Noninvasive imaging of cardiovascular injury related to the treatment of cancer

Cardiac computed tomographic imaging in cardio-oncology: An expert consensus document of the Society of Cardiovascular Computed Tomography (SCCT). Endorsed by the International Cardio-Oncology Society (ICOS)

Cardio-Oncology is a rapidly growing sub-specialty of medicine, however, there is very limited guidance on the use of cardiac CT (CCT) in the care of Cardio-Oncology patients. In order to fill in the existing gaps, this Expert Consensus statement comprised of a multidisciplinary collaboration of experts in Cardiology, Radiology, Cardiovascular Multimodality Imaging, Cardio-Oncology, Oncology and Radiation Oncology aims to summarize current evidence for CCT applications in Cardio-Oncology and provide practice recommendations for clinicians.

Myocardial Contractility Pattern Characterization in Radiation-Induced Cardiotoxicity Using Magnetic Resonance Imaging: A Pilot Study with ContractiX

Radiation therapy (RT) plays an integral role in treating thoracic cancers, despite the risk of radiation-induced cardiotoxicity. We hypothesize that our newly developed magnetic resonance imaging (MRI)-based contractility index (ContractiX) is a sensitive marker for early detection of RT-induced cardiotoxicity in a preclinical rat model of thoracic cancer RT. Adult salt-sensitive rats received image-guided heart RT and were imaged with MRI at 8 weeks and 10 weeks post-RT or sham. The MRI exam included cine and tagging sequences to measure left-ventricular ejection fraction (LVEF), mass, myocardial strain, and ContractiX. Furthermore, ventricular torsion, diastolic strain rate, and mechanical dyssynchrony were measured. Statistical analyses were performed between the sham, 8 weeks post-RT, and 10 weeks post-RT MRI parameters. The results showed that both LVEF and myocardial mass increased post-RT. Peak systolic strain and ContractiX significantly decreased post-RT, with a more relative reduction in ContractiX compared to strain. ContractiX showed an inverse nonlinear relationship with LVEF and continuously decreased with time post-RT. While early diastolic strain rate and mechanical dyssynchrony significantly changed post-RT, ventricular torsion changes were not significant post-RT. In conclusion, ContractiX measured via non-contrast MRI is a sensitive early marker for the detection of subclinical cardiac dysfunction post-RT, and it is superior to other MRI cardiac measures.

Reported Signs, Symptoms, and Diagnostic Tests Before Cardiotoxicity Among Women With Breast Cancer: A Pilot Study

BACKGROUND

Cardiotoxicity after cancer treatment is a potentially preventable life-threatening complication among women with breast cancer. There is no algorithm to identify women with breast cancer at risk of cardiotoxicity.

OBJECTIVES

We quantified signs and symptoms as well as selected laboratory values among women with breast cancer who developed cardiotoxicity.

METHODS

The clinical characteristics (n = 15) were collected from electronic health records. Spearman correlation coefficients and a nonparametric statistical test were used to analyze data.

RESULTS

Significant statistical differences were detected in the laboratory values comparing the first and second half of 6 months before cardiotoxicity including alanine aminotransferase (U/L) (30.67 ± 26.27 and 42.31 ± 35.65, respectively; P = .03, Cohen's d = 0.37). A negative correlation was found between estimated glomerular filtration rate and new onset of more than 1 sign or symptom (Spearman's ρ = -0.5, P = .06).

CONCLUSIONS

Investigating clinical characteristics before cardiotoxicity may determine the mechanism(s) and identify high-risk patients.

Detection of Subclinical Cardiovascular Disease by Cardiovascular Magnetic Resonance in Lymphoma Survivors

BACKGROUND

Long-term survivors of Hodgkin lymphoma (HL) and mediastinal non-Hodgkin lymphoma experience late adverse effects of radiotherapy and/or anthracycline-containing chemotherapy, leading to premature cardiovascular morbidity and mortality.

OBJECTIVES

The aim of this study was to identify markers for subclinical cardiovascular disease using cardiovascular magnetic resonance (CMR) in survivors of HL and non-Hodgkin lymphoma.

METHODS

CMR was performed in 80 lymphoma survivors treated with mediastinal radiotherapy with or without anthracyclines, and results were compared with those among 40 healthy control subjects matched for age and sex.

RESULTS

Of the 80 lymphoma survivors, 98% had histories of HL, the mean age was 47 ± 11 years, and 54% were male. Median radiotherapy dose was 36 Gy (interquartile range: 36-40 Gy), and radiotherapy was combined with anthracyclines in 70 lymphoma survivors (88%). Mean time between diagnosis and CMR was 20 ± 8 years. Significantly lower left ventricular (LV) ejection fraction (53% ± 5% vs 60% ± 5%; P < 0.001) and LV mass (47 ± 10 g/m2 vs 56 ± 8 g/m2; P < 0.001) and higher LV end-systolic volume (37 ± 8 mL/m2 vs 33 ± 7 mL/m2; P = 0.013) were found in lymphoma survivors. LV global strain parameters were also significantly worse in lymphoma survivors (P < 0.02 for all). Native myocardial T1 was significantly higher in lymphoma survivors compared with healthy control subjects (980 ± 33 ms vs 964 ± 25 ms; P = 0.007), and late gadolinium enhancement was present in 11% of the survivors.

CONCLUSIONS

Long-term lymphoma survivors have detectable changes in LV function and native myocardial T1 on CMR. Further longitudinal studies are needed to assess the implication of these changes in relation to treatment and clinical outcome.

Risk Factors for Anthracycline-Induced Cardiotoxicity

Background: Several cardiovascular risk factors have been suggested to be associated with anthracycline-induced cardiotoxicity, but their quantitative effects have not reached a consensus.

Methods: We searched PubMed, EMBASE, and Cochrane Library databases for manuscripts published from inception to February 2021, which reported the results of cardiotoxicity due to anthracycline chemotherapy without trastuzumab. Cardiotoxicity defined by any reduction of left ventricular eject fraction (LVEF) to below 50% or a >10% reduction from baseline was defined as the primary endpoint. Odd ratios (OR) with 95% confidence intervals (CI) were calculated using a random-effects model meta-analysis.

