Recent Advances on Pathophysiology, Diagnostic and Therapeutic Insights in Cardiac Dysfunction Induced by Antineoplastic Drugs

Intrinsic Wave Velocity Propagation: A Novel Parameter for Assessing the Effect of Anthracycline Chemotherapy Agents on Cardiac Diastolic Function in Breast Cancer Patients

OBJECTIVE

Anthracycline chemotherapeutic agents have significant cardiotoxicity. The present study emphasized the effect of anthracycline chemotherapy drugs on left ventricular (LV) myocardial stiffness in breast cancer patients by measuring the intrinsic wave velocity propagation (IVP), and evaluating the potential clinical value of IVP in detecting early LV diastolic function impairment.

METHODS

A total of 68 newly diagnosed breast cancer patients, who were treated with anthracycline-based chemotherapy, were analyzed. Transthoracic echocardiography was performed at baseline (T0), and after 1, 2, 3, 4 and 8 chemotherapeutic cycles (T1, T2, T3, T4 and T5, respectively). Then, the IVP, LV strain parameters [global longitudinal strain (GLS), longitudinal peak strain rate at systole (LSRs), longitudinal peak strain rate at early diastole (LSRe), longitudinal peak strain rate at late diastole (LSRa), and the E/LSRe ratio], and conventional echocardiographic parameters were obtained and further analyzed. A relative reduction of >15% in GLS was considered a marker of early LV subclinical dysfunction.

RESULTS

Compared to the T0 stage, IVP significantly increased at the T1 stage. However, there were no significant changes in GLS, LSRs, or LSRe between the T0 and T1 stages. These parameters significantly decreased from the T2 stage. LSRa started to significantly decrease at the T5 stage, and the E/LSRe ratio started to significantly increase at the T3 stage (all P<0.05). At the T0 stage, IVP (AUC=0.752, P<0.001) had a good predictive value for LV subclinical dysfunction after chemotherapy.

CONCLUSIONS

IVP is a potentially sensitive parameter for the early clinical assessment of anthracycline-related cardiac diastolic impairment.

Capsaicin Ameliorates the Cyclophosphamide-Induced Cardiotoxicity by Inhibiting Free Radicals Generation, Inflammatory Cytokines, and Apoptotic Pathway in Rats

Cyclophosphamide is an antineoplastic agent that has a broad range of therapeutic applications; however, it has numerous side effects, including cardiotoxicity. Furthermore, chili peppers contain a substance called capsaicin, having antioxidant and anti-inflammatory effects. Thus, this research paper focuses on the potential mechanism of capsaicin’s cardioprotective activity against cyclophosphamide-induced cardiotoxicity by measuring the expression of oxidative and inflammatory marker such as interleukins and caspases. The following groups of rats were randomly assigned: only vehicle given for 6 days (control group); cyclophosphamide 200 mg/kg intraperitoneal on 4th day only (positive control group); capsaicin 10 mg/kg orally given for 6 days followed by cyclophosphamide 200 mg/kg on 4th day of treatment; capsaicin 20 mg/kg orally for six days followed by cyclophosphamide 200 mg/kg on 4th day of treatment; and maximum amount of capsaicin alone (20 mg/kg) orally for six days. Using ELISA kits, it was found that the cyclophosphamide administration significantly increased the levels of lactate dehydrogenase, troponin-I (cardiac cell damage marker), lipid peroxidation, triglyceride, interleukin-6, tumor necrosis factor-alpha, and caspase 3. However, it markedly reduced the antioxidant enzymes catalase and glutathione levels. Both doses of capsaicin could reverse cardiac cell damage markers, as shown by a significant decline in (lactate dehydrogenase and troponin-I). In addition, capsaicin significantly reduced the cytokine levels (interleukin-6 and tumor necrosis factor-alpha), caspase 3, lipid peroxidation, and triglycerides. However, capsaicin treatment significantly raised the antioxidant content of enzymes such as glutathione and catalase. The capsaicin-treated group restored the oxidative parameter’s imbalance and generated considerable protection against cardiomyocyte harm from cyclophosphamide in male Wistar rats. These protective effects might be beneficial against the negative impacts of cyclophosphamide when used to treat cancer and immune-mediated diseases.

Cardiotoxicity of Anticancer Drugs: Molecular Mechanisms and Strategies for Cardioprotection

Chemotherapy and targeted therapies have significantly improved the prognosis of oncology patients. However, these antineoplastic treatments may also induce adverse cardiovascular effects, which may lead to acute or delayed onset of cardiac dysfunction. These common cardiovascular complications, commonly referred to as cardiotoxicity, not only may require the modification, suspension, or withdrawal of life-saving antineoplastic therapies, with the risk of reducing their efficacy, but can also strongly impact the quality of life and overall survival, regardless of the oncological prognosis. The onset of cardiotoxicity may depend on the class, dose, route, and duration of administration of anticancer drugs, as well as on individual risk factors. Importantly, the cardiotoxic side effects may be reversible, if cardiac function is restored upon discontinuation of the therapy, or irreversible, characterized by injury and loss of cardiac muscle cells. Subclinical myocardial dysfunction induced by anticancer therapies may also subsequently evolve in symptomatic congestive heart failure. Hence, there is an urgent need for cardioprotective therapies to reduce the clinical and subclinical cardiotoxicity onset and progression and to limit the acute or chronic manifestation of cardiac damages. In this review, we summarize the knowledge regarding the cellular and molecular mechanisms contributing to the onset of cardiotoxicity associated with common classes of chemotherapy and targeted therapy drugs. Furthermore, we describe and discuss current and potential strategies to cope with the cardiotoxic side effects as well as cardioprotective preventive approaches that may be useful to flank anticancer therapies.

