Longitudinal Changes in Multiple Biomarkers Are Associated with Cardiotoxicity in Breast Cancer Patients Treated with Doxorubicin, Taxanes, and Trastuzumab

Biomarkers for monitoring chemotherapy-induced cardiotoxicity

Cardiotoxicity, including acute and late-onset cardiotoxicity, is a well-known adverse effect of many types of antitumor agents. Early identification of patients with cardiotoxicity is important to ensure prompt treatment and minimize toxic effects. The etiology of chemotherapy-induced cardiotoxicity is multifactorial. Traditional methods for assessment of chemotherapy-induced cardiotoxicity typically involve serial measurements of cardiac function via multi-modality imaging techniques. Typically, however, significant left ventricular dysfunction has already occurred when cardiotoxicity is detected by imaging techniques. Biomarkers, most importantly cardiac natriuretic peptides and troponins, are promising markers for identifying patients potentially at risk for clinical heart failure symptoms. This review summarizes the recent progress in clinical utilization of biomarkers for early diagnosis of acute cardiotoxicity and for prediction of late-onset cardiotoxicity. We also discuss the conflicting results of different studies and the association of results with study design.

High-sensitive cardiac troponin-I facilitates timely detection of subclinical anthracycline-mediated cardiac injury

Background

Anthracycline drugs are effective anticancer agents, but their optimal use is limited in many patients by the associated cardiotoxicity, even at designated safe doses. As conventionally sensitive cardiac troponin-I assays fail to reliably quantify concentrations of cardiac troponin-I below 30 ng/L, we investigated the potential role of high-sensitive cardiac troponin-I in the detection of subclinical cardiomyocyte injury in patients treated with anthracycline agents.

Methods

Serial high-sensitive cardiac troponin-I concentrations were assessed in 84 patients, receiving anthracycline-containing ( n = 38) and non-anthracycline-containing ( n = 46) regimens. Results were assessed for change from pretreatment levels and evaluated according to unisex and gender-specific 99th percentiles (25 ng/L and M: 34 ng/L, F: 16 ng/L, respectively).

Results

A significant increase in high-sensitive cardiac troponin-I was observed in the anthracycline cohort following five cycles of treatment, with the greatest change correlating to an absolute δ increase of 30.7 ng/L in the early-dose group (early-dose group: P < 0.0001, late-dose group: P < 0.01 and continuous-dose group: P < 0.0001). Doxorubicin dose did not correlate directly with high-sensitive cardiac troponin-I concentrations (Spearman r < −0.22). No significant changes in high-sensitive cardiac troponin-I were reported among the non-anthracycline cohort with all measurements below the 99th percentiles.

Conclusions

Treatment with anthracycline-based chemotherapeutic regimen demonstrated significant elevations of high-sensitive cardiac troponin-I, indicative of subclinical cardiomyocyte damage. This study demonstrates a role for high-sensitive cardiac troponin-I in evaluating those patients where cardiotoxicity is a concern and a potential future role as a biomarker in optimizing cardioprotective treatments in patients receiving anthracycline therapy.

Cancer treatment-related cardiac toxicity: prevention, assessment and management

Cancer therapies, especially anthracyclines and monoclonal antibodies, have been linked with increased rates of cardiotoxicity. The development of some cardiac side effects happens over several months, and changes in ejection fraction can be detected long before permanent damage or disability occurs. Advanced heart failure could be averted with better and earlier detection. Methodologies for early detection of cardiac changes include stress echocardiograms, cardiac velocity measurements, radionuclide imaging, cardiac MRI and several potential biomarkers. Many agents have been described for prophylaxis of cardiac events precipitated by cancer therapy. Prophylactic use of beta-blockers and ACE inhibitors may be considered for use with trastuzumab in breast cancer as tolerated. Recovery of cardiac function is possible early after the injury from a cancer therapy. Late complications for coronary artery disease, hypertension and arrhythmia are underappreciated. Treatments for severe cancer therapy-related cardiac complications follow the existing paradigms for congestive heart failure and coronary artery disease, although outcomes for cancer patients differ from outcomes for non-cancer patients.