Results: A total of 7,488 patients receiving anthracycline chemotherapy without trastuzumab were included, who had at least one risk factor at baseline. Hypertension (OR: 1.99; 95% CI: 1.43–2.76), diabetes mellitus (OR: 1.74; 95% CI: 1.11–2.74), and obesity (OR: 1.72; 95% CI: 1.13–2.61) were associated with increased risk of cardiotoxicity. In addition, the relative reduction of global longitudinal strain (GLS) from baseline after anthracycline treatment could significantly improve the detection ability of cardiotoxicity (28.5%, 95% CI: 22.1–35.8% vs. 16.4%, 95% CI: 13.4–19.9%) compared with LVEF. The early detection rate of anthracycline-induced cardiotoxicity (3 months after chemotherapy) by GLS was 30.2% (95% CI: 24.9–36.1%), which is similar with the overall result of GLS.

Conclusions: Hypertension, diabetes mellitus, and obesity are associated with increased risk of anthracycline-induced cardiotoxicity, which indicates that corresponding protective strategies should be used during and after anthracycline treatment. The findings of higher detection rate and better early detection ability for cardiotoxicity than LVEF added new proofs for the advantages of GLS in detection of AIC.

Cardiac Magnetic Resonance for Early Detection of Radiation Therapy-Induced Cardiotoxicity in a Small Animal Model

Background

Over half of all cancer patients receive radiation therapy (RT). However, radiation exposure to the heart can cause cardiotoxicity. Nevertheless, there is a paucity of data on RT-induced cardiac damage, with limited understanding of safe regional RT doses, early detection, prevention and management. A common initial feature of cardiotoxicity is asymptomatic dysfunction, which if left untreated may progress to heart failure. The current paradigm for cardiotoxicity detection and management relies primarily upon assessment of ejection fraction (EF). However, cardiac injury can occur without a clear change in EF.

Objectives

To identify magnetic resonance imaging (MRI) markers of early RT-induced cardiac dysfunction.

Methods

We investigated the effect of RT on global and regional cardiac function and myocardial T1/T2 values at two timepoints post-RT using cardiac MRI in a rat model of localized cardiac RT. Rats who received image-guided whole-heart radiation of 24Gy were compared to sham-treated rats.

Results

The rats maintained normal global cardiac function post-RT. However, a deterioration in strain was particularly notable at 10-weeks post RT, and changes in circumferential strain were larger than changes in radial or longitudinal strain. Compared to sham, circumferential strain changes occurred at the basal, mid-ventricular and apical levels (p<0.05 for all at both 8-weeks and 10-weeks post-RT), most of the radial strain changes occurred at the mid-ventricular (p=0.044 at 8-weeks post-RT) and basal (p=0.018 at 10-weeks post-RT) levels, and most of the longitudinal strain changes occurred at the apical (p=0.002 at 8-weeks post-RT) and basal (p=0.035 at 10-weeks post-RT) levels. Regionally, lateral myocardial segments showed the greatest worsening in strain measurements, and histologic changes supported these findings. Despite worsened myocardial strain post-RT, myocardial tissue displacement measures were maintained, or even increased. T1/T2 measurements showed small non-significant changes post-RT compared to values in non-irradiated rats.

Conclusions

Our findings suggest MRI regional myocardial strain is a sensitive imaging biomarker for detecting RT-induced subclinical cardiac dysfunction prior to compromise of global cardiac function.

Cardiac functional magnetic resonance imaging at 7T: Image quality optimization and ultra-high field capabilities

BACKGROUND

7T cardiac magnetic resonance imaging (MRI) introduces several advantages, as well as some limitations, compared to lower-field imaging. The capabilities of ultra-high field (UHF) MRI have not been fully exploited in cardiac functional imaging.

AIM

To optimize 7T cardiac MRI functional imaging without the need for conducting B1 shimming or subject-specific tuning, which improves scan efficiency. In this study, we provide results from phantom and in vivo scans using a multi-channel transceiver modular coil.

METHODS

We investigated the effects of adding a dielectric pad at different locations next to the imaged region of interest on improving image quality in subjects with different body habitus. We also investigated the effects of adjusting the imaging flip angle in cine and tagging sequences on improving image quality, B1 field homogeneity, signal-to-noise ratio (SNR), blood-myocardium contrast-to-noise ratio (CNR), and tagging persistence throughout the cardiac cycle.

RESULTS

The results showed the capability of achieving improved image quality with high spatial resolution (0.75 mm × 0.75 mm × 2 mm), high temporal resolution (20 ms), and increased tagging persistence (for up to 1200 ms cardiac cycle duration) at 7T cardiac MRI after adjusting scan set-up and imaging parameters. Adjusting the imaging flip angle was essential for achieving optimal SNR and myocardium-to-blood CNR. Placing a dielectric pad at the anterior left position of the chest resulted in improved B1 homogeneity compared to other positions, especially in subjects with small chest size.

CONCLUSION

Improved regional and global cardiac functional imaging can be achieved at 7T MRI through simple scan set-up adjustment and imaging parameter optimization, which would allow for more streamlined and efficient UHF cardiac MRI.

Reversal of a rheologic cardiomyopathy following hematopoietic stem cell transplantation for sickle cell disease

Cardiac complications have been well-described in sickle cell disease; however, it has been rare to see improvements in cardiac abnormalities following any interventions. Previous work has shown no significant structural changes after treatment with hydroxyurea. The cardiac effects of red blood cell exchange transfusion (RBCx) and hematopoietic stem cell transplantation (HSCT) have not been well described. We studied 56 patients undergoing HSCT (41 HLA-matched, 15 haploidentical), of whom 32 had RBCx within 3 months before HSCT. Echocardiograms and laboratory parameters were obtained at baseline, and at 3, 6, and 12 months following HSCT. Although hemolytic parameters and anemia improved following RBCx, there was a small increase in left ventricular volume index. Following successful HSCT, however, there were significant improvements in cardiac size, function, and diastolic filling parameters at 3 months followed by continued smaller improvements up to 1 year. There was a significant improvement in N-terminal pro B-type natriuretic peptide levels and a trend toward improvement in 6-minute walk time 1 year after HSCT. The magnitude of cardiac improvement seen following HSCT was comparable to that observed following correction of a volume overload state as seen in pregnancy or after repair of chronic valvular regurgitation. Further studies in sickle cell disease patients will help delineate which cardiac complications and what level of severity should be considered indications for HSCT.