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.

Chrysanthemum morifolium Extract Ameliorates Doxorubicin-Induced Cardiotoxicity by Decreasing Apoptosis

It is well known that the anthracycline anticancer drug doxorubicin (DOX) induces cardiotoxicity. Recently, Chrysanthemum morifolium extract (CME), an extract of the purple chrysanthemum flower, has been reported to possess various physiological activities such as antioxidant and anti-inflammatory effects. However, its effect on DOX-induced cardiotoxicity is still unknown. An 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT)assay revealed that 1 mg/mL of CME reduced DOX-induced cytotoxicity in H9C2 cells but not in MDA-MB-231 cells. A TUNEL assay indicated that CME treatment improved DOX-induced apoptosis in H9C2 cells. Moreover, DOX-induced increases in the expression levels of p53, phosphorylated p53, and cleaved caspase-3,9 were significantly suppressed by CME treatment. Next, we investigated the effect of CME in vivo. The results showed that CME treatment substantially reversed the DOX-induced decrease in survival rate. Echocardiography indicated that CME treatment also reduced DOX-induced left ventricular systolic dysfunction, and a TUNEL assay showed that CME treatment also suppressed apoptosis in the mouse heart. These results reveal that CME treatment ameliorated DOX-induced cardiotoxicity by suppressing apoptosis. Further study is needed to clarify the effect of CME on DOX-induced heart failure in humans.

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.

Cardiovascular safety of the tyrosine kinase inhibitor nintedanib

The intracellular tyrosine kinase inhibitor nintedanib has shown great efficacy for the treatment of idiopathic pulmonary fibrosis (IPF) and other interstitial lung diseases. However, the incidence rate of myocardial infarction (MI) among participants in landmark IPF trials was remarkable, peaking at 3/100 patient-years. Although subjects with IPF often have a high cardiovascular (CV) risk profile, the occurrence of MI in nintedanib-treated patients may not be fully explained by clustering of CV risk factors. Nintedanib inhibits the vascular endothelial growth factor, platelet-derived growth factor and fibroblast growth factor pathways, which play important roles in the biology of the atherosclerotic plaque and in the response of the heart to ischaemia. Hence, unwanted CV effects may partly account for nintedanib-related MI. We review the evidence supporting this hypothesis and discuss possible actions for a safe implementation of nintedanib in clinical practice, building on the experience with tyrosine kinase inhibitors acquired in cardio-oncology.

Cardiac dysfunction in cancer patients: beyond direct cardiomyocyte damage of anticancer drugs: novel cardio-oncology insights from the joint 2019 meeting of the ESC Working Groups of Myocardial Function and Cellular Biology of the Heart

In western countries, cardiovascular (CV) disease and cancer are the leading causes of death in the ageing population. Recent epidemiological data suggest that cancer is more frequent in patients with prevalent or incident CV disease, in particular, heart failure (HF). Indeed, there is a tight link in terms of shared risk factors and mechanisms between HF and cancer. HF induced by anticancer therapies has been extensively studied, primarily focusing on the toxic effects that anti-tumour treatments exert on cardiomyocytes. In this Cardio-Oncology update, members of the ESC Working Groups of Myocardial Function and Cellular Biology of the Heart discuss novel evidence interconnecting cardiac dysfunction and cancer via pathways in which cardiomyocytes may be involved but are not central. In particular, the multiple roles of cardiac stromal cells (endothelial cells and fibroblasts) and inflammatory cells are highlighted. Also, the gut microbiota is depicted as a new player at the crossroads between HF and cancer. Finally, the role of non-coding RNAs in Cardio-Oncology is also addressed. All these insights are expected to fuel additional research efforts in the field of Cardio-Oncology.

The Role of Biomarkers in Cardio-Oncology

In the field of cardio-oncology, it is well recognised that despite the benefits of chemotherapy in treating and possibly curing cancer, it can cause catastrophic damage to bystander tissues resulting in a range of potentially of life-threatening cardiovascular toxicities, and leading to a number of damaging side effects including heart failure and myocardial infarction. Cardiotoxicity is responsible for significant morbidity and mortality in the long-term in oncology patients, specifically due to left ventricular dysfunction. There is increasing emphasis on the early use of biomarkers in order to detect the cardiotoxicity at a stage before it becomes irreversible. The most important markers of cardiac injury are cardiac troponin and natriuretic peptides, whilst markers of inflammation such as interleukin-6, C-reactive protein, myeloperoxidase, Galectin-3, growth differentiation factor-15 are under investigation for their use in detecting cardiotoxicity early. In addition, microRNAs, genome-wide association studies and proteomics are being studied as novel markers of cardiovascular injury or inflammation. The aim of this literature review is to discuss the evidence base behind the use of these biomarkers for the detection of cardiotoxicity.

