Assessment of Early Radiation-Induced Changes in Left Ventricular Function by Myocardial Strain Imaging After Breast Radiation Therapy

Cardiac structure, function, and coronary anatomy 10 years after isolated contemporary adjuvant radiotherapy in breast cancer patients with low cardiovascular baseline risk

AIMS

The effects of isolated contemporary low-dose breast cancer (BC) radiotherapy (RT) on the heart remain poorly understood. This study aims to assess the long-term impacts of BC-RT on cardiac structure and function.

METHODS AND RESULTS

Seventy-six women (62 ± 7 years) without history of prior heart disease, who had undergone RT for either first left (n = 36) or right (n = 40) BC, without additional medical oncology therapy apart from hormonal treatment 11 ± 1 years earlier, underwent transthoracic echocardiography, cardiac magnetic resonance imaging (CMR), computed tomography coronary angiography (CTCA), NT-proBNP, and a 6-min walk test (6MWT). They were compared with 54 age-matched healthy female controls. By CTCA, 68% of BC patients exhibited no or very mild coronary disease, while only 11% had moderate stenosis (50-69%) and 3% had significant stenosis (>70%). Despite slightly reduced regional echocardiographic midventricular strains, BC patients exhibited similar global left and right ventricular volumes, ejection fractions, and global strains by echocardiography and CMR as controls. Mitral E/e' ratios were slightly higher, and mitral deceleration times were slightly lower, but NT-proBNP was similar to controls. Also, 6MWT was normal. None had late gadolinium enhancement, and extracellular volume fraction was similar in BC (28 ± 3 vs. 29 ± 3, P = 0.15) and controls. No differences were observed relative to dose or side of RT.

CONCLUSION

Aside from minor alterations of regional strains and diastolic parameters, women who received isolated RT for BC had low prevalence of coronary disease, normal global systolic function, NT-proBNP, and exercise capacity and showed no structural changes by CMR, refuting significant long-term cardiotoxicity in such low-risk patients.

Cardiac markers in left-sided breast cancer patients receiving adjuvant radiotherapy: a prospective study

OBJECTIVES

To investigate the association between radiotherapy (RT) and cardiac biomarkers in women with left-sided breast cancer.

METHODS

This prospective observational study recruited patients with stage I-III left-sided breast cancer without coronary heart disease who required adjuvant RT. High-sensitivity troponin I(hsTnI), N-terminal pro-brain natriuretic peptide(NT-proBNP), and high-sensitivity C-reactive protein(hsCRP) levels were measured pre-RT, immediately after RT, and 3 months post-RT. Cardiac-sparing RT techniques were utilized (Field-in-Field IMRT/VMAT ± voluntary deep inspiration breath-hold). Statistical analyses were performed using non-parametric tests and multivariable quantile regression (QR).

RESULTS

One hundred five patients completed the study, with 63 evaluable at three months post-RT. Pre- and post-RT biomarkers showed no significant differences. Median pre-RT and post-RT values were: hsTnI (0.012ng/mL; 0.012ng/mL), hsCRP (3.1 mg/L; 2.8 mg/L), and NT-proBNP (59pg/mL; 45pg/mL). Three months post-RT, hsTnI, hsCRP and NT-proBNP levels also showed no significant differences. Multivariable QR revealed no association between heart Dmean [median(IQR): 2.87 Gy (2.05-3.94)] and post-RT biomarkers. Age and BMI were associated with hsCRP and NT-proBNP, respectively.

CONCLUSIONS

hsTnI, NT-proBNP, and hsCRP are not correlated with contemporary low cardiac exposure in left-sided breast cancer patients treated with contemporary RT techniques.

Early Echocardiography and ECG Changes Following Radiotherapy in Patients with Stage II-III HER2-Positive Breast Cancer Treated with Anthracycline-Based Chemotherapy with or without Trastuzumab-Based Therapy

BACKGROUND Cardiotoxicity from radiotherapy and anti-cancer therapies have been reported in patients with breast cancer. This study aimed to investigate the early echocardiography and ECG changes following radiotherapy in 68 patients ages 30-78 years with stages II-III HER2-positive breast cancer treated with anthracycline-based chemotherapy with or without trastuzumab-based therapy from 2015 to 2021. MATERIAL AND METHODS We analyzed data of 68 breast cancer patients aged 30-78 years, predominantly in AJCC stages II-III (61) and HER2-positive (58), treated and monitored from 2015 to 2021. Cardiac function was assessed using echo- and electrocardiography. We employed univariate logistic models to gauge associations between pre-existing cardiac conditions, treatment modalities, and changes in cardiac function. RESULTS A decrease in the left ventricle ejection fraction (EF) by >5% was associated with heart doses >49.3 Gy and with maximum and average doses to the left anterior descending artery (LAD) exceeding 46.9 Gy and 32.7 Gy, respectively. An EF drop of ≥10% was correlated with anti-HER2 therapy, pre-existing ECG changes, and the onset of conditions in the left ventricle, major vessels, and valves. Conditions were exacerbated in patients with prior echocardiographic abnormalities, while some emerged concurrent with the EF decline. CONCLUSIONS This research emphasizes the importance of personalized heart monitoring and care for breast cancer patients undergoing multimodal therapies. Significant and potentially irreversible EF declines can result from radiation and anti-HER2 treatments.

