Cardiac imaging in cardiotoxicity: a focus on clinical practice

Early reduction in cardiorespiratory fitness and diastolic reserve following radiation therapy for lung cancer

BACKGROUND

Contemporary radiotherapy for the treatment of lung cancer is effective in targeting tumor tissue while limiting heart exposure, yet cardiac toxicity still occurs, often becoming clinically apparent years later. Cardiorespiratory fitness (CRF) is an independent predictor of cardiovascular, cancer-related, and overall mortality and may serve as a sensitive measure of subclinical cardiac toxicity following anti-cancer treatments. Prior work has demonstrated a significant relationship between reduced CRF and impaired left-ventricular (LV) diastolic reserve in cancer survivors following thoracic radiotherapy. The purpose of this study was to assess early longitudinal changes in CRF and cardiac function in patients with lung cancer following radiotherapy.

METHODS

Ten patients (69 [61-76] years, 70% female) with lung cancer without known cardiovascular disease scheduled to receive radiotherapy involving a clinically-relevant heart dose (≥ 5 Gy to > 10% of heart volume) were evaluated prior to and following treatment. Changes in CRF (peak oxygen consumption [VO2peak], oxygen uptake efficiency slope [OUES]), cardiac function (LV ejection fraction [LVEF], rest and exercise diastolic function [diastolic functional reserve index (DFRI)]), cardiac biomarkers (N-terminal pro-brain natriuretic peptide [NT-proBNP], high-sensitivity C-reactive protein [hsCRP]), and health-related quality of life (HRQOL; Functional Assessment of Cancer Therapy-General-7 [FACT-G7]) were measured.

RESULTS

The VO2peak was reduced at baseline (1.245 [0.882-1.605] L·min- 1; 70 [62-86] %-predicted) and significantly declined (1.095 [0.810-1.448] L·min- 1, P = 0.047; 62 [56-76] %-predicted, P = 0.005) at 6.0 [3.0-6.0] months post-radiotherapy. Similarly, a significant decline in the OUES was observed (1.63 [1.27-1.88] to 1.57 [1.12-1.75], P = 0.032). Systolic cardiac function was normal at baseline and did not change following radiotherapy (LVEF; 62 [56-65]% to 66 [57-68]%, P = 0.475). The DFRI significantly declined following radiotherapy (34.9 [22.7-41.6] vs. 12.8 [3.1-35.9]). The hsCRP increased significantly from 4.4 [1.4-5.8] to 6.1 [3.7-20.7] g/L, P = 0.047 with a trend towards higher levels of NT-proBNP (65 [49-125] to 121 [88-191] pg/mL, P = 0.110). Health-related quality of life significantly decreased (FACT-G7; 21.5 [18.8-25] to 15.5 [11.5-20]; P = 0.021) post-radiotherapy.

CONCLUSIONS

Patients with lung cancer receiving radiotherapy with a clinically-significant heart dose experience reductions in CRF (VO2peak, OUES) as early as six months following treatment with concurrent reductions in diastolic reserve (DFRI), HRQOL, and increases in cardiac biomarkers (NT-proBNP, hsCRP).

Anthracycline's Effects on Heart Rate Variability in Children with Acute Lymphoblastic Leukemia: Early Toxicity Signs-Pilot Study

Anthracycline treatments are known to cause cardiotoxic long-term side effects in cancer survivors. Recently, a decrease in heart rate variability (HRV) has been identified in these patients, signaling autonomic dysfunction and altered cardiac fitness. This study aimed at evaluating changes in HRV in children treated with anthracyclines. A total of 35 pediatric patients with acute lymphoblastic leukemia were evaluated by means of a 24 h Holter ECG, at baseline and after reaching half the total cumulative dose of doxorubicin equivalent (120 mg/m2). Parameters of HRV were assessed, as well as any arrhythmic episodes, bradycardia and tachycardia percentages. The results showed a significant decrease in both time-domain and frequency-domain HRV parameters, following anthracycline treatment. The low-frequency (LF) to high-frequency (HF) parameters' ratio also displayed a significant difference (p = 0.035), suggestive of early cardiac autonomic dysfunction. Of note, none of the patients presented symptoms of heart disease or elevated troponins, and only two patients presented echocardiographic signs of diastolic dysfunction. The present study showed that cardiac autonomic nervous system regulation is compromised in children treated with anthracyclines even before reaching the total cumulative dose. Therefore, HRV parameters could be the first indicators of subclinical cardiac toxicity, making Holter ECG monitoring of the oncological patient a necessity.