Cardiovascular toxicity induced by anti-VEGF/VEGFR agents: a special focus on definitions, diagnoses, mechanisms and management

INTRODUCTION

Vascular endothelial growth factor (VEGF) is a key target in cancer therapy. However, cardiovascular safety has been one of the most challenging aspects of anti-VEGF/VEGF receptor (VEGFR) agent development and therapy. While accurate diagnostic modalities for assessment of cardiac function have been developed over the past few decades, a lack of an optimal definition and precise mechanism still places a significant limit on the effective management of cardiovascular toxicity.

AREAS COVERED

Here, we report the cardiovascular toxicity profile associated with anti-VEGF/VEGFR agents and summarize the clinical diagnoses as well as management that are already performed in clinical practice or are currently being investigated. Furthermore, the review discusses the potential molecular toxicological mechanisms, which may provide strategies to prevent toxicity and drive drug discovery.

EXPERT OPINION

Cardiovascular toxicity associated with anti-VEGF/VEGFR agents has been a substantial risk for cancer treatment. To improve its management, the development of guidelines for prevention, monitoring and treatment of cardiovascular toxicity has become a hot topic. The summary of cardiovascular toxicity profile, mechanisms and management given in this review is not only significant for the optimal use of existing anti-VEGF/VEGFR agents to protect patients predisposed to cardiovascular toxicity but is also beneficial for drug development.

The Role of Antioxidants in Ameliorating Cyclophosphamide-Induced Cardiotoxicity

The chemotherapeutic and immunosuppressive agent cyclophosphamide has previously been shown to induce complications within the setting of bone marrow transplantation. More recently, cardiotoxicity has been shown to be a dose-limiting factor during cyclophosphamide therapy, and cardiooncology is getting wider attention. Though mechanism of cyclophosphamide-induced cardiotoxicity is not completely understood, it is thought to encompass oxidative and nitrative stress. As such, this review focuses on antioxidants and their role in preventing or ameliorating cyclophosphamide-induced cardiotoxicity. It will give special emphasis to the cardioprotective effects of natural, plant-derived antioxidants that have garnered significant interest in recent times.

Cardiovascular Outcomes in Relation to Antihypertensive Medication Use in Women with and Without Cancer: Results from the Women's Health Initiative

BACKGROUND

Recent clinical trials have evaluated angiotensin-converting enzyme (ACE) inhibitors (ACEis), angiotensin receptor blockers (ARBs), and beta blockers (BBs) in relation to cardiotoxicity in patients with cancer, typically defined by ejection fraction declines. However, these trials have not examined long-term, hard clinical endpoints. Within a prospective study, we examined the risk of heart failure (HF) and coronary heart disease (CHD) events in relation to use of commonly used antihypertensive medications, including ACEis/ARBs, BBs, calcium channel blockers (CCB), and diuretics, comparing women with and without cancer.

MATERIALS AND METHODS

In a cohort of 56,997 Women's Health Initiative study participants free of cardiovascular disease who received antihypertensive treatment, we used multivariable-adjusted Cox regression models to calculate the hazard ratios (HRs) of developing CHD, HF, and a composite outcome of cardiac events (combining CHD and HF) in relation to use of ACEis/ARBs, CCBs, or diuretics versus BBs, separately in women with and without cancer.

RESULTS

Whereas there was no difference in risk of cardiac events comparing ACEi/ARB with BB use among cancer-free women (HR = 0.99 [0.88-1.12]), among cancer survivors ACEi/ARB users were at a 2.24-fold risk of total cardiac events (1.18-4.24); p-interaction = .06). When investigated in relation to CHD only, an increased risk was similarly observed in ACEi/ARB versus BB use for cancer survivors (HR = 1.87 [0.88-3.95]) but not in cancer-free women (HR = 0.91 [0.79-1.06]; p-interaction = .04). A similar pattern was also seen in relation to HF but did not reach statistical significance (p-interaction = .23).

CONCLUSION

These results from this observational study suggest differing risks of cardiac events in relation to antihypertensive medications depending on history of cancer. Although these results require replication before becoming actionable in a clinical setting, they suggest the need for more rigorous examination of the effect of antihypertensive choice on long-term cardiac outcomes in cancer survivors.

IMPLICATIONS FOR PRACTICE

Although additional research is needed to replicate these findings, these data from a large, nationally representative sample of postmenopausal women indicate that beta blockers are favorable to angiotensin-converting enzyme inhibitors in reducing the risk of cardiac events among cancer survivors. This differs from the patterns observed in a noncancer cohort, which largely mirrors what is found in the randomized clinical trials in the general population.