Optimized cardiac functional MRI of small-animal models of cancer radiation therapy

Cardiac MRI of small animal models of cancer radiation therapy (RT) is a valuable tool for studying the effect of RT on the heart. However, standard cardiac MRI exams require long scanning times, which is challenging for sick animals that may not survive extended periods of imaging under anesthesia. The purpose of this study is to develop an optimized, fast MRI exam for comprehensive cardiac functional imaging of small-animal models of cancer RT. Ten adult female rats (2 non-irradiated and 8 irradiated) were scanned using the developed exam. Optimal imaging parameters were determined, which minimized scanning time while ensuring measurement accuracy and avoiding imaging artifacts. This optimized, fast MRI exam lasted for 30 min, which was tolerated by all animals. EF was normal in all imaged rats, although it was significantly increased in the irradiated rats, which also showed ventricular hypertrophy. However, myocardial strain was significantly reduced in the irradiated rats. In conclusion, a fast MRI exam has been developed for comprehensive cardiac functional imaging of rats in 30 min, with optimized imaging parameters to ensure accurate measurements and tolerance by irradiated rats. The generated strain measurements provide an early marker of regional cardiac dysfunction before global function is affected.

Exercise as a diagnostic and therapeutic tool for preventing cardiovascular morbidity in breast cancer patients- the BReast cancer EXercise InTervention (BREXIT) trial protocol

BACKGROUND

Anthracycline chemotherapy (AC) is an efficacious (neo) adjuvant treatment for early-stage breast cancer (BCa), but is associated with an increased risk of cardiac dysfunction and functional disability. Observations suggest that regular exercise may be a useful therapy for the prevention of cardiovascular morbidity but it is yet to be interrogated in a large randomised trial. The primary aims of this study are to: 1) determine if 12-months of ET commenced at the onset of AC can reduce the proportion of BCa patients with functional disability (peak VO2, < 18 ml/kg/min), and 2) compare current standard-of-care for detecting cardiac dysfunction (resting left-ventricular ejection fraction assessed from 3-dimensional echocardiography) to measures of cardiac reserve (peak exercise cardiac output assessed from exercise cardiac magnetic resonance imaging) for predicting the development of functional disability 12-months following AC. Secondary aims are to assess the effects of ET on VO2peak, left ventricular morphology, vascular stiffness, cardiac biomarkers, body composition, bone mineral density, muscle strength, physical function, habitual physical activity, cognitive function, and multidimensional quality of life.

METHODS

One hundred women with early-stage BCa (40-75 years) scheduled for AC will be randomized to 12-months of structured exercise training (n = 50) or a usual care control group (n = 50). Participants will be assessed at baseline, 4-weeks following completion of AC (4-months) and at 12-months for all measures.

DISCUSSION

Women diagnosed with early-stage BCa have increased cardiac mortality. More sensitive strategies for diagnosing and preventing AC-induced cardiovascular impairment are critical for reducing cardiovascular morbidity and improving long-term health outcomes in BCa survivors.

TRIAL REGISTRATION

Australia & New Zealand Clinical Trials Registry (ANZCTR), ID: 12617001408370 . Registered on 5th of October 2017.

The use of cardiovascular magnetic resonance as an early non-invasive biomarker for cardiotoxicity in cardio-oncology

Contemporary cancer therapy has resulted in significant survival gains for patients. However, many current and emerging cancer therapies have an associated risk of cardiotoxicity, either acutely or later in life. Regular cardiac screening and surveillance is recommended for patients undergoing treatment for cancer, with emphasis on the early detection of cardiotoxicity before irreversible complications develop. Cardiovascular magnetic resonance imaging is able to accurately assess cardiac structure, function, and perform advanced myocardial tissue characterisation, including perfusion, features which may facilitate the diagnosis and management of cardiotoxicity in cancer survivors. This review outlines the current standards for the diagnosis and screening of cardiotoxicity, with particular focus on current and future applications of cardiovascular magnetic resonance imaging.

The Utility of Cardiac Reserve for the Early Detection of Cancer Treatment-Related Cardiac Dysfunction: A Comprehensive Overview

With progressive advancements in cancer detection and treatment, cancer-specific survival has improved dramatically over the past decades. Consequently, long-term health outcomes are increasingly defined by comorbidities such as cardiovascular disease. Importantly, a number of well-established and emerging cancer treatments have been associated with varying degrees of cardiovascular injury that may not emerge until years following the completion of cancer treatment. Of particular concern is the development of cancer treatment related cardiac dysfunction (CTRCD) which is associated with an increased risk of heart failure and high risk of morbidity and mortality. Early detection of CTRCD appears critical for preventing long-term cardiovascular morbidity in cancer survivors. However, current clinical standards for the identification of CTRCD rely on assessments of cardiac function in the resting state. This provides incomplete information about the heart's reserve capacity and may reduce the sensitivity for detecting sub-clinical myocardial injury. Advances in non-invasive imaging techniques have enabled cardiac function to be quantified during exercise thereby providing a novel means of identifying early cardiac dysfunction that has proved useful in several cardiovascular pathologies. The purpose of this narrative review is (1) to discuss the different non-invasive imaging techniques that can be used for quantifying different aspects of cardiac reserve; (2) discuss the findings from studies of cancer patients that have measured cardiac reserve as a marker of CTRCD; and (3) highlight the future directions important knowledge gaps that need to be addressed for cardiac reserve to be effectively integrated into routine monitoring for cancer patients exposed to cardiotoxic therapies.