Cardiovascular Risk Stratification by Automatic Coronary Artery Calcium Scoring on Pretreatment Chest Computed Tomography in Diffuse Large B-Cell Lymphoma Receiving Anthracycline-Based Chemotherapy: A Multicenter Study

BACKGROUND

Balancing the cardiovascular risk and benefit of anthracycline-based chemotherapy in patients with diffuse large B-cell lymphoma is an important clinical issue. We aimed to evaluate whether the pretreatment coronary artery calcium score (CACS) can stratify the risk of cancer therapy-related cardiac dysfunction (CTRCD) and major adverse cardiovascular events (MACEs) in patients with diffuse large B-cell lymphoma receiving anthracycline-based chemotherapy.

METHODS

The patients with diffuse large B-cell lymphoma from 4 hospitals were retrospectively enrolled. The CACS was automatically calculated on nongated chest computed tomography before treatment using artificial intelligence-CACS software and divided into 3 categories (0, 1-100, and >100). The associations between the CACS and CTRCD and between the CACS and MACEs were assessed by logistic regression and Fine-Gray competing-risk regression model. Nelson-Aalen cumulative risk curve was performed to assess the cumulative incidence of MACEs.

RESULTS

A total of 1468 patients (785 men and 683 women; 100% Asian) were enrolled, and 362 and 185 patients developed CTRCD and MACEs, respectively. Compared with a CACS of 0 (n=826), there was stepwise higher odds of CTRCD with a CACS between 1 and 100 (n=356; odds ratio, 2.587) and a CACS >100 (n=286; odds ratio, 5.239). The CACS was associated with MACEs (1-100 versus 0: subdistribution hazard ratio 3.726; >100 versus 0: subdistribution hazard ratio 7.858; all P<0.001). Competing risk-adjusted MACEs rates for patients with a CACS of 0, 1 to 100, and >100 were 1.21%, 8.43%, and 11.19%, respectively, at 3 years, and 3.27%, 16.01%, 31.12%, respectively, at 5 years.

CONCLUSIONS

The automatic CACS derived from chest computed tomography before treatment was helpful to identify high-risk patients of CTRCD and MACE and guide clinicians to implement cardiovascular protection strategies in patients with diffuse large B-cell lymphoma who received anthracycline-based chemotherapy.

Echocardiographic strategy for early detection of cardiotoxicity of doxorubicin: a prospective observational study

Background

Cancer chemotherapy using anthracyclines is associated with cardiotoxicity (CTX), and left ventricular ejection fraction (LVEF) analysis is not sensitive to early cardiotoxic changes. Left ventricular global longitudinal strain (LV GLS) monitoring helps screen subclinical CTX; however, the intervals at which it should be performed remain unclear. We aimed to evaluate the incidence of CTX in women with breast cancer and the associated factors and compare two echocardiographic monitoring strategies using two cutoff points for LV GLS variation.

Methods

Patients with breast cancer prescribed doxorubicin underwent serial LVEF and LV GLS assessments using two-dimensional echocardiography every 3 weeks for 6 months.

Results

We included 43 women; none developed a clinical CTX. Considering a relative reduction of LV GLS > 15%, subclinical CTX was present in 12 (27.9%) and six (14%) patients at 3-week and 3-month intervals, respectively (P = 0.28). Additionally, considering a reduction of > 12%, subclinical CTX was present in 17 (39.5%) and 10 (23.3%) patients (P = 0.16), respectively. There were no significant differences in either reference value at 3-week (P = 0.19) and 3-month intervals (P = 0.41). Age ≥ 60 years (P = 0.018) and hypertension (HTN) (P = 0.022) were associated with subclinical CTX in the univariate analysis.