Association of Circulating Cardiomyocyte Cell-Free DNA With Cancer Therapy-Related Cardiac Dysfunction in Patients Undergoing Treatment for ERBB2-Positive Breast Cancer

Importance

Cancer therapy-related cardiac dysfunction (CTRCD) is a potentially serious cardiotoxicity of treatments for ERBB2-positive breast cancer (formerly HER2). Identifying early biomarkers of cardiotoxicity could facilitate an individualized approach to cardiac surveillance and early pharmacologic intervention. Circulating cell-free DNA (cfDNA) of cardiomyocyte origin is present during acute cardiac injury but has not been established as a biomarker of CTRCD.

Objective

To determine whether circulating cardiomyocyte cfDNA is associated with CTRCD in patients with ERBB2-positive breast cancer treated with anthracyclines and ERBB2-targeted therapy.

Design, Setting, and Participants

A prospective cohort of 80 patients with ERBB2-positive breast cancer enrolled at an academic cancer center between July 2014 and April 2016 underwent echocardiography and blood collection at baseline, after receiving anthracyclines, and at 3 months and 6 months of ERBB2-targeted therapy. Participants were treated with doxorubicin-based chemotherapy followed by trastuzumab (+/- pertuzumab). The current biomarker study includes participants with sufficient biospecimen available for analysis after anthracycline therapy. Circulating cardiomyocyte-specific cfDNA was quantified by a methylation-specific droplet digital polymerase chain reaction assay. Data for this biomarker study were collected and analyzed from June 2021 through April 2022.

Main Outcomes and Measures

The outcome of interest was 1-year CTRCD, defined by symptomatic heart failure or an asymptomatic decline in left ventricular ejection fraction (≥10% from baseline to less than lower limit of normal or ≥16%). Values for cardiomyocyte cfDNA and high-sensitivity cardiac troponin I (hs-cTnI) measured after patients completed treatment with anthracyclines were compared between patients who later developed CTRCD vs patients who did not using the Wilcoxon rank sum test, and the association of post-anthracycline cardiomyocyte cfDNA level with CTRCD was estimated using logistic regression.

Results

Of 71 patients included in this study, median (IQR) age was 50 (44-58) years, all were treated with dose-dense doxorubicin, and 48 patients underwent breast radiotherapy. Ten of 71 patients (14%) in this analysis developed CTRCD. The level of cardiomyocyte cfDNA at the post-anthracycline time point was higher in patients who subsequently developed CTRCD (median, 30.5 copies/mL; IQR, 24-46) than those who did not (median, 7 copies/mL; IQR, 2-22; P = .004). Higher cardiomyocyte cfDNA level after completion of anthracycline chemotherapy was associated with risk of CTRCD (hazard ratio, 1.02 per 1-copy/mL increase; 95% CI, 1.00-1.03; P = .046).

Conclusions and Relevance

This study found that higher cardiomyocyte cfDNA level after completion of anthracycline chemotherapy was associated with risk of CTRCD. Cardiomyocyte cfDNA quantification shows promise as a predictive biomarker to refine risk stratification for CTRCD among patients with breast cancer receiving cardiotoxic cancer therapy, and its use warrants further validation.

Trial Registration

ClinicalTrials.gov Identifier: NCT02177175.

Case report: Early acute myocarditis after radiation therapy for breast cancer: A case presentation and review of literature

Breast cancer is the most commonly diagnosed cancer in women worldwide, and with the increased survival of patients by novel treatments, the frequency of complications of cancer treatments rises. Radiotherapy, especially on the chest wall, can damage different cardiac structures. Radiotherapy-induced cardiomyopathy mainly occurs over 10 years after breast cancer treatment; however, there is a gap in the literature on acute myocarditis following radiotherapy. Here, we present a 54-year-old woman who developed acute myocarditis shortly after 25 sessions of radiotherapy with 50 Gy of radiation, successfully diagnosed with the use of speckle tracking echocardiography (STE) and cardiac magnetic resonance (CMR), and responded to the medical treatment with relative clinical improvement until the final follow-up. This case suggests the necessity of detailed examination of patients after radiotherapy, not only for chronic occurrence of cardiomyopathy but also for acute myocarditis. Although STE and CMR resulted in accurate diagnosis, in this case, further studies are required to determine the diagnostic accuracy of these two imaging methods compared with other imaging modalities in such patients and investigate the best diagnostic tool and therapeutic approach for these patients.

Early detection of radiation-induced myocardial damage by [18F]AlF-NOTA-FAPI-04 PET/CT imaging

PURPOSE

Retrospective analysis revealed increased [18F]AlF-NOTA-FAPI-04 uptake in the myocardium of patients with esophageal squamous cell cancer (ESCC) treated with concurrent chemoradiotherapy (CCRT). This study investigated and verified the feasibility of [18F]AlF-NOTA-FAPI-04 PET/CT for detecting radiation-induced myocardial damage (RIMD).

METHODS

Myocardial FAPI uptake was analyzed before and during radiotherapy in thirteen ESCC patients treated with CCRT. In the animal study, a single dose of 50 Gy was delivered to the cardiac apex of Wistar rats (24 rats, including 16 RIMD model rats and 8 control model rats). RIMD model rats were scanned with [18F]AlF-NOTA-FAPI-04 PET/CT weekly for 12 weeks, and left ventricular ejection fraction (LVEF) was measured by magnetic resonance imaging. Dynamic, blocking, and [18F]FDG PET/CT studies (4 rats/group) were performed on RIMD rats at 5 weeks post-radiation, and histopathological analyses were conducted.

