Daunomycin-induced cardiotoxicity in children and adults. A review of 110 cases

Cardiac Arrhythmia Risk after Anti-Cancer Drug Exposure and Related Disease Molecular Imaging Outlook: A Systematic Review, Meta-Analysis, and Network Meta-Analysis

BACKGROUND

Chemotherapy is the main first-line treatment, but there is a problem of adverse reactions to systemic drugs. Chemotherapeutic agents may cause adverse effects on the body, influencing the prognosis. Whether the clinical application of anthracyclines is associated with an increased arrhythmic risk remains controversial. To evaluate the arrhythmic risk of anthracyclines as a class, and the comparative risk for each drug, we conducted a systematic review, meta-analysis, and network meta-analysis.

METHODS

PubMed, Web of Science, EMBASE, and the Cochrane Library were searched, up to March 2022, for randomized controlled trials, cohort studies, and case-control studies that investigated the association between anthracyclines treatment and the risk of arrhythmia. We followed the PRISMA 2020 guidelines for data selection and extraction. Outcomes were pooled using fixed effects models in cohort studies and randomized controlled studies, and random models in single-arm studies. Direct and indirect comparisons in network meta-analysis were performed using frequentist methods.

RESULTS

In total, 4 cohort studies, 8 RCTs, and 18 single-arm studies were included in our analysis. Anthracyclines' use was associated with a statistically significant 90% increase in the risk of arrhythmia (odds ratio [OR] 1.90; 95% confidence interval [CI] 1.62-2.24) and a 114% increase in the risk of supraventricular arrhythmia (OR 2.14; 95% CI 1.18-3.89). And the single-arm studies also indicated that the incidence of arrhythmia rate is 20% and the 95% CI is 15/100-25/100. Epirubicin ranked most likely to have the highest risk of arrhythmia compared with non-anthracycline antineoplastic drugs in the analysis (OR 43.07 [95% CI 2.80-2105.83]) by network meta-analysis.

CONCLUSIONS

Our findings show a significant association between anthracyclines' use and an increased risk of arrhythmia, especially supraventricular arrhythmia. Epirubicin ranked with the highest probability of arrhythmia. These results indicated that cardiac rhythm should be strictly monitored during the application of anthracyclines in clinical practice, and a possible therapy for anthracycline-associated arrhythmia should be explored. Molecular imaging technology is an important means to study the mechanism of drug action on cardiac electrophysiology in the future. By imaging molecular targets in cardiac cells, the effects of drugs on the electrophysiological properties of cardiac cells can be understood, which provides information for the development of safer and more effective drugs.

Risk Factors for Heart Failure Among Pan-European Childhood Cancer Survivors: A PanCareSurFup and ProCardio Cohort and Nested Case-Control Study

PURPOSE

Heart failure (HF) is a potentially life-threatening complication of treatment for childhood cancer. We evaluated the risk and risk factors for HF in a large European study of long-term survivors. Little is known of the effects of low doses of treatment, which is needed to improve current treatment protocols and surveillance guidelines.

METHODS

This study includes the PanCareSurFup and ProCardio cohort of ≥ 5-year childhood cancer survivors diagnosed between 1940 and 2009 in seven European countries (N = 42,361). We calculated the cumulative incidence of HF and conducted a nested case-control study to evaluate detailed treatment-related risk factors.

RESULTS

The cumulative incidence of HF was 2% (95% CI, 1.7 to 2.2) by age 50 years. The case-control study (n = 1,000) showed that survivors who received a mean heart radiation therapy (RT) dose of 5 to < 15 Gy have an increased risk of HF (odds ratio, 5.5; 95% CI, 2.5 to 12.3), when compared with no heart RT. The risk associated with doses 5 to < 15 Gy increased with exposure of a larger heart volume. In addition, the HF risk increased in a linear fashion with higher mean heart RT doses. Regarding total cumulative anthracycline dose, survivors who received ≥ 100 mg/m² had a substantially increased risk of HF and survivors treated with a lower dose showed no significantly increased risk of HF. The dose-response relationship appeared quadratic with higher anthracycline doses.

CONCLUSION

Survivors who received a mean heart RT dose of ≥ 5 Gy have an increased risk of HF. The risk associated with RT increases with larger volumes exposed. Survivors treated with < 100 mg/m² total cumulative anthracycline dose have no significantly increased risk of HF. These new findings might have consequences for new treatment protocols for children with cancer and for cardiomyopathy surveillance guidelines.

Anthracycline-induced cardiotoxicity and senescence

Cancer continues to place a heavy burden on healthcare systems around the world. Although cancer survivorship continues to improve, cardiotoxicity leading to cardiomyopathy and heart failure as a consequence of cancer therapy is rising, and yesterday's cancer survivors are fast becoming today's heart failure patients. Although the mechanisms driving cardiotoxicity are complex, cellular senescence is gaining attention as a major contributor to chemotherapy-induced cardiotoxicity and, therefore, may also represent a novel therapeutic target to prevent this disease. Cellular senescence is a well-recognized response to clinical doses of chemotherapies, including anthracyclines, and is defined by cell cycle exit, phenotypic alterations which include mitochondrial dysfunction, and the expression of the pro-senescent, pro-fibrotic, and pro-inflammatory senescence-associated phenotype. Senescence has an established involvement in promoting myocardial remodeling during aging, and studies have demonstrated that the elimination of senescence can attenuate the pathophysiology of several cardiovascular diseases. Most recently, pharmacology-mediated elimination of senescence, using a class of drugs termed senolytics, has been demonstrated to prevent myocardial dysfunction in preclinical models of chemotherapy-induced cardiotoxicity. In this review, we will discuss the evidence that anthracycline-induced senescence causes the long-term cardiotoxicity of anticancer chemotherapies, consider how the senescent phenotype may promote myocardial dysfunction, and examine the exciting possibility that targeting senescence may prove a therapeutic strategy to prevent or even reverse chemotherapy-induced cardiac dysfunction.

