Early Myocardial Strain Changes During Potentially Cardiotoxic Chemotherapy May Occur as a Result of Reductions in Left Ventricular End-Diastolic Volume: The Need to Interpret Left Ventricular Strain With Volumes

Statins Do Not Significantly Affect Oxidative Nitrosative Stress Biomarkers in the PREVENT Randomized Clinical Trial

PURPOSE

Preventing Anthracycline Cardiovascular Toxicity with Statins (PREVENT; NCT01988571) randomized patients with breast cancer or lymphoma receiving anthracyclines to atorvastatin 40 mg daily or placebo. We evaluated the effects of atorvastatin on oxidative and nitrosative stress biomarkers, and explored whether these biomarkers could explain the lack of effect of atorvastatin on LVEF (left ventricular ejection fraction) in PREVENT.

PATIENTS AND METHODS

Blood samples were collected and cardiac MRI was performed before doxorubicin initiation and at 6 and 24 months. Thirteen biomarkers [arginine-nitric oxide metabolites, paraoxonase-1 (PON-1) activity, and myeloperoxidase] were measured. Dimensionality reduction using principal component analysis was used to define biomarker clusters. Linear mixed-effects models determined the changes in biomarkers over time according to treatment group. Mediation analysis determined whether biomarker clusters explained the lack of effect of atorvastatin on LVEF.

RESULTS

Among 202 participants with available biomarkers, median age was 53 years; 86.6% had breast cancer; median LVEF was 62%. Cluster 1 levels, reflecting arginine methylation metabolites, were lower over time with atorvastatin, although this was not statistically significant (P = 0.081); Cluster 2 levels, reflecting PON-1 activity, were significantly lower with atorvastatin (P = 0.024). There were no significant changes in other biomarker clusters (P > 0.05). Biomarker clusters did not mediate an effect of atorvastatin on LVEF (P > 0.05).

CONCLUSIONS

Atorvastatin demonstrated very modest effects on oxidative/nitrosative stress biomarkers in this low cardiovascular risk population. Our findings provide potential mechanistic insight into the lack of effect of atorvastatin on LVEF in the PREVENT trial.

Cardiovascular magnetic resonance characterization of myocardial tissue injury in a miniature swine model of cancer therapy-related cardiovascular toxicity

BACKGROUND

Left ventricular ejection fraction (LVEF) is the most commonly clinically used imaging parameter for assessing cancer therapy-related cardiac dysfunction (CTRCD). However, LVEF declines may occur late, after substantial injury. This study sought to investigate cardiovascular magnetic resonance (CMR) imaging markers of subclinical cardiac injury in a miniature swine model.

METHODS

Female Yucatan miniature swine (n = 14) received doxorubicin (2 mg/kg) every 3 weeks for 4 cycles. CMR, including cine, tissue characterization via T1 and T2 mapping, and late gadolinium enhancement (LGE) were performed on the same day as doxorubicin administration and 3 weeks after the final chemotherapy cycle. In addition, magnetic resonance spectroscopy (MRS) was performed during the 3 weeks after the final chemotherapy in 7 pigs. A single CMR and MRS exam were also performed in 3 Yucatan miniature swine that were age- and weight-matched to the final imaging exam of the doxorubicin-treated swine to serve as controls. CTRCD was defined as histological early morphologic changes, including cytoplasmic vacuolization and myofibrillar loss of myocytes, based on post-mortem analysis of humanely euthanized pigs after the final CMR exam.

RESULTS

Of 13 swine completing 5 serial CMR scans, 10 (77%) had histological evidence of CTRCD. Three animals had neither histological evidence nor changes in LVEF from baseline. No absolute LVEF <40% or LGE was observed. Native T1, extracellular volume (ECV), and T2 at 12 weeks were significantly higher in swine with CTRCD than those without CTRCD (1178 ms vs. 1134 ms, p = 0.002, 27.4% vs. 24.5%, p = 0.03, and 38.1 ms vs. 36.4 ms, p = 0.02, respectively). There were no significant changes in strain parameters. The temporal trajectories in native T1, ECV, and T2 in swine with CTRCD showed similar and statistically significant increases. At the same time, there were no differences in their temporal changes between those with and without CTRCD. MRS myocardial triglyceride content substantially differed among controls, swine with and without CTRCD (0.89%, 0.30%, 0.54%, respectively, analysis of variance, p = 0.01), and associated with the severity of histological findings and incidence of vacuolated cardiomyocytes.

CONCLUSION

Serial CMR imaging alone has a limited ability to detect histologic CTRCD beyond LVEF. Integrating MRS myocardial triglyceride content may be useful for detection of early potential CTRCD.

Myocardial strain of the left ventricle by speckle tracking echocardiography: From physics to clinical practice

Speckle tracking echocardiography (STE) is a reliable imaging technique of recognized clinical value in several settings. This method uses the motion of ultrasound backscatter speckles within echocardiographic images to derive myocardial velocities and deformation parameters, providing crucial insights on several cardiac pathological and physiological processes. Its feasibility, reproducibility, and accuracy have been widely demonstrated, being myocardial strain of the various chambers inserted in diagnostic algorithms and guidelines for various pathologies. The most important parameters are Global longitudinal strain (GLS), Left atrium (LA) reservoir strain, and Global Work Index (GWI): based on large studies the average of the lower limit of normality are -16%, 23%, and 1442 mmHg%, respectively. For GWI, it should be pointed out that myocardial work relies primarily on non-invasive measurements of blood pressure and segmental strain, both of which exhibit high variability, and thus, this variability constitutes a significant limitation of this parameter. In this review, we describe the principal aspects of the theory behind the use of myocardial strain, from cardiac mechanics to image acquisition techniques, outlining its limitation, and its principal clinical applications: in particular, GLS have a role in determine subclinical myocardial dysfunction (in cardiomyopathies, cardiotoxicity, target organ damage in ambulatory patients with arterial hypertension) and LA strain in determine the risk of AF, specifically in ambulatory patients with arterial hypertension.