RESULTS

Increased FAPI uptake in the myocardium was found after CCRT (1.53 ± 0.53 vs 1.88 ± 0.70, P = 0.015). In RIMD rats, significantly increased FAPI uptake in the damaged myocardium was observed from the 2nd week post-radiation exposure and peaked in the 5th week. Significantly more intense tracer accumulation was observed in the damaged myocardium than in the remote myocardium, as identified by decreased [18F]FDG uptake and confirmed by autoradiography, hematoxylin-eosin, Masson's trichrome, and immunohistochemical staining. The LVEF remained unchanged at the 3rd week post-radiation exposure but was remarkably decreased compared with that in the control group at the 8th week.

CONCLUSION

Through clinical phenomena and animal experimental studies, this study indicated that [18F]AlF-NOTA-FAPI-04 PET/CT imaging can detect RIMD noninvasively and before a decrease in LVEF, indicating the clinical potential of [18F]AlF-NOTA-FAPI-04 as a PET/CT tracer for early monitoring of RIMD.

Cardiac safety analysis of anti-HER2-targeted therapy in early breast cancer

To evaluate the cardiac safety of anti-HER2-targeted therapy for early breast cancer; to investigate whether trastuzumab combined with pertuzumab increases cardiac toxicity compared with trastuzumab; to evaluate the predictive value of high-sensitivity Troponin (hs-TnI) and QTc for the cardiotoxicity associated with anti-HER2 targeted therapy in early breast cancer. A total of 420 patients with early-stage HER2-positive breast cancer who received trastuzumab or trastuzumab combined with pertuzumab for more than half a year in Tianjin Medical University Cancer Hospital from January 2018 to February 2021 were included. Left ventricle ejection fraction (LVEF), hs-TnI values, and QTc were measured at baseline and 3, 6, 9, 12 months. Cardiotoxicity was defined as a decrease in LVEF of at least 10 percentage points from baseline on follow-up echocardiography. Cardiotoxicity developed in 67 of the 420 patients (15.9%) and all patients had LVEF above 50% before and after treatment. The incidence of cardiotoxicity in trastuzumab and trastuzumab combined with pertuzumab was 14.3% and 17.9%, respectively (P > 0.05). Logistic regression analysis showed that age, coronary heart disease, left chest wall radiotherapy, and anthracyclines sequential therapy were independent risk factors for cardiotoxicity (P < 0.05). The value of hs-TnI and QTc at the end of treatment (12th month) were selected for ROC curve prediction analysis and the area under the ROC curve was 0.724 and 0.713, respectively, which was significantly different from the area of 0.5 (P < 0.05). The decrease of LVEF in the study was mostly asymptomatic, from the heart safety point of view, the anti-HER2 targeted therapy for early breast cancer was well tolerated. Trastuzumab combined with pertuzumab did not significantly increase cardiotoxicity. However, subgroup analysis suggests that in the presence of coronary artery disease (CAD) and sequential treatment with anthracene, trastuzumab and pertuzumab may increase the cardiac burden compared with trastuzumab. Hs-TnI and QTc may be useful in monitoring and predicting cardiotoxicity associated with anti-HER2 targeted therapy for early breast cancer.

Current view on radiation-induced heart disease and methods of its diagnosis

In recent years, cardiologists and cardiovascular surgeons are increasingly encountering radiation-induced heart disease (RIHD) in their practice. This complication is described in literature but is poorly understood and clinically challenging. Radiation therapy (RT) is widely used in the treatment of many cancers. Despite the considerable risk of RT complications, it is used in 20–55% of cancer patients. Radiation-associated cardiotoxicity appears to be delayed, typically 10 to 30 years following treatment. Mediastinal irradiation significantly increases the risk of non-ischemic cardiomyopathy. Recent reviews estimate the prevalence of radiation-induced cardiomyopathy at more than 10%. Therefore, it is important to understand the pathophysiology of RIHD, consider risk factors associated with radiation injury, and detect the condition early.

Radiotherapy-Induced Cardiotoxicity: The Role of Multimodality Cardiovascular Imaging

Radiotherapy (RT) is one of the pillars of cancer therapy. High-dose radiation exposure on the thorax is mainly used in the context of adjuvant RT after breast surgery, in lung and esophageal cancer, and as a complement to systemic treatment in lymphoma. Due to the anatomical proximity, the heart inevitably receives some radiation that can result in acute and chronic cardiotoxicity, leading to heart failure, coronary artery disease, pericardial and valvular heart disease. Current evidence suggests there is no safe radiation dose to the heart, which poses a need for early recognition of RT-induced cardiac injury to initiate cardioprotective treatment and prevent further damage. Multimodality cardiac imaging provides a powerful tool to screen for structural and functional abnormalities secondary to RT. Left ventricular ejection fraction, preferably with three-dimensional echocardiography or cardiovascular magnetic resonance (CMR), and global longitudinal strain with speckle-tracking echocardiography are currently the key parameters to detect cardiotoxicity. However, several novel imaging parameters are tested in the ongoing clinical trials. CMR parametric imaging holds much promise as T1, T2 mapping and extracellular volume quantification allow us to monitor edema, inflammation and fibrosis, which are fundamental processes in RT-induced cardiotoxicity. Moreover, the association between serum biomarkers, genetic polymorphisms and the risk of developing cardiovascular disease after chest RT has been demonstrated, providing a platform for an integrative screening approach for cardiotoxicity. The present review summarizes contemporary evidence of RT-induced cardiac injury obtained from multimodality imaging—echocardiography, cardiovascular computed tomography, CMR and nuclear cardiology. Moreover, it identifies gaps in our current knowledge and highlights future perspectives to screen for RT-induced cardiotoxicity.