The effect of adenosine triphosphate on sunitinib-induced cardiac injury in rats

In this study, we aimed to show the effect of adenosine 5'-triphosphate (ATP) on sunitinib-induced cardiac injury in rats. The rats (n = 30) were divided equally into three groups as sunitinib group (SG), sunitinib plus ATP group (SAG), and healthy group (HG); 2 mg/kg ATP was injected intraperitoneally (ip) to the SAG group. Same volume normal saline as solvent was administered ip to the other two groups. After 1 h, 25 mg/kg sunitinib was applied orally via catheter to stomach in the SAG and SG groups. This procedure was repeated once daily for 5 weeks. At the end of this period, all animals were sacrificed and their cardiac tissue was removed. Malondialdehyde (MDA), total glutathione (tGSH), tumor necrosis factor α (TNF-α), and nuclear factor κB (NF-κB) levels in rats' cardiac tissues and troponin I (Tp-I) levels in rats' blood samples were evaluated. Histopathological analysis was also performed in cardiac tissues of the animals. MDA, TNF-α, NF-κB, and Tp-I levels were higher in the SG group compared to the SAG and HG groups (p < 0.001). tGSH levels of the SG group were lower than the SAG and HG groups (p < 0.001). The structure and morphology of cardiac muscle fibers and blood vessels were normal in the control group. In the SG group, obvious cardiac muscle tissue damage with dilated myofibers, locally atrophic myofibers, and congested blood vessels were observed. In the SAG group, marked amelioration in these findings was observed. We showed this for the first time that ATP administration exerts a protective effect against cardiac effects of sunitinib.

From Molecular Mechanisms to Clinical Management of Antineoplastic Drug-Induced Cardiovascular Toxicity: A Translational Overview

Significance: Antineoplastic therapies have significantly improved the prognosis of oncology patients. However, these treatments can bring to a higher incidence of side-effects, including the worrying cardiovascular toxicity (CTX). Recent Advances: Substantial evidence indicates multiple mechanisms of CTX, with redox mechanisms playing a key role. Recent data singled out mitochondria as key targets for antineoplastic drug-induced CTX; understanding the underlying mechanisms is, therefore, crucial for effective cardioprotection, without compromising the efficacy of anti-cancer treatments. Critical Issues: CTX can occur within a few days or many years after treatment. Type I CTX is associated with irreversible cardiac cell injury, and it is typically caused by anthracyclines and traditional chemotherapeutics. Type II CTX is generally caused by novel biologics and more targeted drugs, and it is associated with reversible myocardial dysfunction. Therefore, patients undergoing anti-cancer treatments should be closely monitored, and patients at risk of CTX should be identified before beginning treatment to reduce CTX-related morbidity. Future Directions: Genetic profiling of clinical risk factors and an integrated approach using molecular, imaging, and clinical data may allow the recognition of patients who are at a high risk of developing chemotherapy-related CTX, and it may suggest methodologies to limit damage in a wider range of patients. The involvement of redox mechanisms in cancer biology and anticancer treatments is a very active field of research. Further investigations will be necessary to uncover the hallmarks of cancer from a redox perspective and to develop more efficacious antineoplastic therapies that also spare the cardiovascular system.

Nintedanib in Idiopathic Pulmonary Fibrosis: Practical Management Recommendations for Potential Adverse Events

Idiopathic pulmonary fibrosis (IPF) is a fatal lung disease with a dismal survival rate of only 3 years and no curative pharmacological therapy. The recent approval of 2 anti-fibrotic drugs (nintedanib and pirfenidone) that slow disease progression has provided some hope for patients. However, effectively managing anti-fibrotic treatment can be a challenge due to tolerability issues, the presence of pulmonary and extra-pulmonary comorbidities, and the need for concomitant medications in many patients. In general, making clear evidence-based decisions can be difficult for physicians because patients with comorbidities are often excluded from clinical trials. Since currently anti-fibrotic drugs are the only effective therapeutics capable of slowing disease progression, it is imperative that all treatment options are thoroughly evaluated and exhausted in each individual, irrespective of complicating factors, to permit the best outcome for the patient. In this review, we present data from clinical trials, post hoc analyses, post-marketing surveillance, and real-world studies that are relevant to the management of nintedanib treatment. In addition, we also provide practical recommendations developed by a multidisciplinary panel of experts for the management of nintedanib treatment in patients with IPF associated complications and those experiencing gastrointestinal side effects.

Human-Induced Pluripotent Stem Cell Technology and Cardiomyocyte Generation: Progress and Clinical Applications

Human-induced pluripotent stem cells (hiPSCs) are reprogrammed cells that have hallmarks similar to embryonic stem cells including the capacity of self-renewal and differentiation into cardiac myocytes. The improvements in reprogramming and differentiating methods achieved in the past 10 years widened the use of hiPSCs, especially in cardiac research. hiPSC-derived cardiac myocytes (CMs) recapitulate phenotypic differences caused by genetic variations, making them attractive human disease models and useful tools for drug discovery and toxicology testing. In addition, hiPSCs can be used as sources of cells for cardiac regeneration in animal models. Here, we review the advances in the genetic and epigenetic control of cardiomyogenesis that underlies the significant improvement of the induced reprogramming of somatic cells to CMs; the methods used to improve scalability of throughput assays for functional screening and drug testing in vitro; the phenotypic characteristics of hiPSCs-derived CMs and their ability to rescue injured CMs through paracrine effects; we also cover the novel approaches in tissue engineering for hiPSC-derived cardiac tissue generation, and finally, their immunological features and the potential use in biomedical applications.

