Persistence, Up to 18 Months of Follow‐Up, of Epirubicin‐Induced Myocardial Dysfunction Detected Early by Serial Tissue Doppler Echocardiography: Correlation with Inflammatory and Oxidative Stress Markers

Preventing effect of astragalus polysaccharide on cardiotoxicity induced by chemotherapy of epirubicin: A pilot study

To assess the clinical effect of astragalus polysaccharide in preventing cardiotoxicity induced by chemotherapy of epirubicin. Two hundred forty-eight patients with breast cancer or malignant lymphoma were randomly divided into the experimental group (EG) (n = 124) and the control group (CG) (n = 124). The EG received chemotherapy regimen containing anthracycline epirubicin and astragalus injection, while CG received only chemotherapy regimen containing anthracycline epirubicin. We detected myocardial function (cardiac troponin I [cTnI], creatine kinase isoenzyme [CK-MB], left ventricular ejection fraction [LVEF], and the ratio of mitral annular diastolic peak velocity to atrial systolic velocity [E/A]) and incidences of cardiotoxicity to assess cardiac function, they were compared at before the first treatment course (T1), end of the second course (T2) and 6-month follow-up. We also detected proinflammatory cytokines (IL-6 and TNF-α), reactive oxygen species and antioxidant enzymes, glutathione peroxidase (GPx), and superoxide dismutase (SOD) aimed to discover potential mechanism. There were no statistical significances in differences of LVEF and E/A between 2 groups (P > .05) at T1 and T2, while levels of LVEF and E/A of EG were significant higher than those of the CG at 6 month follow-up, with statistically significant differences (P < .05). At T1, there were no statistical significances in differences of cTnI and CK-MB between 2 groups (P > .05); at T2 and 6 months follow-up, the cTnI, and CK-MB levels of EG was significantly lower than those of the CG, with statistically significant differences (P < .05). The incidence of cardiotoxicity of EG was 15% (17/113), which was significant lower than that of the CG (60%, 66/110), with statistically significant difference (P < .05). Moreover, the level of TNF-α, GPx, and SOD did not show significant difference (P > .05). The data in this pilot study suggested that astragalus polysaccharide may be an effective therapy for preventing cardiotoxicity induced by chemotherapy of epirubicin. Furthermore, larger, placebocontrolled, perspective studies are needed to assess the efficacy of astragalus injection treatment for preventing cardiotoxicity induced by chemotherapy of epirubicin.

Cardiac Toxicity From Adjuvant Targeting Treatment for Breast Cancer Post-Surgery

Breast cancer is one of the most prevalent types of cancers worldwide, especially for females. Surgery is the preferred treatment for breast cancer, and various postoperative adjuvant therapies can be reasonably used according to different pathological characteristics, especially traditional radiotherapy, chemotherapy, and endocrine therapy. In recent years, targeting agent therapy has also become one of the selective breast cancer treatment strategies, including anti-HER-2 drugs, CDK4/6 inhibitor, poly ADP-ribose polymerase inhibitor, PI3K/AKT/mTOR pathway inhibitor, ER targeting drugs, and aromatase inhibitor. Because of the different pathologic mechanisms of these adjuvant therapies, each of the strategies may cause cardiotoxicity in clinic. The cardiac adverse events of traditional endocrine therapy, radiotherapy, and chemotherapy for breast cancer have been widely detected in clinic; however, the targeting therapy agents have been paid more attention with the extension of application. This review will summarize the cardiac toxicity of various adjuvant therapies for breast cancer, especially for targeting drug therapy.

