The role of cardiac biomarkers in cardio-oncology

Anthracycline-induced cardiotoxicity: targeting high-density lipoproteins to limit the damage?

Doxorubicin (DOX) is an anthracycline antibiotic frequently used against a wide range of cancers, including breast cancer. Although the drug is effective as a treatment against cancer, many patients develop heart failure (HF) months to years following their last treatment with DOX. The challenge in preventing DOX-induced cardiotoxicity is that symptoms present after damage has already occurred in the myocardium. Therefore, early biomarkers to assess DOX-induced cardiotoxicity are urgently needed. A better understanding of the mechanisms involved in the toxicity is important as this may facilitate the development of novel early biomarkers or therapeutic approaches. In this review, we discuss the role of high-density lipoprotein (HDL) particles and its components as possible key players in the early development of DOX-induced cardiotoxicity. HDL particles exist in different subclasses which vary in composition and biological functionality. Multiple cardiovascular risk factors are associated with a change in HDL subclasses, resulting in modifications of their composition and physiological functions. There is growing evidence in the literature suggesting that cancer affects HDL subclasses and that healthy HDL particles enriched with sphingosine-1-phosphate (S1P) and apolipoprotein A1 (ApoA1) protect against DOX-induced cardiotoxicity. Here, we therefore discuss associations and relationships between HDL, DOX and cancer and discuss whether assessing HDL subclass/composition/function may be considered as a possible early biomarker to detect DOX-induced cardiotoxicity.

Evaluation of Ibrutinib Cardiotoxicity By Comparative Use of Speckle-Tracking Technique and Biomarkers

BACKGROUND

Ibrutinib, a relatively new antineoplastic agent, has multiple cardiovascular effects that are still insufficiently known and evaluated, including subclinical myocardial damage.

STUDY QUESTION

The present study aims to assess the role of the myocardial strain, alone and in combination with cardiac biomarkers, in the early detection of ibrutinib-induced cardiotoxicity.

STUDY DESIGN

We included 31 outpatients with normal left ventricular ejection fraction (LVEF) on ibrutinib, in a tertiary University Hospital between 2019 and 2020, and evaluated them at inclusion and after 3 months.

MEASURES AND OUTCOMES

Data on myocardial strain, cardiac biomarkers [high-sensitive troponin T (hs TnT) and N-terminal probrain natriuretic peptide (NT-proBNP)], and ambulatory electrocardiographic monitoring were collected.

RESULTS

Myocardial deformation decreased significantly (P < 0.001) at later evaluation and hs TnT and NT-proBNP increased significantly (P = 0.019 and P = 0.03, respectively). The increase in hs TnT correlated with the increase in the left ventricle global longitudinal strain (LVGLS); in other words, it correlated with the decrease in myocardial deformation. No association was found between LVGLS increase and the increase in NT-proBNP. LVGLS modification was not significantly influenced by age, anemia, or arrhythmia burden quantified by 24-hour Holter monitoring (P = 0.747, P = 0.072, respectively; P = 0.812). LVEF did not change significantly during follow-up.

CONCLUSIONS

In patients on ibrutinib, evaluation of myocardial strain is useful in identifying early cardiac drug toxicity, surpassing the sensitivity and specificity limits of LVEF. In these patients, concomitant assessment of hs TnT increases the predictive power for subclinical myocardial involvement.

High-sensitivity cardiac troponin T determines all-cause mortality in cancer patients: a single-centre cohort study

Aims

Cardio‐oncology is a growing interdisciplinary field which aims to improve cardiological care for cancer patients in order to reduce morbidity and mortality. The impact of cardiac biomarkers, echocardiographic parameters, and cardiological assessment regarding risk stratification is still unclear. We aimed to identify potential parameters that allow an early risk stratification of cancer patients.

Methods and results

In this cohort study, we evaluated 930 patients that were admitted to the cardio‐oncology outpatient clinic of the University Hospital Heidelberg from January 2016 to January 2019. We performed echocardiography, including Global Longitudinal Strain (GLS) analysis and measured cardiac biomarkers including N‐terminal pro brain‐type natriuretic peptide (NT‐proBNP) and high‐sensitivity cardiac troponin T levels (hs‐cTnT). Most patients were suffering from breast cancer (n = 450, 48.4%), upper gastrointestinal carcinoma (n = 99, 10.6%) or multiple myeloma (n = 51, 5.5%). At the initial visit, we observed 86.7% of patients having a preserved left ventricular ejection fraction (LVEF >50%). At the second follow up, still 78.9% of patients showed a preserved LVEF. Echocardiographic parameters or elevation of NT‐proBNP did not significantly correlate with all‐cause mortality (ACM) (logistic regression LVEF <50%: P = 0.46, NT‐proBNP: P = 0.16) and failed to identify high‐risk patients. In contrast, hs‐cTnT above the median (≥7 ng/L) was an independent marker to determine ACM (multivariant logistic regression, OR: 2.21, P = 0.0038) among all included patients. In particular, hs‐cTnT levels before start of a chemotherapy were predictive for ACM.