Cardio-Oncology: Mechanisms, Drug Combinations, and Reverse Cardio-Oncology

Chemotherapy, radiotherapy, targeted therapy, and immunotherapy have brought hope to cancer patients. With the prolongation of survival of cancer patients and increased clinical experience, cancer-therapy-induced cardiovascular toxicity has attracted attention. The adverse effects of cancer therapy that can lead to life-threatening or induce long-term morbidity require rational approaches to prevention and treatment, which requires deeper understanding of the molecular biology underpinning the disease. In addition to the drugs used widely for cardio-protection, traditional Chinese medicine (TCM) formulations are also efficacious and can be expected to achieve “personalized treatment” from multiple perspectives. Moreover, the increased prevalence of cancer in patients with cardiovascular disease has spurred the development of “reverse cardio-oncology”, which underscores the urgency of collaboration between cardiologists and oncologists. This review summarizes the mechanisms by which cancer therapy induces cardiovascular toxicity, the combination of antineoplastic and cardioprotective drugs, and recent advances in reverse cardio-oncology.

Cardiovascular Magnetic Resonance Imaging in the Early Detection of Cardiotoxicity Induced by Cancer Therapies

The significant progress in cancer treatment, including chemotherapy, immunotherapy, radiotherapy, and combination therapies, has led to higher long-term survival rates in cancer patients, while the cardiotoxicity caused by cancer treatment has become increasingly prominent. Cardiovascular magnetic resonance (CMR) is a non-invasive comprehensive imaging modality that provides not only anatomical information, but also tissue characteristics and cardiometabolic and energetic assessment, leading to its increased use in the early identification of cardiotoxicity, and is of major importance in improving the survival rate of cancer patients. This review focused on CMR techniques, including myocardial strain analysis, T1 mapping, T2 mapping, and extracellular volume fraction (ECV) calculation in the detection of early myocardial injury induced by cancer therapies. We summarized the existing studies and ongoing clinical trials using CMR for the assessment of subclinical ventricular dysfunction and myocardial changes at the tissue level. The main focus was to explore the potential of clinical and preclinical CMR techniques for continuous non-invasive monitoring of myocardial toxicity associated with cancer therapy.

Cancer Chemotherapy-Induced Sinus Bradycardia: A Narrative Review of a Forgotten Adverse Effect of Cardiotoxicity

Cardiotoxicity is a common adverse effect of anticancer drugs (ACDs), including the so-called targeted drugs, and increases morbidity and mortality in patients with cancer. Attention has focused mainly on ACD-induced heart failure, myocardial ischemia, hypertension, thromboembolism, QT prolongation, and tachyarrhythmias. Yet, although an increasing number of ACDs can produce sinus bradycardia (SB), this proarrhythmic effect remains an underappreciated complication, probably because of its low incidence and severity since most patients are asymptomatic. However, SB merits our interest because its incidence increases with the aging of the population and cancer is an age-related disease and because SB represents a risk factor for QT prolongation. Indeed, several ACDs that produce SB also prolong the QT interval. We reviewed published reports on ACD-induced SB from January 1971 to November 2020 using the PubMed and EMBASE databases. Published reports from clinical trials, case reports, and recent reviews were considered. This review describes the associations between ACDs and SB, their clinical relevance, risk factors, and possible mechanisms of onset and treatment.

Inhibitory effects of Panax ginseng glycoproteins in models of doxorubicin-induced cardiac toxicity in vivo and in vitro

Doxorubicin (DOX) is an effective antineoplastic drug; however, its clinical application is limited owing to the side effect of fatal heart dysfunction on its use. Panax ginseng glycoproteins have antioxidant, antiapoptotic, and anti-inflammatory properties. Thus, the aim of this study was to investigate the effects and possible action mechanisms of P. ginseng glycoproteins against DOX-induced cardiotoxicity. To this end, we used an in vitro model of DOX-treated H9C2 cells and an in vivo model of DOX-treated rats. We found that P. ginseng glycoproteins markedly increased H9C2 cell viability, decreased creatine kinase and lactate dehydrogenase levels, and improved histopathological and electrocardiogram changes in rats, protecting them from DOX-induced cardiotoxicity. Furthermore, P. ginseng glycoproteins significantly inhibited myocardial oxidative insult through adjusting the intracellular ROS, MDA, SOD, and GSH levels in vitro and in vivo. In conclusion, our data suggest that P. ginseng glycoproteins alleviated DOX-induced myocardial oxidative stress-related cardiotoxicity. This natural product could be developed as a new candidate for alleviating DOX-induced cardiotoxicity.

Cardiotoxicity of Antineoplastic Therapies and Applications of Induced Pluripotent Stem Cell-Derived Cardiomyocytes

The therapeutic landscape for the treatment of cancer has evolved significantly in recent decades, aided by the development of effective oncology drugs. However, many cancer drugs are often poorly tolerated by the body and in particular the cardiovascular system, causing adverse and sometimes fatal side effects that negate the chemotherapeutic benefits. The prevalence and severity of chemotherapy-induced cardiotoxicity warrants a deeper investigation of the mechanisms and implicating factors in this phenomenon, and a consolidation of scientific efforts to develop mitigating strategies. Aiding these efforts is the emergence of induced pluripotent stem cells (iPSCs) in recent years, which has allowed for the generation of iPSC-derived cardiomyocytes (iPSC-CMs): a human-based, patient-derived, and genetically variable platform that can be applied to the study of chemotherapy-induced cardiotoxicity and beyond. After surveying chemotherapy-induced cardiotoxicity and the associated chemotherapeutic agents, we discuss the use of iPSC-CMs in cardiotoxicity modeling, drug screening, and other potential applications. Improvements to the iPSC-CM platform, such as the development of more adult-like cardiomyocytes and ongoing advances in biotechnology, will only enhance the utility of iPSC-CMs in both basic science and clinical applications.