Antioxidant Approach as a Cardioprotective Strategy in Chemotherapy-Induced Cardiotoxicity

Significance: Chemotherapy-induced cardiotoxicity (CTX) has been associated with redox signaling imbalance. In fact, redox reactions are crucial for normal heart physiology, whereas excessive oxidative stress can cause cardiomyocyte structural damage. Recent Advances: An antioxidant approach as a cardioprotective strategy in this setting has shown encouraging results in preventing anticancer drug-induced CTX. Critical Issues: In fact, traditional heart failure drugs as well as many other compounds and nonpharmacological strategies, with a partial effect in reducing oxidative stress, have been shown to counterbalance chemotherapy-induced CTX in this setting to some extent. Future Directions: Given the various pathways of toxicity involved in different chemotherapeutic schemes, interactions with redox balance need to be fine-tuned and a personalized cardioprotective approach seems to be required.

Effect of Anticancer Quinones on Reactive Oxygen Production by Adult Rat Heart Myocytes

This study investigated the effect of anthracycline antibiotics, mitomycin C, and menadione on oxygen consumption and hydrogen peroxide production by intact, beating, rat heart myocytes. Doxorubicin produced a dose-dependent increase in the rate of cyanide-resistant respiration by beating myocytes. The anthracycline analogs 4-demethoxydaunorubicin, 4′-epidoxorubicin, 4′-deoxydoxorubicin, and menogaril, as well as the anticancer quinones mitomycin C and menadione, also significantly increased oxygen consumption by cardiac myocytes. However, 5-iminodaunorubicin (which has a substituted quinone group) and mitoxantrone (which is not easily reduced by flavin dehydrogenases) had no effect on cardiac respiration. Both catalase (43%) and acetylated cytochrome c (19%) significantly decreased oxygen consumption that had been stimulated by doxorubicin; furthermore, extracellular hydrogen peroxide production was increased from undetectable control levels to 1.30 ± 0.02 nmol/min/10⁷ myocytes (n = 4, P < 0.01) in the presence of 400 μM doxorubicin. These experiments suggest that the anthracycline antibiotics and other anticancer quinones stimulate cardiac oxygen radical production in intact heart myocytes; such a free radical cascade could contribute to the cardiac toxicity of these drugs.

Clair WH, St. Clair DK. Redox Paradox: A Novel Approach to Therapeutics-Resistant Cancer

SIGNIFICANCE

Cancer cells that are resistant to radiation and chemotherapy are a major problem limiting the success of cancer therapy. Aggressive cancer cells depend on elevated intracellular levels of reactive oxygen species (ROS) to proliferate, self-renew, and metastasize. As a result, these aggressive cancers maintain high basal levels of ROS compared with normal cells. The prominence of the redox state in cancer cells led us to consider whether increasing the redox state to the condition of oxidative stress could be used as a successful adjuvant therapy for aggressive cancers. Recent Advances: Past attempts using antioxidant compounds to inhibit ROS levels in cancers as redox-based therapy have met with very limited success. However, recent clinical trials using pro-oxidant compounds reveal noteworthy results, which could have a significant impact on the development of strategies for redox-based therapies.

CRITICAL ISSUES

The major objective of this review is to discuss the role of the redox state in aggressive cancers and how to utilize the shift in redox state to improve cancer therapy. We also discuss the paradox of redox state parameters; that is, hydrogen peroxide (H2O2) as the driver molecule for cancer progression as well as a target for cancer treatment.

FUTURE DIRECTIONS

Based on the biological significance of the redox state, we postulate that this system could potentially be used to create a new avenue for targeted therapy, including the potential to incorporate personalized redox therapy for cancer treatment.

Comparison of Conventional and Advanced Echocardiographic Techniques in Early Detection of Cardiotoxicity in Patients Undergoing Cancer Chemotherapy