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

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

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The need for exercise prescription to prevent cardiotoxicity in chemotherapy patients

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The molecular basis of exercise as an intervention

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Summary of existing evidence

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

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

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

Liguzinediol protects against cardiac fibrosis in rats in vivo and in vitro

Cardiac fibrosis plays a causal role in the development of heart failure, and anti-fibrotic therapy represents a promising strategy to mitigate heart failure. The purpose of this study was to investigate the effect of a new drug-liguzinediol on cardiac fibrosis of heart failure Male Sprague-Dawley rats (SD) rats and the underlying mechanisms. Liguzinediol was administered to rats that were injected with doxorubicin (Dox) for four weeks. Two weeks later, its effects on cardiac fibrosis were assessed by haematoxylin and eosin (HE) staining and Masson staining. The collagen content was determined by Elisa, and protein expression was detected by western blot in vitro and in vivo. Liguzinediol decreased cardiac muscle fiber break evidenced by HE staining and it significantly reduced cardiac fibrosis evidenced by Masson staining in DOX-treated rats. In addition, the hydroxyproline level and the ratio of type I/III collagens were also significantly decreased, and western blot assays showed that liguzinediol regulated the balance between matrix matalloproteinases (MMPs) and tissue inhibitor of metalloproteinase (TIMPs) to protect cardiac remodeling in vivo and in vitro. These data collectively indicated that liguzinediol could protect against cardiac fibrosis in rats. Liguzinediol could be exploited to be a promising candidate for cardiac fibrosis.

Biomarkers as Predictors of Cardiac Toxicity From Targeted Cancer Therapies

BACKGROUND

Cardiac biomarkers have been extensively investigated as early detectors of cardiac toxicity from cancer therapies. Whereas the role of biomarkers in monitoring anthracycline toxicity is generally well understood, substantial uncertainty remains regarding their role in monitoring newer targeted cancer therapies.

METHODS AND RESULTS

This review article examines all major published studies using cardiac troponins and/or N-terminal pro-B-type natriuretic peptide (NT-proBNP) in monitoring for cardiac toxicity with trastuzumab, tyrosine kinase inhibitors, and mammalian target of rapamycin (mTOR) inhibitors. There is substantial variability among studies regarding biomarker assays used, sensitivity of the assays, and definitions of abnormal results. In general, troponin I predicts early but not late cardiac events when trastuzumab is administered after anthracyclines, but troponin increases likely reflect anthracycline injury rather than trastuzumab injury. NT-proBNP detects cardiac toxicity with tyrosine kinase inhibitors and mTOR inhibitors, but not independently from echocardiography.

CONCLUSIONS

Troponin I can serve as a marker for susceptibility to cardiac toxicity during early trastuzumab treatment in patients who have received recent anthracyclines. NT-proBNP can serve as a useful marker of cardiac toxicity in patients treated with tyrosine kinase inhibitors or mTOR inhibitors if echocardiographic screening is not being used.

The interplay between genetic background and sexual dimorphism of doxorubicin-induced cardiotoxicity

Background

Doxorubicin (DOX) is a very effective anticancer medication that is commonly used to treat hematological malignancies and solid tumors. Nevertheless, DOX is known to have cardiotoxic effects that may lead to cardiac dysfunction and failure. In experimental studies, female animals have been shown to be protected against DOX-induced cardiotoxicity; however, the evidence of this sexual dimorphism is inconclusive in clinical studies. Therefore, we sought to investigate whether genetic background could influence the sexual dimorphism of DOX-induced cardiotoxicity.

Methods

Male and female Wistar Kyoto (WKY) and Spontaneous Hypertensive Heart Failure (SHHF) rats were used. DOX was administered in eight doses of 2 mg/kg/week and the rats were followed for an additional 12 weeks. Cardiac function was assessed by trans-thoracic echocardiography, systolic blood pressure was measured by the tail cuff method, and heart and kidney tissues were collected for histopathology.

Results

Female sex protected against DOX-induced weight loss and increase in blood pressure in the WKY rats, whereas it protected against DOX-induced cardiac dysfunction and the elevation of cardiac troponin in SHHF rats. In both strains, female sex was protective against DOX-induced nephrotoxicity. There was a strong correlation between DOX-induced renal pathology and DOX-induced cardiac dysfunction.

