Mechanisms of Cardiotoxicity of Cancer Chemotherapeutic Agents: Cardiomyopathy and Beyond

In-depth mechanistic analysis including high-throughput RNA sequencing in the prediction of functional and structural cardiotoxicants using hiPSC cardiomyocytes

BACKGROUND

Cardiotoxicity remains one of the most reported adverse drug reactions that lead to drug attrition during pre-clinical and clinical drug development. Drug-induced cardiotoxicity may develop as a functional change in cardiac electrophysiology (acute alteration of the mechanical function of the myocardium) and/or as a structural change, resulting in loss of viability and morphological damage to cardiac tissue.

RESEARCH DESIGN AND METHODS

Non-clinical models with better predictive value need to be established to improve cardiac safety pharmacology. To this end, high-throughput RNA sequencing (ScreenSeq) was combined with high-content imaging (HCI) and Ca2+ transience (CaT) to analyze compound-treated human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs).

RESULTS

Analysis of hiPSC-CMs treated with 33 cardiotoxicants and 9 non-cardiotoxicants of mixed therapeutic indications facilitated compound clustering by mechanism of action, scoring of pathway activities related to cardiomyocyte contractility, mitochondrial integrity, metabolic state, diverse stress responses and the prediction of cardiotoxicity risk. The combination of ScreenSeq, HCI and CaT provided a high cardiotoxicity prediction performance with 89% specificity, 91% sensitivity and 90% accuracy.

CONCLUSIONS

Overall, this study introduces mechanism-driven risk assessment approach combining structural, functional and molecular high-throughput methods for pre-clinical risk assessment of novel compounds.

The small molecule raptinal can simultaneously induce apoptosis and inhibit PANX1 activity

Discovery of new small molecules that can activate distinct programmed cell death pathway is of significant interest as a research tool and for the development of novel therapeutics for pathological conditions such as cancer and infectious diseases. The small molecule raptinal was discovered as a pro-apoptotic compound that can rapidly trigger apoptosis by promoting the release of cytochrome c from the mitochondria and subsequently activating the intrinsic apoptotic pathway. As raptinal is very effective at inducing apoptosis in a variety of different cell types in vitro and in vivo, it has been used in many studies investigating cell death as well as the clearance of dying cells. While examining raptinal as an apoptosis inducer, we unexpectedly identified that in addition to its pro-apoptotic activities, raptinal can also inhibit the activity of caspase-activated Pannexin 1 (PANX1), a ubiquitously expressed transmembrane channel that regulates many cell death-associated processes. By implementing numerous biochemical, cell biological and electrophysiological approaches, we discovered that raptinal can simultaneously induce apoptosis and inhibit PANX1 activity. Surprisingly, raptinal was found to inhibit cleavage-activated PANX1 via a mechanism distinct to other well-described PANX1 inhibitors such as carbenoxolone and trovafloxacin. Furthermore, raptinal also interfered with PANX1-regulated apoptotic processes including the release of the 'find-me' signal ATP, the formation of apoptotic cell-derived extracellular vesicles, as well as NLRP3 inflammasome activation. Taken together, these data identify raptinal as the first compound that can simultaneously induce apoptosis and inhibit PANX1 channels. This has broad implications for the use of raptinal in cell death studies as well as in the development new PANX1 inhibitors.

Major adverse cardiovascular events in advanced-stage lung cancer: a multicenter cohort study

Background

Lung cancers are common worldwide. First-line targeted therapy and chemotherapy are both standard treatments in the current guidelines. With the development of new anticancer therapy, the lifespan of patients with late-stage lung cancer has increased. Cardiovascular events can occur during cancer treatment. This observational study aimed to report the incidence of major adverse cardiovascular events (MACE) after cancer treatment using real-world data.

Objectives

Patients diagnosed with advanced-stage lung cancer between January 2011 and December 2017 were enrolled. Data were collected from the Chang Gung Research Database (CGRD).

Design

Retrospective cohort study.

Methods

Baseline characteristics, clinical stages, pathologies, and outcomes were retrieved from the CGRD.

Results

We identified 4406 patients with advanced lung cancer, of whom 2197 received first-line epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) therapy and 2209 received first-line platinum-based chemotherapy. Most patients in the first-line EGFR-TKI group were never-smokers (74.9%), whereas those in the first-line chemotherapy group were ever-smokers (66.0%). The incidence of MACE was not significantly different between the two groups (12.0% versus 11.9%, p = 0.910). However, the incidence of ischemic stroke was higher in the first-line EGFR-TKI group than in the first-line chemotherapy group (3.9% versus 1.9%, p < 0.001).

Conclusion

MACEs are common in patients with advanced-stage lung cancer during treatment. The incidence of MACE was similar between the first-line EGFR-TKI therapy and first-line chemotherapy groups. Although more patients in the EGFR-TKI group were female and never-smokers, the risk of ischemic stroke was higher in patients who received first-line EGFR-TKI therapy than in those who received first-line chemotherapy.

Protection against cancer therapy-induced cardiovascular injury by planed-derived polyphenols and nanomaterials

Cancer therapy-induced heart injury is a significant concern for cancer patients undergoing chemotherapy, radiotherapy, immunotherapy, and also targeted molecular therapy. The use of these treatments can lead to oxidative stress and cardiomyocyte damage in the heart, which can result in heart failure and other cardiac complications. Experimental studies have revealed that chemotherapy drugs such as doxorubicin and cyclophosphamide can cause severe side effects such as cardiac fibrosis, electrophysiological remodeling, chronic oxidative stress and inflammation, etc., which may increase risk of cardiac disorders and attacks for patients that underwent chemotherapy. Similar consequences may also be observed for patients that undergo radiotherapy for left breast or lung malignancies. Polyphenols, a group of natural compounds with antioxidant and anti-inflammatory properties, have shown the potential in protecting against cancer therapy-induced heart injury. These compounds have been found to reduce oxidative stress, necrosis and apoptosis in the heart, thereby preserving cardiac function. In recent years, nanoparticles loaded with polyphenols have also provided for the delivery of these compounds and increasing their efficacy in different organs. These nanoparticles can improve the bioavailability and efficacy of polyphenols while minimizing their toxicity. This review article summarizes the current understanding of the protective effects of polyphenols and nanoparticles loaded with polyphenols against cancer therapy-induced heart injury. The article discusses the mechanisms by which polyphenols protect the heart, including antioxidant and anti-inflammation abilities. The article also highlights the potential benefits of using nanoparticles for the delivery of polyphenols.

Supportive Care in Older Lymphoma Patients to Reduce Toxicity and Preserve Quality of Life

The treatment paradigm in older patients with malignant hemopathies is the choice between an effective conservative treatment that preserves quality of life and an intensive, potentially curative treatment with more toxicities. For each patient, it is important to determine the risk/benefit ratio. The patient should be involved in the discussion, sufficiently informed and able to express himself and his expectations in terms of quality of life. However, this informed consent is conditioned by the ability of the patient to understand the risks and benefits of the treatment. Decline in quality of life is an important parameter for older patients with cancer and many prospective trials have now confirmed the impact of different side effects of treatment, such as recurrent hospitalization, loss of autonomy in daily activities, loss of contact with grandchildren and loss of cognitive functions. Interventions oriented to vulnerabilities detected in the older patients (by comprehensive geriatric assessment) and an optimal approach, including preventive measures to reduce treatment-related toxicity and mortality, are directly correlated to improvement in quality of life.