Assessment of left ventricular diastolic dysfunction following anthracyclinebased chemotherapy in breast cancer patients

Cardiotoxicity is a side effect of anthracycline-based chemotherapy. Clinical and prognostic significance of left ventricular diastolic dysfunction in heart failure patients is undeniable.The aim. To assess dynamic changes in the left ventricular diastolic function after anthracycline-based chemotherapy (ANT) in breast cancer patients.Material and methods. The study included 40 women aged 35 to 72 years with breast cancer (BC) undergoing ANT chemotherapy. The main group (n = 40) consisted of women with breast cancer examined at admission, after 6 months the same women (n = 37) were examined again. Women without breast cancer (n = 25) were used as the control group.Results. Dynamic changes in mitral annular velocities were revealed by Doppler tissue imaging. Lateral early diastolic mitral annular velocity (e’ lateral) was significantly lower in breast cancer patients as compared to the control group (p = 0.031). Six months after ANT chemotherapy, there was a definite increase in the lateral late diastolic mitral annular velocity (a’ lateral) (p = 0.033). Average early diastolic transmitral flow velocity to early diastolic velocity (E/e’ lateral) ratio was within the normative values in all groups, but E/e’ lateral in the main group was higher compared to the control group (p = 0.003). In the main group, septal early diastolic mitral annular velocity (e’ septal) was lower compared to the control group (p = 0.0005). Moreover, an increase in the septal mitral annular velocity (a’ septal) (p = 0.01) and higher E/e’ septal ratio (p = 0.011) were revealed during dynamic observation. Multiple logistic regression disclosed that E/A, e’ lateral, e’/a’ lateral, and E/e’ lateral were affected by heart rate, psychological status, age, hypertension, and body mass index, but not anthracycline chemotherapy. The total dose of anthracycline was independently associated with e’ septal and E/e’ septal: F(4.18) = 16.466 (p < 0.001; R2 = 0.775) and F(3.16) = 7.271 (p = 0.004; R2 = 0.627).Conclusion. Left ventricular diastolic function worsens in women undergoing anthracycline-based chemotherapy for breast cancer (lower e’, e’/a’ lateral, and e’ septal, higher E/e’ septal ratio). However, anthracycline does not significantly affect LVEF and LV deformation indicators. E/e’ septalande’ septal are independently associated with the total dose of anthracycline.

Early Detection of Cardiac Damage by Two-Dimensional Speckle Tracking Echocardiography After Thoracic Radiation Therapy: Study Protocol for a Prospective Cohort Study

Background

As one of the important treatment methods for cancer patients, radiotherapy may lead to incidental irradiation of the heart, resulting in radiotherapy-induced heart disease (RIHD) arising many years after radiotherapy. While, there are few studies on early subclinical cardiac damage, which may be essential for the protection of late RIHD. To detect and predict RIHD and early subclinical cardiac damage induced by thoracic radiation therapy, based on two-dimensional speckle tracking echocardiography (2D STE) combined with multiple circulating biomarkers and accurate heart dosimetry.

Methods and Analysis

This is a monocentric prospective cohort study in which 104 patients treated for malignant tumors and with cardiac radiation exposure will be included. All participants will be followed for 12 months after radiotherapy. Echocardiography, 2D STE, and blood samples will be underwent at 5-time points (baseline; after completion of RT; 2, 6, and 12 months after RT). Left ventricular ejection fraction (LVEF); global longitudinal, radial, and circumferential strain; diastolic function parameters; creatine kinase (CK); creatine kinase isoenzyme (CK-MB); cardiac troponin T (cTnT); N-terminal pro-B-type natriuretic peptide (NT-proBNP) and hypersensitive C-reactive protein (hs-CRP) will be measured at baseline and every follow-up time. The incidence of major adverse cardiovascular events will be recorded.

Discussion

This study details the protocol and presents the primary limits and advantages of this single-center project. The inclusion of patients began in 2021, and the results are expected to be published in 2023. This study will be allowed to enhance knowledge on detection and prediction of early subclinical cardiac dysfunction induced by thoracic radiation therapy, based on two-dimensional speckle tracking echocardiography (2D STE) combined with circulating biomarkers and accurate heart dosimetry. Furthermore, we will evaluate risk factors of subtle cardiac damage and identify high-risk groups for early heart damage.

Clinical Trial Registration

ClinicalTrials.gov, identifier: NCT04443400.

Subclinical left ventricle impairment following breast cancer radiotherapy: Is there an association between segmental doses and segmental strain dysfunction?

BACKGROUND

Cardiotoxicity following breast cancer radiotherapy (RT) represents one of the most redoubtable toxicities. The Global longitudinal strain measurement (GLS) based on 2D speckle tracking imaging (STI) allows detection of left ventricular (LV) dysfunction at a subclinical stage. The aim of this prospective study was to detect patients at risk of cardiotoxicity using echocardiographic parameters and to determine the association between segmental RT doses and early cardiac toxicity.

