Cancer treatment-related cardiotoxicity: current state of knowledge and future research priorities

Rationale for setting up a cardio-oncology unit: our experience at Mayo Clinic

Background

The diagnosis and management of cardiovascular complications have become a clinical concern for oncologists, cardiologists, surgeons, interventional radiologists, radiation therapy physicians, internists, nurses, pharmacists, administrators, and all the stakeholders involved in the care of cancer patients. Anticancer therapies have extended the lives of patients with cancer, but for some this benefit is attenuated by adverse cardiovascular effects.

Methods

This review article aims to provide an overview of the rationale of setting up a cardio-oncology unit and reflect on our own experience establishing this service, and conclude with some fundamental aspects of consideration for evaluation and management of patients with cancer and cardiovascular diseases.

Results

Cardiotoxicity can lead to congestive heart failure and cardiac death. In fact, chemotherapy-related cardiac dysfunction may carry one of the worst prognoses of all types of cardiomyopathies, and has a profound impact on morbidity and mortality in oncology patients. Other complex clinical situations involve cancer patients who might benefit from a highly curative drug in terms of cancer survival but face limitations of its administration because of concomitant cardiovascular diseases. Indeed, the balance between the benefits and risks of the cancer therapy regimen in the context of the cardiovascular status of the individual patient can sometimes be extraordinarily challenging. A subspecialty with a multidisciplinary integrative approach between oncologists, hematologists, cardiologists, among others has thus emerged to address these issues, termed cardio-oncology. Cardio-oncology addresses the spectrum of prevention, detection, monitoring and treatment of cancer patients with cardiovascular diseases, or at risk for cardiotoxicity, in a multidisciplinary manner. In this field, cardiologists assist oncologists and hematologists with cardiovascular recommendations. This can be mediated through e-consultations or face-to-face evaluations.

Conclusion

Cardio-oncology is a subspecialty that assists in the overall care of cancer patients with and without cardiovascular disease in an interdisciplinary fashion. We believe that this partnership of sharing responsibilities and experiences among health-care team members can potentially decrease cancer therapeutics-related cardiovascular complications and improve clinical outcomes.

Noninvasive Measures of Ventricular-Arterial Coupling and Circumferential Strain Predict Cancer Therapeutics-Related Cardiac Dysfunction

OBJECTIVES

This study sought to determine the relationships between echocardiography-derived measures of myocardial mechanics and cancer therapeutics-related cardiac dysfunction (CTRCD).

BACKGROUND

Doxorubicin and trastuzumab are highly effective breast cancer therapies, but have a substantial risk of CTRCD. There is a critical need for the early detection of patients at increased risk of toxicity.

METHODS

We performed a prospective, longitudinal cohort study of breast cancer participants undergoing doxorubicin and/or trastuzumab therapy. Echocardiography was performed prior to therapy initiation (baseline) and at standardized follow-up intervals during and after completion of therapy. Ejection fraction (EF), strain, strain rate, and ventricular-arterial coupling (effective arterial elastance [Ea]/end-systolic elastance [Ees_sb]) were quantitated. CTRCD was defined as a ≥10% reduction in EF from baseline to <50%. Multivariable logistic regression models were used to determine the associations between baseline levels and changes from baseline in echocardiographic measures and CTRCD. Receiver-operating characteristic curves were used to evaluate the predictive ability of these measures.

RESULTS

In total, 135 participants contributed 517 echocardiograms to the analysis. Over a median follow-up time of 1.9 years (interquartile range: 0.9 to 2.4 years), 21 participants (15%) developed CTRCD. In adjusted models, baseline levels and changes in Ea/Ees_sb, circumferential strain, and circumferential strain rate were associated with 21% to 38% increased odds of CTRCD (p < 0.001). Changes in longitudinal strain (p = 0.037), radial strain (p = 0.015), and radial strain rate (p = 0.006) were also associated with CTRCD. Ea/Ees_sb (area under the curve: 0.703; 95% confidence interval: 0.583 to 0.807) and circumferential strain (area under the curve: 0.655; 95% confidence interval: 0.517 to 0.767) demonstrated the greatest predictive utility. Sensitivity analyses using an alternative CTRCD definition did not impact our results.