Context: The assessment of left ventricular ejection fraction (LVEF) is the most important component in prediction and detection of cardiotoxicity in patients undergoing cancer chemotherapy. LVEF may not be sensitive enough to pick the cardiotoxicity early since drop in LVEF occurs in the last and irreversible stage. A 10%–15% early reduction in global longitudinal strain (GLS) by speckle tracking echocardiography proposed to be the earliest indicator of myocardial dysfunction. Aims: The aim of this study was to compare the early detection of cardiotoxicity (at 0 and 3 months) using drop in LVEF with two-dimensional echocardiography (2DE), three-dimensional echocardiography (3DE), and GLS techniques. Settings and Design: This was a prospective cohort study of patients attending cardiooncology clinic in a tertiary care institute. Subjects and Methods: Newly diagnosed 75 cases of cancer of various etiologies, for whom cardiotoxic chemotherapy drugs has to be used, were included from January 2016 to June 2016. Statistical Analysis Used: Data were analyzed with Pearson’s Chi-square test, mean, standard deviation, and 95% confidence interval. Results: A total of 17 (22.6%) subjects out of 75, had drop in LVEF by GLS (<−18.9%) as compared to 5 (6.6%) in 2DE and 7 (9.3%) in 3DE at 3 months with statistically significant P values (P = 0.0001). In the 17 subjects who had significant fall in GLS at 3 months, the mean GLS was −16.17 ± 1.55% with a significant reduction of 13.48% from baseline. Conclusion: Reduction in GLS preceded decrease in ejection fraction. Early detection allows modification of chemotherapeutic regimens and medical intervention preventing the irreversible cardiac damage.

Cardiovascular imaging in the diagnosis and monitoring of cardiotoxicity: role of echocardiography

The evaluation by cardiovascular imaging of chemotherapy patients became a central topic in the last several years. The use of drugs for the treatment of cancers increased, and new molecules and protocols were developed to improve outcomes in these patients. Although, these novel approaches also produced a progressive increase in side effects, particularly myocardial dysfunction. Imaging of the heart was highly accurate in the early diagnosis of cancer therapeutics related-cardiac dysfunction. Echocardiography is the first-line method to assess ventricular function alterations, and it is required to satisfy the need for an early, easy and accurate diagnosis to stratify the risk of heart failure and manage treatments. A careful monitoring of cardiac function during the course of therapy should prevent the onset of severe heart impairment. This review provides an overview of the most important findings of the role of echocardiography in the management of chemotherapy-treated patients to create a clear and complete description of the efficacy of conventional measurements, the importance of comprehensive heart evaluations, the additional role of new echocardiographic techniques, the utility of integrated studies using other imaging tools and the positions of the most important international societies on this topic.

Preventing antiblastic drug-related cardiomyopathy: old and new therapeutic strategies

Because of the recent advances in chemotherapeutic protocols, cancer survival has improved significantly, although cardiovascular disease has become a major cause of morbidity and mortality among cancer survivors: in addition to the well-known cardiotoxicity (CTX) from anthracyclines, biologic drugs that target molecules that are active in cancer biology also interfere with cardiovascular homeostasis.Pharmacological and non-pharmacological strategies to protect the cardiovascular structure and function are the best approaches to reducing the prevalence of cardiomyopathy linked to anticancer drugs. Extensive efforts have been devoted to identifying and testing strategies to achieve this end, but little consensus has been reached on a common and shared operability.Timing, dose and mode of chemotherapy administration play a crucial role in the development of acute or late myocardial dysfunction. Primary prevention initiatives cover a wide area that ranges from conventional heart failure drugs, such as β-blockers and renin-angiotensin-aldosterone system antagonists to nutritional supplementation and physical training. Additional studies on the pathophysiology and cellular mechanisms of anticancer-drug-related CTX will enable the introduction of novel therapies.We present various typologies of prevention strategies, describing the approaches that have already been used and those that could be effective on the basis of a better understanding of pharmacokinetic and pharmacodynamic CTX mechanisms.