Utilities and Limitations of Cardiac Magnetic Resonance Imaging in Dilated Cardiomyopathy

Dilated cardiomyopathy (DCM) is one of the most common types of non-ischemic cardiomyopathy. DCM is characterized by left ventricle (LV) dilatation and systolic dysfunction without coronary artery disease or abnormal loading conditions. DCM is not a single disease entity and has a complex historical background of revisions and updates to its definition because of its diverse etiology and clinical manifestations. In cases of LV dilatation and dysfunction, conditions with phenotypic overlap should be excluded before establishing a DCM diagnosis. The differential diagnoses of DCM include ischemic cardiomyopathy, valvular heart disease, burned-out hypertrophic cardiomyopathy, arrhythmogenic cardiomyopathy, and non-compaction. Cardiac magnetic resonance (CMR) imaging is helpful for evaluating DCM because it provides precise measurements of cardiac size, function, mass, and tissue characterization. Comprehensive analyses using various sequences, including cine imaging, late gadolinium enhancement imaging, and T1 and T2 mapping, may help establish differential diagnoses, etiological work-up, disease stratification, prognostic determination, and follow-up procedures in patients with DCM phenotypes. This article aimed to review the utilities and limitations of CMR in the diagnosis and assessment of DCM.

Myocardial Elasticity Imaging Correlates with Histopathology in a Model of Anthracycline-Induced Cardiotoxicity

Background

There is considerable focus on developing strategies for identifying subclinical cardiac decline prior to cardiac failure. Myocardial tissue elasticity changes may precede irreversible cardiac damage, providing promise for an early biomarker for cardiac decline. Biomarker strategies are of particular interest in cardio-oncology due to cardiotoxic effects of anti-neoplastic therapies, particularly anthracycline-based chemotherapeutics. Current clinical methods for diagnosing cardiotoxicity are too coarse to identify cardiac decline early enough for meaningful therapeutic intervention, or too cumbersome for clinical implementation.

Methods

Utilizing changes in myocardial elasticity as a biomarker for subclinical cardiac decline, we developed a biomechanical model-based elasticity imaging methodology (BEIM) to estimate spatial maps of left ventricle (LV) myocardial elasticity. In this study, we employ this methodology to assess changes in LV elasticity in a non-human primate model of doxorubicin-induced cardiotoxicity. Cardiac magnetic resonance imaging of five African Green monkeys was acquired at baseline prior to doxorubicin administration, 6-weeks, and 15-weeks after final doxorubicin dose and histopathological samples of the LV were taken at 15-weeks after final doxorubicin dose. Spatial elasticity maps of the mid-short axis plane of the LV were estimated at each image acquisition. Global and regional LV elasticity were calculated and changes between imaging time points was assessed. LV elasticity at baseline and final time point were compared to cardiomyocyte size and collagen volume fraction measurements calculated from histopathological staining of archived tissue bank samples and study endpoint tissue samples utilizing Pearson's correlation coefficients.

Results

We identify significant changes in LV elasticity between each imaging time point both globally and regionally. We also demonstrate strong correlation between LV elasticity and cardiomyocyte size and collagen volume fraction measurements. Results indicate that LV elasticity estimates calculated using BEIM correlate with histopathological changes that occur due to doxorubicin administration, validating LV elasticity solutions and providing significant promise for use of BEIM to non-invasively elucidate cardiac injury.

Conclusions

This methodology can show progressive changes in LV elasticity and has potential to be a more sensitive indicator of elasticity changes than current clinical measures of cardiotoxicity. LV elasticity may provide a valuable biomarker for cardiotoxic effects of anthracycline-based chemotherapeutics and cardiac disease detection.

Physical Activity During Breast Cancer Therapy Associates With Preserved Exercise Capacity and Cardiac Function (WF97415)

Background

Cancer treatment increases cardiovascular disease risk, but physical activity (PA) may prevent cardiovascular disease.

Objectives

This study examined whether greater PA was associated with better submaximal exercise capacity and cardiac function during cancer therapy.

Methods

Participants included 223 women with stage I to III breast cancer (BC) before and 3 months after undergoing treatment and 126 control participants. Leisure-time PA (LTPA) was reported using the Godin-Shephard LTPA questionnaire. Cardiac function was assessed by cardiac magnetic resonance. Submaximal exercise capacity was determined by 6-minute walk distance.

Results

BC participants reported similar baseline LTPA scores (24.7; 95% CI: 21.7-28.0) as control participants (29.4; 95% CI: 25.0-34.2). The BC group declined to 16.9 (95% CI: 14.4-19.6) at 3 months relative to 30.8 (95% CI: 26.2-35.8) in control participants. Among BC participants, more LTPA was related to better exercise capacity (β ± SE: 7.1 ± 1.6; 95% CI: 4.0-10.1) and left ventricular (LV) circumferential strain (-0.16 ± 0.07; 95% CI: -0.29 to -0.02). Increased LTPA over the 3 months was associated with decreased likelihood of treatment-induced cardiac dysfunction according to LV circumferential strain classifications (OR: 0.98; 95% CI: 0.97-0.998). BC participants reporting insufficient LTPA according to PA guidelines exhibited deteriorations in exercise capacity (adjusted mean difference ± SE: -29 ± 10 m; P = 0.029), LV end-systolic volume (5.8 ± 1.3 mL; P < 0.001), LV ejection fraction (-3.2% ± 0.8%; P = 0.002), and LV circumferential strain (2.5% ± 0.5%; P < 0.001), but BC participants meeting LTPA guidelines did not exhibit these adverse changes.

Conclusions

PA declined during BC therapy; however, PA participation was associated with attenuated declines in exercise capacity and cardiac function that are often observed in this population. (Understanding and Predicting Breast Cancer Events After Treatment [WF97415 UPBEAT]; NCT02791581).

Multimodality imaging in cardio-oncology: the added value of CMR and CCTA

During the last 30 years, we have assisted to a great implementation in anticancer treatment with a subsequent increase of cancer survivors and decreased mortality. This has led to an ongoing interest about the possible therapy-related side-effects and their management to better guide patients therapy and surveillance in the chronic and long-term setting. As a consequence cardio-oncology was born, involving several different specialties, among which radiology plays a relevant role. Till the end of August 2022, when European Society of Cardiology (ESC) developed the first guidelines on cardio-oncology, no general indications existed to guide diagnosis and treatment of cancer therapy-related cardiovascular toxicity (CTR-CVT). They defined multimodality imaging role in primary and secondary prevention strategies, cancer treatment surveillance and early CTR-CVT identification and management. Cardiac computed tomography angiography (CCTA) has acquired a central role in coronary assessment, as far as coronary artery disease (CAD) exclusion is concerned; but on the side of this well-known application, it also started to be considered in left ventricular function evaluation, interstitial fibrosis quantification and cardiac perfusion studies. Cardiac magnetic resonance (CMR), instead, has been acknowledged as the gold standard alternative to trans-thoracic echocardiography (TTE) poor acoustic window in quantification of heart function and strain modifications, as well as pre- and post-contrast tissue characterization by means of T1-T2 mapping, early Gadolinium enhancement (EGE), late Gadolinium enhancement (LGE) and extracellular volume (ECV) evaluation. Our review is intended to provide a focus on the actual role of CMR and CCTA in the setting of a better understanding of cardiotoxicity and to draw some possible future directions of cardiac imaging in this field, starting from the recently published ESC guidelines.

