Cardiovascular side effects of cancer therapies: a position statement from the Heart Failure Association of the European Society of Cardiology

Experimental determination of diagnostic window of cardiac troponins in the development of chronic anthracycline cardiotoxicity and estimation of its predictive value

BACKGROUND

Cardiac troponins (cTns) seem to be more sensitive for the detection of anthracycline cardiotoxicity than the currently recommended method of monitoring LV systolic function. However, the optimal timing of blood sampling remains unknown. Hence, the aims of the present study were to determine the precise diagnostic window for cTns during the development of chronic anthracycline cardiotoxicity and to evaluate their predictive value.

METHODS

Cardiotoxicity was induced in rabbits with daunorubicin (3mg/kg, weekly, for 8 weeks). Blood samples were collected 2-168 h after the 1st, 5th and 8th drug administrations, and concentrations of cTns were determined using highly sensitive assays: hs cTnT (Roche) and hs cTnI (Abbott).

RESULTS

The plasma levels of cTns progressively increased with the rising number of chemotherapy cycles. While only a mild non-significant increase in both cTn levels occurred after the first daunorubicin dose, a significant rise was observed after the 5th and 8th administrations. Two hours after these administrations, a significant increase occurred with a peak between 4-6h and a decline until 24h. Discrete cTn release continued even after cessation of the therapy. While greater variability of cTn levels was observed around the peak concentrations, the values did not correspond well with the severity of LV systolic dysfunction. Unlike AMI in cardiotoxicity, cTn elevations may be better associated with cumulative dose and concentrations at steady state than cmax.

CONCLUSIONS

To the best of our knowledge, this is the first study to precisely describe the diagnostic window and predictive value of cTns in anthracycline cardiotoxicity.

Longitudinal Changes in Multiple Biomarkers Are Associated with Cardiotoxicity in Breast Cancer Patients Treated with Doxorubicin, Taxanes, and Trastuzumab

BACKGROUND

Biomarkers may play an important role in identifying patients at risk for cancer therapy cardiotoxicity. Our objectives were to define the patterns of change in biomarkers with cancer therapy and their associations with cardiotoxicity.

METHODS

In a multicenter cohort of 78 breast cancer patients undergoing doxorubicin and trastuzumab therapy, 8 biomarkers were evaluated at baseline and every 3 months over a maximum follow-up of 15 months. These biomarkers, hypothesized to be mechanistically relevant to cardiotoxicity, included high-sensitivity cardiac troponin I (hs-cTnI), high-sensitivity C-reactive protein (hsCRP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), growth differentiation factor 15 (GDF-15), myeloperoxidase (MPO), placental growth factor (PlGF), soluble fms-like tyrosine kinase receptor-1 (sFlt-1), and galectin 3 (gal-3). We determined if biomarker increases were associated with cardiotoxicity at the same visit and the subsequent visit over the entire course of therapy. Cardiotoxicity was defined by the Cardiac Review and Evaluation Criteria; alternative definitions were also considered.

RESULTS

Across the entire cohort, all biomarkers except NT-proBNP and gal-3 demonstrated increases by 3 months; these increases persisted for GDF-15, PlGF, and hs-cTnI at 15 months. Increases in MPO, PlGF, and GDF-15 were associated with cardiotoxicity at the same visit [MPO hazard ratio 1.38 (95% CI 1.10-1.71), P = 0.02; PlGF 3.78 (1.30-11.0), P = 0.047; GDF-15 1.71 (1.15-2.55), P = 0.01] and the subsequent visit. MPO was robust to alternative outcome definitions.

CONCLUSIONS

Increases in MPO are associated with cardiotoxicity over the entire course of doxorubicin and trastuzumab therapy. Assessment with PlGF and GDF-15 may also be of value. These findings motivate validation studies in additional cohorts.

Relationship Between Cancer and Cardiovascular Outcomes Following Percutaneous Coronary Intervention

Background

Cardiovascular disease and cancer increasingly coexist, yet relationships between cancer and long-term cardiovascular outcomes post–percutaneous coronary intervention (PCI) are not well studied.

Methods and Results

We examined stented PCI patients at Duke (1996–2010) using linked data from the Duke Information Systems for Cardiovascular Care and the Duke Tumor Registry (a cancer treatment registry). Our primary outcome was cardiovascular mortality. Secondary outcomes included composite cardiovascular mortality, myocardial infarction, or repeat revascularization and all-cause mortality. We used adjusted cause-specific hazard models to examine outcomes among cancer patients (cancer treatment pre-PCI) versus controls (no cancer treatment pre-PCI). Cardiovascular mortality was explored in a cancer subgroup with recent (within 1 year pre-PCI) cancer and in post-PCI cancer patients using post-PCI cancer as a time-dependent variable. Among 15 008 patients, 3.3% (n=496) were cancer patients. Observed rates of 14-year cardiovascular mortality (31.4% versus 27.7%, P=0.31) and composite cardiovascular death, myocardial infarction, or revascularization (51.1% versus 55.8%, P=0.37) were similar for cancer versus control groups; all-cause mortality rates were higher (79.7% versus 49.3%, P<0.01). Adjusted risk of cardiovascular mortality was similar for cancer patients versus controls (hazard ratio 0.95; 95% CI 0.76 to 1.20) and for patients with versus without recent cancer (hazard ratio 1.46; 95% CI 0.92 to 2.33). Post-PCI cancer, present in 4.3% (n=647) of patients, was associated with cardiovascular mortality (adjusted hazard ratio 1.51; 95% CI 1.11 to 2.03).