Transcriptome-based prediction of drugs, inhibiting cardiomyogenesis in human induced pluripotent stem cells

Animal studies for embryotoxicity evaluation of potential therapeutics and environmental factors are complex, costly, and time-consuming. Often, studies are not of human relevance because of species differences. In the present study, we recapitulated the process of cardiomyogenesis in human induced pluripotent stem cells (hiPSCs) by modulation of the Wnt signaling pathway to identify a key cardiomyogenesis gene signature that can be applied to identify compounds and/or stress factors compromising the cardiomyogenesis process. Among the 23 tested teratogens and 16 non-teratogens, we identified three retinoids including 13-cis-retinoic acid that completely block the process of cardiomyogenesis in hiPSCs. Moreover, we have identified an early gene signature consisting of 31 genes and associated biological processes that are severely affected by the retinoids. To predict the inhibitory potential of teratogens and non-teratogens in the process of cardiomyogenesis we established the "Developmental Cardiotoxicity Index" (CDI31g) that accurately differentiates teratogens and non-teratogens to do or do not affect the differentiation of hiPSCs to functional cardiomyocytes.

Long-term prognostic impact of cardiovascular comorbidities in patients with prostate cancer receiving androgen deprivation therapy: A population-based competing risk analysis

Our study investigated how adverse cardiovascular outcomes are impacted by cardiovascular comorbidities in patients with prostate cancer treated by androgen deprivation therapy (ADT). Using prospective, population-based data, all Hong Kong patients with prostate cancer who received ADT during 1 January 1993 to 3 March 2021 were identified and followed up for the endpoint of cardiovascular hospitalization/mortality until 31 September 2021, whichever earlier. Multivariable competing risk regression was used to compare the endpoint's cumulative incidence between different combinations of major cardiovascular comorbidities (heart failure [HF], myocardial infarction [MI], stroke and/or arrhythmia), with noncardiovascular death as competing event. Altogether, 13 537 patients were included (median age 75.9 [interquartile range 70.0-81.5] years old; median follow-up 3.3 [1.5-6.7] years). Compared to those with none of prior HF/MI/stroke/arrhythmia, the incidence of the endpoint was not different in those with only stroke (subhazard ratio [SHR] 1.06 [95% confidence interval (CI): 0.92-1.23], P = .391), but was higher in those with only HF (SHR 1.67 [1.37-2.02], P < .001), arrhythmia (SHR 1.63 [1.35-1.98], P < .001) or MI (SHR 1.43 [1.14-1.79], P = .002). Those with ≥2 of HF/MI/stroke/arrhythmia had the highest incidence of the endpoint (SHR 1.94 [1.62-2.33], P < .001), among whom different major cardiovascular comorbidities had similar prognostic impacts, with the number of comorbidities present being significantly prognostic instead. In conclusion, in patients with prostate cancer receiving ADT, the sole presence of HF, MI or arrhythmia, but not stroke, may be associated with elevated cardiovascular risks. In those with ≥2 of HF/MI/stroke/arrhythmia, the number of major cardiovascular comorbidities may be prognostically more important than the type of comorbidities.

Cancer Therapy-Related Cardiotoxicity: A Comprehensive Retrospective Analysis at Najran Cancer Center, Saudi Arabia

Background Cardiotoxicity, produced as an adverse effect of anticancer therapy, is a common issue during cancer treatment. Acute coronary syndrome, myocarditis, arrhythmias, or heart failure can all be symptoms of this issue. Little is known about its occurrence among Saudi Arabian cancer patients. This study aims to investigate factors linked to anticancer therapy-related cardiotoxicity. Methods A retrospective study was conducted from April 2020 to May 2022 at the King Khalid Hospital, Najran, Saudi Arabia. The study included adult cancer patients receiving anticancer therapy, regardless of their cardiovascular disease history. Univariate analysis was used to investigate factors associated with the occurrence of cardiotoxicity related to anticancer therapy. Results Of 78 patients receiving anticancer therapy, cardiotoxicity occurred in 12 (15.4%) patients. The mean age was 56.5 ± 13.4 years, with 33.3% aged over 65 years. Comorbidities included hypertension (44; 56.4%), diabetes (41; 52.6%), dyslipidemia (13; 16.7%), smoking (16; 20.5%), heart disease (6; 7.7%), trastuzumab use (9; 11.5%), and chronic kidney disease (2; 2.6%). The most common cancers were breast cancer and gastrointestinal cancer (27.6% each). Monoclonal anticancer agents 35 (46.1%) and alkylating agents 29 (38.2%) were commonly used chemotherapies. Cardiac protective agents were used in 16 (21.1%) of patients, with angiotensin-converting enzyme (ACE) inhibitors 15 (19.7%) and statins (13; 17.1%) being the most prescribed. Baseline ejection fraction (EF) was normal in 69 (90.8%) of cases. The follow-up duration was 1.93 ± 1.90 years. A drop in EF occurred in five (6.6%) of cases. Dyslipidemia (OR: 0.12; 95% CI: 0.03-0.47, p=0.002), previous heart disease (OR: 0.14; 95% CI: 0.02-0.81, p=0.029), and impaired baseline EF (p=0.029) were associated with increased risk of cardiotoxicity. Statin (OR: 0.22; 95% CI: 0.05 to 0.84, p=0.028) and antiplatelet agents (OR: 0.19; 95% CI: 0.03 to 1.01, p=0.051) were protective agents against cardiac toxicity. Conclusion Effective anti-cancer therapy may be accompanied by an increased risk of cardiotoxicity. In this study, a history of prior heart disease, dyslipidemia, low baseline ejection fraction, and the administration of multiple anticancer therapy agents was associated with cardiotoxicity. Proactive management strategies aimed at mitigating the potential cardiotoxic effects of anti-cancer therapies are crucial.

Chemotherapy Induced Cardiotoxicity: A State of the Art Review on General Mechanisms, Prevention, Treatment and Recent Advances in Novel Therapeutics

As medicine advances to employ sophisticated anticancer agents to treat a vast array of oncological conditions, it is worth considering side effects associated with several chemotherapeutics. One adverse effect observed with several classes of chemotherapy agents is cardiotoxicity which leads to reduced ejection fraction (EF), cardiac arrhythmias, hypertension and Ischemia/myocardial infarction that can significantly impact the quality of life and patient outcomes. Research into possible mechanisms has elucidated several mechanisms, such as ROS generation, calcium overload and apoptosis. However, there is a relative scarcity of literature detailing the relationship between the exact mechanism of cardiotoxicity for each anticancer agent and observed clinical effects. This review comprehensively describes cardiotoxicity associated with various classes of anticancer agents and possible mechanisms. Further research exploring possible mechanisms for cardiotoxicity observed with anticancer agents could provide valuable insight into susceptibility for developing symptoms and management guidelines. Chemotherapeutics are associated with several side effects. Several classes of chemotherapy agents cause cardiotoxicity leading to a reduced ejection fraction (EF), cardiac arrhythmias, hypertension, and Ischemia/myocardial infarction. Research into possible mechanisms has elucidated several mechanisms, such as ROS generation, calcium overload, and apoptosis. However, there is a relative scarcity of literature detailing the relationship between the exact mechanism of cardiotoxicity for each anticancer agent and observed clinical effects. This review describes cardiotoxicity associated with various classes of anticancer agents and possible mechanisms. Further research exploring mechanisms for cardiotoxicity observed with anticancer agents could provide insight that will guide management.