CONCLUSIONS

Over an extended follow-up time, ventricular-arterial coupling and circumferential strain were strongly predictive of CTRCD. Our findings suggest a noninvasive strategy to identify high-risk patients prior to, during, and after cardiotoxic cancer therapy.

A Biobehavioral Framework to Address the Emerging Challenge of Multimorbidity

Multimorbidity, the co-occurrence of multiple physical or psychological illnesses, is prevalent particularly among older adults. The number of Americans with multiple chronic diseases is projected to increase from 57 million in 2000 to 81 million in 2020. However, behavioral medicine and health psychology, while focusing on the co-occurrence of psychological/psychiatric disorders with primary medical morbidities, have historically tended to ignore the co-occurrence of primary medical comorbidities, such as diabetes and cancer, and their biopsychosocial implications. This approach may hinder our ecologically valid understanding of the etiology, prevention, and treatment for individual patients with multimorbidity. In this selective review, we propose a heuristic behavioral framework for the etiology of multimorbidity. More acknowledgment and systematic research on multiple, co-existing disorders in behavioral medicine are consistent with the biopsychosocial model's emphasis on treating the "whole person," which means not considering any single illness, its symptoms, risk factors, or mechanisms, in isolation. As systems analytics, big data, machine learning, and mixed-model trajectory analyses, among others, come online and become more widely available, we may be able to tackle multimorbidity more holistically, efficiently, and satisfactorily.

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.

Serum biomarkers evaluation to predict chemotherapy-induced cardiotoxicity in breast cancer patients

Anti-neoplastic chemotherapy can determine various side effects, including cardiotoxicity, and no real guidelines for its early detection and management have been developed. The aim of this study is to find some plasmatic markers able to identify breast cancer patients that are at greater risk of developing cardiovascular complications during chemotherapy, in particular heart failure. A prospective study on 100 breast cancer patients with mean age of 66 years in adjuvant treatment with anthracyclines, taxanes, and trastuzumab was performed. Patients underwent cardiological examination before starting treatment (T0) and at 3 months (T1), 6 months (T2), and 1 year (T3) after treatment. Evaluation of serum cardiac markers and N-terminal pro-brain natriuretic peptide (NT-proBNP) was performed at T0, T1, T2, and T3, simultaneously to electrocardiogram and echocardiogram, showing a significant increase in NT-proBNP concentration (p > 0.0001) at T1, T2, and T3, before left ventricular ejection fraction decrease became evident. Human epidermal growth factor receptor 2 (HER2)-negative patients were more susceptible to mild hematological cardiotoxicity, while HER2-positive patients were more susceptible to severe cardiotoxicity. A significant correlation between NT-proBNP increased values after chemotherapy and prediction of mortality at 1 year was evidenced. From our experience, serum biomarker detection was able to support an early diagnosis of cardiac damage, also in the absence of left ventricular ejection fraction decrease. Therefore, the evaluation of specific plasmatic markers for cardiac damage is more sensitive than echocardiography in the early diagnosis of chemotherapy-related cardiotoxicity; furthermore, it can also add a prognostic value on outcome.

Cardiovascular Health of Patients With Cancer and Cancer Survivors: A Roadmap to the Next Level

Many existing and emerging cancer therapies have a significant effect on the cardiovascular health of patients with cancer and cancer survivors. This paper examines current aspects of interdisciplinary cardio-oncology clinical care delivery and education in the United States and outlines how these data provide a platform for future development of the field. We present the results of the nationwide survey on cardio-oncology services, practices, and opinions, conducted among chiefs of cardiology and program directors, which demonstrate ranges of clinical activities and identify significant interest for increased educational opportunities and expert training of cardiovascular physicians in this field. The survey respondents recognized clinical relevance but emphasized lack of national guidelines, lack of funds, and limited awareness and infrastructure as the main challenges for development and growth of cardio-oncology. We discuss potential solutions to unmet needs through interdisciplinary collaboration and the active roles of professional societies and other stakeholders.