Conclusions

Cancer history was present in a minority of PCI patients but was not associated with worse long-term cardiovascular outcomes. Further investigation into PCI outcomes in this population is warranted.

Heart failure years after cancer treatment

Progress in cancer treatment has significantly improved survival of patients with cancer. However, the incidence of cardiovascular diseases such as left ventricular dysfunction (LVD) and chronic heart failure (HF) is increasing due to the long-term toxic effects of chemotherapy and radiotherapy. Cardio-oncology teams are necessary to ensure the implementation of primary prevention strategies and screening protocols for early recognition of LVD. Moreover, early administration of advanced treatment for HF is crucial to achieve left ventricular recovery. In this article we will focus on the prevalence of chronic HF among cancer survivors, the main risk factors of LVD and chronic HF, the prevention strategies and management based on the current evidence and, finally, the future perspectives in this field.

Chemotherapy-related Cardiomyopathy

Advances in chemotherapeutic agents have resulted in significantly improved cancer survival rates. Cardiac toxicity, however, has emerged as a leading cause of morbidity, both during and years after treatment. One of the most common manifestations of cardiotoxicity is that of heart failure and left ventricular systolic dysfunction. In this review, current opinions and guidelines in this field are discussed, with particular focus on the most common culprits, the anthracyclines, and the monoclonal antibody, trastuzumab.

Identifying cancer patients at risk for cardiotoxicity

Improvements in therapies have significantly changed survival of cancer patients. However, the clinical history and oncologic treatment put cancer patients at higher risk for developing cardiovascular problems. Anthracyclines, but also the targeted therapy and angiogenesis inhibitors, are all treatments associated with cardiotoxicity. The most common adverse event is a reduction in left ventricular ejection fraction that may progress to overt heart failure. Recognition of a cardiac impairment during or after a potential cardiotoxic treatment requires a stringent assessment of clinical symptoms and signs of heart failure associated with an evaluation of the left ventricular ejection fraction, which, however, detects the damage already installed. Circulating cardiac biomarkers are promising in detecting cardiotoxicity and will likely change the approach for identifying patients at risk.

Cardiotoxicity from the cardiologist's perspective

Screening programs and contemporary multidisciplinary management of oncologic patients have resulted in lower mortality and improved outcomes. Nevertheless, treatment-related cardiac toxicity has been recognized as a major side effect, negatively affecting quality of life and prognosis in cancer survivors. Physicians involved in the care of these patients should be familiar with the effects of chemotherapy and radiotherapy on the heart, as well as the tests that may facilitate early diagnosis and prompt referral to cardiology units with expertise in the management of oncologic patients. This special report focuses on the mechanisms of cardiotoxicity and the techniques (including basic and advanced imaging and biomarkers) used in the cardiac evaluation of cancer patients.

Heart failure and chemotherapeutic agents

Advances in chemotherapeutic agents over the past two decades have resulted in significantly improved cancer survival rates. Cardiac toxicity, however, has emerged as a leading cause of morbidity, both during and years after treatment. One of the most common manifestations of cardiotoxicity is that of heart failure and left ventricular systolic dysfunction. Consequently, the field of cardio-oncology is a rapidly emerging field of sub-specialty, with growing research interests in all aspects of management. In this review, current opinions and guidelines in this field are discussed, with particular focus on the most common culprits, the anthracyclines and the monoclonal antibody, trastuzumab.

Early detection of anthracycline cardiotoxicity and improvement with heart failure therapy

BACKGROUND

Three types of anthracycline-induced cardiotoxicities are currently recognized: acute, early-onset chronic, and late-onset chronic. However, data supporting this classification are lacking. We prospectively evaluated incidence, time of occurrence, clinical correlates, and response to heart failure therapy of cardiotoxicity.

METHODS AND RESULTS

We assessed left ventricular ejection fraction (LVEF), at baseline, every 3 months during chemotherapy and for the following year, every 6 months over the following 4 years, and yearly afterward in a heterogeneous cohort of 2625 patients receiving anthracycline-containing therapy. In case of cardiotoxicity (LVEF decrease >10 absolute points, and <50%), heart failure therapy was initiated. Recovery from cardiotoxicity was defined as partial (LVEF increase >5 absolute points and >50%) or full (LVEF increase to the baseline value). The median follow-up was 5.2 (quartile 1 to quartile 3, 2.6-8.0) years. The overall incidence of cardiotoxicity was 9% (n=226). The median time elapsed between the end of chemotherapy and cardiotoxicity development was 3.5 (quartile 1 to quartile 3, 3-6) months. In 98% of cases (n=221), cardiotoxicity occurred within the first year. Twenty-five (11%) patients had full recovery, and 160 (71%) patients had partial recovery. At multivariable analysis, end-chemotherapy LVEF (hazard ratio, 1.37; 95% confidence interval, 1.33-1.42 for each percent unit decrement) and cumulative doxorubicin dose (hazard ratio, 1.09; 95% confidence interval, 1.04-1.15 for each 50 mg/m(2) increment) were independent correlates of cardiotoxicity.