Maternal and neonatal outcomes in women with a history of chemotherapy exposure: a population-based study of 8 million obstetric admissions

PURPOSE

With improvement in cancer care and fertility preservation, increasing numbers of cancer survivors are requiring obstetrical care. The objective of our study was to evaluate the effect of history of chemotherapy exposure on maternal and neonatal outcomes.

METHODS

A retrospective population-based cohort study was conducted using the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample (HCUP-NIS) to obtain data on maternal and newborn outcomes in a cohort of births occurring between the years 2006 and 2015. The annual and overall prevalence of chemotherapy exposure was calculated among pregnant women, and multivariate logistic regression models were used to estimate the effect of history of exposure to chemotherapy on the risk of adverse maternal and newborn outcomes.

RESULTS

Of 7,907,139 birth admissions, 613 had a history of chemotherapy exposure for an overall incidence of 7.75 per 100,000 admissions. The prevalence of chemotherapy exposure in pregnancy increased during the study period (P < 0.001). Women with a history of chemotherapy were more likely to suffer from obstetric and medical complications including pre-eclampsia, chorioamnionitis, postpartum hemorrhage, and venous thromboembolism as well as an increased risk in overall mortality (OR 9.39, 95% CI 1.31-67.32). No differences were observed in the incidence of adverse neonatal outcomes, including stillbirth, intra-uterine growth restriction, or preterm birth.

CONCLUSION

Women with history of chemotherapy have higher incidence of pregnancy complications and maternal death, with no differences in fetal or newborn outcomes.

Assessment of Global Cardiac Function Using AutoSTRAIN Automatic Strain Quantitative Technology in Patients With Breast Cancer Undergoing Anthracycline-Based Chemotherapy

In patients with breast cancer undergoing anthracycline-based chemotherapy, we investigated the deformational parameters of the left ventricle, right ventricle and left atrium, as well as the relationship between these parameters. Ninety-five patients with breast cancer who were treated with anthracycline-based chemotherapy were enrolled. The control group included 116 healthy female volunteers. Parameters including left ventricular global longitudinal strain (LV-GLS); right ventricular free wall longitudinal strain (RVFWSL) and global longitudinal strain (RV4CSL); and peak strain of the left atrium during LV systole (LASR), early LV diastole (LASCD) and late LV diastole (LASCT) were analyzed by speckle tacking echocardiography. LV-GLS, LASR, LASCD, RVFWSL and RV4CSL in the chemotherapy group decreased significantly by 15.6%, 13.8%, 19.8%, 21.8% and 13.2% (p < 0.05), respectively, when compared with the control group. LASCT was slightly increased in the chemotherapy group but the increase was not statistically significant (p > 0.05). Formulas for the influencing factors of LV-GLS were LV-GLS = -18.73738541 + 0.13961 × LVIDd + 0.09672 × LASCD + 0.18113 × RVFWSL in the control group and LV-GLS = -8.026302253 + 0.20811 × LASCD + 0.11084 × LASCT + 0.12153 × RVFWSL in the chemotherapy group. Both LV contraction and RV contraction were impaired after the completion of anthracycline-based therapy, and RVFWSL may be superior to LV-GLS in assessing cardiotoxicity. LA reserve and channel function were significantly reduced, while pump function was slightly increased. Compared with the results among healthy people, the influencing factor of LV-GLS varied after anthracycline treatment, and LA function had a greater impact on LV-GLS.

Pathological Roles of Oxidative Stress in Cardiac Microvascular Injury

Cardiac microvascular injury can be a fundamental pathological process that causes high incidence cardiovascular diseases such heart failure, diabetic cardiomyopathy, and hypertension. It is also an independent risk factor for cardiovascular disease. Oxidative stress is a significant pathological process in which the body interferes with the balance of the endogenous antioxidant defense system by producing reactive oxygen species, leading to property changes and dysfunction. It has been demonstrated that oxidative stress is one of the major causes of cardiac microvascular disease. Therefore, additional investigation into the relationship between oxidative stress and cardiac microvascular injury will direct clinical management in the future. In order to give suggestions and support for future in-depth studies, we give a basic overview of the cardiac microvasculature in relation to physiopathology in this review. We also summarize the role of oxidative stress of mitochondrial and non-mitochondrial origin in cardiac microvascular injury and related drug studies.

Pharmaceutical Prevention and Management of Cardiotoxicity in Hematological Malignancies

Modern treatment modalities in hematology have improved clinical outcomes of patients with hematological malignancies. Nevertheless, many new or conventional anticancer drugs affect the cardiovascular system, resulting in various cardiac disorders, including left ventricular dysfunction, heart failure, arterial hypertension, myocardial ischemia, cardiac rhythm disturbances, and QTc prolongation on electrocardiograms. As these complications may jeopardize the significantly improved outcome of modern anticancer therapies, it is crucial to become familiar with all aspects of cardiotoxicity and provide appropriate care promptly to these patients. In addition, established and new drugs contribute to primary and secondary cardiovascular diseases prevention. This review focuses on the clinical manifestations, preventive strategies, and pharmaceutical management of cardiotoxicity in patients with hematologic malignancies undergoing anticancer drug therapy or hematopoietic stem cell transplantation.

The Role of Nutrition in Primary and Secondary Prevention of Cardiovascular Damage in Childhood Cancer Survivors

Innovative therapeutic strategies in childhood cancer led to a significant reduction in cancer-related mortality. Cancer survivors are a growing fragile population, at risk of long-term side effects of cancer treatments, thus requiring customized clinical attention. Antineoplastic drugs have a wide toxicity profile that can limit their clinical usage and spoil patients’ life, even years after the end of treatment. The cardiovascular system is a well-known target of antineoplastic treatments, including anthracyclines, chest radiotherapy and new molecules, such as tyrosine kinase inhibitors. We investigated nutritional changes in children with cancer from the diagnosis to the end of treatment and dietary habits in cancer survivors. At diagnosis, children with cancer may present variable degrees of malnutrition, potentially affecting drug tolerability and prognosis. During cancer treatment, the usage of corticosteroids can lead to rapid weight gain, exposing children to overweight and obesity. Moreover, dietary habits and lifestyle often dramatically change in cancer survivors, who acquire sedentary behavior and weak adherence to dietary guidelines. Furthermore, we speculated on the role of nutrition in the primary prevention of cardiac damage, investigating the potential cardioprotective role of diet-derived compounds with antioxidative properties. Finally, we summarized practical advice to improve the dietary habits of cancer survivors and their families.

Omega 3 fatty acids can reduce early doxorubicin-induced cardiotoxicity in children with acute lymphoblastic leukemia

OBJECTIVES

Omega 3 polyunsaturated fatty acids are dietary factors with several beneficial cardiovascular effects. This study aimed to assess the possible protective effect of omega 3 fatty acids on early doxorubicin-induced cardiac toxicity in children with acute lymphoblastic leukemia (ALL).

PATIENTS AND METHODS

Sixty children of newly diagnosed ALL were randomized into two groups: group I (n = 30) who received omega 3 fatty acids 1000 mg/day for 6 months in addition to their usual protocol of chemotherapy including doxorubicin; and group II (n = 30) who received their usual doxorubicin protocol during the period from February 2020 till August 2021. Echocardiographic examinations were performed before and after the treatment. Glutathione, malondialdehyde (MDA), superoxide dismutase (SOD), troponin I, creatine kinase MB (CK-MB), and N-terminal pro-brain natriuretic peptide (NT-proBNP) were measured also before and after omega 3 treatment.