Role of biomarkers in monitoring antiblastic cardiotoxicity

Early detection of anticancer drug-induced cardiotoxicity (CTX) has been evaluated by most international scientific cardiology and oncology societies. High expectations have been placed on the use of specific biomarkers. In recent years, conventional biomarkers and molecules of more recent interest have been tested and compared in the context of anticancer drug-related CTX. Encouraging results were obtained from studies on molecules of myocardial damage, such as troponin and markers of myocardial wall stress, including circulating natriuretic peptides, as well as from the assessment of the products of inflammation or circulating levels of free radicals. However, clear guidelines on their sensitivity, specificity, and accuracy are not yet available, and many challenges, such as the optimal time of assessing, optimal schedule for evaluation, optimal cut-off point for positivity with the highest level of specificity, and optimal comparability of different assays for the measurements, remain unresolved. Given the importance of having a reliable and accurate tool for monitoring anticancer drug-induced CTX, this review will focus on the available data on the most effective and widely used biomarkers and the studies that are currently underway that aim to identify the effectiveness of new approaches in this therapeutic setting.

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.

Timing of the negative effects of trastuzumab on cardiac mechanics after anthracycline chemotherapy

Trastuzumab (TZB) has been shown to be extremely effective in breast cancer patients over-expressing HER-2, but careful cardiac monitoring is required when TZB is administered with anthracyclines, since the combination can increase its toxicity. Myocardial deformation indexes associated with speckle tracking echocardiography (STE) have proven to be very sensitive in identifying early myocardial dysfunction. An observational, prospective study was designed to assess TZB-induced cardiac damage using STE in patients with HER-2 positive breast cancer who had been sequentially treated with TZB following epirubicin (EPI). Conventional echocardiographic parameters and STE deformation indexes (longitudinal, radial, and circumferential strain/strain rate and apical rotation) were analyzed at baseline, after each EPI treatment, and 1 week after every other dose of TZB administration until 1 year follow up, in order to focus on the timing and extent of myocardial impairment. In the forty-five enrolled patients, a reduction in subendocardial function after EPI treatment was observed by a significant impairment of the global longitudinal strain/strain rate (GLS/SR), while a significant increase in the activity of the subepicardial fibers was highlighted by an increase in apical rotation. After the second TZB dose, a sudden reduction of the apical rotation was seen, together with circumferential and radial strain/SR. Most importantly, the extent to which the apical rotation increased and decreased was found to strictly correlate with the GLS reduction at follow up. We found that after EPI therapy, subendocardial function was impaired, even while a compensatory increase in apical rotation occurred. Following TZB treatment, we observed impairment in apical rotation, which seems to be the first sign of global LV dysfunction predicting GLS reduction found at the end of treatment.

Cardiotoxicity due to chemotherapy: role of cardiac imaging

The identification of patients at risk of cardiac toxicity (cardiotoxicity) from cancer therapy is challenging. There is an increasing focus on early detection of cardiotoxicity such that interventions can be instituted to prevent advanced heart failure. Clinical risk prediction tools are limited and clinical symptoms are not specific. Direct assessment of myocardial function before and during cancer treatment using cardiac imaging appears to be an objective method to identify patients at risk. Although, multiple imaging modalities and measures of cardiac function are available, the best modality or the optimal measure of function is unknown. Measurement of left ventricular ejection fraction is most commonly used; however, growing literature suggests that it is inadequate for the detection of early cardiac injury. Other measures include left ventricular diastolic function, myocardial deformation, and myocardial tissue characterization. This review will provide an overview of the clinically available measures for the assessment of cardiotoxicity.

Cancer therapy-induced cardiotoxicity: role of ultrasound deformation imaging as an aid to early diagnosis

In the last decade, ultrasound deformation imaging, based on both Doppler and speckle tracking echocardiography techniques, has emerged as a more sensitive tool to identify subtle and subclinical left ventricular systolic dysfunction in several clinical settings compared with ejection fraction. In this article, we review the evidence relative to the application of ultrasound deformation imaging to the oncologic field for detection of left ventricular systolic dysfunction induced by cardiotoxic treatments with the aim of verifying whether this approach may actually help in early diagnosis of chemotherapy-induced cardiotoxicity.