Effects of heavy-load resistance training during (neo-)adjuvant chemotherapy on muscle cellular outcomes in women with breast cancer

INTRODUCTION

(Neo-)adjuvant chemotherapy for breast cancer has a deleterious impact on muscle tissue resulting in reduced cardiorespiratory fitness, skeletal muscle mass and function. Physical exercise during treatment may counteract some of these negative effects. However, the effects of resistance training (RT) alone have never been explored. The present study aims to investigate if heavy-load RT during (neo-)adjuvant chemotherapy counteracts deleterious effects on skeletal muscle in women diagnosed with breast cancer. We hypothesize that (neo-)adjuvant treatment with chemotherapy will reduce muscle fiber size, impair mitochondrial function, and increase indicators of cellular stress and that RT during treatment will counteract these negative effects. We also hypothesize that RT during (neo-)adjuvant chemotherapy will increase muscle and blood levels of potential antitumor myokines and reduce treatment-related side effects on muscle strength and cardiorespiratory fitness.

METHODS

Fifty women recently diagnosed with breast cancer scheduled to start (neo-)adjuvant chemotherapy will be randomized to either randomized to either intervention group or to control group.The intervention group will perform supervised heavy-load RT twice a week over the course of chemotherapy (approximately 16-weeks) whereas the control group will be encouraged to continue with their usual activities. Muscle biopsies from m. vastus lateralis will be collected before the first cycle of chemotherapy (T0), after chemotherapy (T1), and 6 months later (T2) for assessment of muscle cellular outcomes. The primary outcome for this study is muscle fiber size. Secondary outcomes are: regulators of muscle fiber size and function, indicators of cellular stress and mitochondrial function, myokines with potential antitumor effects, muscle strength, and cardiorespiratory fitness.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Regional Ethical Review Board in Uppsala, Sweden (Dnr:2016/230/2). Results will be disseminated through presentations at scientific meetings, publications in peer-reviewed journals, social media, and patient organizations.

TRIAL REGISTRATION NUMBER

NCT04586517.

Topoisomerases inhibition and DNA binding mode of daunomycin-oligoarginine conjugate

Cancer is a major health issue adsorbing the attention of a biomedical research. To fight this disease, new drugs are developed, specifically tailored to target biological pathways or peculiar components of the tumour cells. Particularly interesting is the use of intercalating agents as drugs capable to bind DNA and inhibit enzymes involved in DNA metabolism. Anthracyclines are the most commonly used anticancer drugs. In particular, daunomycin is used to cancer treatment by exploiting its ability to intercalate DNA and inhibit the activity of DNA topoisomerases implicated in the replication processes. Unfortunately, clinical application of anthracyclines is limited by their side effects. The conjugation with specific carriers could affect the selectivity and reduce side effect by improving stability and/or cellular uptake properties. We here report the biochemical characterisation of a daunomycin oligopeptide conjugate containing six residues of arginine, by the analysis of its fluorescence properties, DNA interaction and topoisomerases inhibitory effects.

Cardio-oncology for the general physician: 'old' and 'new' cardiovascular toxicities and how to manage them

Cardio-oncology is the care of cancer patients with cardiovascular disease. The need for a dedicated subspecialty emerged to address heart failure caused by drugs such as anthracyclines and anti-human epidermal growth factor receptor 2 (HER2) therapies, but over time has expanded into an exciting subspecialty with widening horizons. While still dealing with a lot of commonly recognised toxicities, such as heart failure, hypertension and coronary disease, new and revolutionary cancer therapies have been associated with challenging cardiovascular complications, requiring specialist input to manage effectively. Echocardiography is a key investigation, with advanced techniques such as three-dimensional and strain assessment allowing more accurate diagnosis and earlier detection of subtle changes. Cardiac magnetic resonance and biomarkers are useful adjuncts to aid diagnosis and management. With increasing cancer incidence and improved cancer survival rates, it is important that general cardiologists and physicians are aware of cardiac complications associated with cancer and how to manage them.

Prevention of anthracycline-induced cardiotoxicity: a systematic review and network meta-analysis

Background Anthracycline based chemotherapy is commonly used in many malignancies. While life expectancy increases with the use of this medication, cardiac toxicity causes a risk for patients' health due to anthracyclines. Objective This systematic review and meta-analysis emphasizes on prevention of anthracycline-associated cardiotoxicity in breast cancer and lymphoma patients. Methods We conducted a systematic review of electronic databases including PubMed, Medline, EMBASE, ClinicalTrials.gov, Web of Science, and the Cochrane Library from inception to June 2019 collecting published articles on primary prevention of anthracycline-associated cardiotoxicity in breast cancer and lymphoma patients. We conducted a network meta-analysis and a pairwise meta-analysis in order to compare direct and indirect cardiac agents group with control group calculate left ventricular ejection fraction change. Primary studies results were pooled using random effects model, frequent network meta-analyses, and performed pairwise meta-analysis using netmeta and meta packages respectively in R software version 3.5.1. Results Twelve studies reported left ventricular ejection fraction outcome among 526 patients in the cardiac agent group and 508 in the control group. Based on Surface Under the Cumulative Ranking cure result, spironolactone was the best in left ventricular ejection fraction change and based on meta-analysis, cardiac group had 1.98 unit left ventricular ejection fraction more than the control group (MD = 1.98, 95% CI 0.15-3.81, p value = 0.03). Conclusions The amount of left ventricular ejection fraction used by cardiac agents in anthracycline-based chemotherapy was reduced to a lesser extent. The effective and ineffective drugs were spironolactone and metoprolol, respectively.

Healthcare fragmentation and cardiovascular risk control among older cancer survivors in the Reasons for Geographic And Racial Differences in Stroke (REGARDS) study

Purpose:

Cardiovascular disease (CVD) is the number one cause of death among 5-year cancer survivors. Survivors see many providers and poor coordination may contribute to worse CVD risk factor control. We sought to determine associations between fragmentation and CVD risk factor control among survivors overall and by self-rated health.