RESULTS

After 6 months of omega 3 administration, group I had a significantly lower MDA level and a significantly higher glutathione and SOD levels than group II. Similarly, the levels of troponin I, CK-MB, and NT-proBNP were significantly high in group II, whereas they were unchanged in group I after treatment. Similarly, systolic function (presented with peak mitral annular systolic velocity and two-dimensional global longitudinal strain) of the heart was preserved in omega 3-treated patients, unlike the control group that showed significant impairment of left ventricular function after 6 months.

CONCLUSION

Omega 3 fatty acids may decrease early cardiac injury and doxorubicin-induced cardiotoxicity in children with ALL.

Naringin Interferes Doxorubicin-Induced Myocardial Injury by Promoting the Expression of ECHS1

Doxorubicin (DOX) leads to myocardial cell damage and irreversible heart failure, which limits the clinical application of DOX. Naringin has biological functions of inhibiting inflammation, oxidative stress and apoptosis. Our aim was to investigate whether Naringin could prevent DOX-related cardiotoxicity in mice. Naringin was administered by gavage and mice were intraperitoneally injected with doxorubicin (1 mg/kg/day) for 15 days. H&E, Masson, TUNEL and others experiments were examined. NRVMs and H9C2 cells were treated with Naringin and DOX in vitro. Using IF, ELISA and Western Blot to detect the effect of Naringin and ECHS1 on cells. The results showed that Naringin could prevent DOX related cardiac injury, inhibit cardiac oxidative stress, inflammation and apoptosis in vivo and in vitro. Inhibition of ECHS1 could interfere the effect of Naringin on DOX-induced myocardial injury. Naringin may provide a new cardiac protective tool for preventing the cardiotoxicity of anthracycline drugs.

Risk factors and early cardiovascular outcomes in cancer patients treated with anthracycline-based chemotherapy in Tanzania: a protocol for a quasi-experimental study

The objective of this quasi-experimental study is to assess the risk factors and early cardiovascular outcomes in cancer patients treated with anthracycline-based chemotherapy in Tanzania. The study will be conducted at Ocean Road Cancer Institute in Dar es salaam, Tanzania. The study will have three phases: baseline survey, follow-up, and end-line survey. Participants will be newly diagnosed adult cancer patients who are eligible for anthracycline-based chemotherapy. A total of 427 participants will be involved. At baseline, participants will be evaluated for the cardiovascular risk factors before commencing chemotherapy. During follow-up, participants will commence their prescribed anthracycline and the cardiovascular indices monitored throughout until the patient completes the prescribed anthracycline cycles. After completing the prescribed anthracycline cycles, an end line survey will be conducted to evaluate any change in cardiovascular indices. The outcome variable in this study will be the change in biochemical data (high-density lipoprotein, low-density lipoprotein, triglyceride, and troponin I), blood pressure, and electrocardiographic information (heart rate and Bazett QT interval). Independent variables will be demographic characteristics, risk factors for cardiovascular disorders, current dietary practices, and body mass index. Descriptive statistics will be used to describe the participants. Independent and paired t-tests will be performed to make comparisons between and within groups. P-values <0.05 will be considered statistically significant. The results of this study will help clinicians and policymakers to understand the burden of early cardiovascular outcomes and plan for appropriate preventive strategies.

From dissection of fibrotic pathways to assessment of drug interactions to reduce cardiac fibrosis and heart failure

Cardiac fibrosis is characterized by extracellular matrix deposition in the cardiac interstitium, and this contributes to cardiac contractile dysfunction and progression of heart failure. The main players involved in this process are the cardiac fibroblasts, which, in the presence of pro-inflammatory/pro-fibrotic stimuli, undergo a complete transformation acquiring a more proliferative, a pro-inflammatory and a secretory phenotype. This review discusses the cellular effectors and molecular pathways implicated in the pathogenesis of cardiac fibrosis and suggests potential strategies to monitor the effects of specific drugs designed to slow down the progression of this disease by specifically targeting the fibroblasts.

From cardio-oncology to cardio-onco-pharmacology: Towards a multidisciplinary approach in the understanding and management of cardiotoxicity

Cardio-oncology is an emerging field that transformed the medical management of patients with cancer. It encompasses the prevention and treatment of cardiovascular toxicities related to cancer treatments, aiming to reduce cardiac adverse events among cancer survivors. Cardiovascular toxicities related to cancer treatments are described through data collected during phase I to phase III therapeutic trials, and post-marketing surveillance (phase IV). Pharmacovigilance analyses, based on datamining from these extensive databases, allowed to understanding and identifying new adverse drug reactions, some recently made available, such as immunotherapy or inhibitor of Bruton tyrosine kinase (IBTK).

Elevation Mechanisms and Diagnostic Consideration of Cardiac Troponins under Conditions Not Associated with Myocardial Infarction. Part 2

This article proceeds with a discussion of the causes and mechanisms of an elevation in cardiac troponins in pathological conditions not associated with acute myocardial infarction. The second part of the article discusses the causes and mechanisms of cardiac troponins elevation in diabetes mellitus, arterial hypertension, hereditary cardiomyopathies, cardiac arrhythmias (atrial fibrillation, supraventricular tachycardia), acute aortic dissection, and diseases of the central nervous system (strokes, subarachnoidal hemorrhage). The final chapter of this article discusses in detail the false-positive causes and mechanisms of elevated cardiac troponins.

Anticancer Drug-Induced Cardiotoxicity: Insights and Pharmacogenetics

The advancement in therapy has provided a dramatic improvement in the rate of recovery among cancer patients. However, this improved survival is also associated with enhanced risks for cardiovascular manifestations, including hypertension, arrhythmias, and heart failure. The cardiotoxicity induced by chemotherapy is a life-threatening consequence that restricts the use of several chemotherapy drugs in clinical practice. This article addresses the prevalence of cardiotoxicity mediated by commonly used chemotherapeutic and immunotherapeutic agents. The role of susceptible genes and radiation therapy in the occurrence of cardiotoxicity is also reviewed. This review also emphasizes the protective role of antioxidants and future perspectives in anticancer drug-induced cardiotoxicities.

Gender aspects in cardiooncology

BACKGROUND

Cardiooncology is a relatively new subspeciality, investigating the side effects of cytoreductive therapies on the cardiovascular (CV) system. Gender differences are well known in oncological and CV diseases, but are less elucidated in cardiooncological collectives.

METHODS

Five hundred and fifty-one patients (278 male, 273 female) with diagnosed cancer who underwent regular cardiological surveillance were enrolled in the 'MAnnheim Registry for CardioOncology' and followed over a median of 41 (95% confidence interval: 40-43) months.

RESULTS

Female patients were younger at the time of first cancer diagnosis [median 60 (range 50-70) vs. 66 (55-75), P = 0.0004], while the most common tumour was breast cancer (49.8%). Hyperlipidaemia was more often present in female patients (37% vs. 25%, P = 0.001). Male patients had a higher cancer susceptibility than female patients. They suffered more often from hypertension (51% vs. 67%, P = 0.0002) or diabetes (14% vs. 21%, P = 0.02) and revealed more often vitamin D deficiency [(U/l) median 26.0 (range 17-38) vs. 16 (9-25), P = 0.002] and anaemia [(g/dl) median 11.8 (range 10.4-12.9) vs. 11.7 (9.6-13.6), P = 0.51]. During follow-up, 140 patients died (male 77, female 63; P = 0.21). An increased mortality rate was observed in male patients (11.4% vs. 14%, P = 0.89), with even higher mortality rates of up to 18.9% vs. 7.7% (P = 0.02) considering tumours that can affect both sexes compared.