Ventricular Ejection Fraction and Global Strains in Connection with the Volume Regulation Graph

Ejection fraction (EF) is traditionally considered useful to infer ventricular function. Newer metrics such as global function index (GFI) and various strains add supplemental diagnostic or prognostic value. All these candidates refer to dimensionless ratios, rather than to the characteristics of the underlying components. Therefore, we introduced the volume regulation graph (VRG), relating end-systolic volume (ESV) to end-diastolic volume (EDV). An individual patient is then uniquely defined by the prevailing working point in the volume domain. Alternatively, the combination of EF=(1-ESV/EDV) and any suitable companion (denoted as C) metric (e.g. the Pythagorean mean) specifies this working point.An expression relates EF to global longitudinal (GLS) and circumferential strain (GCS): ESV/EDV = (GLS+1) (GCS+1)2, resembling the empirical regression equation for the VRG. However, the latter has a non-zero intercept (mL). The discrepancy can be solved by the introduction of one or more pertinent companion metrics.We studied 96 patients by cardiac magnetic resonance imaging and calculated EF, EFC, GFI, GLS and GCS. The GFI is inversely related to GLS (R2=0.26). For regression we found: ESV=0.74 EDV-27.0 with R2=0.81 for N=96. Similar results were obtained for echocardiography data (N=25). Graphs relating EF to GLS and GCS indicate that EFC can distinguish patients with nearly identical values for these 3 metrics.Thus, the VRG offers a unifying framework that visualizes the association between ESV and EDV, while documenting iso-EF and iso-EFC trajectories. Newer metrics including GFI, GLS and GCS require consideration of a companion variable such as EFC to permit a comprehensive analysis.Clinical Relevance- The VRG allows insight into ventricular functioning and illustrates the working point concept. Companion metrics (having a physical dimension) should be considered in conjunction with any traditional ratio-based index.

Global Longitudinal Strain in Cardio-Oncology: A Review

Several therapies used in cancer treatment are potentially cardiotoxic and may cause left ventricular (LV) dysfunction and heart failure. For decades, echocardiography has been the main modality for cardiac assessment in cancer patients, and the parameter examined in the context of cardiotoxicity was the left ventricular ejection fraction (LVEF). The assessment of the global longitudinal strain (GLS) using speckle tracking echocardiography (STE) is an emerging method for detecting and quantifying subtle disturbances in the global long-axis LV systolic function. In the latest ESC guidelines on cardio-oncology, GLS is an important element in diagnosing the cardiotoxicity of oncological therapy. A relative decrease in GLS of >15% during cancer treatment is the recommended cut-off point for suspecting subclinical cardiac dysfunction. An early diagnosis of asymptomatic cardiotoxicity allows the initiation of a cardioprotective treatment and reduces the risk of interruptions or changes in the oncological treatment in the event of LVEF deterioration, which may affect survival.

Diagnosis and Management of Cancer Treatment-Related Cardiac Dysfunction and Heart Failure in Children

It is disheartening for parents to discover that their children have long-term cardiac dysfunction after being cured of life-threatening childhood cancers. As the number of childhood cancer survivors increases, early and late oncology-therapy-related cardiovascular complications continues to rise. It is essential to understand that cardiotoxicity in childhood cancer survivors is persistent and progressive. A child's cancer experience extends throughout his lifetime, and ongoing care for long-term survivors is recognized as an essential part of the cancer care continuum. Initially, there was a lack of recognition of late cardiotoxicities related to cancer therapy. About 38 years ago, in 1984, pioneers like Dr. Lipshultz and others published anecdotal case reports of late cardiotoxicities in children and adolescents exposed to chemotherapy, including some who ended up with heart transplantation. At that time, cardiac tests for cancer survivors were denied by insurance companies because they did not meet appropriate use criteria. Since then, cardio-oncology has been an emerging field of cardiology that focuses on the early detection of cancer therapy-related cardiac dysfunction occurring during and after oncological treatment. The passionate pursuit of many healthcare professionals to make life better for childhood cancer survivors led to more than 10,000 peer-reviewed publications in the last 40 years. We synthesized the existing evidence-based practice and described our experiences in this review to share our current method of surveillance and management of cardiac dysfunction related to cancer therapy. This review aims to discuss the pathological basis of cancer therapy-related cardiac dysfunction and heart failure, how to stratify patients prone to cardiotoxicity by identifying modifiable risk factors, early detection of cardiac dysfunction, and prevention and management of heart failure during and after cancer therapy in children. We emphasize serial longitudinal follow-ups of childhood cancer survivors and targeted intervention for high-risk patients. We describe our experience with the new paradigm of cardio-oncology care, and collaboration between cardiologist and oncologist is needed to maximize cancer survival while minimizing late cardiotoxicity.

Cardiac MRI assessment of anthracycline-induced cardiotoxicity

The objective of this review article is to discuss how cardiovascular magnetic resonance (CMR) imaging measures left ventricular (LV) function, characterizes tissue, and identifies myocardial fibrosis in patients receiving anthracycline-based chemotherapy (Anth-bC). Specifically, CMR can measure LV ejection fraction (EF), volumes at end-diastole (LVEDV), and end-systole (LVESV), LV strain, and LV mass. Tissue characterization is accomplished through T1/T2-mapping, late gadolinium enhancement (LGE), and CMR perfusion imaging. Despite CMR’s accuracy and efficiency in collecting data about the myocardium, there are challenges that persist while monitoring a cardio-oncology patient undergoing Anth-bC, such as the presence of other cardiovascular risk factors and utility controversies. Furthermore, CMR can be a useful adjunct during cardiopulmonary exercise testing to pinpoint cardiovascular mediated exercise limitations, as well as to assess myocardial microcirculatory damage in patients undergoing Anth-bC.