Antineoplastic Drug-Induced Cardiotoxicity: A Redox Perspective

Antineoplastic drugs can be associated with several side effects, including cardiovascular toxicity (CTX). Biochemical studies have identified multiple mechanisms of CTX. Chemoterapeutic agents can alter redox homeostasis by increasing the production of reactive oxygen species (ROS) and reactive nitrogen species RNS. Cellular sources of ROS/RNS are cardiomyocytes, endothelial cells, stromal and inflammatory cells in the heart. Mitochondria, peroxisomes and other subcellular components are central hubs that control redox homeostasis. Mitochondria are central targets for antineoplastic drug-induced CTX. Understanding the mechanisms of CTX is fundamental for effective cardioprotection, without compromising the efficacy of anticancer treatments. Type 1 CTX is associated with irreversible cardiac cell injury and is typically caused by anthracyclines and conventional chemotherapeutic agents. Type 2 CTX, associated with reversible myocardial dysfunction, is generally caused by biologicals and targeted drugs. Although oxidative/nitrosative reactions play a central role in CTX caused by different antineoplastic drugs, additional mechanisms involving directly and indirectly cardiomyocytes and inflammatory cells play a role in cardiovascular toxicities. Identification of cardiologic risk factors and an integrated approach using molecular, imaging, and clinical data may allow the selection of patients at risk of developing chemotherapy-related CTX. Although the last decade has witnessed intense research related to the molecular and biochemical mechanisms of CTX of antineoplastic drugs, experimental and clinical studies are urgently needed to balance safety and efficacy of novel cancer therapies.

Cardiotoxicity of Anticancer Therapeutics

As cancer therapeutics continues to improve and progress, the adverse side effects associated with anticancer treatments have also attracted more attention and have become extensively explored. Consequently, the importance of posttreatment follow-ups is becoming increasingly relevant to the discussion. Contemporary treatment methods, such as tyrosine kinase inhibitors, anthracycline chemotherapy, and immunotherapy regimens are effective in treating different modalities of cancers; however, these reagents act through interference with DNA replication or prevent DNA repair, causing endothelial dysfunction, generating reactive oxygen species, or eliciting non-specific immune responses. Therefore, cardiotoxic effects, such as hypertension, heart failure, and left ventricular dysfunction, arise posttreatment. Rising awareness of cardiovascular complications has led to meticulous attention for the evolution of treatment strategies and carefully monitoring between enhanced treatment effectiveness and minimization of adverse toxicity to the cardiovasculature, in which psychological assessments, early detection methods such as biomarkers, magnetic resonance imaging, and various drugs to reverse the damage from cardiotoxic events are more prevalent and their emphasis has increased tremendously. Fully understanding the mechanisms by which the risk factors action for various patients undergoing cancer treatment is also becoming more prevalent in preventing cardiotoxicity down the line.

Precision cardio-oncology: understanding the cardiotoxicity of cancer therapy

Current oncologic treatments have brought a strong reduction in mortality in cancer patients. However, the cancer therapy-related cardiovascular complications, in particular chemo-therapy and radiation therapy-induced cardiotoxicities are a major cause of morbidity and mortality in people living with or surviving cancer. The simple fact is that all antineoplastic agents and radiation therapy target tumor cells but also result in collateral damage to other tissues including the cardiovascular system. The commonly used anthracycline chemotherapy agents can induce cardiomyopathy and congestive heart failure. Targeted therapies with human epidermal growth factor antibodies, tyrosine kinase inhibitors or vascular endothelial growth factor antibodies, and the antimetabolites also have shown to induce cardiomyopathy and myocardial ischemia. Cardiac arrhythmias and hypertension have been well described with the use of tyrosine kinase inhibitors and antimicrotubule agents. Pericarditis can happen with the use of cyclophosphamide or cytarabine. Mediastinal radiation can cause constrictive pericarditis, myocardial fibrosis, valvular lesions, and coronary artery disease. Despite significant progresses in the understanding of the molecular and pathophysiologic mechanisms behind the cardiovascular toxicity of cancer therapy, there is still lack of evidence-based approach for the monitoring and management of patients. This review will focus mainly on the recent advances in the molecular mechanisms of cardiotoxicity related to common cancer therapies while introducing the concept of cardio-oncology service. Applying the general principles of multi-disciplinary approaches toward the diagnosis, prevention, monitoring, and treatment of cancer therapy-induced cardiomyopathy and heart failure will also be discussed.