CONCLUSIONS

Although female patients were younger at the time of first cancer diagnosis, male patients had both higher cancer susceptibility and an increased mortality risk. Concomitant CV diseases were more common in male patients.

Left ventricular dyssynchrony in long-term childhood cancer survivors treated with anthracyclines: a retrospective cross-sectional study

The purpose of this study was to investigate left ventricular contraction patterns in asymptomatic Childhood cancer survivors (CCS) using two-dimensional speckle tracking echocardiography (2DSTE). Left ventricular longitudinal and circumferential myocardial parameters were assessed using 2DSTE, in asymptomatic CCS and age matched healthy controls. Time to peak (T2P) systolic strain was quantified. Dyssynchrony index (DI) was measured by calculating the standard deviation of T2P systolic strain of six segments in each view. Difference between T2P systolic longitudinal strain of septal and lateral wall was also assessed as a parameter for dyssynchrony. We included 115 CCS with a median age of 17.2 years (range 5.6–39.5) and a median follow up of 11.3 years (range 4.9–29.5) and 119 controls. Conventional echocardiographic parameters and global longitudinal strain were significantly decreased in CCS compared to controls (p < 0.01 and p = 0.02, respectively). Dyssynchrony index did not differ between CCS and controls. There was a clinically insignificant smaller absolute difference between T2P systolic longitudinal of septal and lateral wall in CCS compared to controls. We showed no difference in longitudinal or circumferential left ventricular dyssynchrony in CCS compared to controls using 2DSTE. Future research should focus on assessing dyssynchrony in more segments and a larger CCS population, using both 2D and 3DSTE.

Shenlijia Attenuates Doxorubicin-Induced Chronic Heart Failure by Inhibiting Cardiac Fibrosis

Application of the anticancer drug doxorubicin (DOX) is restricted due to its adverse, cardiotoxic side effects, which ultimately result in heart failure. Moreover, there are a limited number of chemical agents for the clinical prevention of DOX-induced cardiotoxicity. Based on the theories of traditional Chinese medicine (TCM) on chronic heart failure (CHF), Shenlijia (SLJ), a new TCM compound, has been developed to fulfill multiple functions, including improving cardiac function and inhibiting cardiac fibrosis. In the present study, the protective effects and molecular mechanisms of SLJ on DOX-induced CHF rats were investigated. The CHF rat model was induced by intraperitoneal injection of DOX for six weeks with the cumulative dose of 15 mg/kg. All rats were then randomly divided into the control, CHF, CHF + SLJ (3.0 g/kg per day), and CHF + captopril (3.8 mg/kg per day) groups and treated for further four weeks. Echocardiography and the assessment of hemodynamic parameters were performed to evaluate heart function. A protein chip was applied to identify proteins with diagnostic values that were differentially expressed following SLJ treatment. The data from these investigations showed that SLJ treatment significantly improved cardiac function by increasing the left ventricular ejection fraction, improving the hemodynamic index, and inhibiting interstitial fibrosis. Protein chip analysis revealed that SLJ upregulated MCP-1, MDC, neuropilin-2, TGF-β3, thrombospondin, TIE-2, EG-VEGF/PK1, and TIMP-1/2/3 expressions and downregulated that of MMP-13. In addition, immunohistochemistry and western blot results further confirmed that SLJ promoted TIMP-1/2/3 and inhibited MMP-13 expression. The results of the present study suggest that SLJ was effective against DOX-induced CHF rats and is related to the improvement of heart function and ultrastructure and the inhibition of myocardial fibrosis.

Unraveling the biomechanistic role of Rac1/TWEAK/Fn14/NF-κB intricate network in experimentally doxorubicin-induced cardiotoxicity in rats: The role of curcumin

Doxorubicin (DOX) is an important chemotherapeutic drug. Cardiotoxicity diminishes its clinical efficacy. We aimed to focus on the mechanism of DOX-induced cardiotoxicity, in addition, to evaluate curcumin's protective effect against it. Twenty-eight rats were divided into the normal control group I, curcumin-treated (200 mg/kg body weight [b.w.]) group II, DOX-treated (4 mg/kg b.w.) group III, and DOX + curcumin group IV. Cardiac injury markers, heart tissue oxidative stress indices, interferon-gamma (INF-γ), tumor necrosis factor-like weak inducer of apoptosis (TWEAK), upregulated modulator of apoptosis (PUMA), p53 and nuclear factor kappa-B p65 (NF-κB p65) levels as well as messenger RNA gene expression of Rac1 and fibroblast growth factor-inducible protein 14 (Fn14) were assayed, besides the assay of DNA damage, histopathological changes, survivin immunohistochemistry and electron microscopic examination. Curcumin significantly downregulated Rac1 and Fn14 gene expression and significantly decreased p53, NF-κB p65, INF-γ, and PUMA levels in the cardiac tissue. In addition, curcumin improved oxidative stress indices, DNA damage, and cardiac toxicity markers in the form of lactate dehydrogenase (LD), creatine kinase isoenzyme-MB (CK-MB), and cardiac troponin-I (cTn-I). Meanwhile, upregulated antiapoptotic marker survivin was observed. Light and electron microscopic findings confirmed our biochemical and molecular outcomes. The current study established the antioxidant, anti-inflammatory, and antiapoptotic roles of curcumin against DOX cardiotoxicity.

Role of cardiovascular magnetic resonance imaging in cardio-oncology

Advances in cancer therapy have led to significantly longer cancer-free survival times over the last 40 years. Improved survivorship coupled with increasing recognition of an expanding range of adverse cardiovascular effects of many established and novel cancer therapies has highlighted the impact of cardiovascular disease in this population. This has led to the emergence of dedicated cardio-oncology services that can provide pre-treatment risk stratification, surveillance, diagnosis, and monitoring of cardiotoxicity during cancer therapies, and late effects screening following completion of treatment. Cardiovascular imaging and the development of imaging biomarkers that can accurately and reliably detect pre-clinical disease and enhance our understanding of the underlying pathophysiology of cancer treatment-related cardiotoxicity are becoming increasingly important. Multi-parametric cardiovascular magnetic resonance (CMR) is able to assess cardiac structure, function, and provide myocardial tissue characterization, and hence can be used to address a variety of important clinical questions in the emerging field of cardio-oncology. In this review, we discuss the current and potential future applications of CMR in the investigation and management of cancer patients.

Systems pharmacology reveals the multi-level synergetic mechanism of action of Ginkgo biloba L. leaves for cardiomyopathy treatment

ETHNOPHARMACOLOGICAL RELEVANCE

Cardiomyopathy is a common cause of heart failure and may lead to increased risk of sudden cardiac death, lacking simple, safe and effective treatment strategies due to unclear pathogenesis. Ginkgo biloba L. leaves (GBLs), a traditional Chinese medicine (TCM), has been widely used in clinical medicine for improving blood circulation, and was demonstrated to be effective on cardiomyopathy in preclinical studies. However, because of the widely known holistic therapeutic philosophy via multi-target and multi-pathway effect for most TCMs, to explore its underlying molecular mechanisms of action (MoA) remains a great challenge.

