Anthracycline Therapy Is Associated With Cardiomyocyte Atrophy and Preclinical Manifestations of Heart Disease

OBJECTIVES

The goal of this study was to demonstrate that cardiac magnetic resonance could reveal anthracycline-induced early tissue remodeling and its relation to cardiac dysfunction and left ventricular (LV) atrophy.

BACKGROUND

Serum biomarkers of cardiac dysfunction, although elevated after chemotherapy, lack specificity for the mechanism of myocardial tissue alterations.

METHODS

A total of 27 women with breast cancer (mean age 51.8 ± 8.9 years, mean body mass index 26.9 ± 3.6 kg/m²), underwent cardiac magnetic resonance before and up to 3 times after anthracycline therapy. Cardiac magnetic resonance variables were LV ejection fraction, normalized T2-weighted signal intensity for myocardial edema, extracellular volume (ECV), LV cardiomyocyte mass, intracellular water lifetime (τ_ic; a marker of cardiomyocyte size), and late gadolinium enhancement.

RESULTS

At baseline, patients had a relatively low (10-year) Framingham cardiovascular event risk (median 5%), normal LV ejection fractions (mean 69.4 ± 3.6%), and normal LV mass index (51.4 ± 8.0 g/m²), a mean ECV of 0.32 ± 0.038, mean τ_ic of 169 ± 69 ms, and no late gadolinium enhancement. At 351 to 700 days after anthracycline therapy (240 mg/m²), mean LV ejection fraction had declined by 12% to 58 ± 6% (p < 0.001) and mean LV mass index by 19 g/m² to 36 ± 6 g/m² (p < 0.001), and mean ECV had increased by 0.037 to 0.36 ± 0.04 (p = 0.004), while mean τ_ic had decreased by 62 ms to 119 ± 54 ms (p = 0.004). Myocardial edema peaked at about 146 to 231 days (p < 0.001). LV mass index was associated with τ_ic (β = 4.1 ± 1.5 g/m² per 100-ms increase in τ_ic, p = 0.007) but not with ECV. Cardiac troponin T (mean 4.6 ± 1.4 pg/ml at baseline) increased significantly after anthracycline treatment (p < 0.001). Total LV cardiomyocyte mass, estimated as: (1 - ECV) × LV mass, declined more rapidly after anthracycline therapy, with peak cardiac troponin T >10 pg/ml. There was no evidence for any significant interaction between 10-year cardiovascular event risk and the effect of anthracycline therapy.

CONCLUSIONS

A decrease in LV mass after anthracycline therapy may result from cardiomyocyte atrophy, demonstrating that mechanisms other than interstitial fibrosis and edema can raise ECV. The loss of LV cardiomyocyte mass increased with the degree of cardiomyocyte injury, assessed by peak cardiac troponin T after anthracycline treatment. (Doxorubicin-Associated Cardiac Remodeling Followed by CMR in Breast Cancer Patients; NCT03000036).

From Molecular Mechanisms to Clinical Management of Antineoplastic Drug-Induced Cardiovascular Toxicity: A Translational Overview

Significance: Antineoplastic therapies have significantly improved the prognosis of oncology patients. However, these treatments can bring to a higher incidence of side-effects, including the worrying cardiovascular toxicity (CTX). Recent Advances: Substantial evidence indicates multiple mechanisms of CTX, with redox mechanisms playing a key role. Recent data singled out mitochondria as key targets for antineoplastic drug-induced CTX; understanding the underlying mechanisms is, therefore, crucial for effective cardioprotection, without compromising the efficacy of anti-cancer treatments. Critical Issues: CTX can occur within a few days or many years after treatment. Type I CTX is associated with irreversible cardiac cell injury, and it is typically caused by anthracyclines and traditional chemotherapeutics. Type II CTX is generally caused by novel biologics and more targeted drugs, and it is associated with reversible myocardial dysfunction. Therefore, patients undergoing anti-cancer treatments should be closely monitored, and patients at risk of CTX should be identified before beginning treatment to reduce CTX-related morbidity. Future Directions: Genetic profiling of clinical risk factors and an integrated approach using molecular, imaging, and clinical data may allow the recognition of patients who are at a high risk of developing chemotherapy-related CTX, and it may suggest methodologies to limit damage in a wider range of patients. The involvement of redox mechanisms in cancer biology and anticancer treatments is a very active field of research. Further investigations will be necessary to uncover the hallmarks of cancer from a redox perspective and to develop more efficacious antineoplastic therapies that also spare the cardiovascular system.

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.

Cardiac autonomic modulation induced by doxorubicin in a rodent model of colorectal cancer and the influence of fullerenol pretreatment