MATERIAL AND METHODS

The STI was performed prior to RT and at 3, 6 and 12 months after. The association between subclinical LV dysfunction, defined as a reduction of GLS more than 10% from the initial value, radiation doses to different LV segments and non-radiation factors were performed based on multivariate analyses.

RESULTS

From June 2017 to August 2018, a total of 103 female patients were included. Sixty patients had left sided RT. Seven patients (7.8%) developed a GSL impairment. The segmental alterations predominated in the anteroseptal and apical LV segments. The mean Dmean in altered segments was significantly higher than in non-altered segments (6.7 ± 8.8Gy-7.8 ± 8.9Gy vs 4.9 ± 7.9-5.4 ± 8.2Gy; p < 0.05). Age > 55 years and obesity were important confounding factors that should be considered during radiotherapy planning.

CONCLUSION

The results of our study show that radiation dose is correlated with the subclinical LV segments' alteration. Global heart delineation seems to be insufficient during the breast radiotherapy planning. Segmental delineation of the LV may be an interesting alternative to limit segmental doses and to reduce the risk of subclinical alterations. A mean dose of 5Gy could be proposed in exposed heart segment.

Two-dimensional Speckle Tracking Echocardiography in Evaluating Radiation-induced Heart Damage

Objective

Radiation-induced heart damage (RIHD) in malignant tumor patients with thoracic radiotherapy has been well documented. However, there is no study on the cardiac toxicity of stereotactic body radiotherapy (SBRT) based on two-dimensional speckle tracking echocardiography (2D STE).

Methods

In a prospective cohort trial, 48 patients with malignant tumor (including patients with lung cancer, pulmonary metastases and other tumor) were assigned to receive thoracic SBRT. Circulating biomarkers, electrocardiogram (ECG), echocardiography, and 2D STE were performed prior to and within two months after thoracic radiotherapy. The primary outcome of the trial was a decrease in global longitudinal strain (GLS) ≥ 10%. The secondary outcomes were major adverse cardiovascular events (MACE). Analysis were conducted using paired sample t-test, Wilcoxon signed rank test and Chi square test.

Results

The morbidity of RIHD is 44% within 2 months after SBRT in malignant tumor patients. Compared with pre-RT, a significant decrease in GLS was observed post-RT (−17.98 ​± ​3.54% vs. −16.92 ​± ​3.41%; P ​= ​0.008), without any significant change in left ventricular ejection fraction (LVEF) (68.54 ​± ​6.06 vs. 69.63 ​± ​4.45; P ​= ​0.234), left ventricular mass (LVM) (P ​= ​0.342), ECG parameters, creatine kinase (P ​= ​0.074), cardiac troponin T (P ​= ​0.829) or N-terminal pro-B-type natriuretic peptide (P ​= ​0.453) at during the post-RT period. There was no evidence that RIHD was correlated with age (P ​= ​1.000), mean heart dose (P ​= ​0.602), BED (P ​= ​0.234), EQD2/2 (P ​= ​0.615), V5 (P ​= ​0.506), V10 (P ​= ​0.578), V20 (P ​= ​0.670) and V30 (P ​= ​0.741). Subgroup analysis showed, there is still a significant decline of GLS (−18.30 ​± ​3.79% vs. −17.11 ​± ​3.58%; P ​= ​0.018) in patients without anthracycline treatment. And the decrease of GLS (−19.14 ​± ​2.42% vs. −16.85 ​± ​2.46%; P ​= ​0.004) was more significantly post-RT in anthracycline treatment group. MACE were found in one patient over a period of two months after SBRT.

Conclusions

By using strain analysis subclinical cardiac dysfunction was found to be evident early after SBRT, despite unchanged conventional indices such as LVEF, ECG parameters or circulating biomarkers. And the decrease of GLS is still existed after the effect of anthracycline was removed.

Trial registration

ClinicalTrials.gov, registration number: NCT04443400.

Role of Cardiac Biomarkers in Cancer Patients

Simple Summary

Cardiac biomarkers have proved increasingly useful in the various branches of cardiology, not sparing the field of cardio-oncology. With specific reference to the latter subject, they have been investigated as predictors and/or diagnostic and monitoring tools, as well as prognostic factors, with the purpose of allowing the early prevention of many cardiovascular complications related to the direct action of some cancer types or related to the toxicity of its treatments. However, despite this great potential and excellent cost-effectiveness, their usefulness in some areas still seems to be limited due to lack of sufficient specificity or sensitivity. In fact, in clinical practice, while their use is nowadays standard in some circumstances, evidence does not yet support their routine use in other cases.