Clinical Experience of Patients Referred to a Multidisciplinary Cardiac Oncology Clinic: An Observational Study

Cardiotoxicity is the second leading cause of long-term morbidity and mortality among cancer survivors. The purpose of this retrospective observational study is to report on the clinical and cardiac outcomes in patients with early stage and advanced cancer who were referred to our multidisciplinary cardiac oncology clinic (COC). A total of 428 patients were referred to the COC between October 2008 and January 2013. The median age of patients at time of cancer diagnosis was 60. Almost half of patients who received cancer therapy received first-line chemotherapy alone (169, 41.7%), of which 84 (49.7%) were exposed to anthracyclines. The most common reasons for referral to the cardiac oncology clinic were decreased LVEF (34.6%), prechemotherapy assessment (11.9%), and arrhythmia (8.4%). A total of 175 (40.9%) patients referred to the COC were treated with cardiac medications. The majority (331, 77.3%) of patients were alive as of January 2013, and 93 (21.7%) patients were deceased. Through regular review of cardiac oncology clinic referral patterns, management plans, and patient outcomes, we aim to continuously improve delivery of cardiac care to our patient population and optimize cardiac health.

Cardiotoxicity of anticancer treatments

Patients with cancer can experience adverse cardiovascular events secondary to the malignant process itself or its treatment. Patients with cancer might also have underlying cardiovascular illness, the consequences of which are often exacerbated by the stress of the tumour growth or its treatment. With the advent of new treatments and subsequent prolonged survival time, late effects of cancer treatment can become clinically evident decades after completion of therapy. The heart's extensive energy reserve and its ability to compensate for reduced function add to the complexity of diagnosis and timely initiation of therapy. Additionally, modern oncological treatment regimens often incorporate multiple agents whose deleterious cardiac effects might be additive or synergistic. Treatment-related impairment of cardiac contractility can be either transient or irreversible. Furthermore, cancer treatment is associated with life-threatening arrhythmia, ischaemia, infarction, and damage to cardiac valves, the conduction system, or the pericardium. Awareness of these processes has gained prominence with the arrival of strategies to monitor and to prevent or to mitigate the effects of cardiovascular damage. A greater understanding of the mechanisms of injury can prolong the lives of those cured of their malignancy, but left with potentially devastating cardiac sequelae.

Predictors of late-onset heart failure in breast cancer patients treated with doxorubicin

PURPOSE

Anthracyclines are an integral component of breast cancer chemotherapy. They exert many cardiotoxic effects, including heart failure. The onset of anthracycline-induced heart failure (AIHF) can occur years after completion of chemotherapy and incurs significant morbidity and mortality. Few studies have attempted to characterize risk factors for its development. Our purpose was to determine the incidence of early and late AIHF in breast cancer survivors and to identify factors that increase the risk for late-onset AIHF.

METHODS

Patients with invasive breast cancer who received doxorubicin-containing chemotherapy at University Hospitals Case Medical Center from 1998 to 2006 were included. Medical history and tumor and treatment characteristics were abstracted from medical records. Patients who developed heart failure were compared to those who did not and were also stratified based on timing of heart failure.

RESULTS

One thousand one hundred fifty-three patients received doxorubicin-based chemotherapy for invasive breast cancer with an average follow-up of 7.6 years (standard deviation (SD) = 3.4). The overall incidence of heart failure was 10.4, with a 2.9 and 7.6 % incidence of early- and late-onset heart failure, respectively. Human epidermal growth factor receptor 2 (HER2) status, hypertension, and coronary artery disease were significant predictors for both heart failure groups (p < 0.001). Type II diabetes was a risk factor for the late-onset AIHF group (p < 0.001).

CONCLUSIONS

HER2 status and cardiovascular risk factors increased the risk of heart failure among doxorubicin users. Patients with type II diabetes were at increased risk of late-onset AIHF.

IMPLICATIONS FOR CANCER SURVIVORS

We identified at risk survivors who may benefit from prolonged monitoring and/or early intervention.