The very effective anticancer drug doxorubicin (DOX) is known to have cardiotoxic side effects, which could be accompanied by autonomic modulation. Autonomic disbalance might even be an initiating mechanism underlying DOX-induced cardiotoxicity and can be studied noninvasively by the analysis of heart rate variability (HRV). A number of strategies have been assessed to predict chemotherapy-induced cardiac dysfunction while HRV, a potential detecting tool, has not yet been tested. Thus, we aimed to determine the effect of DOX treatment on HRV in a rat model of colorectal cancer. While pretreatment with fullerenol (Frl) acts protectively on DOX-induced cardiotoxicity, we aimed to test the effect of Frl pretreatment on DOX-induced HRV alterations. After the induction of colorectal cancer, adult male Wistar rats were treated with saline (n = 7), DOX (1.5 mg/kg per week, n = 7) or DOX after pretreatment with Frl (25 mg/kg per week, n = 7) for three weeks (cumulative DOX dose 4.5 mg/kg). One week after treatment rats were anaesthetized, standard ECG was measured and HRV was analyzed in time and frequency domain. During autopsy the intestines and hearts were gathered for biochemical analysis and histopathological examination. DOX treatment significantly decreased parasympathetically mediated high-frequency component (p<0.05) and increased the low-frequency component of HRV (p<0.05), resulting in an increased LF/HF ratio (p<0.05) in cancerous rats. When pretreated with Frl, DOX-induced HRV alterations were prevented: the high-frequency component of HRV increased (p<0.01), the low-frequency decreased (p<0.01), LF/HF ratio decreased consequently (p<0.01) compared to DOX only treatment. In all DOX-treated animals, disbalance of oxidative status in heart tissue and early myocardial lesions were found and were significantly reduced in rats receiving Frl pretreatment. Autonomic modulation accompanied the development of DOX-induced cardiotoxicity in rat model of colorectal cancer and was prevented by Frl pretreatment. Our results demonstrated the positive prognostic power of HRV for the early detection of DOX-induced cardiotoxicity.

The Use of Imaging in the Prediction and Assessment of Cancer Treatment Toxicity

Multimodal imaging is commonly used in the management of patients with cancer. Imaging plays pivotal roles in the diagnosis, initial staging, treatment response assessment, restaging after treatment and the prognosis of many cancers. Indeed, it is difficult to imagine modern precision cancer care without the use of multimodal molecular imaging, which is advancing at a rapid pace with innovative developments in imaging sciences and an improved understanding of the complex biology of cancer. Cancer therapy often leads to undesirable toxicity, which can range from an asymptomatic subclinical state to severe end organ damage and even death. Imaging is helpful in the portrayal of the unwanted effects of cancer therapy and may assist with optimal clinical decision-making, clinical management, and overall improvements in the outcomes and quality of life for patients.

A recommended practical approach to the management of target therapy and angiogenesis inhibitors cardiotoxicity: an opinion paper of the working group on drug cardiotoxicity and cardioprotection, Italian Society of Cardiology

The US National Cancer Institute estimates that cardiotoxicity (CTX) from target therapy refers mostly to four groups of drugs: epidermal growth factor receptor 2 inhibitors, angiogenic inhibitors, directed Abelson murine leukemia viral oncogene homolog inhibitors, and proteasome inhibitors. The main cardiotoxic side-effects related to antiepidermal growth factor receptor 2 therapy are left ventricular systolic dysfunction and heart failure. Angiogenesis inhibitors are associated with hypertension, left ventricular dysfunction/heart failure, myocardial ischemia, QT prolongation, and thrombosis. Moreover, other agents may be related to CTX induced by treatment. In this study, we review the guidelines for a practical approach for the management of CTX in patients under anticancer target therapy.

Carvedilol Administration Can Prevent Doxorubicin-Induced Cardiotoxicity: A Double-Blind Randomized Trial

OBJECTIVE

The aim of this study is to evaluate the preventive effects of carvedilol on doxorubicin-induced cardiotoxicity.

METHODS

In this trial, 70 female patients with breast cancer who were candidates to receive doxorubicin were enrolled, from which 30 were selected randomly to receive carvedilol 6.25 mg daily during chemotherapy, with the rest receiving placebo as the control group. Both groups were evaluated 1 week before and 1 week after chemotherapy by measuring the left ventricular ejection fraction and strain/strain rate.

RESULTS

Data analysis showed that the case group presented no significant reduction in strain and strain-rate parameters after intervention, while there was a significant reduction in these parameters in the control group (all p values <0.001). Also, the mean differences of strain parameters in the case group were significantly less than in the control group in all evaluated heart walls (basal septal strain, p = 0.005, basal lateral strain, p = 0.001, basal inferior strain, p < 0.001, and basal anterior strain, p < 0.001); the same was true for the strain-rate parameters (the p values for basal septal, basal lateral, basal inferior and basal anterior strain rate were 0.037, 0.037, 0.002 and <0.001, respectively).

CONCLUSION

This study shows that carvedilol can prevent doxorubicin-induced cardiotoxicity. Whether this prophylaxis should be considered as the preferred method needs further investigation.

Recent Advances on Pathophysiology, Diagnostic and Therapeutic Insights in Cardiac Dysfunction Induced by Antineoplastic Drugs

Along with the improvement of survival after cancer, cardiotoxicity due to antineoplastic treatments has emerged as a clinically relevant problem. Potential cardiovascular toxicities due to anticancer agents include QT prolongation and arrhythmias, myocardial ischemia and infarction, hypertension and/or thromboembolism, left ventricular (LV) dysfunction, and heart failure (HF). The latter is variable in severity, may be reversible or irreversible, and can occur soon after or as a delayed consequence of anticancer treatments. In the last decade recent advances have emerged in clinical and pathophysiological aspects of LV dysfunction induced by the most widely used anticancer drugs. In particular, early, sensitive markers of cardiac dysfunction that can predict this form of cardiomyopathy before ejection fraction (EF) is reduced are becoming increasingly important, along with novel therapeutic and cardioprotective strategies, in the attempt of protecting cardiooncologic patients from the development of congestive heart failure.