Abstract

In patients with cancer—and especially some specific subtypes—the heart can be pathologically affected due to the direct action of the tumor or its secretion products or due to the toxicity of some oncological treatments. Cardiac biomarkers have been investigated as inexpensive and easily accessible tools for prediction, early diagnosis, monitoring, or prognosis of various forms of cancer-related cardiac diseases. However, their clinical usefulness was not always clearly demonstrated in every area of cardioncology. For the identification of anthracycline related cardiotoxicity in the very early stages troponins proved to be more efficient detectors than imaging methods. Nevertheless, the lack of a standardized dosage methodology and of cardiotoxicity specific thresholds, do not yet allow to outline the precise way to employ them in clinical routine and to incorporate them into appropriate diagnostic or managing algorithms. Cardiac biomarkers proved also effective in patients with primary cardiac amyloidosis, in which both troponins and natriuretic peptides were able to predict adverse outcome, and carcinoid heart disease, where a precise diagnostic cut-off for N-terminal prohormone of brain natriuretic peptide (NT-proBNP) was identified to screen patients with valvular involvement. Likewise, NT-proBNP proved to be an excellent predictor of postoperative atrial fibrillation (POAF). On the contrary, evidence is still not sufficient to promote the routine use of cardiac biomarkers to early diagnose myocarditis due to immune check points inhibitors (ICIs), radiotherapy induced cardiotoxicity and cardiac complications related to androgenetic deprivation. In this review we present all the evidence gathered so far regarding the usefulness and limitations of these relatively inexpensive diagnostic tools in the field of cardio-oncology.

Association of Breast Cancer Irradiation With Cardiac Toxic Effects: A Narrative Review

IMPORTANCE

To promptly recognize and manage cardiovascular (CV) risk factors before, during, and after cancer treatment, decreasing the risk of cancer therapy-related cardiac dysfunction is crucial. After recent advances in breast cancer treatment, mortality rates from cancer have decreased, and the prevalence of survivors with a potentially higher CV disease risk has increased. Cardiovascular risks might be associated with the multimodal approach, including systemic therapies and breast radiotherapy (RT).

OBSERVATIONS

The heart disease risk seems to be higher in patients with tumors in the left breast, when other classic CV risk factors are present, and when adjunctive anthracycline-based chemotherapy is administered, suggesting a synergistic association. Respiratory control as well as modern RT techniques and their possible further refinement may decrease the prevalence and severity of radiation-induced heart disease. Several pharmacological cardioprevention strategies for decreasing cardiac toxic effects have been identified in several guidelines. However, further research is needed to ascertain the feasibility of these strategies in routine practice.

CONCLUSIONS AND RELEVANCE

This review found that evidence-based recommendations are lacking on the modalities for and intensity of heart disease screening, surveillance of patients after RT, and treatment of these patients. A multidisciplinary and multimodal approach is crucial to guide optimal management.

Breast Radiotherapy-Related Cardiotoxicity. When, How, Why. Risk Prevention and Control Strategies

In recent decades, improvements in breast cancer management have increased overall patient survival; however, many cancer therapies have been linked to an important risk of cardiovascular adverse events. Cardio-oncology has been proposed as an emerging specialty to coordinate preventive strategies that improve the cardiovascular health of oncologic patients. It employs the most suitable personalized multidisciplinary management approach for each patient to optimize their cardiovascular health and improve their survival and quality of life. Radiotherapy is an essential part of the therapeutic regimen in breast cancer patients but can also increase the risk of cardiovascular disease. Therefore, minimizing the negative impact of radiation therapy is an important challenge for radiotherapy oncologists and cardiologists specializing in this field. The aim of the present review is to update our knowledge about radiation-induced cardiotoxicity in breast cancer patients by undertaking a critical review of the relevant literature to determine risk prevention and control strategies currently available.

Early Cardiac Effects of Contemporary Radiation Therapy in Patients With Breast Cancer

PURPOSE

To characterize the early changes in echocardiographically derived measures of cardiac function with contemporary radiation therapy (RT) in breast cancer and to determine the associations with radiation dose-volume metrics, including mean heart dose (MHD).

METHODS AND MATERIALS

In a prospective longitudinal cohort study of 86 patients with breast cancer treated with photon or proton thoracic RT, clinical and echocardiographic data were assessed at 3 time points: within 4 weeks before RT initiation (T0), within 3 days before 6 weeks after the end of RT (T1), and 5 to 9 months after RT completion (T2). Associations between MHD and echocardiographically derived measures of cardiac function were assessed using generalized estimating equations to define the acute (T0 to T1) and subacute (T0 to T2) changes in cardiac function.

RESULTS

The median estimates of MHD were 139 cGy (interquartile range, 99-249 cGy). In evaluating the acute changes in left ventricular ejection fraction (LVEF) from T0 to T1, and accounting for the time from RT, age, race, preexisting cardiovascular disease, and an interaction term with anthracycline or trastuzumab exposure and MHD, there was a modest decrease in LVEF of borderline significance (0.22%; 95% confidence interval [CI], -0.44% to 0.01%; P = .06) per 30-day interval for every 100 cGy increase of MHD. Similarly, there was a modest worsening in longitudinal strain (0.19%; 95% CI, -0.01% to 0.39%; P = .06) per 30-day interval for each 100 cGy increase in MHD. We did not find significant associations between MHD and changes in circumferential strain or diastolic function.

CONCLUSIONS

With modern radiation planning techniques, there are modest subclinical changes in measures of cardiac function in the short-term. Longer-term follow-up studies are needed to determine whether these early changes are associated with the development of overt cardiac disease.

Long-term Cardiopulmonary Consequences of Treatment-Induced Cardiotoxicity in Survivors of ERBB2-Positive Breast Cancer

Importance

Trastuzumab improves outcomes in patients with ERBB2-positive (formerly HER2) breast cancer but is associated with treatment-induced cardiotoxicity, most commonly manifest by an asymptomatic decline in left ventricular ejection fraction (LVEF). Little is known to date regarding the long-term effects of treatment-induced cardiotoxicity on cardiopulmonary function in patients who survive trastuzumab-treated breast cancer.