Association of body mass index and cardiotoxicity related to anthracyclines and trastuzumab in early breast cancer: French CANTO cohort study

BACKGROUND

In patients treated with cardiotoxic chemotherapies, the presence of cardiovascular risk factors and previous cardiac disease have been strongly correlated to the onset of cardiotoxicity. The influence of overweight and obesity as risk factors in the development of treatment-related cardiotoxicity in breast cancer (BC) was recently suggested. However, due to meta-analysis design, it was not possible to take into account associated cardiac risk factors or other classic risk factors for anthracycline (antineoplastic antibiotic) and trastuzumab (monoclonal antibody) cardiotoxicity.

METHODS AND FINDINGS

Using prospective data collected from 2012-2014 in the French national multicenter prospective CANTO (CANcer TOxicities) study of 26 French cancer centers, we aimed to examine the association of body mass index (BMI) and cardiotoxicity (defined as a reduction in left ventricular ejection fraction [LVEF] > 10 percentage points from baseline to LVEF < 50%). In total, 929 patients with stage I-III BC (mean age 52 ± 11 years, mean BMI 25.6 ± 5.1 kg/m2, 42% with 1 or more cardiovascular risk factors) treated with anthracycline (86% epirubicin, 7% doxorubicin) and/or trastuzumab (36%), with LVEF measurement at baseline and at least 1 assessment post-chemotherapy were eligible in this interim analysis. We analyzed associations between BMI and cardiotoxicity using multivariate logistic regression. At baseline, nearly 50% of the study population was overweight or obese. During a mean follow-up of 22 ± 2 months following treatment completion, cardiotoxicity occurred in 29 patients (3.2%). The obese group was more prone to cardiotoxicity than the normal-weight group (9/171 versus 8/466; p = 0.01). In multivariate analysis, obesity (odds ratio [OR] 3.02; 95% CI 1.10-8.25; p = 0.03) and administration of trastuzumab (OR 12.12; 95% CI 3.6-40.4; p < 0.001) were independently associated with cardiotoxicity. Selection bias and relatively short follow-up are potential limitations of this national multicenter observational cohort.

CONCLUSIONS

In BC patients, obesity appears to be associated with an important increase in risk-related cardiotoxicity (CANTO, ClinicalTrials.gov registry ID: NCT01993498).

TRIAL REGISTRATION

ClinicalTrials.gov NCT01993498.

Contemporary Role of Echocardiography for Clinical Decision Making in Patients During and After Cancer Therapy

Early recognition of cancer therapy-related cardiac dysfunction (CTRCD) provides an opportunity to mitigate cardiac injury and risk of developing late cardiac events. Echocardiography serves as the cornerstone in the detection and surveillance of CTRCD in patients during and after cancer therapy. Guidelines from professional societies and regulatory agencies have been published on approaches to surveillance, diagnosis, and treatment of CTRCD, although adoption as standard of care remains limited given the lack of evidence on the prognostic value of asymptomatic left ventricular (LV) dysfunction in the oncology population. The frequency of cardiac monitoring and the appropriateness of the Food and Drug Administration (FDA)-recommended cardiac monitoring schedule in all patients receiving trastuzumab for breast cancer has been challenged. Interruption versus continuation of oncological therapy in the setting of asymptomatic LV dysfunction remains a clinical conundrum given the uncertain balance of the risk of cardiac dysfunction and benefit of oncology efficacy. Despite their limitations, echocardiographic measures of LV function continue to play a pivotal role in clinical decision making, with global longitudinal strain emerging as a promising tool in informing and facilitating the selection of cancer treatment and optimizing cardiovascular outcomes. This review highlights the key recommendations of the existing guidelines and discusses recent developments in cardio-oncology imaging practices with the aim of providing practical guidance on the role and use of echocardiography in challenging clinical cases in cardio-oncology.

Imaging of Chemotherapy-Induced Acute Cardiotoxicity with 18F-Labeled Lipophilic Cations

Many chemotherapy agents are toxic to the heart, such that increasing numbers of cancer survivors are now living with the potentially lethal cardiovascular consequences of their treatment. Earlier and more sensitive detection of chemotherapy-induced cardiotoxicity may allow improved treatment strategies and increase long-term survival. Lipophilic cation PET tracers may be suitable for early detection of cardiotoxicity. This study aimed to evaluate an ¹⁸F-labeled lipophilic phosphonium cation, [1-(2-¹⁸F-fluoroethyl),1H[1,2,3]triazole-4-ethylene]triphenylphosphonium bromide (¹⁸F-MitoPhos), as a cardiac imaging agent, comparing it with leading PET and SPECT lipophilic cationic tracers before further assessing its potential for imaging cardiotoxicity in an acute doxorubicin model. Methods: Cardiac uptake and response to decreased mitochondrial membrane potential of ¹⁸F-MitoPhos and ^99mTc-sestamibi were tested in isolated perfused rat hearts. Baseline pharmacokinetic profiles of ¹⁸F-MitoPhos and ¹⁸F-fluorobenzyltriphenylphosphonium and their response to acute doxorubicin-induced cardiotoxicity were assessed in rats in vivo (10, 15, or 20 mg of doxorubicin per kilogram, intravenously, 48 h beforehand). Results: Cardiac retention of ¹⁸F-MitoPhos was more than double that of ^99mTc-sestamibi in isolated perfused rat hearts. A favorable biodistribution of ¹⁸F-MitoPhos in vivo was observed, with heart-to-tissue ratios of 304 ± 186, 11.2 ± 1.2, and 3.8 ± 0.6 for plasma, liver, and lung, respectively (60 min). A significant dose-dependent loss of cardiac retention of ¹⁸F-MitoPhos was observed on doxorubicin treatment, with average cardiac SUV from 30 to 60 min (mean ± SD) decreasing from 3.5 ± 0.5 (control) to 1.8 ± 0.1 (doxorubicin, 20 mg/kg). Other assessed biomarkers showed no alterations. Conclusion: ¹⁸F-MitoPhos showed pharmacokinetic parameters suitable for cardiac imaging. A significant dose response of cardiac uptake to doxorubicin treatment was observed before detectable biomarker alterations. ¹⁸F-MitoPhos is therefore a promising tracer for imaging chemotherapy-induced cardiotoxicity. To our knowledge, this is the first demonstration of radiolabeled lipophilic cations being used for the PET imaging of chemotherapy-induced cardiotoxicity and indicates the potential application of these compounds in this area.

