination of care between cardiologists and oncologists remains critical to maximizing the oncologic benefit of cancer therapy while minimizing any early or late cardiovascular effects.

Cardiac comorbidity is an independent risk factor for radiation-induced lung toxicity in lung cancer patients

PURPOSE

To test the hypothesis that cardiac comorbidity before the start of radiotherapy (RT) is associated with an increased risk of radiation-induced lung toxicity (RILT) in lung cancer patients.

MATERIAL AND METHODS

A retrospective analysis was performed of a prospective cohort of 259 patients with locoregional lung cancer treated with definitive radio(chemo)therapy between 2007 and 2011 (ClinicalTrials.gov Identifiers: NCT00572325 and NCT00573040). We defined RILT as dyspnea CTCv.3.0 grade ≥2 within 6 months after RT, and cardiac comorbidity as a recorded treatment of a cardiac pathology at a cardiology department. Univariate and multivariate analyses, as well as external validation, were performed. The model-performance measure was the area under the receiver operating characteristic curve (AUC).

RESULTS

Prior to RT, 75/259 (28.9%) patients had cardiac comorbidity, 44% of whom (33/75) developed RILT. The odds ratio of developing RILT for patients with cardiac comorbidity was 2.58 (p<0.01). The cross-validated AUC of a model with cardiac comorbidity, tumor location, forced expiratory volume in 1s, sequential chemotherapy and pretreatment dyspnea score was 0.72 (p<0.001) on the training set, and 0.67 (p<0.001) on the validation set.

CONCLUSION

Cardiac comorbidity is an important risk factor for developing RILT after definite radio(chemo)therapy of lung cancer patients.

Imaging of early modification in cardiomyopathy: the doxorubicin-induced model

Doxorubicin chemotherapy is effective and widely used to treat acute lymphoblastic leukemia. However, its effectiveness is hampered by a wide spectrum of dose-dependent cardiotoxicity including both morphological and functional changes, affecting primarily the myocardium. Non-invasive imaging techniques are used for the diagnosis and monitoring of these cardiotoxic effects. The purpose of this review is to summarize and compare the most common imaging techniques used in early detection and therapeutic monitoring of doxorubicin-induced cardiotoxicity and the suggested mechanisms of such side effects. Imaging techniques using echocardiography including conventional 2D and 3D echocardiography along with MRI sequences including Tagging, Cine, and quantitative MRI in detecting early myocardial damage are also reviewed. As there is a multitude of reported indices and imaging methods to assess particular functional alterations, we limit this review to the most relevant techniques based on their clinical application and their potential to early detection of doxorubicin-induced cardiotoxic effects.

Strategies to prevent and treat cardiovascular risk in cancer patients

Cardiotoxicity due to cancer treatment is of rising concern, for both cardiologists and oncologists, because it may have a significant impact on cancer patient management and outcome. The most typical manifestation of cardiotoxicity is a hypokinetic cardiomyopathy leading to heart failure. However, the spectrum of the toxic effects that can impair the cardiovascular system may also include acute coronary syndromes, hypertension, arrhythmias, and thromboembolic events. Patients undergoing cancer treatment are more vulnerable to cardiovascular injuries, and their risk of premature cardiovascular disease and death is higher than that of the general population. Prevention of cardiotoxicity remains the most important strategy, and several measures, including cardiac function monitoring, limitation of chemotherapy dose, use of anthracycline analogues and cardioprotectants, and early detection of myocardial cell injury by biomarkers, have been proposed. The response to modern heart failure therapy of cancer treatment-induced cardiomyopathy has never been evaluated in clinical trials, and currently there are no definitive guidelines. Although it is likely that medications used for other forms of cardiomyopathy, particularly angiotensin-converting enzyme inhibitors and β-blockers, may be highly effective, there is still some unjustified concern regarding their use in cancer patients. Specific guidelines that take cardiologic conditions of cancer patients into account are currently lacking and need to be developed.