AIM OF STUDY

Decipher the underlying MoA of GBLs for cardiomyopathy treatment: Study design and methods: An integrated systems pharmacology framework was employed to screen potential active compounds, identify therapeutic targets, explore the action pathways and verify mechanisms of GBLs with in vitro experiments.

RESULTS

We firstly confirmed the therapeutic effect of GBLs on cardiomyopathy and subsequently screened 27 active compounds from GBLs according to their pharmacokinetic properties. Then Probability Ensemble Approach was applied to identify the compound combinations that exert synergetic effect from GBLs. Network analysis and functional enrichment analysis demonstrated that these compounds exhibit synergistic therapeutic effect by acting on multiple targets and thereby regulating multiple pathways mainly involved in pro-survival, anti-apoptotic and anti-inflammatory processes. Finally, using a doxorubicin-induced myocardial injury model, therapeutic effect of ginkgolide A, ginkgolide B, isorhamnetin, as well as their synergistic effect on PI3K-AKT and NF-κB signaling pathways were validated in vitro. Importantly, we demonstrated that Ginkgo diterpene lactone meglumine injection (GDJ), an approved injection derived from GBLs, could be a promising agent for cardiomyopathy treatment.

CONCLUSION

Collectively, the multi-level synergetic mechanism of GBLs on cardiomyopathy treatment was demonstrated with systems pharmacology approach, providing a paradigm for deciphering the complicated MoA of TCMs.

Statin Exposure and Risk of Heart Failure After Anthracycline- or Trastuzumab-Based Chemotherapy for Early Breast Cancer: A Propensity Score‒Matched Cohort Study

Background Statins are hypothesized to reduce the risk of cardiotoxicity associated with anthracyclines and trastuzumab. Our aim was to study the association of statin exposure with hospitalization or emergency department visits (hospital presentations) for heart failure (HF) after anthracycline- and/or trastuzumab-containing chemotherapy for early breast cancer. Methods and Results Using linked administrative databases, we conducted a retrospective cohort study of women aged ≥66 years without prior HF who received anthracyclines or trastuzumab for newly diagnosed early breast cancer in Ontario between 2007 to 2017. Statin-exposed and unexposed women were matched 1:1 using propensity scores. Trastuzumab-treated women were also matched on anthracycline exposure. We matched 666 statin-discordant pairs of anthracycline-treated women and 390 pairs of trastuzumab-treated women (median age, 69 and 71 years, respectively). The 5-year cumulative incidence of HF hospital presentations after anthracyclines was 1.2% (95% CI, 0.5%-2.6%) in statin-exposed women and 2.9% (95% CI, 1.7%-4.6%) in unexposed women (P value, 0.01). The cause-specific hazard ratio associated with statins in the anthracycline cohort was 0.45 (95% CI, 0.24-0.85; P value, 0.01). After trastuzumab, the 5-year cumulative incidence of HF hospital presentations was 2.7% (95% CI, 1.2%-5.2%) in statin-exposed women and 3.7% (95% CI, 2.0%-6.2%) in unexposed women (P value 0.09). The cause-specific hazard ratio associated with statins in the trastuzumab cohort was 0.46 (95% CI, 0.20-1.07; P value, 0.07). Conclusions Statin-exposed women had a lower risk of HF hospital presentations after early breast cancer chemotherapy involving anthracyclines, with non-significant trends towards lower risk following trastuzumab. These findings support the development of randomized controlled trials of statins for prevention of cardiotoxicity.

Cardiotoxicity: A Major Setback in Childhood Leukemia Treatment

Ongoing research in the field of pediatric oncology has led to an increased number of childhood cancer survivors reaching adulthood. Therefore, ensuring a good quality of life for these patients has become a rising priority. Considering this, the following review focuses on summarizing the most recent research in anthracycline-induced cardiac toxicity in children treated for leukemia. For pediatric cancers, anthracyclines are one of the most used anticancer drugs, with over half of the childhood cancer survivors believed to have been exposed to them. Anthracyclines cause irreversible cardiomyocyte loss, leading to chronic, progressive heart failure. The risk of developing cardiotoxicity has been known to increase with the treatment-free interval and total cumulative dose. However, because of individual variations in anthracycline metabolism, it has recently been shown that there is no risk-free dose. Moreover, studies have shown that diagnosing anthracycline-induced cardiomyopathy in the symptomatic phase is associated with poor treatment response and prognosis. Thus, early and systematic evaluation of these patients is crucial to allow optimal therapeutic intervention. Although currently echocardiographic assessment of left ventricle ejection fraction and cardiac biomarker evaluation are being used for cardiac function monitoring in oncologic patients, there is no established follow-up and treatment protocol for these patients, and these methods are neither specific nor sensitive for identifying early cardiac dysfunction. All things considered, the need for ongoing research in the field of pediatric cardiooncology is crucial to offer these patients a chance at a good quality of life as adults.

Rationale and proposal for cardio-oncology services in Italy

: In the last 20 years, a substantial improvement in the efficacy of cancer treatment has induced a progressive increase in cancer survival, with an obvious parallel increase in morbidity and mortality related to the adverse effects of anticancer therapy, in particular, cardiovascular complications. In relation to the peculiar aspects related to cardiac and vascular toxicity, clinical management of patients should be ideally reserved for experts in the field of this novel medical discipline, which has been defined as cardio-oncology. The rationale for this choice corresponds to the aim of identifying patients more prone to developing cardiovascular damage, prevent overt cardiotoxicity and conduct active surveillance of treated patients for early identification of cardiac and vascular involvement during short- and long-term follow-up. Due to the burden of treated cancer patients, the development of dedicated cardio-oncology services has become one of the main goals of contemporary medicine, needed to accomplish the peculiar mission of guiding the patients through the narrow path of cancer survival without the expense of cardiovascular damage. The main purpose of cardio-oncology services is to provide dedicated cardiologic care to cancer patients affected by concomitant (subclinical or overt) cardiovascular diseases, either preexisting the cancer onset or acquired during and after the time course of anticancer therapy. In this article, we describe a possible spoke-hub model of cardio-oncology services, which could be appropriately applied in Italy. Rationale, organization, definition of referral criteria, strategies, interventional programs, long-term surveillance and home assistance of this model are described and discussed.

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.

Protective Role of Enalapril in Anthracycline-Induced Cardiotoxicity: A Systematic Review

Background

Evidence of the preventive and therapeutic effects of enalapril on cardiotoxicity caused by chemotherapy needs to be further confirmed and updated.

Methods

We performed a systematic review of studies from electronic databases that were searched from inception to January 29, 2019, and included relevant studies analyzing enalapril as a cardioprotective agent before or during the use of anthracyclines by oncology patients. Homogeneous results from different studies were pooled using RevMan 5.3 software. The Cochrane risk-of-bias tool was used to determine the quality of the studies.

Results

We examined and screened 626 studies according to specific criteria and ultimately included seven studies that were relevant to the indicated topic. Among them, three studies reported the incidence of death during 6- and 12-month follow-up periods. Six of the seven included studies showed possible positive results, suggesting that enalapril plays a cardioprotective role, while five of these studies showed that there was a significant difference in the left ventricular ejection fraction (LVEF) between an enalapril group and a control group (weighted mean difference (WMD) = 7.18, 95% CI: 2.49–11.87, I² = 96%, P < .001). Moreover, enalapril was beneficial in reducing troponin I (TnI), creatine kinase myocardial band (CK-MB) and N-terminal pro-b-type natriuretic peptide (NT-proBNP) levels in cancer patients treated with anthracycline.