Conclusions

There was no difference in the incidence of subclinical CTX between the two cutoff points and no benefit in performing echocardiography every 3 weeks compared with quarterly monitoring. Advanced age and HTN were associated with the development of subclinical CTX.

Comparison of Patients’ Phenotypes, Guideline-Directed Recommendations Compliance and Rates of Cardiotoxicity between Caribbean and United States Cardio-oncology Programs

Background:

Little is known about the characteristics of oncological patients, cancer therapy-induced cardiotoxicity, and guidelines-directed interventions in the Caribbean; analysis of cardio-oncology services may shed light on this and clarify links between ethnicity, cultural, and local socioeconomic factors.

Objectives:

This study compared patients’ phenotypes, adherence to guidelines recommendations, and patterns of cardiotoxicity between two cardio-oncology programs: one in the Dominican Republic (DR) and the other in Chicago IL, United States (US).

Methods:

Patients being considered for or treated with potentially cardiotoxic drugs were followed before, during, and after chemotherapy through both cardio-oncology clinics, where we recorded and compared clinical, demographic, and echocardiographic data.

Results:

We studied 597 consecutive patients, 330 (55%) from the DR and 267 (45%) from the US. DR vs. US mean age 55± 13/52 ± 13 years; female 77/87% (p < 0.001); breast cancer 57/73% (p < 0.001); treated with anthracyclines + taxanes 47/40% (p = 0.151); monoclonal antibodies + taxanes or platins 37/45% (p < 0.001). Cardiotoxicity DR vs. US occurred in 15/7% (p = 0.001); multivariate logistic regression (OR 2.29; 95% CI, 1.31–3.99; p < 0.005) did not identify age >60, HTN, DM, BMI, tobacco or chemotherapy as predictors. Compliance with ASCO guidelines was similar among both cohorts.

Conclusion:

Compared to the US cohort, the Caribbean cohort of cancer patients has similar rates of CV risk factors but a higher likelihood of developing drug-induced LV dysfunction. Programs’ compliance with ASCO guidelines was equivalent. While further research is needed to ascertain regional variations of cardiotoxicity, these findings underline the relevance of cardio-oncology services in nations with limited resources and high CV risk.

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

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

Advanced Echocardiographic Techniques in Cardio-Oncology: the Role for Early Detection of Cardiotoxicity

PURPOSE OF REVIEW

Implementation of advanced echocardiographic techniques in cardio-oncology is a growing need as they are the cornerstone of early detection of cancer therapy-related cardiovascular toxicity (CTR-CVT).

RECENT FINDINGS

Three-dimensional echocardiography and myocardial deformation techniques have shown more accuracy and reproducibility than classic 2D measurements in detecting cardiovascular adverse effects in patients undergoing anticancer therapies. Application of advanced echo techniques to daily monitoring of patients with cancer helps to identify those at risk of developing CTR-CVT during and after cancer treatment. Furthermore, advanced echo parameters improve early initiation of cardioprotective treatments in order to minimize cardiovascular events and cancer treatment interruption.

LVEF by Multigated Acquisition Scan Compared to Other Imaging Modalities in Cardio-Oncology: a Systematic Review

Purpose of Review

The prevalence of cancer therapy-related cardiac dysfunction (CTRCD) is increasing due to improved cancer survival. Serial monitoring of cardiac function is essential to detect CTRCD, guiding timely intervention strategies. Multigated radionuclide angiography (MUGA) has been the main screening tool using left ventricular ejection fraction (LVEF) to monitor cardiac dysfunction. However, transthoracic echocardiography (TTE) and cardiac magnetic resonance imaging (CMR) may be more suitable for serial assessment. We aimed to assess the concordance between different non-radiating imaging modalities with MUGA to determine whether they can be used interchangeably.