Chemotherapy-induced cardiotoxicity

Anthracycline-based chemotherapeutics have long been recognized as effective agents for treating a wide range of malignancies. However, their use is not without significant adverse cardiotoxic side effects. Strategies for prevention involve limiting free-radical production and subsequent cardiac myocyte damage. Dexrazoxane remains the most widely studied cardioprotective medication. Alternative agents may reduce cardiotoxicity but may still cause significant cardiovascular problems. The role of β-blockers and angiotensin-converting enzyme inhibitors in the treatment of heart failure is well proven. The role of these medications in the prevention and treatment of chemotherapy-induced cardiotoxicity is not well established.

Early detection of chemotherapy-related left ventricular dysfunction

Modern advances in cancer treatment have resulted in improved survival. As a result, effects of cancer therapy on other organ systems such as the heart are more likely to become clinically relevant. One such possibility is chemotherapy-related left ventricular dysfunction. Although in clinical practice cardiotoxicity is evaluated by symptoms and left ventricular ejection fraction, these occur relatively late in the disease process after the heart's compensatory mechanisms have been expended. Ideally, left ventricular dysfunction would be identified early so that cancer patients and their physicians can make informed decisions about their therapeutic options and institute careful surveillance and early initiation of cardioprotective medication where appropriate. This review discusses the role of echocardiography to detect subclinical left ventricular dysfunction in cancer patients exposed to chemotherapy with potential cardiotoxicity, particularly anthracyclines and trastuzumab.

Berberine attenuates doxorubicin-induced cardiotoxicity in mice

This study investigated the effects of berberine, a natural alkaloid, on doxorubicin-induced cardiotoxicity in mice. Mice were injected intraperitoneally with saline 10 ml/kg (n = 10), doxorubicin 2.5 mg/kg (n = 10), 60 mg/kg berberine 1 h before doxorubicin 2.5 mg/kg (n = 10), or 60 mg/kg berberine alone (n = 10) every other day for 14 days. Body weight, general condition and mortality were recorded over the 14-day study period. Electro cardiography was performed before the start of treatment and after 14 days and plasma lactate dehydrogenase (LDH) activity was measured after 14 days. At the end of the study period the heart was excised and examined histologically. An increase in mortality, an initial decrease in body weight, increased LDH activity, prolongation of QRS duration and increased myocardial injury were seen in the doxorubicin-treated group compared with the saline control group. These changes were significantly attenuated by pretreatment with berberine. The study suggests that berberine may have a potential protective role against doxorubicin-induced cardiotoxicity in mice.

Cancer survivors in the United States: a review of the literature and a call to action

BACKGROUND

The number of cancer survivors in the U.S. has increased from 3 million in 1971, when the National Cancer Act was enacted, to over 12 million today. Over 70% of children affected by cancer survive more than 10 years, and most are cured. Most cancer survivors are adults, with two-thirds of them 65 years of age or older and two-thirds alive at five years. The most common cancer diagnoses among survivors include breast, prostate and colorectal cancers. This review was conducted to better appreciate the challenges associated with cancer survivors and the opportunities healthcare providers have in making a difference for these patients.

METHODS

Comprehensive review of literature based on PubMed searches on topics related to cancer survivorship, and associated physical, cognitive, socio-economic, sexual/behavioral and legal issues.

RESULTS

At least 50% of cancer survivors suffer from late treatment-related side effects, often including physical, psychosocial, cognitive and sexual abnormalities, as well as concerns regarding recurrence and/or the development of new malignancies. Many are chronic in nature and some are severe and even life-threatening. Survivors also face issues involving lack of appropriate health maintenance counseling, increased unemployment rate and workplace discrimination.

CONCLUSIONS

Advances in the diagnosis and treatment of cancer will lead to more survivors and better quality of life. However, tools to recognize potentially serious long-lasting side effects of cancer therapy earlier in order to treat and/or prevent them must be developed. It is incumbent upon our health care delivery systems to make meeting these patients' needs a priority.