Methods:

We included REGARDS participants aged 66+ years who: 1) had a cancer history; 2) reported diabetes, hypertension or hyperlipidemia; and 3) had continuous Medicare coverage. Twelve month ambulatory care fragmentation was calculated using the Bice-Boxerman Index (BBI). We determined associations between fragmentation and CVD risk factors, defining “control” as fasting glucose <126 mg/dL or non-fasting glucose <200 mg/dL for diabetes; blood pressure <140/90 mm Hg for hypertension; and total cholesterol <240 mg/dL, low-density lipoprotein cholesterol <160 mg/dL, or high-density lipoprotein cholesterol >40 mg/dL for hyperlipidemia.

Results:

The 1,002 cancer survivors (2+ years since cancer treatment) had mean age of 75 years, 39% were women, and 23% were Black. Among individuals with diabetes (N=225), hypertension (N=660), and hyperlipidemia (N=516), separately, approximately 60% had CVD risk factor control. Overall, more fragmented care was not associated with worse control. However, among cancer survivors with excellent, very good or good health, more fragmentation was associated with a decreased likelihood of diabetes control (OR 0.78, 95% CI 0.61–0.99), adjusting for confounders.

Conclusions:

More fragmented care was associated with worse glycemic control among cancer survivors with diabetes who reported excellent, very good, or good health. Associations were not observed for control of hypertension or hyperlipidemia.

Implications for cancer survivors:

Reducing fragmentation may support glucose control among survivors with diabetes.

Clinical and Research Tools for the Study of Cardiovascular Effects of Cancer Therapy

The expansion of cancer therapeutics has paved the way for improved cancer-related outcomes. Cardiotoxicity from cancer therapy occurs in a small but significant subset of patients, is often poorly understood, and contributes to adverse outcomes at all stages of cancer treatment. Given the often-idiopathic occurrence of cardiotoxicity, novel strategies are needed for risk-stratification and early identification of cancer patients experiencing cardiotoxicity. Clinical and research tools extending from imaging to blood-based biomarkers and pluripotent stem cells are being explored as methods to study the cardiovascular impact of various cancer treatments. Here we provide an overview of tools currently available for evaluation of cardiotoxicity and highlight novel techniques in development aimed at understanding underlying pathophysiologic mechanisms.

Burden of chronic diseases among sarcoma survivors treated with anthracycline chemotherapy: results from an observational study

Aim:

Cardiovascular disease is a leading cause of mortality among long-term cancer survivors treated with large total doses of doxorubicin. An increase in coronary artery disease (CAD) among childhood cancer survivors by age 45 has been observed and is driven by primarily anthracycline chemotherapy and to a lesser extent chest radiation that includes the heart in the radiation field. The risk factors and associated chronic diseases (hypertension, etc.) are well known for CAD and can be often prevented or treated, thus reducing the risk of CAD in these patients. We piloted a risk-based survivorship clinic in an academic medical center to characterize the distribution of risk factors for CAD and improve the quality of life in a population of sarcoma survivors treated with doxorubicin.

Methods:

We followed a prospective cohort of sixty-one survivors of bone and soft tissue sarcoma treated with doxorubicin chemotherapy (> 400 mg/m²) and at least 2 years post-therapy attending the sarcoma survivorship clinic. We collected clinical, demographic data, and patient reported outcomes via PROMIS questionnaires annually.

Results:

We demonstrated a high burden of chronic diseases in this population. Among six chronic conditions that are known risk factors for CAD (hypertension, diabetes, obesity, chronic inflammation, kidney disease and dyslipidemia), more than one-fourth (26%, 16/61) of patients had three or more of these risk factors at baseline visit, and 49% (30/61) had two or more.

Conclusion:

The results of this pilot study support the presence of modifiable CAD risk factors in this population of sarcoma survivors. Evidence-based guidelines for high-risk survivors of rare cancers are needed.

Yellow Wine Polyphenolic Compounds prevents Doxorubicin-induced cardiotoxicity through activation of the Nrf2 signalling pathway

Doxorubicin (DOX) is considered as the major culprit in chemotherapy‐induced cardiotoxicity. Yellow wine polyphenolic compounds (YWPC), which are full of polyphenols, have beneficial effects on cardiovascular disease. However, their role in DOX‐induced cardiotoxicity is poorly understood. Due to their antioxidant property, we have been suggested that YWPC could prevent DOX‐induced cardiotoxicity. In this study, we found that YWPC treatment (30 mg/kg/day) significantly improved DOX‐induced cardiac hypertrophy and cardiac dysfunction. YWPC alleviated DOX‐induced increase in oxidative stress levels, reduction in endogenous antioxidant enzyme activities and inflammatory response. Besides, administration of YWPC could prevent DOX‐induced mitochondria‐mediated cardiac apoptosis. Mechanistically, we found that YWPC attenuated DOX‐induced reactive oxygen species (ROS) and down‐regulation of transforming growth factor beta 1 (TGF‐β1)/smad3 pathway by promoting nuclear factor (erythroid‐derived 2)‐like 2 (Nrf2) nucleus translocation in cultured H9C2 cardiomyocytes. Additionally, YWPC against DOX‐induced TGF‐β1 up‐regulation were abolished by Nrf2 knockdown. Further studies revealed that YWPC could inhibit DOX‐induced cardiac fibrosis through inhibiting TGF‐β/smad3‐mediated ECM synthesis. Collectively, our results revealed that YWPC might be effective in mitigating DOX‐induced cardiotoxicity by Nrf2‐dependent down‐regulation of the TGF‐β/smad3 pathway.

Cancer therapy-induced cardiomyopathy: can human induced pluripotent stem cell modelling help prevent it?

Cardiotoxic effects from cancer therapy are a major cause of morbidity during cancer treatment. Unexpected toxicity can occur during treatment and/or after completion of therapy, into the time of cancer survivorship. While older drugs such as anthracyclines have well-known cardiotoxic effects, newer drugs such as tyrosine kinase inhibitors, proteasome inhibitors, and immunotherapies also can cause diverse cardiovascular and metabolic complications. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) are increasingly being used as instruments for disease modelling, drug discovery, and mechanistic toxicity studies. Promising results with hiPSC-CM chemotherapy studies are raising hopes for improving cancer therapies through personalized medicine and safer drug development. Here, we review the cardiotoxicity profiles of common chemotherapeutic agents as well as efforts to model them in vitro using hiPSC-CMs.