Use of myocardial strain imaging by echocardiography for the early detection of cardiotoxicity in patients during and after cancer chemotherapy: a systematic review

The literature exploring the utility of advanced echocardiographic techniques (such as deformation imaging) in the diagnosis and prognostication of patients receiving potentially cardiotoxic cancer therapy has involved relatively small trials in the research setting. In this systematic review of the current literature, we describe echocardiographic myocardial deformation parameters in 1,504 patients during or after cancer chemotherapy for 3 clinically-relevant scenarios. The systematic review was performed following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using the EMBASE (1974 to November 2013) and MEDLINE (1946 to November 2013) databases. All studies of early myocardial changes with chemotherapy demonstrate that alterations of myocardial deformation precede significant change in left ventricular ejection fraction (LVEF). Using tissue Doppler-based strain imaging, peak systolic longitudinal strain rate has most consistently detected early myocardial changes during therapy, whereas with speckle tracking echocardiography (STE), peak systolic global longitudinal strain (GLS) appears to be the best measure. A 10% to 15% early reduction in GLS by STE during therapy appears to be the most useful parameter for the prediction of cardiotoxicity, defined as a drop in LVEF or heart failure. In late survivors of cancer, measures of global radial and circumferential strain are consistently abnormal, even in the context of normal LVEF, but their clinical value in predicting subsequent ventricular dysfunction or heart failure has not been explored. Thus, this systematic review confirms the value of echocardiographic myocardial deformation parameters for the early detection of myocardial changes and prediction of cardiotoxicity in patients receiving cancer therapy.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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

Long-term, up to 18 months, protective effects of the angiotensin II receptor blocker telmisartan on Epirubin-induced inflammation and oxidative stress assessed by serial strain rate

PURPOSE

The primary objective of the present study was to show the long lasting cardioprotective activity, at different time-points, up to 18 month-follow-up, of telmisartan in preserving the systolic function (assessed as Strain Rate-SR) in cancer patients treated with EPI both in the adjuvant and metastatic setting; the secondary objective was to confirm the correlation of the cardioprotective activity of telmisartan with a reduction of inflammation and oxidative stress induced by EPI.

METHODS

Phase II single blind placebo-controlled randomized trial. Sample size 50 patients per arm: based on a pre-planned interim analysis for early stopping rules, the study was discontinued for ethical reasons at 49 patients. Cardiovascular disease-free patients with cancer at different sites eligible for EPI-based treatment randomized to: telmisartan n = 25 or placebo n = 24. Echocardiography Tissue Doppler imaging (TDI) strain and strain rate was performed, serum levels of proinflammatory cytokines (IL-6, TNF-α) and oxidative stress (reactive oxygen species, ROS) were assessed at baseline, every 100 mg/m(2) EPI dose and at 6-, 12- and 18-month follow-up (FU).

RESULTS

Significant SR peak reduction in both arms was observed at t2 (cumulative dose EPI 200 mg/m(2)) vs t0. Conversely, at t3, t4, 6-, 12- and 18-month FU SR increased towards normal range in the telmisartan arm, while in the placebo arm SR remained significantly lower. Differences between SR changes in the placebo and telmisartan arm were significant from t3 up to 18 month-FU. IL-6 and ROS increased significantly in the placebo arm at t2 but did not change in the telmisartan arm. A significant (p < 0.05) correlation between changes of SR vs IL-6 and ROS was observed.

CONCLUSIONS

Our results suggest that the protective effect of telmisartan is long lasting, probably by ensuring a permanent (at least up to 18-month FU) defense against chronic or late-onset types of anthracycline-induced cardiotoxicity.

Association of anthracycline-related cardiac histological lesions with NADPH oxidase functional polymorphisms

OBJECTIVE

Treatment with anthracyclines may cause cardiac dysfunction, but the sequence of anthracycline-induced heart lesions has been incompletely characterized. NADPH oxidase, a key mediator of oxidative cardiac damage and remodeling, modulates anthracycline clinical cardiotoxicity. Our aim was to determine which cardiac histological lesions are specifically induced by anthracycline treatment and to investigate the role of NADPH functional genetic polymorphisms in their development.