Management of chemotherapy induced cardiomyopathy

Chemotherapy related cardiac dysfunction (CRCD) is a serious complication of anticancer therapy. CRCD can be classified into two types. Type I CRCD is exemplified by anthracyline- induced cardiac dysfunction and type II CRCD is exemplified by trastuzumab- induced cardiac dysfunction. The mechanism of cardiac toxicity in both types is not well defined. Certain risk factors may play a role in developing the cardiac injury, most importantly, the cumulative dose when dealing with anthracycline induced cardiotoxicity. Establishing an early diagnosis and initiating early treatment may be an important step in preventing irreversible cardiac injury especially in type I CRCD. Currently there are no guidelines developed specifically for the treatment of chemotherapy induced cardiomyopathy (CIC), however a few small studies support the use of neurohormonal antagonists in the treatment and prevention of CIC. Large multi- centers trials are needed to establish guidelines for CIC. Until then, we advocate following the American College of Cardiology/ American Heart Association (ACC/AHA) and Heart Failure Society of America (HFSA) guidelines. Additionally, a close collaboration between the patient's cardiologist and oncologist is strongly recommended in order to establish a long term plan for the patient.

Medical interventions for treating anthracycline-induced symptomatic and asymptomatic cardiotoxicity during and after treatment for childhood cancer

BACKGROUND

Anthracyclines are frequently used chemotherapeutic agents for childhood cancer that can cause cardiotoxicity during and after treatment. Although several medical interventions in adults with symptomatic or asymptomatic cardiac dysfunction due to other causes are beneficial, it is not known if the same treatments are effective for childhood cancer patients and survivors with anthracycline-induced cardiotoxicity.

OBJECTIVES

To compare the effect of medical interventions on anthracycline-induced cardiotoxicity in childhood cancer patients or survivors with the effect of placebo, other medical interventions or no treatment.

SEARCH STRATEGY

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2011, issue 1), MEDLINE/PubMed (1949 to May 2011) and EMBASE/Ovid (1980 to May 2011) for potentially relevant articles. We additionally searched reference lists of relevant articles, conference proceedings and ongoing trial databases.

SELECTION CRITERIA

Randomised controlled trials (RCTs) or controlled clinical trials (CCTs) comparing the effectiveness of medical interventions to treat anthracycline-induced cardiotoxicity with either placebo, other medical interventions or no treatment.

DATA COLLECTION AND ANALYSIS

Two review authors independently performed the study selection. One review author performed the data extraction and 'Risk of bias' assessments which were checked by another review author.

MAIN RESULTS

We identified two RCTs. One trial (135 patients) compared enalapril with placebo in childhood cancer survivors with asymptomatic anthracycline induced cardiac dysfunction. The other trial (68 patients) compared a two-week treatment of phosphocreatine with a control treatment (vitamin C, ATP, vitamin E, oral coenzyme Q10) in leukaemia patients with anthracycline-induced cardiotoxicity. Both studies had methodological limitations.The RCT on enalapril showed no (statistically) significant differences in overall survival, mortality due to heart failure, development of clinical heart failure and quality of life between treatment and control group. A post-hoc analysis showed a decrease (i.e. improvement) in one measure of cardiac function (left ventricular end systolic wall stress (LVESWS): -8.62% change) compared with placebo (+1.66% change) in the first year of treatment (P = 0.036), but not afterwards. Patients treated with enalapril had a higher risk of dizziness or hypotension (RR 7.17, 95% CI 1.71 to 30.17) and fatigue (Fisher's exact test, P = 0.013).The RCT on phosphocreatine found no differences in overall survival, mortality due to heart failure, echocardiographic cardiac function and adverse events between treatment and control group.

AUTHORS' CONCLUSIONS

For the effect of enalapril in childhood cancer survivors with asymptomatic cardiac dysfunction, only one RCT is available. Although there is some evidence that enalapril temporarily improves one parameter of cardiac function (LVESWS), it is unclear whether it improves clinical outcomes. Enalapril was associated with a higher risk of dizziness or hypotension and fatigue. Clinicians should weigh the possible benefits with the known side-effects of enalapril in childhood cancer survivors with asymptomatic anthracycline-induced cardiotoxicity.For the effect of phosphocreatine in childhood cancer patients with anthracycline-induced cardiotoxicity, only one RCT is available. Limited data with a high risk of bias showed no significant difference between phosphocreatine and control treatment on echocardiographic function and clinical outcomes.We did not identify any RCTs or CCTs studying other medical interventions for symptomatic or asymptomatic cardiotoxicity in childhood cancer patients or survivors.High-quality studies should be performed.