CONCLUSIONS

Most cardiotoxicity after anthracycline-containing therapy occurs within the first year and is associated with anthracycline dose and LVEF at the end of treatment. Early detection and prompt therapy of cardiotoxicity appear crucial for substantial recovery of cardiac function.

The EJHF last Editor's legacy: how can a high impact factor be built?

The European Journal of Heart Failure (EJHF) has reached a high impact factor making it one of the most important cardiology journals. I discuss herein what could be the main causes of such high ranking. Publication of the European Society of Cardiology guidelines for the diagnosis and treatment of acute and chronic heart failure has had the most important role with a number of citations, which has been approximately 10 times that of the other most cited articles of the same year. Other position statements, reviews, design papers, and research articles about landmark topics have given major contributions. With respect to the different clinical presentations, articles about heart failure with preserved ejection fraction and about advanced heart failure have gained many citations. Epidemiology, biomarkers, medical treatment, and devices have attracted most of the interest. In conclusion, being able to look ahead and to publish what is going to become important remains a major challenge. That of EJHF has been a success story, to date, and learning from the past may help to build upon this achievement.

SIRT1 activation rescues doxorubicin-induced loss of functional competence of human cardiac progenitor cells

BACKGROUND

The search for compounds able to counteract chemotherapy-induced heart failure is extremely important at the age of global cancer epidemic. The role of SIRT1 in the maintenance of progenitor cell homeostasis may contribute to its cardioprotective effects. SIRT1 activators, by preserving progenitor cells, could have a clinical relevance for the prevention of doxorubicin (DOXO)-cardiotoxicity.

METHODS

To determine whether SIRT1 activator, resveratrol (RES), interferes with adverse effects of DOXO on cardiac progenitor cells (CPCs): 1) human CPCs (hCPCs) were exposed in vitro to DOXO or DOXO+RES and their regenerative potential was tested in vivo in an animal model of DOXO-induced heart failure; 2) the in vivo effects of DOXO+RES co-treatment on CPCs were studied in a rat model.

RESULTS

In contrast to healthy cells, DOXO-exposed hCPCs were ineffective in a model of anthracycline cardiomyopathy. The in vitro activation of SIRT1 decreased p53 acetylation, overcame suppression of the IGF-1/Akt pro-survival and anti-apoptotic signaling, enhanced oxidative stress defense and prevented senescence and growth arrest of hCPCs. Priming with RES counterbalanced the onset of dysfunctional phenotype in DOXO-exposed hCPCs, partly restoring their ability to repair the damage with improvement in cardiac function and animal survival. The in vivo co-treatment DOXO+RES prevented the anthracycline-induced alterations in CPCs, partly preserving cardiac function.

CONCLUSION

SIRT1 activation protects DOXO-exposed CPCs and re-establishes their proper function. Pharmacological intervention at the level of tissue-specific progenitor cells may provide cardiac benefits for the growing population of long-term cancer survivors that are at risk of chemotherapy-induced cardiovascular toxicity.

Large-scale automatic extraction of side effects associated with targeted anticancer drugs from full-text oncological articles

Targeted anticancer drugs such as imatinib, trastuzumab and erlotinib dramatically improved treatment outcomes in cancer patients, however, these innovative agents are often associated with unexpected side effects. The pathophysiological mechanisms underlying these side effects are not well understood. The availability of a comprehensive knowledge base of side effects associated with targeted anticancer drugs has the potential to illuminate complex pathways underlying toxicities induced by these innovative drugs. While side effect association knowledge for targeted drugs exists in multiple heterogeneous data sources, published full-text oncological articles represent an important source of pivotal, investigational, and even failed trials in a variety of patient populations. In this study, we present an automatic process to extract targeted anticancer drug-associated side effects (drug-SE pairs) from a large number of high profile full-text oncological articles. We downloaded 13,855 full-text articles from the Journal of Oncology (JCO) published between 1983 and 2013. We developed text classification, relationship extraction, signaling filtering, and signal prioritization algorithms to extract drug-SE pairs from downloaded articles. We extracted a total of 26,264 drug-SE pairs with an average precision of 0.405, a recall of 0.899, and an F1 score of 0.465. We show that side effect knowledge from JCO articles is largely complementary to that from the US Food and Drug Administration (FDA) drug labels. Through integrative correlation analysis, we show that targeted drug-associated side effects positively correlate with their gene targets and disease indications. In conclusion, this unique database that we built from a large number of high-profile oncological articles could facilitate the development of computational models to understand toxic effects associated with targeted anticancer drugs.