PATIENTS AND METHODS

Using a retrospective case-control design, we evaluated cardiac histological lesions and NADPH genotype (polymorphisms rs1883112, rs4673, and rs13058338) in 97 consecutive decedents with a cancer diagnosis (48 treated with anthracyclines).

RESULTS

Myocytolysis (60%), patched myocardial necrosis (19%), and myocardial fibrosis (diffuse and patched; 62% and 23%, respectively) were associated with anthracycline treatment. In patients receiving anthracyclines, NADPH oxidase polymorphism rs4673 protected against focal myocardial necrosis (odds ratio [OR], 0.11; 95% confidence interval [CI], 0.20-0.63) whereas rs1883112 was strongly associated with cardiac fibrosis (OR, 5.11; 95% CI, 1.59-16.43), which was present in all homozygotes.

CONCLUSION

Anthracyclines induce a cardiac remodeling pattern characterized by interstitial or patched fibrosis. The contribution of the functionally relevant NADPH polymorphisms rs1883112 and rs4673 to anthracycline-related heart lesions provides a plausible explanation for their modulation of cardiotoxicity. If confirmed, these findings may lead to better individualized strategies for early detection and prevention of anthracycline cardiotoxicity.

Long-term heart function after adjuvant epirubicin chemotherapy for breast cancer

BACKGROUND

Newer studies raise concern that adjuvant anthracycline treatment for breast cancer (BC) causes long-term heart damage. We aimed to examine whether heart failure or impairment could be demonstrated several years after low-dose epirubicin-based adjuvant treatment.

MATERIAL AND METHODS

The study-population was a historical cohort comprising 980 women who were randomized to receive one of two adjuvant regimens for treatment for BC: 7-9 cycles of cyclophosphamide-epirubicin-5-fluorouracil [CEF (600 + 60 + 600 mg/m(2))] or cyclophosphamide-methotrexate-5- fluorouracil [CMF (600 + 40 + 600 mg/m(2))]. We collected information in national registries of death and diagnoses and a sample of 77 survivors was examined with tissue-Doppler imaging (TDI), echocardiography, radionuclide ventriculography and N-terminal-pro-B-type-natriuretic peptide (NT-proBNP), an established marker for heart failure.

RESULTS AND CONCLUSION

Median follow-up was 12 years (39 days-20 years). Fifty-one percent had died. Incidence of CHF was 2.6/1000/year and equal in the treatment groups. In the sample, individuals who had received CEF showed no cardiac impairment when compared to individuals who received CMF. NT-proBNP-levels were within normal limits but higher in the CEF-group than in the CMF-group (confidence limits 105-226%, p = 0.03). Results of our study seem reassuring regarding the long-term risk of cardiotoxicity following low-dose adjuvant epirubicin treatment. However, larger, longitudinal studies are needed to establish the clinical implications.

Protective effects of salidroside on epirubicin-induced early left ventricular regional systolic dysfunction in patients with breast cancer

Background

Salidroside [2-(4-hydroxyphenyl)ethyl-β-D-glucopyranoside], one of the most potent ingredients extracted from the plant Rhodiola rosea L., has been shown to have a cardiovascular protective effect as an antioxidant, and early treatment of epirubicin-induced cardiotoxicity has been the focus of clinical chemotherapy in patients with breast cancer. However, the cardioprotective effects of salidroside on epirubicin-induced cardiotoxicity, especially early left ventricular regional systolic dysfunction, have to date been sparsely investigated.

Objective

The aim of this study was to investigate the protective effects of salidroside in preventing early left ventricular regional systolic dysfunction induced by epirubicin.