Heart failure following oncological treatment

PURPOSE OF REVIEW

The aim of this review is to give the reader an up-to-date overview of the progress made in the burgeoning field of cardio-oncology, encompassing oncological treatments conferring risk, prediction strategies to identify patients at risk, imaging and biomarker monitoring for emergent or subclinical toxicity and prevention in primary and secondary settings with a focus on heart failure.

RECENT FINDINGS

The rapid recent advances in cancer management, particularly with the expansion of targeted and immunotherapies, have led to substantial improvements in outcome, but have also added to the potential causes of cardiac toxicity, which can lead to heart failure. Against this, there has been progression in the field of imaging for cardiac toxicity, identification of at-risk individuals and the clarification of the role of therapy for prevention and treatment of cardiac toxicity.

SUMMARY

The findings described in this review provide guidance to clinicians in order to direct monitoring strategy and therapy choice, both in the individual with preexisting cardiac comorbidities and in those predicted to be at the highest risk of cardiac toxicity wherever therapy elements carrying cardiac risk are considered oncologically appropriate.

Predicting and Preventing Anthracycline-Related Cardiotoxicity

Anthracyclines (doxorubicin, daunorubicin, epirubicin, and idarubicin) are among the most potent chemotherapeutic agents and have truly revolutionized the management of childhood cancer. They form the backbone of chemotherapy regimens used to treat childhood acute lymphoblastic leukemia, acute myeloid leukemia, Hodgkin lymphoma, Ewing sarcoma, osteosarcoma, and neuroblastoma. More than 50% of children with cancer are treated with anthracyclines. The clinical utility of anthracyclines is compromised by dose-dependent cardiotoxicity, manifesting initially as asymptomatic cardiac dysfunction and evolving irreversibly to congestive heart failure. Childhood cancer survivors are at a five- to 15-fold increased risk for congestive heart failure compared with the general population. Once diagnosed with congestive heart failure, the 5-year survival rate is less than 50%. Prediction models have been developed for childhood cancer survivors (i.e., after exposure to anthracyclines) to identify those at increased risk for cardiotoxicity. Studies are currently under way to test risk-reducing strategies. There remains a critical need to identify patients with childhood cancer at diagnosis (i.e., prior to anthracycline exposure) such that noncardiotoxic therapies can be contemplated.

Optimizing Cardiovascular Care in Children With Acute Myeloid Leukemia to Improve Cancer-Related Outcomes

The Oncology Grand Rounds series is designed to place original reports published in the Journal into clinical context. A case presentation is followed by a description of diagnostic and management challenges, a review of the relevant literature, and a summary of the authors' suggested management approaches. The goal of this series is to help readers better understand how to apply the results of key studies, including those published in Journal of Clinical Oncology, to patients seen in their own clinical practice. A 14-year-old African American female presented with fatigue, easy bruising, and fever. On examination, she had scattered bruising, lymphadenopathy, and hepatosplenomegaly. Laboratory evaluation revealed pancytopenia with peripheral blasts, and acute myeloid leukemia (AML; French-American-British M2, t[8;21][q22;q22.1]) was diagnosed on bone marrow biopsy. A baseline echocardiogram revealed normal left ventricular (LV) systolic function (ejection fraction [EF], 60%; shortening fraction [SF], 32%), and conventional chemotherapy was initiated that consisted of two cycles of remission induction (cytarabine, etoposide, and daunorubicin [50 mg/m² × 3 days per cycle]) followed by intensification 1 (high-dose cytarabine and etoposide), intensification 2 (high-dose cytarabine and mitoxantrone [12 mg/m²/dose daily; four total doses]), and intensification 3 (high-dose cytarabine and l-asparaginase). Of note, an echocardiogram was not repeated before the start of intensification 1. During intensification 1, the patient developed Streptococcus viridans sepsis, which required 4 days in the intensive care unit with antimicrobial and inotropic support. Repeat echocardiogram after recovery from the sepsis episode demonstrated low-normal LV systolic function (EF, 53%; SF, 27%), and she subsequently began intensification 2. On day 3 of intensification 2, the patient developed afebrile tachypnea, tachycardia, and an increasing oxygen requirement. Chest x-ray revealed cardiomegaly and pulmonary vascular congestion. Cardiac troponins were normal, whereas N-terminal pro B-type natriuretic peptide was 10 times the upper limit of normal. Repeat echocardiogram showed an enlarged LV with moderate to severely depressed LV function (EF, 28%; SF, 14%). Day 4 mitoxantrone was omitted and a cardiology consult obtained.

Management of Cancer Therapeutics-Related Cardiac Dysfunction

Improvements in detection and treatment of cancer have resulted in a significant increase in cancer survivors. However, cancer survivorship comes with long-term risk of adverse effects of cancer therapies, including cardiomyopathy, heart failure, arrhythmias, ischemic heart disease, atherosclerosis, thrombosis, and hypertension. There is a renewed interest in understanding the pathophysiology of cancer therapeuticserelated cardiac dysfunction. In recent years, efforts have been directed to the management of cancer therapeuticserelated cardiac dysfunction. This article discusses the pathophysiology and molecular mechanisms that contribute to cancer therapeutics-related cardiac dysfunction and presents an napproach to the evaluation and treatment of these patients.