Recent Findings

In order to identify relevant studies, a PubMed search was performed. We included cross-sectional studies comparing MUGA LVEF to that of 2D TTE, 3D TTE, and CMR. From 470 articles, 22 were selected, comprising 1017 patients in total. Among others, this included three 3D TTE, seven 2D harmonic TTE + contrast (2DHC), and seven CMR comparisons. The correlations and Bland-Altman limits of agreement varied for CMR but were stronger for 3D TTE and 2DHC.

Summary

Our findings suggest that MUGA and CMR should not be used interchangeably whereas 3D TTE and 2DHC are appropriate alternatives following an initial MUGA scan. We propose a multimodality diagnostic imaging strategy for LVEF monitoring in patients undergoing cancer treatment.

Key Characteristics of Cardiovascular Toxicants

BACKGROUND

The concept of chemical agents having properties that confer potential hazard called key characteristics (KCs) was first developed to identify carcinogenic hazards. Identification of KCs of cardiovascular (CV) toxicants could facilitate the systematic assessment of CV hazards and understanding of assay and data gaps associated with current approaches.

OBJECTIVES

We sought to develop a consensus-based synthesis of scientific evidence on the KCs of chemical and nonchemical agents known to cause CV toxicity along with methods to measure them.

METHODS

An expert working group was convened to discuss mechanisms associated with CV toxicity.

RESULTS

The group identified 12 KCs of CV toxicants, defined as exogenous agents that adversely interfere with function of the CV system. The KCs were organized into those primarily affecting cardiac tissue (numbers 1-4 below), the vascular system (5-7), or both (8-12), as follows: 1) impairs regulation of cardiac excitability, 2) impairs cardiac contractility and relaxation, 3) induces cardiomyocyte injury and death, 4) induces proliferation of valve stroma, 5) impacts endothelial and vascular function, 6) alters hemostasis, 7) causes dyslipidemia, 8) impairs mitochondrial function, 9) modifies autonomic nervous system activity, 10) induces oxidative stress, 11) causes inflammation, and 12) alters hormone signaling.

DISCUSSION

These 12 KCs can be used to help identify pharmaceuticals and environmental pollutants as CV toxicants, as well as to better understand the mechanistic underpinnings of their toxicity. For example, evidence exists that fine particulate matter [PM ≤2.5μm in aerodynamic diameter (PM2.5)] air pollution, arsenic, anthracycline drugs, and other exogenous chemicals possess one or more of the described KCs. In conclusion, the KCs could be used to identify potential CV toxicants and to define a set of test methods to evaluate CV toxicity in a more comprehensive and standardized manner than current approaches. https://doi.org/10.1289/EHP9321.

Cardiotoxicity Associated with Chemotherapy Used in Gastrointestinal Tumours

Cardiotoxicity is a well-recognised side effect of cancer-related therapies with a great impact on outcomes and quality of life in the cancer survivor population. The pathogenesis of chemotherapy-induced cardiotoxicity in patients with gastrointestinal cancers involves various molecular mechanisms, and the combined use of various chemotherapies augments the risk of each drug used alone. In terms of cardiotoxicity diagnosis, novel biomarkers, such as troponins, brain natriuretic peptide (BNP), myeloperoxidases and miRNAs have been recently assessed. Echocardiography is a noninvasive imaging method of choice for the primary assessment of chemotherapy-treated patients to generally evaluate the cardiovascular impact of these drugs. Novel echocardiography techniques, like three-dimensional and stress echocardiography, will improve diagnosis efficacy. Cardiac magnetic resonance (CMR) can evaluate cardiac morphology, function and wall structure. Corroborated data have shown the importance of CMR in the early evaluation of patients with gastrointestinal cancers, treated with anticancer drugs, but further studies are required to improve risk stratification in these patients. In this article, we review some important aspects concerning the cardiotoxicity of antineoplastic drugs used in gastrointestinal cancers. We also discuss the mechanism of cardiotoxicity, the role of biomarkers and the imaging methods used in its detection.