Cardiac autonomic modulation induced by doxorubicin in a rodent model of colorectal cancer and the influence of fullerenol pretreatment

The very effective anticancer drug doxorubicin (DOX) is known to have cardiotoxic side effects, which could be accompanied by autonomic modulation. Autonomic disbalance might even be an initiating mechanism underlying DOX-induced cardiotoxicity and can be studied noninvasively by the analysis of heart rate variability (HRV). A number of strategies have been assessed to predict chemotherapy-induced cardiac dysfunction while HRV, a potential detecting tool, has not yet been tested. Thus, we aimed to determine the effect of DOX treatment on HRV in a rat model of colorectal cancer. While pretreatment with fullerenol (Frl) acts protectively on DOX-induced cardiotoxicity, we aimed to test the effect of Frl pretreatment on DOX-induced HRV alterations. After the induction of colorectal cancer, adult male Wistar rats were treated with saline (n = 7), DOX (1.5 mg/kg per week, n = 7) or DOX after pretreatment with Frl (25 mg/kg per week, n = 7) for three weeks (cumulative DOX dose 4.5 mg/kg). One week after treatment rats were anaesthetized, standard ECG was measured and HRV was analyzed in time and frequency domain. During autopsy the intestines and hearts were gathered for biochemical analysis and histopathological examination. DOX treatment significantly decreased parasympathetically mediated high-frequency component (p<0.05) and increased the low-frequency component of HRV (p<0.05), resulting in an increased LF/HF ratio (p<0.05) in cancerous rats. When pretreated with Frl, DOX-induced HRV alterations were prevented: the high-frequency component of HRV increased (p<0.01), the low-frequency decreased (p<0.01), LF/HF ratio decreased consequently (p<0.01) compared to DOX only treatment. In all DOX-treated animals, disbalance of oxidative status in heart tissue and early myocardial lesions were found and were significantly reduced in rats receiving Frl pretreatment. Autonomic modulation accompanied the development of DOX-induced cardiotoxicity in rat model of colorectal cancer and was prevented by Frl pretreatment. Our results demonstrated the positive prognostic power of HRV for the early detection of DOX-induced cardiotoxicity.

Fetal and perinatal stem cells in cardiac regeneration: Moving forward to the paracrine era

Cardiovascular disease (CD) is a major burden for Western society. Regenerative medicine has provided encouraging results, yet it has not addressed the focal defects causing CD and mainly related to the inefficient repair programme of the heart. In this scenario, stem cells have been broadly investigated and their paracrine effect proposed as a possible working strategy to boost endogenous mechanisms of repair and regeneration from within the cardiac tissue. The scientific community is now focusing on identifying the most effective stem cell secretome, as the whole of bioactive factors and extracellular vesicles secreted by stem cells and endowed with regenerative potential. Indeed, the adult stem cell-paracrine potential for cardiac regeneration have been widely analyzed with positive outcome. Nevertheless, low yield, invasive sampling and controversial self-renewal may limit adult stem cell application. On the contrary, fetal and perinatal stem cells, which can be easily isolated from leftover sample via prenatal screening during gestation or as clinical waste material after birth, can offer an ideal alternative. These broadly multipotent immature progenitors share features with both adult and embryonic stem cells, show high self-renewal, but they are not tumorigenic neither cause any ethical concern. While fetal and perinatal stem cells demonstrated to improve cardiac function when injected in the injured heart, the comprehensive characterization of their secretome for future applications is still at its infancy. In this review, we will discuss the paracrine potential of the fetal and perinatal stem cell secretome to provide cardiac repair and resurge the dormant mechanisms of cardiac regeneration for future therapy.

ER Protein Quality Control and the Unfolded Protein Response in the Heart

Cardiac myocytes are the cells responsible for the robust ability of the heart to pump blood throughout the circulatory system. Cardiac myocytes grow in response to a variety of physiological and pathological conditions; this growth challenges endoplasmic reticulum-protein quality control (ER-PQC), a major feature of which includes the unfolded protein response (UPR). ER-PQC and the UPR in cardiac myocytes growing under physiological conditions, including normal development, exercise, and pregnancy, are sufficient to support hypertrophic growth of each cardiac myocyte. However, the ER-PQC and UPR are insufficient to respond to the challenge of cardiac myocyte growth under pathological conditions, including myocardial infarction and heart failure. In part, this insufficiency is due to a continual decline in the expression levels of important adaptive UPR components as a function of age and during myocardial pathology. This chapter will discuss the physiological and pathological conditions unique to the heart that involves ER-PQC, and whether the UPR is adaptive or maladaptive under these circumstances.

Anticancer therapy-induced vascular toxicity: VEGF inhibition and beyond

Cardiotoxicity induced by chemotherapeutic agents and radiotherapy is a growing problem. In recent years, an increasing number of new drugs with targeted action have been designed. These molecules, such as monoclonal antibodies and tyrosine kinase inhibitors, can cause different type of toxicities compared to traditional chemotherapy. However, they can also cause cardiac complications such as heart failure, arterial hypertension, QT interval prolongation and arrhythmias. Currently, a field of intense research is the vascular toxicity induced by new biologic drugs, particularly those which inhibit vascular endothelial growth factor (VEGF) and its receptor (VEGF-R) and other tyrosine kinases. In this review, we aim at focusing on the problem of vascular toxicity induced by new targeted therapies, chemotherapy and radiotherapy, and describe the main mechanisms and emphasizing the importance of early diagnosis of vascular damage, in order to prevent clinical complications.