Cardiovascular Magnetic Resonance in the Oncology Patient

Patients with or receiving potentially cardiotoxic treatment for cancer are susceptible to developing decrements in left ventricular mass, diastolic function, or systolic function. They may also experience valvular heart disease, pericardial disease, or intracardiac masses. Cardiovascular magnetic resonance may be used to assess cardiac anatomy, structure, and function and to characterize myocardial tissue. This combination of features facilitates the diagnosis and management of disease processes in patients with or those who have survived cancer. This report outlines and describes prior research involving cardiovascular magnetic resonance for assessing cardiovascular disease in patients with or previously having received treatment for cancer.

Cardiovascular Disease in Survivors of Childhood Cancer: Insights Into Epidemiology, Pathophysiology, and Prevention

Cardiovascular disease (CVD), which includes cardiomyopathy/heart failure, coronary artery disease, stroke, pericardial disease, arrhythmias, and valvular and vascular dysfunction, is a major concern for long-term survivors of childhood cancer. There is clear evidence of increased risk of CVD largely attributable to treatment exposures at a young age, most notably anthracycline chemotherapy and chest-directed radiation therapy, and compounded by traditional cardiovascular risk factors accrued during decades after treatment exposure. Preclinical studies are limited; thus, it is a high priority to understand the pathophysiology of CVD as a result of anticancer treatments, taking into consideration the growing and developing heart. Recently developed personalized risk prediction models can provide decision support before initiation of anticancer therapy or facilitate implementation of screening strategies in at-risk survivors of cancer. Although consensus-based screening guidelines exist for the application of blood and imaging biomarkers of CVD, the most appropriate timing and frequency of these measures in survivors of childhood cancer are not yet fully elucidated. Longitudinal studies are needed to characterize the prognostic importance of subclinical markers of cardiovascular injury on long-term CVD risk. A number of prevention trials across the survivorship spectrum are under way, which include primary prevention (before or during cancer treatment), secondary prevention (after completion of treatment), and integrated approaches to manage modifiable cardiovascular risk factors. Ongoing multidisciplinary collaborations between the oncology, cardiology, primary care, and other subspecialty communities are essential to reduce therapeutic exposures and improve surveillance, prevention, and treatment of CVD in this high-risk population.

Developing a Reliable Mouse Model for Cancer Therapy-Induced Cardiovascular Toxicity in Cancer Patients and Survivors

Background

The high incidence of cardiovascular events in cancer survivors has long been noted, but the mechanistic insights of cardiovascular toxicity of cancer treatments, especially for vessel diseases, remain unclear. It is well known that atherosclerotic plaque formation begins in the area exposed to disturbed blood flow, but the relationship between cancer therapy and disturbed flow in regulating plaque formation has not been well studied. Therefore, we had two goals for this study; (1) Generate an affordable, reliable, and reproducible mouse model to recapitulate the cancer therapy-induced cardiovascular events in cancer survivors, and (2) Establish a mouse model to investigate the interplay between disturbed flow and various cancer therapies in the process of atherosclerotic plaque formation.

Methods and Results

We examined the effects of two cancer drugs and ionizing radiation (IR) on disturbed blood flow-induced plaque formation using a mouse carotid artery partial ligation (PCL) model of atherosclerosis. We found that doxorubicin and cisplatin, which are commonly used anti-cancer drugs, had no effect on plaque formation in partially ligated carotid arteries. Similarly, PCL-induced plaque formation was not affected in mice that received IR (2 Gy) and PCL surgery performed one week later. In contrast, when PCL surgery was performed 26 days after IR treatment, not only the atherosclerotic plaque formation but also the necrotic core formation was significantly enhanced. Lastly, we found a significant increase in p90RSK phosphorylation in the plaques from the IR-treated group compared to those from the non-IR treated group.

Conclusions

Our results demonstrate that IR not only increases atherosclerotic events but also vulnerable plaque formation. These increases were a somewhat delayed effect of IR as they were observed in mice with PCL surgery performed 26 days, but not 10 days, after IR exposure. A proper animal model must be developed to study how to minimize the cardiovascular toxicity due to cancer treatment.

Priorities in the Cardiovascular Care of Breast Cancer Survivors

Breast cancer is the most common malignancy in women with more than 3 million breast cancer survivors in the United States alone. Survivors of breast cancer suffer from an increased burden of cardiovascular risk factors and disease. The focus of this review is to describe the epidemiology of cardiovascular disease in breast cancer survivors, including the cardiovascular concerns observed with common cancer therapies. Strategies to improve upon the early detection and treatment of cardiovascular disease, including clinical prediction algorithms, biomarkers, and imaging measures are also reviewed, and the use of cardioprotective therapies to mitigate risk are summarized. Finally, the need for evidence-based research to inform and improve upon the multidisciplinary care of this growing population is highlighted.

The Role of Cardiovascular Magnetic Resonance in the Management of Patients with Cancer

PURPOSE OF REVIEW

This article reviews the utility of cardiovascular magnetic resonance imaging (CMR) to detect abnormalities of the cardiovascular system that may result from cancer or its treatment.

RECENT FINDINGS

With CMR, one may assess cardiac anatomy, function, myocardial perfusion, tissue composition, and blood flow. For those with cancer, these capabilities allow one to differentiate myocardial masses that may relate to the presence of cancer and evaluate diseases of the pericardium. These features facilitate measurement of left ventricular (LV) volumes, ejection fraction, mass, strain, T1 and T2 relaxation properties, and the extracellular volume fraction all of which may be useful for detecting subclinical cardiovascular injury that results from the receipt of potentially cardiotoxic cancer treatment. CMR can provide an effective and efficient means to identify clinical abnormalities resulting from the diagnosis of cancer or subclinical cardiac injury that may be related to receipt of the therapy for cancer.