Statins and Left Ventricular Ejection Fraction Following Doxorubicin Treatment

BACKGROUND

Statins taken for cardiovascular indications by patients with breast cancer and lymphoma during doxorubicin treatment may attenuate left ventricular ejection fraction (LVEF) decline, but the effect of statins on LVEF among patients with no cardiovascular indications is unknown.

METHODS

A double-blind, placebo-controlled, 24-month randomized trial of 40 mg of atorvastatin per day administered to patients with breast cancer and lymphoma receiving doxorubicin was conducted within the National Cancer Institute Community Oncology Research Program across 31 sites in the United States. At pretreatment and then 6 and 24 months after initiating doxorubicin, we assessed left ventricular (LV) volumes, strain, mass, and LVEF through cardiac magnetic resonance imaging, along with cognitive function and serum markers of inflammation. The primary outcome was the difference in 24-month LVEF between placebo and treatment groups, adjusted for pretreatment LVEF.

RESULTS

A total of 279 participants were enrolled in the trial. Participants had a mean (±SD) age of 49±12 years; 92% were women; and 83% were White. The mean (±SD) LVEF values were 61.7±5.5% before treatment and 57.4±6.8% at 24 months in the placebo group and 62.6±6.4% before treatment and 57.7±5.6% at 24 months in the atorvastatin group. On the basis of a multiple imputed data set for missing data and adjusted for each individual's pretreatment LVEF, 24-month declines in LVEF averaged 3.3±0.6 percentage points and 3.2±0.7 percentage points, for those randomly assigned to placebo versus statins, respectively (P=0.93). Across both treatment arms, similar percentages of individuals experienced changes of more than 10 percentage points in LVEF, LV strain, LV mass, cognition, and inflammation biomarkers, including among those with greater than 90% drug compliance.

CONCLUSIONS

In patients with breast cancer and lymphoma with no existing indication for statin therapy, prospective statin administration did not affect LVEF declines 2 years after doxorubicin. (Funded by the National Institutes of Health; ClinicalTrials.gov number, NCT01988571.).

Multimodality Advanced Cardiovascular and Molecular Imaging for Early Detection and Monitoring of Cancer Therapy-Associated Cardiotoxicity and the Role of Artificial Intelligence and Big Data

Cancer mortality has improved due to earlier detection via screening, as well as due to novel cancer therapies such as tyrosine kinase inhibitors and immune checkpoint inhibitions. However, similarly to older cancer therapies such as anthracyclines, these therapies have also been documented to cause cardiotoxic events including cardiomyopathy, myocardial infarction, myocarditis, arrhythmia, hypertension, and thrombosis. Imaging modalities such as echocardiography and magnetic resonance imaging (MRI) are critical in monitoring and evaluating for cardiotoxicity from these treatments, as well as in providing information for the assessment of function and wall motion abnormalities. MRI also allows for additional tissue characterization using T1, T2, extracellular volume (ECV), and delayed gadolinium enhancement (DGE) assessment. Furthermore, emerging technologies may be able to assist with these efforts. Nuclear imaging using targeted radiotracers, some of which are already clinically used, may have more specificity and help provide information on the mechanisms of cardiotoxicity, including in anthracycline mediated cardiomyopathy and checkpoint inhibitor myocarditis. Hyperpolarized MRI may be used to evaluate the effects of oncologic therapy on cardiac metabolism. Lastly, artificial intelligence and big data of imaging modalities may help predict and detect early signs of cardiotoxicity and response to cardioprotective medications as well as provide insights on the added value of molecular imaging and correlations with cardiovascular outcomes. In this review, the current imaging modalities used to assess for cardiotoxicity from cancer treatments are discussed, in addition to ongoing research on targeted molecular radiotracers, hyperpolarized MRI, as well as the role of artificial intelligence (AI) and big data in imaging that would help improve the detection and prognostication of cancer-treatment cardiotoxicity.

Diastolic Cardiac Function by MRI-Imaging Capabilities and Clinical Applications

Most cardiac studies focus on evaluating left ventricular (LV) systolic function. However, the assessment of diastolic cardiac function is becoming more appreciated, especially with the increasing prevalence of pathologies associated with diastolic dysfunction like heart failure with preserved ejection fraction (HFpEF). Diastolic dysfunction is an indication of abnormal mechanical properties of the myocardium, characterized by slow or delayed myocardial relaxation, abnormal LV distensibility, and/or impaired LV filling. Diastolic dysfunction has been shown to be associated with age and other cardiovascular risk factors such as hypertension and diabetes mellitus. In this context, cardiac magnetic resonance imaging (MRI) has the capability for differentiating between normal and abnormal myocardial relaxation patterns, and therefore offers the prospect of early detection of diastolic dysfunction. Although diastolic cardiac function can be assessed from the ratio between early and atrial filling peaks (E/A ratio), measuring different parameters of heart contractility during diastole allows for evaluating spatial and temporal patterns of cardiac function with the potential for illustrating subtle changes related to age, gender, or other differences among different patient populations. In this article, we review different MRI techniques for evaluating diastolic function along with clinical applications and findings in different heart diseases.

The Utility of Advanced Cardiovascular Imaging in Cancer Patients-When, Why, How, and the Latest Developments

Cardio-oncology encompasses the risk stratification, prognostication, identification and management of cancer therapeutics related cardiac dysfunction (CTRCD). Cardiovascular imaging (CVI) plays a significant role in each of these scenarios and has broadened from predominantly quantifying left ventricular function (specifically ejection fraction) to the identification of earlier bio-signatures of CTRCD. Recent data also demonstrate the impact of chemotherapy on the right ventricle, left atrium and pericardium and highlight a possible role for CVI in the identification of CTRCD through tissue characterization and assessment of these cardiac chambers. This review aims to provide a contemporary perspective on the role of multi-modal advanced cardiac imaging in cardio-oncology.