Scintigraphic techniques for early detection of cancer treatment-induced cardiotoxicity

New antitumor agents have resulted in significant survival benefits for cancer patients. However, several agents may have serious cardiovascular side effects. Left ventricular ejection fraction measurement by (99m)Tc multigated radionuclide angiography is regarded as the gold standard to measure cardiotoxicity in adult patients. It identifies left ventricular dysfunction with high reproducibility and low interobserver variability. A decrease in left ventricular ejection fraction, however, is a relatively late manifestation of myocardial damage. Nuclear cardiologic techniques that visualize pathophysiologic processes at the tissue level could detect myocardial injury at an earlier stage. These techniques may give the opportunity for timely intervention to prevent further damage and could provide insights into the mechanisms and pathophysiology of cardiotoxicity caused by anticancer agents. This review provides an overview of past, current, and promising newly developed radiopharmaceuticals and describes the role and recent advances of scintigraphic techniques to measure cardiotoxicity. Both first-order functional imaging techniques (visualizing mechanical [pump] function), such as (99m)Tc multigated radionuclide angiography and (99m)Tc gated blood-pool SPECT, and third-order functional imaging techniques (visualizing pathophysiologic and neurophysiologic processes at the tissue level) are discussed. Third-order functional imaging techniques comprise (123)I-metaiodobenzylguanidine scintigraphy, which images the efferent sympathetic nervous innervations; sympathetic neuronal PET, with its wide range of tracers; (111)In-antimyosin, which is a specific marker for myocardial cell injury and necrosis; (99m)Tc-annexin V scintigraphy, which visualizes apoptosis and cell death; fatty-acid-use scintigraphy, which visualizes the storage of free fatty acids in the lipid pool of the cytosol (which can be impaired by cardiotoxic agents); and (111)In-trastuzumab imaging, to study trastuzumab targeting to the myocardium. To define the prognostic importance and clinical value of each of these functional imaging techniques, prospective clinical trials are warranted.

Anthracycline-associated cardiotoxicity in survivors of childhood cancer

Anthracycline chemotherapeutic agents are widely used to treat childhood cancers, helping to create an increasing population of childhood cancer survivors. Cardiac complications can occur years after exposure to anthracyclines and are a leading cause of noncancerous morbidity and mortality in this population. The mechanism of its cardiotoxicity is not completely known, although oxidative stress is believed to play a significant role. This pathway and other nonoxidative mechanisms are reviewed. Several risk factors such as age, dose, female gender, and concomitant radiation therapy are known, but the relative risks of many comorbidities such as diabetes and hypertension are not well studied. No standard, evidence-based guidelines for appropriate screening methods to detect cardiotoxicity exist. Periodic imaging with echocardiography or radionuclide angiography is appropriately recommended for long-term survivors but is of limited use during therapy. Biomarkers such as cardiac troponins and brain natriuretic peptides may aid in detecting cardiotoxicity. Studies investigating the use of agents such as angiotensin-converting enzyme (ACE)-inhibitors and beta-blockers to treat anthracycline cardiotoxicity have shown promise, but more data are needed. Structural analogs such as epirubicin were developed to minimize cardiotoxicity but have not sufficiently reduced it. Liposome-encapsulated anthracyclines have shown a considerable decrease of cardiotoxicity in adults without sacrificing efficacy, but the data related to children are sparse. The only agent proven to be cardioprotective is the iron chelator, dexrazoxane. Studies have shown that dexrazoxane is safe and significantly reduces the incidence of cardiotoxicity. Dexrazoxane should be considered for pediatric oncology protocols using anthracyclines that include longitudinal assessment.