Cardiovascular toxicity of multi-tyrosine kinase inhibitors in advanced solid tumors: a population-based observational study

Background

Treatment with small molecule tyrosine kinase inhibitors (TKIs) has improved survival in many cancers, yet has been associated with an increased risk of adverse events. Warnings of cardiovascular events are common in drug labels of many TKIs. Despite these warnings, cardiovascular toxicity of patients treated with TKIs remains unclear. Here, we evaluate the cardiovascular outcomes of advanced cancer patients treated with small molecule tyrosine kinase inhibitors.

Methods

A population based cohort study was undertaken involving adults aged >18 years in Ontario, Canada, diagnosed with any advanced malignancy between 2006 and 2012. Data were extracted from linked administrative governmental databases. Adults with advanced cancer receiving TKIs were identified and followed throughout the time period. The main outcomes of interest were rates of hospitalization for ischemic heart disease (acute myocardial infarction and angina) or cerebrovascular accidents and death.

Results

1642 patients with a mean age of 62.5 years were studied; 1046 were treated with erlotinib, 166 with sorafenib and 430 with sunitinib. Over the 380 day median follow-up period (range 6-1970 days), 1.1% of all patients had ischemic heart events, 0.7% had cerebrovascular accidents and 72.1% died. Rates of cardiovascular events were similar to age and gender-matched individuals without cancer. In a subgroup analysis of treatment patients with a prior history of ischemic heart disease, 3.3% had ischemic heart events while 1.2% had cerebrovascular accidents.

Conclusions

TKIs do not appear to increase the cause-specific hazard of ischemic heart disease and cerebrovascular accidents compared to age and gender-matched individuals without advanced cancer.

Evaluation, prevention and management of cancer therapy-induced cardiotoxicity: a contemporary approach for clinicians

PURPOSE OF REVIEW

While targeted therapies have improved cancer outcomes, unique cardiovascular toxicities are increasingly recognized, particularly when administered sequentially after anthracyclines or radiation. Patients with cancer therapy-induced cardiotoxicity benefit from collaborative care involving cardiology and oncology, leading to a new interdisciplinary field called cardio-oncology. The present review will highlight contemporary clinical issues in cardio-oncology.

RECENT FINDINGS

Recently, risk factors for cancer therapy-induced cardiotoxicity have been evaluated in real-world rather than in clinical trial patients. Biomarkers and advanced echocardiography are emerging as sensitive tools for preclinical identification of cancer therapy-induced cardiotoxicity. Single-center studies suggest that cancer therapy-induced cardiotoxicity responds to prompt heart failure medical treatment, and such therapy may even prevent cardiotoxicity.

SUMMARY

Modern cancer therapy has short-term cardiac risk that may require collaborative management by clinicians with expertise in cardiology and oncology. The increased effectiveness of modern cancer therapy is resulting in a growing population of cancer survivors who are at long-term risk for cardiovascular disease. The present review of contemporary clinical issues in cardio-oncology will be of interest to healthcare providers who manage cardiotoxicity during cancer therapy, and who follow patients who survive cancer but face increased long-term cardiovascular risk.

Individualized cardiovascular risk assessment by cardiovascular magnetic resonance

Cardiovascular magnetic resonance (CMR) is gaining clinical importance in preventive medicine. Evidence on diagnostic accuracy and prognostic value, in addition to the development of faster imaging, increased availability of equipment and imaging expertise have led to a wide-spread use of CMR in a growing number of clinical indications. The first part of this review summarizes the role of CMR biomarkers for risk assessment focusing on the patients groups that benefit from the use of CMR. In the second part, the future directions for CMR are discussed and their role in prevention of cardiovascular disease.

Use of biomarkers for the assessment of chemotherapy-induced cardiac toxicity

OBJECTIVES

To review the evidence for the use of various biomarkers in the detection of chemotherapy associated cardiac damage.

DESIGN AND METHODS

Pubmed.gov was queried using the search words chemotherapy and cardiac biomarkers with the filters of past 10years, humans, and English language. An emphasis was placed on obtaining primary research articles looking at the utility of biomarkers for the detection of chemotherapy-mediated cardiac injury.

RESULTS

Biomarkers may help identify patients undergoing treatment who are at high risk for cardiotoxicity and may assist in identification of a low risk cohort that does not necessitate continued intensive screening. cTn assays are the best studied biomarkers in this context and may represent a promising and potentially valuable modality for detecting cardiac toxicity in patients undergoing chemotherapy. Monitoring cTnI levels may provide information regarding the development of cardiac toxicity before left ventricular dysfunction becomes apparent on echocardiography or via clinical symptoms. A host of other biomarkers have been evaluated for their utility in the field of chemotherapy related cardiac toxicity with intermittent success; further trials are necessary to determine what role they may end up playing for prediction and prognostication in this setting.

CONCLUSIONS

Biomarkers represent an exciting potential complement or replacement for echocardiographic monitoring of chemotherapy related cardiac toxicity which may allow for earlier realization of the degree of cardiac damage occurring during treatment, creating the opportunity for more timely modulation of therapy.