Objective

To determine whether treatment-induced cardiotoxicity recovers or is associated with long-term cardiopulmonary dysfunction in survivors of ERBB2-positive breast cancer.

Design, Setting, and Participants

This cross-sectional case-control study enrolled patients with nonmetastatic ERBB2-positive breast cancer after completion of trastuzumab-based therapy (median, 7.0 [interquartile range (IQR), 6.2-8.7] years after therapy) who met 1 of 2 criteria: (1) cardiotoxicity (TOX group) developed during trastuzumab treatment (ie, asymptomatic decrease of LVEF≥10% from baseline to <55% [n = 22]) or (2) no evidence of cardiotoxicity during trastuzumab treatment (NOTOX group [n = 20]). Patients were treated at the Memorial Sloan Kettering Cancer Center. Fifteen healthy control participants (HC group) were also enrolled for comparison purposes. All groups were frequency matched by age strata (<55, 55-64, and ≥65 years). Data were collected from September 9, 2016, to August 10, 2018, and analyzed from November 20, 2018, to August 12, 2019.

Main Outcomes and Measures

Speckle-tracking echocardiography and maximal cardiopulmonary exercise testing were performed to measure indices of left ventricular function (including LVEF and global longitudinal strain [GLS]) and peak oxygen consumption (peak VO2).

Results

A total of 57 participants (median age, 60.8 [IQR, 52.7-65.7] years) were included in the analysis. Overall, 38 of 42 patients with breast cancer (90%) were treated with anthracyclines before trastuzumab. Resting mean (SD) LVEF was significantly lower in the TOX group (56.9% [5.2%]) compared with the NOTOX (62.4% [4.0%]) and HC (65.3% [2.9%]) groups; similar results were found for GLS (TOX group, -17.8% [2.2%]; NOTOX group, -19.8% [2.2%]; HC group, -21.3% [1.8%]) (P < .001). Mean peak VO2 in the TOX group (22.9 [4.4] mL/kg/min) was 15% lower compared with the NOTOX group (27.0 [5.3] mL/kg/min; P = .03) and 25% lower compared with the HC group (30.5 [3.4] mL/ kg/min; P < .001). In patients with breast cancer, GLS was significantly associated with peak VO2 (β coefficient, -0.75; 95% CI, -1.32 to -0.18).

Conclusions and Relevance

Treatment-induced cardiotoxicity appears to be associated with long-term marked impairment of cardiopulmonary function and may contribute to increased risk of late-occurring cardiovascular disease in survivors of ERBB2-positive breast cancer.

A Pilot Study of Cardiac MRI in Breast Cancer Survivors After Cardiotoxic Chemotherapy and Three-Dimensional Conformal Radiotherapy

PURPOSE/OBJECTIVES

Node-positive breast cancer patients often receive chemotherapy and regional nodal irradiation. The cardiotoxic effects of these treatments, however, may offset some of the survival benefit. Cardiac magnetic resonance (CMR) is an emerging modality to assess cardiac injury. This is a pilot trial assessing cardiac damage using CMR in patients who received anthracycline-based chemotherapy and three-dimensional conformal radiotherapy (3DCRT) regional nodal irradiation using heart constraints.

MATERIALS AND METHODS

Node-positive breast cancer patients (2000-2008) treated with anthracycline-based chemotherapy and 3DCRT regional nodal irradiation (including the internal mammary chain nodes) with heart ventricular constraints (V25 < 10%) were invited to participate. Cardiac tissues were contoured and analyzed separately for whole heart (pericardium) and for combined ventricles and left atrium (myocardium). CMR obtained ventricular function/dimensions, late gadolinium enhancement (LGE), global longitudinal strain (GLS), and extracellular volume fraction (ECV) as measures of cardiac injury and/or early fibrosis. CMR parameters were correlated with dose-volume constraints using Spearman correlations.

RESULTS

Fifteen left-sided and five right-sided patients underwent CMR. Median diagnosis age was 50 (32-77). No patients had baseline cardiac disease before regional nodal irradiation. Median time after 3DCRT was 8.3 years (5.2-14.4). Median left-sided mean heart dose (MHD) was 4.8 Gy (1.1-11.2) and V25 was 5.7% (0-12%). Median left ventricular ejection fraction (LVEF) was 63%. No abnormal LGE was observed. No correlations were seen between whole heart doses and LVEF, LV mass, GLS, or LV dimensions. Increasing ECV did not correlate with increased heart or ventricular doses. However, correlations between higher LV mass and ventricular mean dose, V10, and V25 were seen.

CONCLUSION

At a median follow-up of 8.3 years, this cohort of node-positive breast cancer patients who received anthracycline-based chemotherapy and regional nodal irradiation had no clinically abnormal CMR findings. However, correlations between ventricular mean dose, V10, and V25 and LV mass were seen. Larger corroborating studies that include advanced techniques for measuring regional heart mechanics are warranted.