The Effects of CYP2C19 genotype on the susceptibility for nephrosis in cardio-cerebral vascular disease treated by anticoagulation

In recent years, the genetic factor has become one of the important predisposing factors of nephropathy susceptibility. There is a high incidence of nephropathy in CCVd. The CYP2C19 enzyme metabolizes most the drugs, including proton pump inhibitors commonly used medicines to treat CCVd, CYP2C19 genetic polymorphisms is association with multi-pathogenesis factors of nephropathy. The purpose of the study is to reveal the association between CYP2C19 genotype and the susceptibility of nephropathy in the CCVd patients. The study is composed of 623 samples from CCVd treated by anticoagulation. The patients were studied, including CCVd with hyperuricemia, coronary heart disease, diabetes, and other complication. Biochemical tests and CYP2C19 variants measurements were performed by the gene chip method. The association among CYP2C19 variants, complications, and nephropathy was analyzed in the CCVd. There is no correlation between nephropathy and complications in CCVd. In hyperuricemia, coronary heart disease and diabetes groups, the differences of renal function tests were significant between CYP2C19 mutant (P < 0.05). The nephropathy risk of wild genotype is 3.288 times higher than of mutation genotype in hyperuricemic group, 1.928 times higher than mutation genotype in coronary heart disease group, and 5.248 times higher than CYP2C19 mutation genotype in the diabetic group. There was significant correlation between the CYP2C19 wild type and the nephropathy susceptibility in CCVd patients. The CYP2C19 gene plays a potential maker to evaluate nephropathy in CCVd patients. We deduced that identification of CYP2C19 gene type may benefit for reducing and avoiding nephropathy caused by abnormal metabolism function in CCVd patients.

Progress on the cardiotoxicity of sunitinib: Prognostic significance, mechanism and protective therapies

Tyrosine kinase inhibitors (TKIs) are multi-targeted anti-cancer agents effective in the treatment of renal cell carcinoma (RCC), imatinib-resistant gastrointestinal stromal tumor (GIST) and pancreatic cancer (PC). Targeting and inhibiting a wide range of oncogenically relevant receptor tyrosine kinases (RTKs), TKIs have been the golden standard treatment of several types of cancer. The cardiotoxicity of TKIs, however, has also emerged alongside their anti-cancer potencies and has attracted research attention. Over the past few years significant progress has been made in developing a deeper understanding of aspects such as extent of cardiotoxicity, prognostic implications and survival predictions, toxicological mechanisms, and potential cardioprotective therapies. In this review we focus on a typical TKI sunitinib and summarize the up-to-date knowledge of sunitinib-induced cardiac abnormalities reported in clinical studies, weighing their implications of prognostic values. We also examine recent findings in underlying mechanisms, and development of potential cardioprotective agents.

Cancer drug related cardiotoxicity during breast cancer treatment

INTRODUCTION

Breast cancer (BC) is the most common cancer in women. Although therapeutic armamentarium like chemotherapy, endocrine and target agents have increased survival, cardiovascular side effects have been observed. A comprehensive risk assessment, early detection and management of cardiac adverse events is therefore needed.

AREAS COVERED

In this review we focus on cardiotoxicity data deriving from Phase III randomized trials, systematic reviews and meta-analysis in BC patients. We provide insight into advances that have been made in the molecular mechanisms, clinical presentation and management of such adverse event.

EXPERT OPINION

Despite the large number of data from Phase III trials about cardiac events incidence, there are poor evidences for detection, monitoring and management of cardiotoxicity during BC treatment. Future cardiotoxicity-oriented clinical cancer research can help to predict the risk of cardiac adverse events and improve patients' outcome. Multidisciplinary approach as well as integration of blood biomarkers with imaging will be desirable.

The human amniotic fluid stem cell secretome effectively counteracts doxorubicin-induced cardiotoxicity

The anthracycline doxorubicin (Dox) is widely used in oncology, but it may cause a cardiomyopathy with bleak prognosis that cannot be effectively prevented. The secretome of human amniotic fluid-derived stem cells (hAFS) has previously been demonstrated to significantly reduce ischemic cardiac damage. Here it is shown that, following hypoxic preconditioning, hAFS conditioned medium (hAFS-CM) antagonizes senescence and apoptosis of cardiomyocytes and cardiac progenitor cells, two major features of Dox cardiotoxicity. Mechanistic studies with mouse neonatal ventricular cardiomyocytes (mNVCM) reveal that hAFS-CM inhibition of Dox-elicited senescence and apoptosis is associated with decreased DNA damage, nuclear translocation of NF-kB, and upregulation of the NF-kB controlled genes, Il6 and Cxcl1, promoting mNVCM survival. Furthermore, hAFS-CM induces expression of the efflux transporter, Abcb1b, and Dox extrusion from mNVCM. The PI3K/Akt signaling cascade, upstream of NF-kB, is potently activated by hAFS-CM and pre-treatment with a PI3K inhibitor abrogates NF-kB accumulation into the nucleus, modulation of Il6, Cxcl1 and Abcb1b, and prevention of Dox-initiated senescence and apoptosis in response to hAFS-CM. These results support the concept that hAFS are a valuable source of cardioprotective factors and lay the foundations for the development of a stem cell-based paracrine treatment of chemotherapy-related cardiotoxicity.