Assessing left ventricular systolic function: from ejection fraction to strain analysis

The measurement of left ventricular ejection fraction (LVEF) is a ubiquitous component of imaging studies used to evaluate patients with cardiac conditions and acts as an arbiter for many management decisions. This follows early trials investigating heart failure therapies which used a binary LVEF cut-off to select patients with the worst prognosis, who may gain the most benefit. Forty years on, the cardiac disease landscape has changed. Left ventricular ejection fraction is now a poor indicator of prognosis for many heart failure patients; specifically, for the half of patients with heart failure and truly preserved ejection fraction (HF-PEF). It is also recognized that LVEF may remain normal amongst patients with valvular heart disease who have significant myocardial dysfunction. This emphasizes the importance of the interaction between LVEF and left ventricular geometry. Guidelines based on LVEF may therefore miss a proportion of patients who would benefit from early intervention to prevent further myocardial decompensation and future adverse outcomes. The assessment of myocardial strain, or intrinsic deformation, holds promise to improve these issues. The measurement of global longitudinal strain (GLS) has consistently been shown to improve the risk stratification of patients with heart failure and identify patients with valvular heart disease who have myocardial decompensation despite preserved LVEF and an increased risk of adverse outcomes. To complete the integration of GLS into routine clinical practice, further studies are required to confirm that such approaches improve therapy selection and accordingly, the outcome for patients.

Role of cardiovascular magnetic resonance in early detection and treatment of cardiac dysfunction in oncology patients

The purpose of this review is to provide an overview of the essential role that cardiovascular magnetic resonance (CMR) has in the field of cardio-oncology. Recent findings: CMR has been increasingly used for early identification of cancer therapy related cardiac dysfunction (CTRCD) due to its precision in detecting subtle changes in cardiac function and for myocardial tissue characterization. Summary: CMR is able to identify subclinical CTRCD in patients receiving potentially cardiotoxic chemotherapy and guide initiation of cardio protective therapy. Multiparametric analysis with myocardial strain, tissue characterization play a critical role in understanding important clinical questions in cardio-oncology.

Both intermuscular fat and LVEF decline promote heart failure symptoms in cancer survivors

Background

Approximately 20% of cancer survivors treated with chemotherapy experience worsening heart failure (HF) symptoms post-cancer treatment. While research has predominantly investigated the role of cardiotoxic treatments, much less attention has focused on other risk factors, such as adiposity. However, emerging data in cancer survivors indicates that adiposity may also impact a variety of cardiovascular outcomes. Methods: In a prospective study of 62 patients diagnosed with cancer followed for 24 months from cancer diagnosis through to survivorship (post-cancer treatment), we ascertained baseline fat depots including intermuscular fat (IMF) of the erector spinae muscles; and pre- and post-cancer treatment left ventricular ejection fraction (LVEF) and HF symptoms at baseline and 24-months, respectively. Linear regression was used to model independent variables in relation to HF symptoms at 24-months.

Results

Baseline IMF and LVEF change over 24-months significantly interacted to predict HF score at 24-months. The highest HF symptom score was observed for participants who experienced high IMF at baseline and a high decline in LVEF over 24-months (HF score = 11.0) versus all other categories of baseline IMF and LVEF change.

Conclusions

Together IMF and LVEF decline may play an important role in the worsening of HF symptoms in cancer survivors. The finding that IMF at cancer diagnosis led to elevated HF scores post-treatment suggests that IMF may be a potential target for intervention studies.

Update in imaging of cancer therapy-related cardiac toxicity in adults

Over the past decades, prognosis of patients with cancer has strongly improved and the number of cancer survivors is rapidly growing. Despite this success, cancer treatment is associated with development of serious cardiovascular diseases including left ventricular (LV) systolic dysfunction, heart failure, valvular disease, myocardial infarction, arrhythmias or pericardial diseases. Serial non-invasive cardiac imaging is an important tool to detect early signs of cardiotoxicity, to allow for timely intervention and provide optimal circumstances for long-term prognosis. Currently, echocardiographic imaging is the method of choice for the evaluation of myocardial function during and after cancer therapy. However, 2D echocardiography may fail to detect subtle changes in myocardial function, potentially resulting in a significant delay of therapeutic intervention to impede advanced cardiac disease states with more overt systolic dysfunction. Strain imaging is a promising method for early detection of myocardial dysfunction and may predict future changes in LV ejection fraction. The use of three-dimensional echocardiography may overcome the limitations of 2D echocardiography with more precise and reproducible measurements of LV performance. Cardiac MRI is the gold standard for volumetric assessment and can also be used to perform myocardial tissue characterisation. Visualisation of oedema and fibrosis may provide insights into the degree and disease course of cardiotoxicity and underlying pathophysiological mechanisms. There is growing body of literature regarding the promising role of these advanced imaging modalities in early detection of cardiotoxicity. With this overview paper, new insights and recent results in literature regarding echocardiographic and cardiac magnetic resonance imaging of cancer therapy-related cardiac dysfunction in post-cancer therapy adults will be highlighted.

Monitoring of anthracycline-induced myocardial injury using serial cardiac magnetic resonance: An animal study

PURPOSE

To assess the feasibility of using comprehensive serial cardiovascular MR (CMR) to evaluate bilateral ventricle mechanical changes and myocardial tissue characteristics, as well as correlations between the serial CMR and histology in a beagle model of anthracycline-induced cardiotoxicity.

METHODS

This animal study was approved by the institutional review board. Serial CMR imaging was performed in a total of fifteen beagles at baseline (n = 15), at week 16 (n = 10) and week 24 (n = 7) post-anthracycline. Feature-tracking CMR (FT-CMR) was applied to measure bilateral ventricular (left ventricle (LV) and right ventricle (RV)) global peak strain including radial (GRS), circumferential (GCS) and longitudinal (GLS) strain. The changes in strain, LV/RV functional parameters, native T1, extracellular volume fraction (ECV) and collagen volume fraction (CVF) were calculated.

RESULTS

Compared to baseline at weeks 16 and 24, significantly decreases to LV-GLS and native T1 were observed, while ECV significantly increased (all P < 0.05). LVEF significantly decreased and LV-EDV/ESV significantly increased at week 16 compared to baseline (all P < 0.05), but no further progression was seen at week 24. RV-GLS significantly decreased at week 16, but no further progression was seen at week 24, while RVEF was different until week 24. CVF increased significantly during modeling. Native T1 and ECV showed positive correlation with CVF (r = 0.645, P < 0.001), while LV-GLS showed negative correlation with CVF (r = -0.736, P < 0.05).

CONCLUSION

Cardiotoxicity affects the RV slightly and less progressively than the LV. FT-CMR-based GLS, native T1 and ECV may potentially be used as imaging biomarkers for early monitoring of anthracycline-induced myocardial Injury.