Conclusions

This study highlights the importance of studying the interaction between sex and genetic background to determine the risk of DOX-induced cardiotoxicity. In addition, our findings suggest that DOX-induced nephrotoxicity may play a role in DOX-induced cardiac dysfunction in rodent models.

Prevention of cardiac dysfunction during adjuvant breast cancer therapy (PRADA): a 2 × 2 factorial, randomized, placebo-controlled, double-blind clinical trial of candesartan and metoprolol

Aims

Contemporary adjuvant treatment for early breast cancer is associated with improved survival but at the cost of increased risk of cardiotoxicity and cardiac dysfunction. We tested the hypothesis that concomitant therapy with the angiotensin receptor blocker candesartan or the β-blocker metoprolol will alleviate the decline in left ventricular ejection fraction (LVEF) associated with adjuvant, anthracycline-containing regimens with or without trastuzumab and radiation.

Methods and results

In a 2 × 2 factorial, randomized, placebo-controlled, double-blind trial, we assigned 130 adult women with early breast cancer and no serious co-morbidity to the angiotensin receptor blocker candesartan cilexetil, the β-blocker metoprolol succinate, or matching placebos in parallel with adjuvant anticancer therapy. The primary outcome measure was change in LVEF by cardiac magnetic resonance imaging. A priori, a change of 5 percentage points was considered clinically important. There was no interaction between candesartan and metoprolol treatments (P = 0.530). The overall decline in LVEF was 2.6 (95% CI 1.5, 3.8) percentage points in the placebo group and 0.8 (95% CI −0.4, 1.9) in the candesartan group in the intention-to-treat analysis (P-value for between-group difference: 0.026). No effect of metoprolol on the overall decline in LVEF was observed.

Conclusion

In patients treated for early breast cancer with adjuvant anthracycline-containing regimens with or without trastuzumab and radiation, concomitant treatment with candesartan provides protection against early decline in global left ventricular function.

Cardio-oncology: Concepts and practice

Substantial progress in cancer therapy increasingly allows higher cure rates, and even advanced disease can be stabilized, allowing improved survival with quality of life for months to years, meaning comorbid diseases are a growing determinant of outcome. Cardiovascular events substantially contribute to long-term morbidity and mortality in people living with or surviving cancer. In recognition of this, the subspecialty of cardio-oncology has emerged, and aims to promote cardiovascular heath, whilst facilitating the most effective cancer therapy. This review describes the concept of cardio-oncology, and illustrates the role played by a specialist team in improving outcomes, using heart failure secondary to breast cancer treatment as an example. We aim to highlight pivotal original research and comprehensive summaries of the most relevant topics, providing an overview for cardiologists and oncologists about this increasingly important medical problem.

Roadmap for biomarkers of cancer therapy cardiotoxicity

Contemporary cancer treatment uses multiple modalities such as chemotherapy, targeted therapy and radiotherapy. These therapies, often used in combination, are associated with an increased risk of cardiotoxicity, specifically cardiomyopathy and heart failure. Cardiologists and oncologists are faced with the challenge of maximising the clinical benefit from cancer therapy while minimising the risk of early and late-onset cardiotoxicity. The current paradigm for cardiotoxicity detection and management relies primarily upon the assessment of left ventricular ejection fraction (LVEF). However, LVEF alone is limited in both diagnostic and prognostic ability. There is growing enthusiasm over the identification of newer biomarkers of cardiotoxicity that can detect cardiac injury at earlier stages of disease and could be used as an adjunctive prognostic measure to routine LVEF assessment. Thus, imaging and circulating biomarkers are currently under active investigation for use throughout the continuum of cancer care-for risk stratification of cardiotoxicity prior to treatment, detection of early cardiotoxicity during treatment and diagnosis of late cardiotoxicity in survivorship. Myocardial strain, cardiac troponin and brain natriuretic peptide are the most prominent biomarkers currently being studied, although data on novel circulating biomarkers are emerging.