Conclusions

Although a protective effect of enalapril on myocardial toxicity was observed in terms of the LVEF values and TnI, CK-MB and NT-proBNP levels, its use in the prevention and treatment of cardiotoxicity caused by anthracycline needs to be investigated by more scientific research.

Advanced Imaging Modalities to Monitor for Cardiotoxicity

Early detection and treatment of cardiotoxicity from cancer therapies is key to preventing a rise in adverse cardiovascular outcomes in cancer patients. Over-diagnosis of cardiotoxicity in this context is however equally hazardous, leading to patients receiving suboptimal cancer treatment, thereby impacting cancer outcomes. Accurate screening therefore depends on the widespread availability of sensitive and reproducible biomarkers of cardiotoxicity, which can clearly discriminate early disease. Blood biomarkers are limited in cardiovascular disease and clinicians generally still use generic screening with ejection fraction, based on historical local expertise and resources. Recently, however, there has been growing recognition that simple measurement of left ventricular ejection fraction using 2D echocardiography may not be optimal for screening: diagnostic accuracy, reproducibility and feasibility are limited. Modern cancer therapies affect many myocardial pathways: inflammatory, fibrotic, metabolic, vascular and myocyte function, meaning that multiple biomarkers may be needed to track myocardial cardiotoxicity. Advanced imaging modalities including cardiovascular magnetic resonance (CMR), computed tomography (CT) and positron emission tomography (PET) add improved sensitivity and insights into the underlying pathophysiology, as well as the ability to screen for other cardiotoxicities including coronary artery, valve and pericardial diseases resulting from cancer treatment. Delivering screening for cardiotoxicity using advanced imaging modalities will however require a significant change in current clinical pathways, with incorporation of machine learning algorithms into imaging analysis fundamental to improving efficiency and precision. In the future, we should aspire to personalized rather than generic screening, based on a patient’s individual risk factors and the pathophysiological mechanisms of the cancer treatment they are receiving. We should aspire that progress in cardiooncology is able to track progress in oncology, and to ensure that the current ‘one size fits all’ approach to screening be obsolete in the very near future.

Role of oxidative stress in cardiotoxicity of antineoplastic drugs

Tumors and heart disease are two of the leading causes of human death. With the development of anti-cancer therapy, the survival rate of cancer patients has been significantly improved. But at the same time, the incidence of cardiovascular adverse events caused by cancer treatment has also been considerably increased, such as arrhythmia, left ventricular (LV) systolic and diastolic dysfunction, and even heart failure (HF), etc., which seriously affects the quality of life of cancer patients. More importantly, the occurrence of adverse events may lead to the adjustment or the cessation of anti-cancer treatment, which affects the survival rate of patients. Understanding the mechanism of cardiotoxicity (CTX) induced by antineoplastic drugs is the basis of adequate protection of the heart without impairing the efficacy of antineoplastic therapy. Based on current research, a large amount of evidence has shown that oxidative stress (OS) plays an essential role in CTX induced by antineoplastic drugs and participates in its toxic reaction directly and indirectly. Here, we will review the mechanism of action of OS in cardiac toxicity of antineoplastic drugs, to provide new ideas for researchers, and provide further guidance for clinical prevention and treatment of cardiac toxicity of anti-tumor drugs in the future.

An update on the conquests and perspectives of cardio-oncology in the field of tumor angiogenesis-targeting TKI-based therapy

INTRODUCTION

The angiogenesis mechanism is considered a crucial point in neoplastic development. A growing number of multi-targeted tyrosine kinase inhibitors (TKI) has been developed and approved for cancer treatment during the last few years. Cardiac side effects still remain an issue to manage nowadays. These drugs mechanisms and toxicities have already been discussed, hence the authors will report updates on these already available drugs.

AREAS COVERED

This manuscript provides an updated review on the new mechanisms involved in angiogenesis and cardiotoxicity that are TKI-related. Here is reported an overview of the already available and the most recent TKIs under investigation in the oncology field. A literature review has been performed, focusing on the most relevant phase II and phase III trial results.

EXPERT OPINION

TKIs represent a new and important resource in the oncology field. Since the use and the number of VEGFR-TKI is constantly increasing, a specific focus on cardiotoxicity development and management appears as justified. Oncologists must record cardiovascular risk factors at baseline in order to stratify patients' risk before undergoing TKI-VEGFRs. A collaboration between oncologists and cardio-oncologists is strongly recommended to earlier manage cardiovascular events (i.e. arterial hypertension) that could interfere with oncological results.

The BET Bromodomain Inhibitor I-BET-151 Induces Structural and Functional Alterations of the Heart Mitochondria in Healthy Male Mice and Rats

The bromodomain and extra-terminal domain family inhibitors (BETi) are a promising new class of anticancer agents. Since numerous anticancer drugs have been correlated to cardiomyopathy, and since BETi can affect non-cancerous tissues, we aimed to investigate in healthy animals any ultrastructural BETi-induced alterations of the heart as compared to skeletal muscle. Male Wistar rats were either treated during 3 weeks with I-BET-151 (2 or 10 mg/kg/day) (W3) or treated for 3 weeks then allowed to recover for another 3 weeks (W6) (3-weeks drug washout). Male C57Bl/6J mice were only treated during 5 days (50 mg/kg/day). We demonstrated the occurrence of ultrastructural alterations and progressive destruction of cardiomyocyte mitochondria after I-BET-151 exposure. Those mitochondrial alterations were cardiac muscle-specific, since the skeletal muscles of exposed animals were similar in ultrastructure presentation to the non-exposed animals. I-BET-151 decreased the respiration rate of heart mitochondria in a dose-dependent manner. At the higher dose, it also decreased mitochondrial mass, as evidenced by reduced right ventricular citrate synthase content. I-BET-151 reduced the right and left ventricular fractional shortening. The concomitant decrease in the velocity-time-integral in both the aorta and the pulmonary artery is also suggestive of an impaired heart function. The possible context-dependent cardiac side effects of these drugs have to be appreciated. Future studies should focus on the basic mechanisms of potential cardiovascular toxicities induced by BETi and strategies to minimize these unexpected complications.

Cardiovascular Implications of Diabetes, Metabolic Syndrome, Thyroid Disease, and Cardio-Oncology in Women

Cardiovascular disease may be associated with several comorbidities, including diabetes mellitus, thyroid disorders, and the metabolic syndrome, which are predominantly observed in women and often starting at particular ages. In addition, common treatment options for carcinomas frequently seen in women may induce serious cardiotoxic effects. We review the scope of the problem, the pathophysiologic mechanisms involved, as well as the resulting abnormalities regarding cardiac structure and function as observed by using imaging techniques.

The cardioprotective effect of dexrazoxane (Cardioxane) is consistent with sequestration of poly(ADP-ribose) by self-assembly and not depletion of topoisomerase 2B

Following systematic scrutiny of the evidence in support of the hypothesis that the cardioprotective mechanism of action of dexrazoxane is mediated by a 'depletion' or 'downregulation' of Top2β protein levels in heart tissue, the author concludes that this hypothesis is untenable. In seeking to understand how dexrazoxane protects the heart, the outcomes of a customised association rule learning algorithm incorporating the use of antecedent surrogate variables (CEME, 2017 McCormack Pharma) reveal a previously unknown relationship between dexrazoxane and poly(ADP-ribose) (PAR) polymer. The author shows how this previously unknown relationship explains both acute and long-term cardioprotection in patients receiving anthracyclines. In addition, as a direct inhibitor of PAR dexrazoxane has access to the epigenome and this offers a new insight into protection by dexrazoxane against doxorubicin-induced late-onset damage [McCormack K, manuscript in preparation]. Notably, through this review article, the author illustrates the practical application of probing natural language text using an association rule learning algorithm for the discovery of new and interesting associations that, otherwise, would remain lost. Historically, the use of CEME enabled the first report of the capacity of a small molecule to catalyse the hybrid self-assembly of a nucleic acid biopolymer via canonical and non-canonical, non-covalent interactions analogous to Watson Crick and Hoogsteen base pairing, respectively.