Engineered nanoparticles: thrombotic events in cancer

Engineered nanoparticles are being increasingly produced for specific applications in medicine. Broad selections of nano-sized constructs have been developed for applications in diagnosis, imaging, and drug delivery. Nanoparticles as contrast agents enable conjugation with molecular markers which are essential for designing effective diagnostic and therapeutic strategies. Such investigations can also lead to a better understanding of disease mechanisms such as cancer-associated thrombosis which remains unpredictable with serious bleeding complications and high risk of death. Here we review the recent and current applications of engineered nanoparticles in diagnosis and therapeutic strategies, noting their toxicity in relation to specific markers as a target.

Stem cell therapy and breast cancer treatment: review of stem cell research and potential therapeutic impact against cardiotoxicities due to breast cancer treatment

A new problem has emerged with the ever-increasing number of breast cancer survivors. While early screening and advances in treatment have allowed these patients to overcome their cancer, these treatments often have adverse cardiovascular side effects that can produce abnormal cardiovascular function. Chemotherapeutic and radiation therapy have both been linked to cardiotoxicity; these therapeutics can cause a loss of cardiac muscle and deterioration of vascular structure that can eventually lead to heart failure (HF). This cardiomyocyte toxicity can leave the breast cancer survivor with a probable diagnosis of dilated or restrictive cardiomyopathy (DCM or RCM). While current HF standard of care can alleviate symptoms, other than heart transplantation, there is no therapy that replaces cardiac myocytes that are killed during cancer therapies. There is a need to develop novel therapeutics that can either prevent or reverse the cardiac injury caused by cancer therapeutics. These new therapeutics should promote the regeneration of lost or deteriorating myocardium. Over the last several decades, the therapeutic potential of cell-based therapy has been investigated for HF patients. In this review, we discuss the progress of pre-clinical and clinical stem cell research for the diseased heart and discuss the possibility of utilizing these novel therapies to combat cardiotoxicity observed in breast cancer survivors.

Cancer cachexia: understanding the molecular basis

Cancer cachexia is a devastating, multifactorial and often irreversible syndrome that affects around 50-80% of cancer patients, depending on the tumour type, and that leads to substantial weight loss, primarily from loss of skeletal muscle and body fat. Since cachexia may account for up to 20% of cancer deaths, understanding the underlying molecular mechanisms is essential. The occurrence of cachexia in cancer patients is dependent on the patient response to tumour progression, including the activation of the inflammatory response and energetic inefficiency involving the mitochondria. Interestingly, crosstalk between different cell types ultimately seems to result in muscle wasting. Some of the recent progress in understanding the molecular mechanisms of cachexia may lead to new therapeutic approaches.

Dual loss of PI3Kα and PI3Kγ signaling leads to an age-dependent cardiomyopathy

Phosphatidylinositide 3-kinase (PI3K) signaling plays a critical role in maintaining normal cardiac structure and function. PI3Kα and PI3Kγ are the dominant cardiac isoforms and have both adaptive and maladaptive roles in heart disease. Broad spectrum PI3K inhibitors are emerging as potential new chemotherapeutic agents which may have deleterious long-term effects on the heart. We created a double mutant (PI3KDM) model by crossing p110γ(-/-) (PI3KγKO) with cardiac-specific PI3KαDN mice and studied cardiac structure and function at 1-year of age. Pressure-volume loop analysis and echocardiographic assessment showed PI3KDM mice developed marked impairment in systolic function while the wildtype, PI3KαDN, and PI3KγKO mice maintained normal systolic and diastolic function at 1-year of age. The PI3KDM hearts displayed increased expression of disease markers, increased myocardial fibrosis and matrix metalloproteinase (MMP) activity, depolymerization of intracellular F-actin, loss of phospho(threonine-308)-Akt, and normalization of phospho-Erk1/2 signaling. Dual loss of PI3Kα and PI3Kγ isoforms results in an age-dependent cardiomyopathy implying that long-term exposure to pan-PI3K inhibitors may lead to severe cardiotoxicity.

HGF/Met Axis in Heart Function and Cardioprotection

Hepatocyte growth factor (HGF) and its tyrosine kinase receptor (Met) play important roles in myocardial function both in physiological and pathological situations. In the developing heart, HGF influences cardiomyocyte proliferation and differentiation. In the adult, HGF/Met signaling controls heart homeostasis and prevents oxidative stress in normal cardiomyocytes. Thus, the possible cardiotoxicity of current Met-targeted anti-cancer therapies has to be taken in consideration. In the injured heart, HGF plays important roles in cardioprotection by promoting: (1) prosurvival (anti-apoptotic and anti-autophagic) effects in cardiomyocytes, (2) angiogenesis, (3) inhibition of fibrosis, (4) anti-inflammatory and immunomodulatory signals, and (5) regeneration through activation of cardiac stem cells. Furthermore, we discuss the putative role of elevated HGF as prognostic marker of severity in patients with cardiac diseases. Finally, we examine the potential of HGF-based molecules as new therapeutic tools for the treatment of cardiac diseases.