Echocardiography and Cardio-Oncology

Owing to the ongoing increase in cancer survivors because of the remarkable and continuous progress in cancer management, a paradigm shift is occurring from cancer as a 'terminal illness' to a 'chronic condition' with cardiovascular risks. This also affects cardiology practice with increased cardiovascular morbidity and mortality rates among patients with cancer due to direct and/or indirect side effects of anticancer treatment. Thus, cardio-oncology has emerged as a new cardiology subspecialty, which focusses on risk stratification, prevention, diagnosis, treatment, and follow-up of cardiovascular disease related to cancer treatment. This review summarises echocardiographic evaluation of cardiac dysfunction and heart failure as they are the most concerning cardiovascular complications of cancer therapy and worsen its morbidity and mortality. This review covers cardiac function assessment and proposed cut-off values before/during/after cancer chemotherapy. The goal of this review is to aid clinicians to manage the patients with cancer sufficiently by connecting the existing knowledge in clinical cardiology with novel information from current advances in cardio-oncology.

Doxorubicin-induced cardiotoxicity is maturation dependent due to the shift from topoisomerase IIα to IIβ in human stem cell derived cardiomyocytes

Doxorubicin (DOX) is widely used to treat various cancers affecting adults and children; however, its clinical application is limited by its cardiotoxicity. Previous studies have shown that children are more susceptible to the cardiotoxic effects of DOX than adults, which may be related to different maturity levels of cardiomyocyte, but the underlying mechanisms are not fully understood. Moreover, researchers investigating DOX‐induced cardiotoxicity caused by human‐induced pluripotent stem cell‐derived cardiomyocytes (hiPSC‐CMs) have shown that dexrazoxane, the recognized cardioprotective drug for treating DOX‐induced cardiotoxicity, does not alleviate the toxicity of DOX on hiPSC‐CMs cultured for 30 days. We have suggested that this may be ascribed to the immaturity of the 30 days hiPSC‐CMs. In this study, we investigated the mechanisms of DOX induced cardiotoxicity in cardiomyocytes of different maturity. We selected 30‐day‐old and 60‐day‐old hiPSC‐CMs (day 30 and day 60 groups), which we term ‘immature’ and ‘relatively mature’ hiPSC‐CMs, respectively. The day 30 CMs were found to be more susceptible to DOX than the day 60 CMs. DOX leads to more ROS (reactive oxygen species) production in the day 60 CMs than in the relatively immature group due to increased mitochondria number. Moreover, the day 60 CMs mainly expressed topoisomerase IIβ presented less severe DNA damage, whereas the day 30 CMs dominantly expressed topoisomerase IIα exhibited much more severe DNA damage. These results suggest that immature cardiomyocytes are more sensitive to DOX as a result of a higher concentration of topoisomerase IIα, which leads to more DNA damage.

Personalized medicine in cardio-oncology: the role of induced pluripotent stem cell

Treatment of cancer has evolved in the last decade with the introduction of new therapies. Despite these successes, the lingering cardiotoxic side-effects from chemotherapy remain a major cause of morbidity and mortality in cancer survivors. These effects can develop acutely during treatment, or even years later. Although many risk factors can be identified prior to beginning therapy, unexpected toxicity still occurs, often with lasting consequences. Specifically, cardiotoxicity results in cardiac cell death, eventually leading to cardiomyopathy and heart failure. Certain risk factors may predispose an individual to experiencing adverse cardiovascular effects, and when unexpected cardiotoxicity occurs, it is generally managed with supportive care. Animal models of chemotherapy-induced cardiotoxicity have provided some mechanistic insights, but the precise mechanisms by which these drugs affect the heart remains unknown. Moreover, the genetic rationale as to why some patients are more susceptible to developing cardiotoxicity has yet to be determined. Many genome-wide association studies have identified genomic variants that could be associated with chemotherapy-induced cardiotoxicity, but the lack of validation has made these studies more speculative rather than definitive. With the advent of human induced pluripotent stem cell (iPSC) technology, researchers not only have the opportunity to model human diseases, but also to screen drugs for their efficacy and toxicity using human cell models. Furthermore, it allows us to conduct validation studies to confirm the role of genomic variants in human diseases. In this review, we discuss the role of iPSCs in modelling chemotherapy-induced cardiotoxicity.

Cancer and the Broken Heart: Complications and Implications of Therapy-Related Cardiotoxicity

The growing number of adult long-term cancer survivors has expanded our knowledge of negative physiologic sequelae associated with curative therapies. Of note are the cardiovascular corollaries of chest radiotherapy and some commonly used chemotherapy agents. A contemporary understanding of risk factors has facilitated the development of guidelines for prevention and surveillance of cardiac compromise. The future holds promise with enhanced opportunities to use cardioprotectant drugs and biomarkers to prevent and detect early myocardial changes. Infusion therapy nurses must keep abreast of these developments to facilitate their roles as patient educators and advocates in the face of this toxicity's prevalence.

5-Fuorouracil Cardiotoxicity

Two cases of 5-fluorouracil cardiotoxicity, resulting in one patient in myocardial infarction, are described. A review of the literature confirms that cardiotoxicity is a rare but genuine complication of 5-fluorouracil treatment; the cardiotoxic effect seems to range from mild angina without persistent electrocardiographic changes to severe myocardial infarction. No factors predictive of this complication were identified. The authors therefore feel it is advisable to stop 5-fluorouracil treatment when precordial pain occurs, even if the ECG (after angina) is normal, since angina can in some cases result in myocardial infarction.

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

Objective:

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

Methods:

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

Results:

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

Conclusion:

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

Interventions for preventing cardiomyopathy due to anthracyclines: a Bayesian network meta-analysis

Background

The relative efficacy of interventions for primary prevention of anthracycline-associated cardiotoxicity is unknown.