Serial Cardiovascular Magnetic Resonance Strain Measurements to Identify Cardiotoxicity in Breast Cancer: Comparison With Echocardiography

OBJECTIVES

This study sought to compare the prognostic value of cardiovascular magnetic resonance (CMR) and 2-dimensional echocardiography (2DE) derived left ventricular (LV) strain, volumes, and ejection fraction for cancer therapy-related cardiac dysfunction (CTRCD) in women with early stage breast cancer.

BACKGROUND

There are limited comparative data on the association of CMR and 2DE derived strain, volumes, and LVEF with CTRCD.

METHODS

A total of 125 prospectively recruited women with HER2+ early stage breast cancer receiving sequential anthracycline/trastuzumab underwent 5 serial CMR and 6 of 2DE studies before and during treatment. CMR LV volumes, left ventricular ejection fraction tagged-CMR, and feature-tracking (FT) derived global systolic longitudinal (GLS) and global circumferential strain (GCS) and 2DE-based LV volumes, function, GLS, and GCS were measured. CTRCD was defined by the cardiac review and evaluation committee criteria.

RESULTS

Twenty-eight percent of patients developed CTRCD by CMR and 22% by 2DE. A 15% relative reduction in 2DE-GLS increased the CTRCD odds by 133% at subsequent follow-up, compared with 47%/50% by tagged-CMR GLS/GCS and 87% by FT-GCS. CMR and 2DE-LVEF and indexed left ventricular end-systolic volume (LVESVi) were also associated with subsequent CTRCD. The prognostic threshold change in CMR-left ventricular ejection fraction and FT strain for subsequent CTRCD was similar to the known minimum-detectable difference for these measures, whereas for tagged-CMR strain it was lower than the minimum-detectable difference; for 2DE, only the prognostic threshold for GLS was greater than the minimum-detectable difference. Of all strain methods, 2DE-GLS provided the highest increase in discriminatory value over baseline clinical risk factors for subsequent CTRCD. The combination of 2DE-left ventricular ejection fraction or LVESVi and strain provided greater increase in the area under the curve for subsequent CTRCD over clinical risk factors than CMR left ventricular ejection fraction or LVESVi and strain (18% to 22% vs. 9% to 14%).

CONCLUSIONS

In women with HER2+ early stage breast cancer, changes in CMR and 2DE strain, left ventricular ejection fraction, and LVESVi were prognostic for subsequent CTRCD. When LVEF can be measured precisely by CMR, FT strain may function as an additional confirmatory prognostic measure, but with 2DE, GLS is the optimal prognostic measure. (Evaluation of Myocardial Changes During BReast Adenocarcinoma Therapy to Detect Cardiotoxicity Earlier With MRI [EMBRACE-MRI]; NCT02306538).

The Role of Cardiovascular MRI in Cardio-Oncology

"Cardiac imaging is an essential tool in the field of cardio-oncology. Cardiovascular magnetic resonance (CMR) stands out for its accuracy, reproducibility, and ability to provide tissue characterization. These attributes are particularly helpful in screening and diagnosing cardiotoxicity, infiltrative disease, and inflammatory cardiac disease. The ability of CMR to detect subtle changes in cardiac function and tissue composition has made it a useful tool for understanding the pathophysiology of cardiotoxicity. Because of these unique features, CMR is gaining prominence in both the clinical and research aspects of cardio-oncology."

The relationship between abdominal fat and change in left ventricular ejection fraction in cancer patients

Objectives

Prior studies have identified a relationship between body mass index (BMI) and intraperitoneal (IP) fat with heart failure; however, in prior studies of cancer patients receiving potentially cardiotoxic chemotherapy, elevations in BMI have not necessarily been associated with decrements in heart function. This study tested the hypothesis that IP fat may be associated with left ventricular ejection fraction (LVEF) decline among cancer patients receiving potentially cardiotoxic chemotherapy.

Methods

In this prospective study of 61 cancer patients (23 breast cancer, 32 lymphoma, and 6 sarcoma), IP fat and other assessments of body composition, and changes in LVEF from pre- to postcancer treatment using noninvasive magnetic resonance imaging was ascertained.

Results

After accounting for age, baseline LVEF, and confounding variables, pre- to 24-month post-treatment LVEF changes were inversely correlated with IP fat (r = -0.33; p = 0.02) and positively correlated with measures of subcutaneous (SQ) fat (r = 0.33; p = 0.01). These LVEF changes were not correlated with BMI (r = 0.12; p = 0.37).

Conclusion

Among patients receiving potentially cardiotoxic chemotherapy, pretreatment IP fat was associated with subsequent declines in LVEF. There was no association between BMI and LVEF decline. These findings may be related to a potential protective effect of SQ fat.

The role of cardiac magnetic resonance imaging in the detection and monitoring of cardiotoxicity in patients with breast cancer after treatment: a comprehensive review

The use of chemotherapy medicines for breast cancer (BC) has been associated with an increased risk of cardiotoxicity. In recent years, there have been growing interests regarding the application of cardiovascular magnetic resonance (CMR) imaging, a safe and noninvasive modality, with the potential to identify subtle morphological and functional changes in the myocardium. In this investigation, we aimed to review the performance of various CMR methods in diagnosing cardiotoxicity in BC, induced by chemotherapy or radiotherapy. For this purpose, we reviewed the literature available in PubMed, MEDLINE, Cochrane, Google Scholar, and Scopus databases. Our literature review showed that CMR is a valuable modality for identifying and predicting subclinical cardiotoxicity induced by chemotherapy. The novel T1, T2, and extracellular volume mapping techniques may provide critical information about cardiotoxicity, in addition to other CMR features such as functional and structural changes. However, further research is needed to verify the exact role of these methods in identifying cardiotoxicity and patient management. Since multiple studies have reported the improvement of left ventricular performance following the termination of chemotherapy regimens, CMR remains an essential imaging tool for the prediction of cardiotoxicity and, consequently, decreases the mortality rate of BC due to heart failure.

Detection of subclinical myocardial dysfunction in cocaine addicts with feature tracking cardiovascular magnetic resonance

BACKGROUND

Cocaine is an addictive, sympathomimetic drug with potentially lethal effects. We have previously shown with cardiovascular magnetic resonance (CMR) the presence of cardiovascular involvement in a significant percentage of consecutive asymptomatic cocaine addicts. CMR with feature-tracking analysis (CMR-FT) allows for the quantification of myocardial deformation which may detect preclinical involvement. Therefore, we aimed to assess the effects of cocaine on the left ventricular myocardium in a group of asymptomatic cocaine users with CMR-FT.