Concomitant low-dose doxorubicin treatment and exercise

Cardiotoxicity is a side effect for cancer patients treated with doxorubicin (DOX). We tested the hypothesis that low-intensity aerobic exercise concomitant with DOX treatment would offset DOX-induced cardiotoxicity while also improving the therapeutic efficacy of DOX on tumor progression. B16F10 melanoma cells (3 × 10(5)) were injected subcutaneously into the scruff of 6- to 8-wk-old male C57BL/6 mice (n = 48). A 4 mg/kg cumulative dose of DOX was administered over 2 wk, and exercise (EX) consisted of treadmill walking (10 m/min, 45 min/day, 5 days/wk, 2 wk). Four experimental groups were tested: 1) sedentary (SED) + vehicle, 2) SED + DOX, 3) EX + vehicle, and 4) EX + DOX. Tumor volume was attenuated in DOX and lowest in EX + DOX. DOX-treated animals had less gain in body weight, reduced heart weights (HW), smaller HW-to-body weight ratios, and shorter tibial lengths by the end of the protocol; and exercise did not reverse the cardiotoxic effects of DOX. Despite decreased left ventricular (LV) mass with DOX, cardiomyocyte cross-sectional area, β-myosin heavy chain gene expression, and whole heart systolic (fractional shortening) and diastolic (E/A ratio) function were similar among groups. DOX also resulted in increased LV fibrosis with lower LV end diastolic volume and stroke volume. Myocardial protein kinase B activity was increased with both DOX and EX treatments, and tuberous sclerosis 2 (TSC2) abundance was reduced with EX. Downstream phosphorylation of TSC2 and mammalian target of rapamycin were similar across groups. We conclude that exercise increases the efficacy of DOX in inhibiting tumor growth without mitigating subclinical DOX-induced cardiotoxicity in a murine model of melanoma.

Patient-Reported Outcome Measures in Safety Event Reporting: PROSPER Consortium guidance

The Patient-Reported Outcomes Safety Event Reporting (PROSPER) Consortium was convened to improve safety reporting by better incorporating the perspective of the patient. PROSPER comprises industry, regulatory authority, academic, private sector and patient representatives who are interested in the area of patient-reported outcomes of adverse events (PRO-AEs). It has developed guidance on PRO-AE data, including the benefits of wider use and approaches for data capture and analysis. Patient-reported outcomes (PROs) encompass the full range of self-reporting, rather than only patient reports collected by clinicians using validated instruments. In recent years, PROs have become increasingly important across the spectrum of healthcare and life sciences. Patient-centred models of care are integrating shared decision making and PROs at the point of care; comparative effectiveness research seeks to include patients as participatory stakeholders; and industry is expanding its involvement with patients and patient groups as part of the drug development process and safety monitoring. Additionally, recent pharmacovigilance legislation from regulatory authorities in the EU and the USA calls for the inclusion of patient-reported information in benefit-risk assessment of pharmaceutical products. For patients, technological advancements have made it easier to be an active participant in one's healthcare. Simplified internet search capabilities, electronic and personal health records, digital mobile devices, and PRO-enabled patient online communities are just a few examples of tools that allow patients to gain increased knowledge about conditions, symptoms, treatment options and side effects. Despite these changes and increased attention on the perceived value of PROs, their full potential has yet to be realised in pharmacovigilance. Current safety reporting and risk assessment processes remain heavily dependent on healthcare professionals, though there are known limitations such as under-reporting and discordant perspectives between patient reports and clinician perceptions of adverse outcomes. PROSPER seeks to support the wider use of PRO-AEs. The scope of this guidance document, which was completed between July 2011 and March 2013, considered a host of domains related to PRO-AEs, including definitions and suitable taxonomies, the range of datasets that could be used, data collection mechanisms, and suitable analytical methodologies. PROSPER offers an innovative framework to differentiate patient populations. This framework considers populations that are prespecified (such as those in clinical trials, prospective observational studies and some registries) and non-prespecified populations (such as those in claims databases, PRO-enabled online patient networks, and social websites in general). While the main focus of this guidance is on post-approval PRO-AEs from both prespecified and non-prespecified population groups, PROSPER has also considered pre-approval, prespecified populations. The ultimate aim of this guidance is to ensure that the patient 'voice' and perspective feed appropriately into collection of safety data. The guidance also covers a minimum core dataset for use by industry or regulators to structure PRO-AEs (accessible in the online appendix) and how data, once collected, might be evaluated to better inform on the safe and effective use of medicinal products. Structured collection of such patient data can be considered both a means to an end (improving patient safety) as well as an end in itself (expressing the patient viewpoint). The members of the PROSPER Consortium therefore direct this PRO-AE guidance to multiple stakeholders in drug safety, including industry, regulators, prescribers and patients. The use of this document across the entirety of the drug development life cycle will help to better define the benefit-risk profile of new and existing medicines. Because of the clinical relevance of 'real-world' data, PROs have the potential to contribute important new knowledge about the benefits and risks of medicinal products, communicated through the voice of the patient.