Cardiac toxicity of trastuzumab in elderly patients with breast cancer

Breast cancer (BC) is diagnosed in ≥ 65 year old women in about half of cases. Experts currently recommend that systemic therapy is offered to elderly patients with BC, if, based on their overall conditions and life expectancy, it can be reasonably anticipated that the benefits will outweigh the risks of treatment. Like for young subjects, the monoclonal antibody against human epidermal growth factor receptor-2 (HER-2), trastuzumab, represents a valid therapeutic option when BC over-expresses this receptor. Unfortunately, administration of trastuzumab is associated with the occurrence of left ventricular dysfunction and chronic heart failure (CHF), possibly because of interference with the homeostatic functions of HER-2 in the heart. Registry-based, retrospective analyses have reported an incidence of CHF around 25% in elderly women receiving trastuzumab compared with 10%-15% in those not given any therapy for BC, and the risk of CHF has been estimated to be two-fold higher in > 60-65 year old trastuzumab users vs. non-users. Extremely advanced age and preexisting cardiac disease have been shown to predispose to trastuzumab cardiotoxicity. Therefore, selection of older patients for treatment with trastuzumab should be primarily based on their general status and the presence of comorbidities; previous chemotherapy, especially with anthracyclines, should be also taken into account. Once therapy has started, efforts should be made to ensure regular cardiac surveillance. The role of selected biomarkers, such as cardiac troponin, or new imaging techniques (three-dimension, tissue Doppler echocardiography, magnetic resonance imaging) is promising, but must be further investigated especially in the elderly. Moreover, additional studies are needed in order to better understand the mechanisms by which trastuzumab affects the old heart.

Models of Heart Failure Based on the Cardiotoxicity of Anticancer Drugs

Heart failure (HF) is a complication of oncological treatments that may have dramatic clinical impact. It may acutely worsen a patient's condition or it may present with delayed onset, even years after treatment, when cancer has been cured or is in stable remission. Several studies have addressed the mechanisms of cancer therapy-related HF and some have led to the definition of disease models that hold valid for other and more common types of HF. Here, we review these models of HF based on the cardiotoxicity of antineoplastic drugs and classify them in cardiomyocyte-intrinsic, paracrine, or potentially secondary to effects on cardiac progenitor cells. The first group includes HF resulting from the combination of oxidative stress, mitochondrial dysfunction, and activation of the DNA damage response, which is typically caused by anthracyclines, and HF resulting from deranged myocardial energetics, such as that triggered by anthracyclines and sunitinib. Blockade of the neuregulin-1/ErbB4/ErbB2, vascular endothelial growth factor/vascular endothelial growth factor receptor and platelet-derived growth factor /platelet-derived growth factor receptor pathways by trastuzumab, sorafenib and sunitinib is proposed as paradigm of cancer therapy-related HF associated with alterations of myocardial paracrine pathways. Finally, anthracyclines and trastuzumab are also presented as examples of antitumor agents that induce HF by affecting the cardiac progenitor cell population.

Targeting endothelial cell metabolism for cardio-protection from the toxicity of antitumor agents

The vascular endothelium plays a fundamental role in the maintenance of tissue homeostasis, regulating local blood flow and other physiological processes. Chemotherapeutic drugs and target therapies, including antiangiogenic drugs targeting vascular endothelial growth factor (VEGF) or its receptors, not only efficiently act against tumor growth, but may also induce endothelial dysfunction and cardiovascular toxicity. Continued research efforts aim to better understand, prevent and mitigate these chemotherapy associated cardiovascular diseases. Conventional chemotherapeutic agents, such as anthracyclines, platinum compounds, and taxanes, and newer targeted agents, such as bevacizumab, trastuzumab, and tyrosine kinase inhibitors, have known risk of cardiovascular toxicity, which can limit their effectiveness by promoting increased morbidity and/or mortality. This review describes a) the activity of anticancer agents in inducing endothelial dysfunction, b) the metabolic pathways and signalling cascades which may be targeted by protective agents able to maintain or restore endothelial cell function, such as endothelial nitric oxide synthase/fibroblast growth factor-2 (eNOS-FGF-2) pathway, and c) the drugs/strategies reported to improve endothelial function and to reduce the risks of cardiovascular diseases such as angiotensin converting enzyme inhibitors (ACEi) and beta blockers, that are fundamental therapies in chronic heart failure (HF), as well as non-standard HF treatments such ad nitric oxide donors and antioxidant strategies. There is increasing interest in whether ACEi, beta-blockers, and/or statins might prevent and/or therapeutically control cardiotoxic effects in cancer patients. Maintaining endothelial function during or following treatments with chemotherapeutic agents, without affecting anti-tumor drug-effectiveness, is essential for preserving or recovering cardiovascular homeostasis. In this respect, the early detection and immediate therapy of cardiovascular toxicity appear crucial for substantial recovery of cardiac function in cancer patients.