METHODS

In a cohort of asymptomatic cocaine addicts (CA) who had been submitted to CMR at 3 T, we used CMR-FT to measure strain, strain rate and dyssynchrony index in CA with mildly decreased left ventricular ejection fraction (CA-LVEFd) and in CA with preserved ejection fraction (CA-LVEFp). We also measured these parameters in 30 age-matched healthy subjects.

RESULTS

There were no differences according to age. Significant differences were seen in global longitudinal, radial and circumferential strain, in global longitudinal and radial strain rate and in radial and circumferential dyssynchrony index among the groups, with the lowest values in CA-LVEFd and intermediate values in CA-LVEFp. Longitudinal, radial and circumferential strain values were significantly lower in CA-LVEFp with respect to controls.

CONCLUSIONS

CA-LVEFp show decreased systolic strain and strain rate values, with intermediate values between healthy controls and CA-LVEFd. Signs suggestive of dyssynchrony were also detected. In CA, CMR-FT based strain analysis can detect early subclinical myocardial involvement.

Cardiotoxicity of HER2-targeted therapies

PURPOSE OF REVIEW

Cardiotoxicity is a well recognized adverse effect of human epidermal growth factor receptor 2 (HER2)-targeted therapies. The goal of this review is to highlight recent studies that have advanced our knowledge of the diagnosis, prevention, and management of cardiotoxicity associated with HER2-targeted agents.

RECENT FINDINGS

Several clinical risk factors for cardiotoxicity associated with HER2-targeted therapies have been identified including age, low-baseline left ventricular ejection fraction, and treatment with anthracyclines; however, these remain insufficient to identify all patients at risk for cardiotoxicity. Routine cardiac monitoring remains the standard for cardiotoxicity surveillance, although the optimal frequency and modality of monitoring remains uncertain. Global longitudinal strain, T1/T2 weighted CMR imaging protocols, and circulating biomarkers can detect early signs of cardiotoxicity, but studies are needed to investigate whether use of these markers in clinical practice improves patient outcomes. Cardioprotective medications (e.g. beta-blockers or ACE-inhibitors) may be of benefit to patients at increased risk for cardiotoxicity from HER2-taregeted therapies, particularly those who are treated with an anthracycline-containing regimen.

SUMMARY

Improved risk stratification of patients during HER2-targeted therapy and effective prevention and management strategies for cardiotoxicity are needed to enhance the value of longitudinal cardiac monitoring and increase cardiac safety so that optimal breast cancer treatment can be delivered.

Management of cardiac disease in cancer patients throughout oncological treatment: ESMO consensus recommendations

Cancer and cardiovascular (CV) disease are the most prevalent diseases in the developed world. Evidence increasingly shows that these conditions are interlinked through common risk factors, coincident in an ageing population, and are connected biologically through some deleterious effects of anticancer treatment on CV health. Anticancer therapies can cause a wide spectrum of short- and long-term cardiotoxic effects. An explosion of novel cancer therapies has revolutionised this field and dramatically altered cancer prognosis. Nevertheless, these new therapies have introduced unexpected CV complications beyond heart failure. Common CV toxicities related to cancer therapy are defined, along with suggested strategies for prevention, detection and treatment. This ESMO consensus article proposes to define CV toxicities related to cancer or its therapies and provide guidance regarding prevention, screening, monitoring and treatment of CV toxicity. The majority of anticancer therapies are associated with some CV toxicity, ranging from asymptomatic and transient to more clinically significant and long-lasting cardiac events. It is critical however, that concerns about potential CV damage resulting from anticancer therapies should be weighed against the potential benefits of cancer therapy, including benefits in overall survival. CV disease in patients with cancer is complex and treatment needs to be individualised. The scope of cardio-oncology is wide and includes prevention, detection, monitoring and treatment of CV toxicity related to cancer therapy, and also ensuring the safe development of future novel cancer treatments that minimise the impact on CV health. It is anticipated that the management strategies discussed herein will be suitable for the majority of patients. Nonetheless, the clinical judgment of physicians remains extremely important; hence, when using these best clinical practices to inform treatment options and decisions, practitioners should also consider the individual circumstances of their patients on a case-by-case basis.

Simultaneous Left Ventricular Volume and Strain Changes During Chemotherapy Associate With 2-Year Postchemotherapy Measures of Left Ventricular Ejection Fraction

Background Although changes in left ventricular end-systolic volume (LVESV), left ventricular end-diastolic volume, and global circumferential strain occur during cancer treatment, the relationship of these changes to the 2-year post-cancer-treatment measures of left ventricular ejection fraction (LVEF) are unknown. Methods and Results In a prospective, continuously recruited cohort of 95 patients scheduled to receive potentially cardiotoxic chemotherapy for breast cancer, lymphoma, or soft tissue sarcoma, measures of left ventricular end-diastolic volume, LVESV, global circumferential strain, and LVEF were acquired via cardiac magnetic resonance imaging before and then 3 and 24 months after initiating treatment by individuals blinded to all patient identifiers. Participants had an average age of 54±15 years; 68% were women, and 82% were of white race. LVEF declined from 62±7% to 58±9% over the 24 months (P<0.0001), with 42% of participants experiencing a >5% decline in LVEF at 24 months. Predictors of a 24-month >5% decline in LVEF included the following factors from baseline to 3 months into treatment: (1) >3-mL increases in LVESV (P=0.033), (2) >3-mL increases in LVESV or 10-mL declines in left ventricular end-diastolic volume with little change in LVESV (P=0.001), or (3) ≥10% deteriorations in global circumferential strain with little change in LVESV (P=0.036). Conclusion During receipt of potentially cardiotoxic chemotherapy, increases in LVESV, the absence of its deterioration during decreases of left ventricular end-diastolic volume, or the deterioration of global circumferential strain without a marked decrease in LVESV help identify those who will develop more permanent 2-year declines in LVEF.

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.

MRI of Cardiotoxicity

Cardiovascular magnetic resonance (CMR) imaging is useful to identify systolic dysfunction, particularly when echocardiographic imaging is not acceptable because of poor acoustic windows or when left ventricular ejection fraction (LVEF) is inconclusive by other modalities and an accurate LVEF measurement is needed. Of particular advantage in cardio-oncology is CMR's capability to perform tissue characterization to noninvasively identify changes in pathologic conditions related to cancer therapy or to discriminate causes of disease that may confound presentation in cardio-oncology patients. For these reasons, there is an increasing use of CMR in the screening and surveillance of cardio-oncology patients.