Cancer treatment-related cardiotoxicity: current state of knowledge and future research priorities

Cardiotoxicity resulting from direct myocyte damage has been a known complication of cancer treatment for decades. More recently, the emergence of hypertension as a clinically significant side effect of several new agents has been recognized as adversely affecting cancer treatment outcomes. With cancer patients living longer, in part because of treatment advances, these adverse events have become increasingly important to address. However, little is known about the cardiovascular pathogenic mechanisms associated with cancer treatment and even less about how to optimally prevent and manage short- and long-term cardiovascular complications, leading to improved patient safety and clinical outcomes. To identify research priorities, allocate resources, and establish infrastructure required to address cardiotoxicity associated with cancer treatment, the National Cancer Institute (NCI) and National Heart, Lung and Blood Institute (NHLBI) sponsored a two-day workshop, "Cancer treatment-related cardiotoxicity: Understanding the current state of knowledge and future research priorities," in March 2013 in Bethesda, MD. Participants included leading oncology and cardiology researchers and health professionals, patient advocates and industry representatives, with expertise ranging from basic to clinical science. Attendees were charged with identifying research opportunities to advance the understanding of cancer treatment-related cardiotoxicity across basic and clinical science. This commentary highlights the key discussion points and overarching recommendations from that workshop.

Left ventricular function in long-term survivors of childhood lymphoma

Survivors of childhood lymphoma (CL) have markedly increased risk of developing heart failure. Echocardiographic studies after cardiotoxic treatment have primarily demonstrated left ventricular (LV) systolic dysfunction. In the present study, we hypothesized that longer follow-up and a more comprehensive echocardiographic examination would reveal more cardiac abnormalities. We conducted a cross-sectional study with echocardiography 20.4 ± 8.6 years after diagnosis in 125 survivors of CL, grouped according to treatment methods, and compared with matched controls. Treatment included mediastinal radiotherapy (median 40.0 Gy) in 66 and anthracyclines (median dose 160 mg/m(2)) in 92 survivors of CL. Abnormal LV function, left-sided valve dysfunction, or both occurred in 62 patients (50%). Diastolic dysfunction occurred in 29%. Compared with control subjects, mitral annular early diastolic velocities (e') were reduced in patients (septal e' 0.09 ± 0.03 vs 0.12 ± 0.03 m/s, p <0.001), and the E/e' ratio was increased, particularly after mediastinal radiotherapy (10.6 ± 6.4 vs 5.6 ± 1.3, p <0.001). Survivors of CL had lower fractional shortening than control subjects (32 ± 6 vs 36 ± 7, p <0.001), but mean ejection fraction was equal and overt systolic dysfunction was infrequent. After mediastinal radiotherapy alone, global longitudinal myocardial strain was lower (p <0.05) compared with other treatment groups. Left-sided valvular dysfunction occurred in 55% of patients after mediastinal radiotherapy. In conclusion, survivors of CL had reduced LV diastolic function assessed by tissue Doppler imaging. This was more pronounced after mediastinal radiotherapy, which also frequently led to valvular disease. Systolic function was normal in most survivors of CL.

Nuclear imaging in detection and monitoring of cardiotoxicity

Cardiotoxicity as a result of cancer treatment is a novel and serious public health issue that has a significant impact on a cancer patient’s management and outcome. The coexistence of cancer and cardiac disease in the same patient is more common because of aging population and improvements in the efficacy of antitumor agents. Left ventricular dysfunction is the most typical manifestation and can lead to heart failure. Left ventricular ejection fraction measurement by echocardiography and multigated radionuclide angiography is the most common diagnostic approach to detect cardiac damage, but it identifies a late manifestation of myocardial injury. Early non-invasive imaging techniques are needed for the diagnosis and monitoring of cardiotoxic effects. Although echocardiography and cardiac magnetic resonance are the most commonly used imaging techniques for cardiotoxicity assessment, greater attention is focused on new nuclear cardiologic techniques, which can identify high-risk patients in the early stage and visualize the pathophysiologic process at the tissue level before clinical manifestation. The aim of this review is to summarize the role of nuclear imaging techniques in the non-invasive detection of myocardial damage related to antineoplastic therapy at the reversible stage, focusing on the current role and future perspectives of nuclear imaging techniques and molecular radiotracers in detection and monitoring of cardiotoxicity.

Neuregulin-1/erbB activities with focus on the susceptibility of the heart to anthracyclines

Neuregulin-1 (NRG1) signaling through the tyrosine kinase receptors erbB2 and erbB4 is required for cardiac morphogenesis, and it plays an essential role in maintaining the myocardial architecture during adulthood. The tyrosine kinase receptor erbB2 was first linked to the amplification and overexpression of erbb2 gene in a subtype of breast tumor cells, which is indicative of highly proliferative cells and likely a poor prognosis following conventional chemotherapy. The development of targeted therapies to block the survival of erbB2-positive cancer cells revealed that impaired NRG1 signaling through erbB2/erbB4 heterodimers combined with anthracycline chemotherapy may lead to dilated cardiomyopathy in a subpopulation of treated patients. The ventricular-specific deletion of either erbb2 or erbb4 manifested dilated cardiomyopathy, which is aggravated by the administration of doxorubicin. Based on the exacerbated toxicity displayed by the combined treatment, it is expected that the relevant pathways would be affected in a synergistic manner. This review examines the NRG1 activities that were monitored in different model systems, focusing on the emerging pathways and molecular targets, which may aid in understanding the acquired dilated cardiomyopathy that occurs under the conditions of NRG1-deficient signaling.