Methods

Sixty patients with histologically confirmed breast cancer were enrolled. Eligible patients were randomized to receive salidroside (600 mg/day; n= 30) or placebo (n = 30) starting 1 week before chemotherapy. Patients were investigated by means of echocardiography and strain rate (SR) imaging. We also measured plasma concentrations of reactive oxygen species (ROS). All parameters were assessed at baseline and 7 days after each new epirubicin dose of 100 mg/m².

Results

A decline of the SR peak was observed at an epirubicin dose of 200 mg/m², with no significant differences between salidroside and placebo (1.35 ± 0.36 vs 1.42 ± 0.49/second). At growing cumulative doses of epirubicin, the SR normalized only with salidroside, showing a significant difference in comparison with placebo at epirubicin doses of 300 mg/m² (1.67 ± 0.43 vs 1.32 ± 0.53/second, p< 0.05) and 400 mg/m² (1.68±0.29 vs 1.40 ± 0.23/second, p < 0.05). Moreover, a significant increase in plasma concentrations of ROS was found with placebo, but they remained unchanged with salidroside.

Conclusion

Salidroside can provide a protective effect on epirubicin-induced early left ventricular regional systolic dysfunction in patients with breast cancer.

Detection and prevention of cardiac complications of cancer chemotherapy

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

Chemotherapy-induced weakness and fatigue in skeletal muscle: the role of oxidative stress

SIGNIFICANCE

Fatigue is one of the most common symptoms of cancer and its treatment, manifested in the clinic through weakness and exercise intolerance. These side effects not only compromise patient's quality of life (QOL), but also diminish physical activity, resulting in limited treatment and increased morbidity.

RECENT ADVANCES

Oxidative stress, mediated by cancer or chemotherapeutic agents, is an underlying mechanism of the drug-induced toxicity. Nontargeted tissues, such as striated muscle, are severely affected by oxidative stress during chemotherapy, leading to toxicity and dysfunction.

CRITICAL ISSUES

These findings highlight the importance of investigating clinically applicable interventions to alleviate the debilitating side effects. This article discusses the clinically available chemotherapy drugs that cause fatigue and oxidative stress in cancer patients, with an in-depth focus on the anthracycline doxorubicin. Doxorubicin, an effective anticancer drug, is a primary example of how chemotherapeutic agents disrupt striated muscle function through oxidative stress.

FUTURE DIRECTIONS

Further research investigating antioxidants could provide relief for cancer patients from debilitating muscle weakness, leading to improved quality of life.

Long-term protective effects of the angiotensin receptor blocker telmisartan on epirubicin-induced inflammation, oxidative stress and myocardial dysfunction

Chronic inflammation, oxidative stress and the renin-angiotensin system (RAS) play a significant role in chemotherapy-induced cardiotoxicity (CTX). Telmisartan (TEL), an antagonist of the angiotensin II type-1 receptor, was found to reduce anthracycline (ANT)-induced CTX. We carried out a phase II placebo (PLA)-controlled randomized trial to assess the possible role of TEL in the prevention of cardiac subclinical damage induced by epirubicin (EPI). Forty-nine patients (mean age ± SD, 53.0±8 years), cardiovascular disease-free with cancer at different sites and eligible for EPI-based treatment, were randomized to one of two arms: TEL n=25; PLA n=24. A conventional echocardiography equipped with Tissue Doppler imaging, strain and strain rate (SR) was performed, and serum levels of proinflammatory cytokines, IL-6 and TNF-α, and oxidative stress parameters, reactive oxygen species (ROS) and glutathione peroxidase were determined. All assessments were carried out at baseline, after every 100 mg/m(2) of EPI dose and at the 12-month follow-up (FU). A significant reduction in the SR peak both in the TEL and PLA arms was observed at t(2) (cumulative dose of 200 mg/m(2) of EPI) in comparison to t(0). Conversely, at t(3) (300 mg/m(2) EPI), t(4) (400 mg/m(2) EPI) and the 12-month FU, the SR increased reaching the normal range only in the TEL arm, while in the PLA arm the SR remained significantly lower as compared to t(0) (baseline). The differences between SR changes in the PLA and TEL arms were significant from 300 mg/m(2) EPI (t(3)) up to the 12-month FU. Serum levels of IL-6 increased significantly in the PLA arm at 200 mg/m(2) EPI (t(2)) in comparison to baseline, but remained unchanged in the TEL arm. The same trend was demonstrated for ROS levels which significantly increased at t(2) vs. baseline in the PLA arm, while remained unchanged in the TEL arm. The mean change in ROS and IL-6 at t(2) was significantly different between the two arms. In the present study, we confirmed at the 3-month FU a trend toward a decrease in ROS and IL-6 from t(2) in the PLA arm. Our results suggest that TEL is able to reverse acute (early) EPI-induced myocardial dysfunction and to maintain later a normal systolic function up to the 12-month FU. These effects are likely to be due to different mechanisms, RAS blockade and prevention of chronic inflammation/oxidative stress.