Methods

We conducted a systematic review of randomized controlled trials for primary prevention of anthracycline-associated cardiotoxicity in adult cancer patients. We used hierarchal outcome definitions in the following order of priority: (1) composite of heart failure or decline in left ventricular ejection fraction, (2) decline in ejection fraction, or (3) heart failure. Data were analyzed using a Bayesian network meta-analysis with random effects.

Results

A total of 16 trials reported cardiotoxicity as a dichotomous outcome among 1918 patients, evaluating dexrazoxane, angiotensin antagonists, beta-blockers, combination angiotensin antagonists and beta-blockers, statins, Co-enzyme Q-10, prenylamine, and N-acetylcysteine. Compared with control, dexrazoxane reduced cardiotoxicity with a pooled odds ratio (OR) of 0.26 (95% credible interval [CrI] 0.11-0.74) and had the highest probability (33%) of being most effective. No other agent was demonstrably better than placebo. Angiotensin antagonists had an 84% probability of being most effective in a sensitivity analysis excluding one outlying study (OR 0.06 [95% CrI 0.01- 0.24]). When the outcome was restricted to heart failure, dexrazoxane was associated with an OR of 0.12 (95% CrI 0.06-0.23) relative to control and had 58% probability of being most effective, while angiotensin antagonists had an OR of 0.18 (95% CrI 0.05-0.55). Available data suggested that dexrazoxane and angiotensin antagonists did not affect malignancy response rate or risk of death.

Conclusion

Moderate quality data suggest that dexrazoxane, and low quality data suggest angiotensin antagonists, are likely to be effective for cardiotoxicity prevention.

Low-Dose Anthracycline and Risk of Heart Failure in a Pharmacokinetic Model of Human Myocardium Exposure: Analog Specificity and Role of Secondary Alcohol Metabolites

Cumulative doses of doxorubicin and other antitumor anthracyclines may cause heart failure (HF). Cardiotoxicity is determined by cardiac exposure to anthracyclines and to more toxic secondary alcohol metabolites that are formed inside cardiomyocytes or diffuse from the bloodstream. Concerns exist that HF might be caused by cumulative anthracycline doses that were thought to be safe. Patients with gain-of-function polymorphism of carbonyl reductase 3 (CBR3), which converts anthracyclines to secondary alcohol metabolites, would be at a higher risk of HF. Recently, a pharmacokinetic model was developed that simulated clinical exposure of human myocardium to anthracyclines and incorporated simulations of CBR3 polymorphism. It was shown that HF risk could occur after lower doxorubicin doses than previously reported, particularly for patients with CBR3 polymorphism. In this study, we show that also daunorubicin and idarubicin, but not epirubicin, might cause HF after reportedly safe cumulative doses. CBR3 polymorphism increased HF risk from daunorubicin and idarubicin to a greater extent as compared with doxorubicin. This was caused by daunorubicin and idarubicin forming higher levels of toxic metabolites in human myocardium; moreover, daunorubicin and idarubicin metabolites diffused from plasma and accumulated in cardiac tissue, whereas doxorubicin metabolite did not. CBR3 polymorphism did not aggravate HF risk from epirubicin, which was caused by the very low levels of formation of its toxic metabolite. These results support concerns about HF risk from low-dose anthracycline, characterize the analog specificity of HF risk, and illuminate the role of secondary alcohol metabolites.

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.

Breast cancer treatment-induced cardiotoxicity

INTRODUCTION

Breast cancer is the most frequent cancer affecting women worldwide. In every setting, the majority of women are treated with an evergrowing arsenal of therapeutic agents that have greatly improved their outcomes. However, these therapies can also be associated with significant adverse events. Areas covered: This review aims to thoroughly describe the current state of the evidence regarding the potential cardiotoxicity of agents commonly used in the treatment of breast cancer. These include chemotherapeutic agents, anti-HER2 therapies and CDK4/6 and mTOR inhibitors. Furthermore, issues related to the risk stratification and monitoring tools are explored. Expert opinion: Anthracycline- and trastuzumab-related cardiac toxicities have been extensively studied. Substantial evidence is now available concerning additional anti-HER2 agents such as pertuzumab, T-DM1 and tyrosine kinase inhibitors; overall, the cardiotoxicity profile is reassuring. Cardiac events due to endocrine therapy are mostly ischemic and, in the context of prolonged therapy, need specific attention. Novel agents implicated in the treatment of hormone receptor-positive disease are potentially arrhythmogenic and the exact risk will need to be further refined. As for today, assessment of baseline risk factors prior to treatment initiation and cardiac imaging before and during treatment remains the optimal way to prevent cardiac dysfunction. Cardioprotective therapy in primary prevention is still a matter of debate.

Developing a Comprehensive Cardio-Oncology Program at a Cancer Institute: The Moffitt Cancer Center Experience

Cardio-oncology is a multidisciplinary field focusing on the management and prevention of cardiovascular complications in cancer patients and survivors. While the initial focus of this specialty was on heart failure associated with anthracycline use, novel anticancer agents are increasingly utilized and are associated with many other cardiotoxicities including hypertension, arrhythmias and vascular disease. Since its inception, the field has developed at a rapid pace with the establishment of programs at many major academic institutions and community practices. Given the complexities of this patient population, it is important for providers to possess knowledge of not only cardiovascular disease but also cancer subtypes and their specific therapeutics. Developing a cardio-oncology program at a stand-alone cancer center can present unique opportunities and challenges when compared to those affiliated with other institutions including resource allocation, cardiovascular testing availability and provider education. In this review, we present our experiences establishing the cardio-oncology program at Moffitt Cancer Center and provide guidance to those individuals interested in developing a program at a similar independent cancer institution.

Yield of screening echocardiograms during pediatric follow-up in survivors treated with anthracyclines and cardiotoxic radiation

BACKGROUND

Guidelines published by the Children's Oncology Group recommend screening echocardiograms for childhood cancer survivors exposed to anthracyclines and/or cardiotoxic radiation. This study aims to assess risk factors for cardiac late effects while evaluating the overall yield of screening echocardiograms.