Anthracycline-mediated cardiomyopathy: basic molecular knowledge for the cardiologist

Anthracyclines are cytostatic antibiotics discovered almost half a century ago exerting their action through inhibition of topoisomerase II. The two most representative drugs are doxorubicin and daunorubicin and they have been proven as useful antineoplastics and are widely prescribed in daily oncology practice; unfortunately, cardiotoxicity has been a limiting factor when it comes to their use. Diverse mechanisms have been involved in anthracycline cardiotoxicity, none of which are capable of causing the whole clinical picture by itself. Traditionally, reactive oxygen species (ROS) have received more attention, although recently basic research has proven other factors to be as important as ROS. These factors mainly involve sarcomeric structure disruption, toxic accumulation of metabolites, iron metabolism, energetic alterations and inflammation. The role of genetics has been studied by some groups, although a clear genotype-response relationship is yet to be elucidated. With the improved survival from different oncologic diseases we are witnessing more cases of chemotherapy-induced cardiotoxicity and the advent of new anticancer drugs poses several challenges for the cardiologist, highlighting the importance of a deep knowledge of the main mechanisms inducing this toxicity.

Cardiovascular disease after cancer therapy

Improvements in treatment and earlier diagnosis have both contributed to increased survival for many cancer patients. Unfortunately, many treatments carry a risk of late effects including cardiovascular diseases (CVDs), possibly leading to significant morbidity and mortality. In this paper we describe current knowledge of the cardiotoxicity arising from cancer treatments, outline gaps in knowledge, and indicate directions for future research and guideline development, as discussed during the 2014 Cancer Survivorship Summit organised by the European Organisation for Research and Treatment of Cancer (EORTC). Better knowledge is needed of the late effects of modern systemic treatments and of radiotherapy to critical structures of the heart, including the effect of both radiation dose and volume of the heart exposed. Research elucidating the extent to which treatments interact in causing CVD, and the mechanisms involved, as well as the extent to which treatments may increase CVD indirectly by increasing cardiovascular risk factors is also important. Systematic collection of data relating treatment details to late effects is needed, and great care is needed to obtain valid and generalisable results. Better knowledge of these cardiac effects will contribute to both primary and secondary prevention of late complications where exposure to cardiotoxic treatment is unavoidable. Also surrogate markers would help to identify patients at increased risk of cardiotoxicity. Evidence-based screening guidelines for CVD following cancer are also needed. Finally, risk prediction models should be developed to guide primary treatment choice and appropriate follow up after cancer treatment.

Cardiotoxicity of systemic agents used in breast cancer

Several breast cancer therapies can lead to cardiovascular toxicity: drugs such anthracyclines can cause permanent damage, anti-HER2 agents may cause transitory and reversible cardiac dysfunction and others, such as those used in endocrine therapy, primarily disturb lipid metabolism. Considering the seriousness of these complications, trials are now being conducted to address cardiotoxicity associated with new drugs; however, to fully understand their toxicity profiles, longer follow-up is needed. In this review, we compile the information available about cardiac toxicity related to well-established systemic breast cancer treatments, as well as newer drugs, including antiangiogenics, mTOR inhibitors and novel anti-HER2 agents. We also describe current and next generation cardiac biomarkers and functional tests that can optimize treatment and reduce and prevent the incidence of treatment-related cardiotoxicity.

Cardiac complications of chemotherapy: role of biomarkers

OPINION STATEMENT

Both conventional and novel antineoplastic drugs may cause damage to the heart, ultimately affecting patients' survival and quality of life. In fact, the most frequent and typical clinical manifestation of cardiotoxicity, asymptomatic or symptomatic left ventricular dysfunction, may be induced not only by conventional cancer therapy, like anthracyclines, but also by new antitumoral targeted therapy such as trastuzumab. At present, left ventricular ejection fraction assessment represents the main standard practice for cardiac monitoring during cancer therapy, but it detects myocardial damage only when a functional impairment has already occurred, not allowing for early preventive strategies. In the last decade, a newer approach based on the measurement of cardiospecific biomarkers has been proposed, proving to have higher prognostic value than imaging modalities. In particular, cardiac troponin elevation during chemotherapy allows us to identify patients who are more prone to develop myocardial dysfunction and cardiac events during follow up. In these patients, the use of an angiotensin-converting enzyme inhibitor, such as enalapril, has shown to be effective in improving clinical outcome, giving the chance for a cardioprotective strategy in a selected population.

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

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

Myocardial tissue engineering: in vitro models

Modeling integrated human physiology in vitro is a formidable task not yet achieved with any of the existing cell/tissue systems. However, tissue engineering is becoming increasingly successful at authentic representation of the actual environmental milieu of tissue development, regeneration and disease progression, and in providing real-time insights into morphogenic events. Functional human tissue units engineered to combine biological fidelity with the high-throughput screening and real-time measurement of physiological responses are poised to transform drug screening and predictive modeling of disease. In this review, we focus on the in vitro engineering of functional human myocardium that mimics heart tissue for analysis of myocardial function, in the context of physiological studies, drug screening for therapeutics, and safety pharmacology.

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

BACKGROUND

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

METHODS AND RESULTS

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

CONCLUSIONS

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