Subclinical Left Ventricular Dysfunction During Chemotherapy

Subclinical left ventricular dysfunction is the most common cardiac complication after chemotherapy administration. Detection and early treatment are major issues for better cardiac outcomes in this cancer population. The most common definition of cardiotoxicity is a 10-percentage point decrease of left ventricular ejection fraction (LVEF) to a value <53%. The myocardial injury induced by chemotherapies is probably a continuum starting with cardiac biomarkers increase before the occurence of a structural myocardial deformation leading to a LVEF decline. An individualised risk profile (depending on age, cardiovascular risk factors, type of chemotherapy, baseline troponin, baseline global longitudinal strain and baseline LVEF) has to be determined before starting chemotherapy to consider cardioprotective treatment. To date, there is no proof of a systematic cardioprotective treatment (angiotensin-converting enzyme inhibitor and/or beta-blocker) in all cancer patients. However, early cardioprotective treatment in case of subclinical left ventricular dysfunction seems to be promising in the prevention of cardiac events.

Cardiac MRI for the evaluation of oncologic cardiotoxicity

Cancer therapeutics-related cardiac dysfunction (CTRCD) is a well-established adverse effect resulting from a number of cancer therapeutics. Newer immunotherapy has been associated with cardiomyopathy and myocarditis making comprehensive imaging useful for early recognition. Cardiac MRI (CMR) offers a comprehensive evaluation to detect CTRCD. Established guidelines for monitoring left ventricular ejection fraction for potential cardiotoxicity have recently incorporated CMR. We will review the utility of CMR in contemporary evaluation for potential oncologic cardiotoxicity.

Early diastolic strain rate measurements by cardiac MRI in breast cancer patients treated with trastuzumab: a longitudinal study

We evaluated temporal changes in early diastolic strain rates by cardiovascular magnetic resonance (CMR) as an early detector of trastuzumab-induced ventricular dysfunction. We conducted a prospective, multi-centre, longitudinal observational study of 41 trastuzumab-treated breast cancer women who underwent serial CMR (baseline, 6, 12, and 18 months). Two blinded readers independently measured left ventricular ejection fraction (LVEF), peak systolic strain parameters (global longitudinal strain [GLS] and global circumferential strain [GCS]), and early diastolic strain rate parameters (global longitudinal diastolic strain rate [GLSR-E], global circumferential diastolic strain rate [GCSR-E], and global radial diastolic strain rate [GRSR-E]), by feature tracking (FT-CMR) using CMR42. There was a significant decline in peak systolic strain GLS and GCS at 6 months (p = 0.024 and p < 0.001, respectively) and 12 months (p = 0.002 and p < 0.001, respectively), followed by recovery at 18 months, which paralleled decline in LVEF at 6 months (p = 0.034) and 12 months (p = 0.012). Conversely, early diastolic strain rates GLSR-E and GCSR-E did not significantly change over 18 months (p > 0.10), while GRSR-E was marginally significant at 12 months (p = 0.021). There was no significant correlation between changes at 6 months in LVEF and GLSR-E or GRSR-E (p > 0.10), and a marginally significant weak correlation between LVEF and GCSR-E (p = 0.046). Among trastuzumab-treated patients without overt cardiotoxicity, there was no consistent temporal change in FT-CMR-derived diastolic strain rate parameters up to 18 months, in contrast to decline in systolic strain and LVEF. Systolic strains by FT-CMR are likely more useful than diastolic strain rates for monitoring subclinical trastuzumab-related myocardial dysfunction.ClinicalTrials.gov identifier NCT01022086.

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.

Advanced imaging modalities to detect cardiotoxicity

Recent advances in cancer treatments have significantly improved survival rates, reemphasizing the focus on reducing the potential complications associated with some therapies. Cardiovascular disease associated with chemotherapies is a major cause of morbidity and mortality in cancer survivors. Early detection of cardiotoxicity improves cardiac outcomes among cancer patients. The review will focus on imaging modalities used to assess cardiotoxicity - the cardiovascular consequences of chemotherapies. The review will discuss the benefits and limitations associated with each technique, as well as the guidelines available to help identify at risk patients. We will discuss novel techniques that may help detect earlier signs of cardiotoxicity, directing management that may improve clinical outcomes.

Myocardial strain imaging by cardiac magnetic resonance for detection of subclinical myocardial dysfunction in breast cancer patients receiving trastuzumab and chemotherapy

BACKGROUND

Our objectives were to evaluate the temporal changes in CMR-based strain imaging, and examine their relationship with left ventricular ejection fraction (LVEF), in patients treated with trastuzumab.

PATIENTS AND METHODS

In this prospective longitudinal observational study, 41 women with HER2+ breast cancer treated with chemotherapy underwent serial CMR (baseline, 6, 12, and 18 months) after initiation of trastuzumab (treatment duration 12 months). LVEF and LV strain (global longitudinal[GLS] and circumferential[GCS]) measurements were independently measured by 2 blinded readers.

RESULTS

Of the 41 patients, 56% received anthracycline-based chemotherapy. Compared to baseline (60.4%, 95%CI 59.2-61.7%), there was a small but significant reduction in LVEF at 6 months (58.4%, 95%CI 56.7-60.0%, p = 0.034) and 12 months (57.9%, 95%CI 56.4-59.7%, p = 0.012), but not at 18 months (60.2%, 95%CI 58.2-62.2%, p = 0.93). Similarly, compared to baseline, GLS and GCS decreased significantly at 6 months (p = 0.024 and < 0.001, respectively) and 12 months (p = 0.002 and < 0.001, respectively) with an increase in LV end-diastolic volume, but not at 18 months. There were significant correlations between the temporal (6 month-baseline) changes in LVEF, and all global strain measurements (Pearson's r = -0.60 and r = -0.75 for GLS and GCS, respectively, all p < 0.001).

CONCLUSION

There was a significant reduction in LV strain during trastuzumab treatment, which correlated with a concurrent subtle decline in LVEF and was associated with an increase in LV end-diastolic volume. LV strain assessment by CMR may be a promising method to monitor for subclinical myocardial dysfunction in breast cancer patients receiving chemotherapy. Future studies are needed to determine its prognostic and therapeutic implications.

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.