PROCEDURE

Demographics, exposures, and echocardiogram results were abstracted from the medical records of survivors diagnosed at ≤ 21 years old and ≥ 2 years off therapy who were exposed to anthracyclines and/or potentially cardiotoxic radiotherapy. Descriptive statistics and logistic regressions were performed and the yield of screening echocardiograms was calculated.

RESULTS

Of 853 patients, 1,728 screening echocardiograms were performed, and 37 patients had an abnormal echocardiogram (overall yield 2.1%). Yields were only somewhat higher in more frequently screened patients. Risk factors for an abnormal result included anthracycline dose of ≥300 mg/m² (adjusted odds ratio [aOR] 3.1; 95% confidence interval [CI]: 1.3-7.2; P < 0.01) with a synergist relationship in patients who also received radiation doses ≥30 Gy (aOR 7.0; 95% CI: 1.6-31.9; P = 0.01), as well as autologous bone marrow transplant (OR 3.3; 95% CI: 1.3-8.5; P = 0.01). Sex, race, age at diagnosis, and cyclophosphamide exposure were not statistically significant risk factors, and no patient receiving <100 mg/m² anthracycline dose without concomitant radiation had an abnormal echocardiogram.

CONCLUSIONS

Dose-dependent and synergist anthracycline and cardiotoxic radiotherapy risks for developing cardiomyopathy were confirmed. However, previously identified risk factors including female sex, black race, and early age at diagnosis were not replicated in this cohort. The yields showed weak correlation across frequency categories. Echocardiographic screening recommendations for low-risk pediatric patients may warrant re-evaluation.

Erythropoietin activates SIRT1 to protect human cardiomyocytes against doxorubicin-induced mitochondrial dysfunction and toxicity

The hormone erythropoietin (EPO) has been demonstrated to protect against chemotherapy drug doxorubicin (DOX)-induced cardiotoxicity, but the underlying mechanism remains obscure. We hypothesized that silent mating type information regulation 2 homolog 1 (SIRT1), an NAD⁺-dependent protein deacetylase that activates peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α), plays a crucial role in regulating mitochondrial function and mediating the beneficial effect of EPO. Our study in human cardiomyocyte AC16 cells showed that DOX-induced cytotoxicity and mitochondrial dysfunction, as manifested by decreased mitochondrial DNA (mtDNA) copy number, mitochondrial membrane potential, and increased mitochondrial superoxide accumulation, can be mitigated by EPO pretreatment. EPO was found to upregulate SIRT1 activity and protein expression to reverse DOX-induced acetylation of PGC-1α and suppression of a suite of PGC-1α-activated genes involved in mitochondrial function and biogenesis, such as nuclear respiratory factor-1 (NRF1), mitochondrial transcription factor A (TFAM), citrate synthase (CS), superoxide dismutase 2 (SOD2), cytochrome c oxidase IV (COXIV), and voltage-dependent anion channel (VDAC). Silencing of SIRT1 via small RNA interference sensitized AC16 cells to DOX-induced cytotoxicity and reduction in mtDNA copy number. Although with SIRT1 silenced, EPO could reverse to some extent DOX-induced mitochondrial superoxide accumulation, loss of mitochondrial membrane potential and ATP depletion, it failed to normalize protein expression of PGC-1α and its downstream genes. Taken together, our results indicated that EPO may activate SIRT1 to enhance mitochondrial function and protect against DOX-induced cardiotoxicity.

Cardiac Atrophy and Heart Failure In Cancer

Functional changes in the heart in patients with cancer can be a result of both the disease itself and various cancer therapies, and limiting cardiac damage has become an increasingly important issue as survival rates in patients with cancer have improved. Processes involved in cancer-induced cardiac atrophy may include cardiomyocyte atrophy and apoptosis, decreased protein synthesis, increased autophagy and proteolysis via the ubiquitin-proteosome system. Further to direct effects of malignancy on the heart, several chemotherapeutic agents are known to affect the myocardium, in particular the anthracyclines. The aim of this report is to review the effects of cancer and cancer treatment on the heart and what is known about the underlying mechanisms. Furthermore, clinical strategies to limit and treat cancer-associated cardiac atrophy are discussed, emphasising the benefit of a multidisciplinary approach by cardiologists and oncologists to optimise models of care to improve outcomes for patients with cancer.

Oncocardiology-Past, Present, and Future: A Review

Importance

Oncocardiology is a medical discipline that focuses on the identification, prevention, and treatment of cardiovascular complications related to cancer therapy. This discipline has gained interest from the cardiology community in recent years because of a remarkable increase in the number of cancer survivors and the proliferation of new cancer therapies causing cardiovascular complications, such as hypertension, heart failure, vascular complications, and cardiac arrhythmia. In this review, we provide historical perspectives, highlight new discoveries, and speculate on the opportunity created by merging the research interests and clinical practices of cardiology and oncology.

Observations

The old paradigm of anthracycline cardiotoxic effects is replaced by new insights that anthracycline targets topoisomerase II β to cause DNA double-strand breaks and a profound change in the transcriptome leading to the generation of reactive oxygen species and the development of mitochondriopathy. Prevention of anthracycline cardiotoxic effects should be based on inhibiting or degrading topoisomerase II β. New challenges were posed by the introduction of trastuzumab and tyrosine kinase inhibitors that revolutionized cancer therapy. The on-target cardiotoxic effects of trastuzumab were owing to a prosurvival benefit of Her2 that binds to neuregulin, whereas the off-target effect of multitargeted tyrosine kinase inhibitors may be mediated by disruption of the vascular endothelial growth factor signaling pathway or the stress-induced angiogenesis. Sensitive imaging techniques, such as global strain, and biomarkers have allowed for early detection of cardiotoxic effects. Early treatment with heart failure medications may be beneficial in preventing the development of late cardiotoxic effects.

Conclusions and Relevance

Close collaboration between cardiologists and oncologists is required to meet the demand of an increasing number of cancer survivors. New insights based on mechanistic studies or genetic discoveries will pave the way for better prevention, diagnosis, and treatment of cancer therapy-induced cardiovascular complications.