Radiotherapy-induced heart disease: a review of the literature

Radiotherapy as one of the four pillars of cancer therapy plays a critical role in the multimodal treatment of thoracic cancers. Due to significant improvements in overall cancer survival, radiotherapy-induced heart disease (RIHD) has become an increasingly recognized adverse reaction which contributes to major radiation-associated toxicities including non-malignant death. This is especially relevant for patients suffering from diseases with excellent prognosis such as breast cancer or Hodgkin’s lymphoma, since RIHD may occur decades after radiotherapy. Preclinical studies have enriched our knowledge of many potential mechanisms by which thoracic radiotherapy induces heart injury. Epidemiological findings in humans reveal that irradiation might increase the risk of cardiac disease at even lower doses than previously assumed. Recent preclinical studies have identified non-invasive methods for evaluation of RIHD. Furthermore, potential options preventing or at least attenuating RIHD have been developed. Ongoing research may enrich our limited knowledge about biological mechanisms of RIHD, identify non-invasive early detection biomarkers and investigate potential treatment options that might attenuate or prevent these unwanted side effects. Here, we present a comprehensive review about the published literature regarding clinical manifestation and pathological alterations in RIHD. Biological mechanisms and treatment options are outlined, and challenges in RIHD treatment are summarized.

Early detection of subclinical left ventricular dysfunction after breast cancer radiation therapy using speckle-tracking echocardiography: association between cardiac exposure and longitudinal strain reduction (BACCARAT study)

BACKGROUND

Breast cancer (BC) radiotherapy (RT) can induce cardiotoxicity, with adverse events often observed many years after BC RT. Subclinical left ventricular (LV) dysfunction can be detected early after BC RT with global longitudinal strain (GLS) measurement based on 2D speckle-tracking echocardiography. This 6-month follow-up analysis from the BACCARAT prospective study aimed to investigate the association between cardiac radiation doses and subclinical LV dysfunction based on GLS reduction.

METHODS

The patient study group consisted of 79 BC patients (64 left-sided BC, 15 right-sided BC) treated with RT without chemotherapy. Echocardiographic parameters, including GLS, were measured before RT and 6 months post-RT. The association between subclinical LV dysfunction, defined as GLS reduction > 10%, and radiation doses to whole heart and the LV were performed based on logistic regressions. Non-radiation factors associated with subclinical LV dysfunction including age, BMI, hypertension, hypercholesterolemia and endocrine therapy were considered for multivariate analyses.

RESULTS

A mean decrease of 6% in GLS was observed (- 15.1% ± 3.2% at 6 months vs. - 16.1% ± 2.7% before RT, p = 0.01). For left-sided patients, mean heart and LV doses were 3.1 ± 1.3 Gy and 6.7 ± 3.4 Gy respectively. For right-sided patients, mean heart dose was 0.7 ± 0.5 Gy and median LV dose was 0.1 Gy. Associations between GLS reduction > 10% (37 patients) and mean doses to the heart and the LV as well as the V20 were observed in univariate analysis (Odds Ratio = 1.37[1.01-1.86], p = 0.04 for Dmean Heart; OR = 1.14 [1.01-1.28], p = 0.03 for Dmean LV; OR = 1.08 [1.01-1.14], p = 0.02 for LV V20). In multivariate analysis, these associations did not remain significant after adjustment for non-radiation factors. Further exploratory analysis allowed identifying a subgroup of patients (LV V20 > 15%) for whom a significant association with subclinical LV dysfunction was found (adjusted OR = 3.97 [1.01-15.70], p = 0.048).

CONCLUSIONS

This analysis indicated that subclinical LV dysfunction defined as a GLS decrease > 10% is associated with cardiac doses, but adjustment for non-radiation factors such as endocrine therapy lead to no longer statistically significant relationships. However, LV dosimetry may be promising to identify high-risk subpopulations. Larger and longer follow-up studies are required to further investigate these associations.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT02605512, Registered 6 November 2015 - Retrospectively registered.

Imaging and heart failure: myocardial strain

PURPOSE OF REVIEW

To summarize literature on the application of myocardial strain in patients with heart failure published since 2018.

RECENT FINDINGS

Left ventricular (LV) and right ventricular strain provides important prognostic information in patients with acute and chronic heart failure and new insights in disease mechanisms in amyloidosis. The addition of left atrial strain to current societal diastolic dysfunction criteria may improve detection of clinically relevant diastolic dysfunction. The recently developed method for noninvasive estimation of myocardial work incorporates loading conditions into the evaluation of LV performance that may be important for selection of patients for cardiac resynchronization therapy.

SUMMARY

Evidence linking myocardial strain to adverse outcomes in heart failure is steadily being developed. Although GLS seems to be ready for clinical use, further validation and standardization of RV, LA strain and myocardial work is needed.

Cardiotoxicity of Contemporary Breast Cancer Treatments

OPINION STATEMENT

Treatment-related cardiotoxicity remains a significant concern for breast cancer patients undergoing cancer treatment and extends into the survivorship period, with adverse cardiovascular (CV) outcomes further compounded by the presence of pre-existing CV disease or traditional CV risk factors. Awareness of the cardiotoxicity profiles of contemporary breast cancer treatments and optimization of CV risk factors are crucial in mitigating cardiotoxicity risk. Assessment of patient- and treatment-specific risk with appropriate CV surveillance is another key component of care. Mismatch between baseline cardiotoxicity risk and intensity of cardiotoxicity surveillance can lead to unnecessary downstream testing, increased healthcare expenditure, and interruption or discontinuation of potentially life-saving treatment. Efforts to identify early imaging and/or circulating biomarkers of cardiotoxicity and develop effective management strategies are needed to optimize the CV and cancer outcomes of breast cancer survivors.