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.

Myocardial strain and strain rate in monitoring subclinical heart failure in asymptomatic long-term survivors of childhood cancer

We studied the role of global myocardial strain and strain rate in monitoring subclinical heart failure in a large group of asymptomatic long-term survivors of childhood cancer. Global strain (rate) parameters of survivors were compared with those in healthy controls and were related to conventional echocardiographic parameters, N-terminal-pro-natriuretic peptide (NT-pro-BNP) levels and clinical parameters. Two-dimensional (2-D) echocardiography was performed in 111 survivors and 107 healthy controls. Blood samples were taken from survivors to determine NT-pro-BNP levels. We showed that global myocardial strain, strain rate and time to peak systolic strain in asymptomatic survivors of childhood cancer were significantly lower compared with healthy controls (p values <0.0001) and were significantly related to several systolic and diastolic left ventricular parameters. Whether myocardial strain and strain rate are superior to conventional echocardiography in the early detection of subclinical heart failure needs to be explored in further longitudinal prospective studies.

Protective effects of the angiotensin II receptor blocker telmisartan on epirubicin-induced inflammation, oxidative stress, and early ventricular impairment

BACKGROUND

Oxidative stress and RAAS play an important role in the occurrence of anthracyclines-induced cardiotoxicity. Telmisartan, an angiotensin II type 1 receptor blocker, inhibits activation of superoxide sources and induces anti-inflammatory effects.

METHODS

The possible role of telmisartan in preventing myocardial damage induced by epirubicin (EPI) was investigated. Forty-nine patients free from cardiovascular diseases affected by a variety of solid cancers were examined. Eligible patients were randomized to receive telmisartan (40 mg/d; TEL, n = 25) or placebo (PLA, n = 24) starting 1 week before chemotherapy. Patients were studied by means of echocardiography, tissue Doppler, and strain and strain rate (SR) imaging. We also measured plasma levels of inflammatory and oxidative stress markers. All parameters were assessed at baseline and 7 days after every new EPI dose of 100 mg/m(2).

RESULTS

An impairment of the SR peak was observed at the EPI dose of 200 mg/m(2), with no significant differences between TEL and PLA (1.41 +/- 0.31 vs 1.59 +/- 0.36/s). At growing cumulative doses of EPI, SR normalized only in TEL, showing a significant difference in comparison to PLA at EPI doses of 300 mg/m(2) (1.69 +/- 0.42 vs 1.34 +/- 0.18/s, P < .001) and 400 mg/m(2) (1.74 +/- 0.27 vs 1.38 +/- 0.24/s, P < .001). Moreover, a significant increase in reactive oxygen species and interleukin-6 was found in PLA; but these remained unchanged in TEL.

CONCLUSIONS

We confirmed that EPI-induced cardiotoxicity is primarily related to the inactivation of the cardiac antioxidant defenses. In addition, we showed that telmisartan can reduce EPI-induced radical species, antagonize the inflammation, and reverse the early myocardial impairment.