Cardiovascular disease in cancer survivors

Certain cancer therapies, including radiation therapy and some types of chemotherapies, are associated with increased risk of cardiovascular disease (CVD) and events. Some of these effects such as those presented by anthracyclines, radiation therapy, cisplatin, as well as those presented by hormone therapy for breast cancer-usually taken for many years for some breast and prostate cancers-are long-lasting and associated with cardiovascular events risk more than 20 years after cancer treatment. Cardiovascular testing, diagnostic assessment of suspected cardiovascular symptomatology, as well as laboratory tests for CVD risk factors are imperative. The early recognition and treatment of CVD processes that arise in survivorship years is pivotal, with specific attention to some CVD processes with specific suggested treatment modalities. Preventive measures include adequate screening, the use of medications such as ACE inhibitors/angiotensin receptor blockers and/or beta blockers, statin therapy and aspirin in persons who warrant these medications, as well as therapeutic lifestyle modifications such as exercise/physical activity, weight loss and appropriate diet for a healthy lifestyle. Periodic follow-up with a good primary care physician who understands the risks associated with cancer therapy is important, and referral to onco-cardiology for further management of cardiovascular risk in these survivors is based on a patient's cardiovascular risk level and the type, amount and duration of cancer therapies received during the patient's lifetime.

Late Cardiac Events after Childhood Cancer: Methodological Aspects of the Pan-European Study PanCareSurFup

Background and Aim

Childhood cancer survivors are at high risk of long-term adverse effects of cancer and its treatment, including cardiac events. The pan-European PanCareSurFup study determined the incidence and risk factors for cardiac events among childhood cancer survivors. The aim of this article is to describe the methodology of the cardiac cohort and nested case-control study within PanCareSurFup.

Methods

Eight data providers in Europe participating in PanCareSurFup identified and validated symptomatic cardiac events in their cohorts of childhood cancer survivors. Data on symptomatic heart failure, ischemia, pericarditis, valvular disease and arrhythmia were collected and graded according to the Criteria for Adverse Events. Detailed treatment data, data on potential confounders, lifestyle related risk factors and general health problems were collected.

Results

The PanCareSurFup cardiac cohort consisted of 59,915 5-year childhood cancer survivors with malignancies diagnosed between 1940 and 2009 and classified according to the International Classification of Childhood Cancer 3. Different strategies were used to identify cardiac events such as record linkage to population/ hospital or regional based databases, and patient- and general practitioner-based questionnaires.

Conclusion

The cardiac study of the European collaborative research project PanCareSurFup will provide the largest cohort of 5-year childhood cancer survivors with systematically ascertained and validated data on symptomatic cardiac events. The result of this study can provide information to minimize the burden of cardiac events in childhood cancer survivors by tailoring the follow-up of childhood cancer survivors at high risk of cardiac adverse events, transferring this knowledge into evidence-based clinical practice guidelines and providing a platform for future research studies in childhood cancer patients. 

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

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

Coenzyme Q10 for Prevention of Anthracycline-Induced Cardiotoxicity

Preclinical and clinical studies suggest that anthracycline-induced cardiotoxicity can be prevented by administering coenzyme Q10 during cancer chemotherapy that includes drugs such as doxorubicin and daunorubicin. Studies further suggest that coenzyme Q10 does not interfere with the antineoplastic action of anthracyclines and might even enhance their anticancer effects. Preventing cardiotoxicity might allow for escalation of the anthracycline dose, which would further enhance the anticancer effects. Based on clinical investigation, although limited, a cumulative dose of doxorubicin of up to 900 mg/m2, and possibly higher, can be administered safely during chemotherapy as long as coenzyme Q10 is administered concurrently. The etiology of the dose-limiting cardiomyopathy that is induced by anthracyclines can be explained by irreversible damage to heart cell mitochondria, which differ from mitochondria of other cells in that they possess a unique enzyme on the inner mitochondrial membrane. This enzyme reduces anthracyclines to their semiquinones, resulting in severe oxidative stress, disruption of mitochondrial energetics, and irreversible damage to mitochondrial DNA. Damage to mitochondrial DNA blocks the regenerative capability of the organelle and ultimately leads to apoptosis or necrosis of myocytes. Coenzyme Q10, an essential component of the electron transport system and a potent intracellular antioxidant, appears to prevent damage to the mitochondria of the heart, thus preventing the development of anthracycline-induced cardiomyopathy.

Model-based contextualization of in vitro toxicity data quantitatively predicts in vivo drug response in patients

Understanding central mechanisms underlying drug-induced toxicity plays a crucial role in drug development and drug safety. However, a translation of cellular in vitro findings to an actual in vivo context remains challenging. Here, physiologically based pharmacokinetic (PBPK) modeling was used for in vivo contextualization of in vitro toxicity data (PICD) to quantitatively predict in vivo drug response over time by integrating multiple levels of biological organization. Explicitly, in vitro toxicity data at the cellular level were integrated into whole-body PBPK models at the organism level by coupling in vitro drug exposure with in vivo drug concentration–time profiles simulated in the extracellular environment within the organ. PICD was exemplarily applied on the hepatotoxicant azathioprine to quantitatively predict in vivo drug response of perturbed biological pathways and cellular processes in rats and humans. The predictive accuracy of PICD was assessed by comparing in vivo drug response predicted for rats with observed in vivo measurements. To demonstrate clinical applicability of PICD, in vivo drug responses of a critical toxicity-related pathway were predicted for eight patients following acute azathioprine overdoses. Moreover, acute liver failure after multiple dosing of azathioprine was investigated in a patient case study by use of own clinical data. Simulated pharmacokinetic profiles were therefore related to in vivo drug response predicted for genes associated with observed clinical symptoms and to clinical biomarkers measured in vivo. PICD provides a generic platform to investigate drug-induced toxicity at a patient level and thus may facilitate individualized risk assessment during drug development.

Anthracycline-Induced Cardiomyopathy in Adults

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