Technological Advances in Cardiovascular Safety Assessment Decrease Preclinical Animal Use and Improve Clinical Relevance

Cardiovascular (CV) safety liabilities are significant concerns for drug developers and preclinical animal studies are predominately where those liabilities are characterized before patient exposures. Steady progress in technology and laboratory capabilities is enabling a more refined and informative use of animals in those studies. The application of surgically implantable and telemetered instrumentation in the acute assessment of drug effects on CV function has significantly improved historical approaches that involved anesthetized or restrained animals. More chronically instrumented animals and application of common clinical imaging assessments like echocardiography and MRI extend functional and in-life structural assessments into the repeat-dose setting. A growing portfolio of circulating CV biomarkers is allowing longitudinal and repeated measures of cardiac and vascular injury and dysfunction better informing an understanding of temporal pathogenesis and allowing earlier detection of undesirable effects. In vitro modeling systems of the past were limited by their lack of biological relevance to the in vivo human condition. Advances in stem cell technology and more complex in vitro modeling platforms are quickly creating more opportunity to supplant animals in our earliest assessments for liabilities. Continuing improvement in our capabilities in both animal and nonanimal modeling should support a steady decrease in animal use for primary liability identification and optimize the translational relevance of the animal studies we continue to do.

Alpha-linolenic acid stabilizes HIF-1 α and downregulates FASN to promote mitochondrial apoptosis for mammary gland chemoprevention

Alpha linolenic acid is an essential polyunsaturated fatty acid and is reported to have the anti-cancer potential with no defined hypothesis or mechanism/s. Henceforth present study was in-quested to validate the effect of alpha linolenic acid on mitochondrial apoptosis, hypoxic microenvironment and de novo fatty acid synthesis using in-vitro and in-vivo studies. The IC₅₀ value of alpha linolenic acid was recorded to be 17.55μM against ER+MCF-7 cells. Treatment with alpha linolenic acid was evident for the presence of early and late apoptotic signals along with mitochondrial depolarization, when studied through acridine orange/ethidium bromide and JC-1 staining. Alpha linolenic acid arrested the cell cycle in G2/M phase. Subsequently, the in-vivo efficacy was examined against 7, 12-dimethylbenz anthracene induced carcinogenesis. Treatment with alpha linolenic acid demarcated significant effect upon the cellular proliferation as evidenced through decreased in alveolar bud count, restoration of the histopathological architecture and loss of tumor micro vessels. Alpha linolenic acid restored the metabolic changes to normal when scrutinized through ¹H NMR studies. The immunoblotting and qRT-PCR studies revealed participation of mitochondrial mediated death apoptosis pathway and curtailment of hypoxic microenvironment after treatment with alpha linolenic acid. With all above, it was concluded that alpha linolenic acid mediates mitochondrial apoptosis, curtails hypoxic microenvironment along with inhibition of de novo fatty acid synthesis to impart anticancer effects.

Cardiac Metabolic Deregulation Induced by the Tyrosine Kinase Receptor Inhibitor Sunitinib is rescued by Endothelin Receptor Antagonism

The growing field of cardio-oncology addresses the side effects of cancer treatment on the cardiovascular system. Here, we explored the cardiotoxicity of the antiangiogenic therapy, sunitinib, in the mouse heart from a diagnostic and therapeutic perspective. We showed that sunitinib induces an anaerobic switch of cellular metabolism within the myocardium which is associated with the development of myocardial fibrosis and reduced left ventricular ejection fraction as demonstrated by echocardiography. The capacity of positron emission tomography with [18F]fluorodeoxyglucose to detect the changes in cardiac metabolism caused by sunitinib was dependent on fasting status and duration of treatment. Pan proteomic analysis in the myocardium showed that sunitinib induced (i) an early metabolic switch with enhanced glycolysis and reduced oxidative phosphorylation, and (ii) a metabolic failure to use glucose as energy substrate, similar to the insulin resistance found in type 2 diabetes. Co-administration of the endothelin receptor antagonist, macitentan, to sunitinib-treated animals prevented both metabolic defects, restored glucose uptake and cardiac function, and prevented myocardial fibrosis. These results support the endothelin system in mediating the cardiotoxic effects of sunitinib and endothelin receptor antagonism as a potential therapeutic approach to prevent cardiotoxicity. Furthermore, metabolic and functional imaging can monitor the cardiotoxic effects and the benefits of endothelin antagonism in a theranostic approach.

Comprehensive review on cardio-oncology: Role of multimodality imaging

Cancer and cardiovascular disease are the two leading causes of mortality worldwide. Evolving oncologic therapy, including the use of newer targeted agents, has led to an improvement in survival from childhood- and adult-onset cancers. Consequently, there has been a growing realization of cardiotoxic complications related to cancer therapy, with some complications manifesting over months to decades after completion of cancer treatment. This paper reviews cancer therapeutics-related cardiovascular toxicity and its manifestations, multimodality imaging techniques for surveillance and detection of this complication, and the current state of knowledge in this emerging field.

Anthracycline-Associated T1 Mapping Characteristics Are Elevated Independent of the Presence of Cardiovascular Comorbidities in Cancer Survivors

BACKGROUND

Cardiovascular magnetic resonance T1 mapping characteristics are elevated in adult cancer survivors; however, it remains unknown whether these elevations are related to age or presence of coincident cardiovascular comorbidities.

METHODS AND RESULTS

We performed blinded cardiovascular magnetic resonance analyses of left ventricular T1 and extracellular volume (ECV) fraction in 327 individuals (65% women, aged 64±12 years). Thirty-seven individuals had breast cancer or a hematologic malignancy but had not yet initiated their treatment, and 54 cancer survivors who received either anthracycline-based (n=37) or nonanthracycline-based (n=17) chemotherapy 2.8±1.3 years earlier were compared with 236 cancer-free participants. Multivariable analyses were performed to determine the association between T1/ECV measures and variables associated with myocardial fibrosis. Age-adjusted native T1 was elevated pre- (1058±7 ms) and post- (1040±7 ms) receipt of anthracycline chemotherapy versus comparators (965±3 ms; P<0.0001 for both). Age-adjusted ECV, a marker of myocardial fibrosis, was elevated in anthracycline-treated cancer participants (30.4±0.7%) compared with either pretreatment cancer (27.8±0.7%; P<0.01) or cancer-free comparators (26.9±0.2%; P<0.0001). T1 and ECV of nonanthracycline survivors were no different than pretreatment survivors (P=0.17 and P=0.16, respectively). Native T1 and ECV remained elevated in cancer survivors after accounting for demographics (including age), myocardial fibrosis risk factors, and left ventricular ejection fraction or myocardial mass index (P<0.0001 for all).