Mechanism and Management of Cancer Chemotherapy-Induced Atherosclerosis

The advent of new chemotherapeutic and immunotherapeutic treatments has markedly improved outcomes in patients with cancer. However, increasing numbers of elderly patients with cancer and prolonged periods of treatment have made the management of cardiovascular complications and treatment-induced cardiotoxicity an important concern, and onco-cardiology has received increasing attention. The number of patients with cardiotoxicity, particularly atherosclerotic lesions, and the usage of angiogenesis inhibitors have increased, making the involvement of onco-cardiologists essential for effective disease management. A paradigm shift in immunotherapy was caused by the development of immune checkpoint inhibitors. Because vascular endothelial growth factors (VEGF) in the cancer microenvironment and cancer immune function are interrelated angiogenesis inhibitors will most likely play an increasingly important role in combined immunotherapy. To ensure the optimal long-term diagnosis and long-term treatment of cancer and the effective management of treatment-related atherosclerotic diseases, the long-term continuous participation of onco-cardiologists is essential.

Doxorubicin-Induced Myocardial Fibrosis Involves the Neurokinin-1 Receptor and Direct Effects on Cardiac Fibroblasts

BACKGROUND

Cancer patients receiving anthracycline-based chemotherapy (Anth-bC) may experience early cardiac fibrosis, which could be an important contributing mechanism to the development of impaired left ventricular (LV) function. Substance P, a neuropeptide that predominantly acts via the neurokinin 1 receptor (NK-1R), contributes to adverse myocardial remodelling and fibrosis in other cardiomyopathies. We sought to determine if NK-1R blockade is effective against doxorubicin (Dox - a frequently used Anth-bC)-induced cardiac fibrosis and cardiomyocyte apoptosis. In addition, we explored the direct effects of Dox on cardiac fibroblasts.

METHODS

Male Sprague-Dawley rats were randomised to receive saline, six cycles of Dox (1.5mg Dox/kg/cycle) or Dox with an NK-1R antagonist (L732138, 5mg/kg/daily through Dox treatment). At 8 weeks after the initial dose of Dox, LV function and histopathological myocardial fibrosis and cell apoptosis were assessed. Collagen secretion was measured in vitro to test direct Dox activation of cardiac fibroblasts.

RESULTS

Rats undergoing Dox treatment (9mg/kg cumulative dose) developed cardiac fibrosis and cardiomyocyte apoptosis. NK-1R blockade partially mitigated cardiac fibrosis while completely preventing cardiomyocyte apoptosis. This resulted in improved diastolic function. Furthermore, we found that Dox had direct effects on cardiac fibroblasts to cause increased collagen production and enhanced cell survival.

CONCLUSIONS

This study demonstrates that cardiac fibrosis induced by Anth-bC can be reduced by NK-1R blockade. The residual fibrotic response is likely due to direct Dox effects on cardiac fibroblasts to produce collagen.

Anticancer drugs-related QTc prolongation, torsade de pointes and sudden death: current evidence and future research perspectives

Anticancer drugs may have proarrhythmic effects including drug-induced QT interval prolongation, which is of particular importance because it can lead to a fatal polymorphic ventricular tachycardia termed torsade de pointes (TdP). QT interval prolongation and TdP are rare life-threatening untoward effects of anticancer therapy, particularly with arsenic trioxides and anthracyclines, and even some novel molecular targeted drugs touted as 'tumor specific'. Several factors that affect myocardial repolarization can further increase the risk of TdP. This article reviews the mechanism of QT interval prolongation, risk factors for TdP and the QT toxicity of anticancer drugs as well as its management. Specific attention should be paid to high-risk populations such as patients with underlying heart diseases, electrolyte imbalance and bradycardia. To minimize the occurrence of QT interval prolongation and TdP, it is advisable to conduct a careful risk factor assessment before antitumor therapy. To this end, several new biomarkers have been introduced to predict TdP triggering and recent studies have pointed out the potential clinical relevance of genetic testing.

Mitochondrial protein 18 (MTP18) plays a pro-apoptotic role in chemotherapy-induced gastric cancer cell apoptosis

One of the severe limitations of chemotherapy is the development of drug resistance. However, the mechanisms underlying chemotherapy resistance remain to be elucidated. Mitochondrial mediated apoptosis is a form of cell death induced by chemotherapy. Several chemotherapeutic agents have been shown to induce mitochondrial fission, and finally activate the apoptosis cascade in various cancer cells. Here, we report that the mitochondrial membrane protein 18 (MTP18) induced mitochondrial fragmentation in gastric cancer cells under doxorubicin (DOX) exposure. Upon over-expression of MTP18, a sub-cytotoxic dose of DOX could sensitize a significant number of cells to undergo mitochondrial fission and subsequent apoptosis. These findings suggest that MTP18 can enhance the sensitivity of gastric cancer cells to DOX. Mechanistically, we found that MTP18 enriched dynamic-related protein 1 (DRP1) accumulation in mitochondria and it was responsible for mediating DOX-induced signaling required for mitochondrial fission. Intriguingly, MTP18 expression was downregulated during DOX treatment. Thus, down-regulation of MTP18 expression could be one of the resistance factors interfering with DOX-induced apoptosis in gastric cancer cells.

The influence of chemotherapy on the right ventricle: did we forget something?

BACKGROUND

A large number of chemotherapy-induced cardiovascular complications were discovered in studies over the last several decades. The focus of the majority of these studies was left ventricular (LV) remodeling. The aim of this article was to provide a comprehensive overview of potential mechanisms of chemotherapy-induced right ventricular (RV) remodeling and summarize clinical studies on this topic.

HYPOTHESIS

Chemotherapy induces RV structural, functional, and mechanical changes.

METHODS

We searched PubMed, MEDLINE, Ovid and Embase databases for studies published from January 1990 up to September 2016 in the English language using the following keyword "chemotherapy," "heart," "right ventricle," "anthracyclines," and "trastuzumab."

RESULTS

The existing research show that RV remodeling occurs simultaneously with LV remodeling, which is why RV remodeling should not be neglected in the overall cardiac assessment of patients treated with chemotherapy, and especially those protocols that involve anthracyclines and trastuzumab. Investigations showed that these agents could significantly impact RV structure, function, and mechanics. These medications induce fibrosis of the RV myocardium, RV dilatation, decline in RV systolic function, worsening of its diastolic function, and finally impairment of RV mechanics (strain). The mechanisms of chemotherapy-induced RV remodeling are still not entirely clear, but it is considered that direct destructive influence of chemotherapy on myocardium, oxidative stress, endothelial dysfunction, and negative impact on pulmonary circulation could significantly contribute to RV impairment.

CONCLUSIONS

Chemotherapy induces the impairment of RV structure, function, and mechanics by different complex mechanisms.