CONCLUSIONS

Three years after anthracycline-based chemotherapy, elevations in myocardial T1 and ECV occur independent of underlying cancer or cardiovascular comorbidities, suggesting that imaging biomarkers of interstitial fibrosis in cancer survivors are related to prior receipt of a potentially cardiotoxic cancer treatment regimen.

Photothermally induced accumulation and retention of polymeric nanoparticles in tumors for long-term fluorescence imaging

Photothermal induced accumulation and retention of polymeric nanoparticles in tumor is used for long-term fluorescent imaging.

Heart failure in chemotherapy-related cardiomyopathy: Can exercise make a difference?

Medical therapies in oncology have resulted in better survival resulting in a large population who are at risk of early and late cardiac complications of chemotherapy. Cardiotoxicity related to chemotherapy can manifest decades after treatment with a threefold higher mortality rate as compared to idiopathic dilated cardiomyopathy. The leading cause of death in cancer survivors seems to be cardiac. Early detection and intervention could prevent progression of heart failure to end stage disease requiring advanced therapies such as implantation of ventricular assist devices or cardiac transplantation. This review focuses on the role of exercise in cardioprotection in this population. The current practice of depending on ejection fraction for diagnosis of heart failure is suboptimal to detect subclinical disease. It is also important to diagnose and treat early diastolic dysfunction as this tends to lead to heart failure with preserved ejection fraction. Hence we suggest an algorithm here that is based on using strain rate and tissue Doppler imaging modalities to detect subclinical systolic and diastolic dysfunction. Further research is warranted in terms of defining exercise prescriptions in this population. Human studies with multicenter participation in randomized controlled trials should be done to elucidate the intricacies of aerobic exercise intervention in cardiotoxicity dependent heart failure. It is also necessary to assess the utility of exercise interventions in the different chemotherapeutic regimens as they impact the outcomes.

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The need for exercise prescription to prevent cardiotoxicity in chemotherapy patients

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The molecular basis of exercise as an intervention

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Summary of existing evidence

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Need for further studies on the role of exercise in different chemotherapeutic regimens

Cardiotoxicity in anthracycline therapy: Prevention strategies

The increasing use of anthracyclines, together with the longer survival of cancer patients, means the toxic effects of these drugs need to be monitored. In order to detect, prevent or mitigate anthracycline-induced cardiomyopathy, it is essential that all patients undergo a rigorous initial cardiovascular assessment, followed by close monitoring. Several clinical trials have shown the cardioprotective effect of non-pharmacological measures such as exercise, healthy lifestyles, control of risk factors and treatment of comorbidities; a cardioprotective effect has also been observed with pharmacological measures such as beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor antagonists, statins, dexrazoxane and liposomal formulations. However, there are currently no guidelines for managing prevention in these patients. In this review the authors discuss the state of the art of the assessment, monitoring, and, above all, the prevention of anthracycline-induced cardiotoxicity.

Cancer Therapy-Related Cardiac Dysfunction and Heart Failure: Part 1: Definitions, Pathophysiology, Risk Factors, and Imaging

Advances in cancer therapy have resulted in significant improvement in long-term survival for many types of cancer but have also resulted in untoward side effects associated with treatment. One such complication that has become increasingly recognized is the development of cardiomyopathy and heart failure. Whether a previously healthy person from a cardiovascular perspective develops cancer therapy-related cardiac dysfunction or a high-risk cardiovascular patient requires cancer therapy, the team of oncologists and cardiologists must be better equipped with an evidence-based approach to care for these patients across the spectrum. Although the toxicities associated with various cancer therapies are well recognized, limitations to our understanding of the appropriate course of action remain. In this first of a 2-part review, we discuss the epidemiologic, pathophysiologic, risk factors, and imaging aspects of cancer therapy-related cardiac dysfunction and heart failure. In a subsequent second part, we discuss the prevention and treatment aspects, concluding with a section on evidence gap and future directions. We focus on adult patients in all stages of cancer therapy from pretreatment surveillance, to ongoing therapy, and long-term follow-up.

Cardio-Oncology Training: A Proposal From the International Cardioncology Society and Canadian Cardiac Oncology Network for a New Multidisciplinary Specialty

There is an increasing awareness and clinical interest in cardiac safety during cancer therapy as well as in optimally addressing cardiac issues in cancer survivors. Although there is an emerging expertise in this area, known as cardio-oncology, there is a lack of organization in the essential components of contemporary training. This proposal, an international consensus statement organized by the International Cardioncology Society and the Canadian Cardiac Oncology Network, attempts to marshal the important ongoing efforts for training the next generation of cardio-oncologists. The necessary elements are outlined, including the expectations for exposure necessary to develop adequate training. There should also be a commitment to local, regional, and international education and research in cardio-oncology as a requirement for advancement in the field.

Update on cardiac imaging techniques 2014

In this article, we review the contributions of the most important imaging techniques used in cardiology, reported in 2014. Echocardiography remains the cornerstone for diagnosing and monitoring valvular heart disease, and there has been a continuing effort to improve quantification of this condition and obtain prognostic parameters for follow-up. The study of regional myocardial function is anchored in the diagnosis of subclinical ventricular dysfunction, and 3-dimensional transesophageal echocardiography has become the perfect ally in interventional procedures for structural heart disease. Cardiac magnetic resonance imaging and cardiac computed tomography are the focus of most publications on cardiac imaging in ischemic heart disease, reflecting their consolidated use in clinical practice. Nuclear medicine excels in the study of myocardial viability after interventional treatment of acute coronary syndromes and its performance is validated in the diagnosis of ischemic heart disease.