Conclusions

Based on our non‐selected cohort of cardio‐oncological patients, hs‐cTnT was able to identify patients with high mortality by using a low cutoff of 7 ng/L. We conclude that measurement of hs‐cTnT is an important tool to stratify the risk for mortality of cancer patients before starting chemotherapy.

What Does a Cardio-oncology Service Offer to the Oncologist and the Haematologist?

Cardio-oncology is an emerging subspecialty arising from the need for multidisciplinary collaboration to address the increasing prominence of cardiovascular disease (CVD) among cancer patients. This overview outlines the case for establishing cardio-oncology services and defines the ways in which these services benefit cancer patients. The primary objective of cardio-oncology is to manage CVDs in order to allow cancer patients to complete the best cancer treatments safely and with minimal interruption. In the decades since the first discovery of heart failure induced by anthracycline chemotherapy, both cardiovascular and oncological science have advanced considerably. Cardio-oncology services aim to bring together expertise from these two fast moving fields in order to provide optimal evidence-based care for cancer patients with CVDs. Here we discuss the basis of cardio-oncology services by presenting their rationale and key components, as well as their essential roles in education, training and research. At each stage of the cancer care pathway, a cardio-oncology service can add value by ensuring cancer patients have timely access to specialist care backed up by cutting edge diagnostic tools and treatment options, as well as holistic supports. We highlight areas of recent and upcoming developments in the field that are likely to change established clinical practice. Improved cardiac imaging modalities can detect chemotherapy-related cardiac dysfunction earlier and are also essential for the prompt diagnosis of an expanding range of cardiovascular effects complicating newer cancer therapeutics, such as immune checkpoint inhibitors and other targeted therapies. Modern cancer therapy has dramatically improved cancer survival and as such CVD is becoming one of the principal determinants of overall outcome for cancer patients. A dedicated cardio-oncology service can facilitate the optimisation of cardiovascular treatment and enable the completion of cancer therapy. A multidisciplinary collaborative approach is key to achieving these objectives.

Qualification of translational safety biomarkers

Safety biomarkers are important drug development tools, both preclinically and clinically. It is a straightforward process to correlate the performance of nonclinical safety biomarkers with histopathology, and ideally, the biomarker is useful in all species commonly used in safety assessment. In clinical validation studies, where histopathology is not feasible, safety biomarkers are compared to the response of standard biomarkers and/or to clinical adjudication. Worldwide, regulatory agencies have put in place processes to qualify biomarkers to provide confidence in the manner of use and interpretation of biomarker data in drug development studies. This paper describes currently qualified safety biomarkers which can be utilized to monitor for nephrotoxicity and cardiotoxicity and ongoing projects to qualify safety biomarkers for liver, skeletal muscle, and vascular injury. In many cases, the development and use of these critical drug development tools is dependent upon partnerships and the precompetitive sharing of data to support qualification efforts.

Antioxidant Approach as a Cardioprotective Strategy in Chemotherapy-Induced Cardiotoxicity

Significance: Chemotherapy-induced cardiotoxicity (CTX) has been associated with redox signaling imbalance. In fact, redox reactions are crucial for normal heart physiology, whereas excessive oxidative stress can cause cardiomyocyte structural damage. Recent Advances: An antioxidant approach as a cardioprotective strategy in this setting has shown encouraging results in preventing anticancer drug-induced CTX. Critical Issues: In fact, traditional heart failure drugs as well as many other compounds and nonpharmacological strategies, with a partial effect in reducing oxidative stress, have been shown to counterbalance chemotherapy-induced CTX in this setting to some extent. Future Directions: Given the various pathways of toxicity involved in different chemotherapeutic schemes, interactions with redox balance need to be fine-tuned and a personalized cardioprotective approach seems to be required.

Prevention of anthracycline-induced cardiotoxicity: a systematic review and meta-analysis

Anthracyclines are extensively used in oncologic patients, in particular for breast cancer and hematological malignancies. Cardiac injury is a potentially dangerous side effect of these drugs. In this systematic review, we analyzed published randomized controlled trials (RCTs) to assess if potential cardioprotective drugs (i.e., renin-angiotensin-aldosterone system [RAAS] blockers and β-blockers) may prevent heart damage by anthracyclines. Studies were identified by electronic search of MEDLINE and EMBASE database until August 2020. The impact of cardioprotective drugs to prevent anthracyclines-induced cardiac injury was expressed as mean difference (MD) or odds ratio (OR) and 95% confidence intervals (95% CI). Statistical heterogeneity was assessed with the I² statistic. Twelve RCTs for a total of 1.035 cancer patients treated with anthracyclines were included. RAAS blockers, β-blockers, and aldosterone antagonists showed a statistically significant benefit in preventing left ventricular ejection fraction (LVEF) reduction (MD 3.57, 95% CI 1.04, 6.09) in 11 studies. A non-statistically significant difference was observed in preventing E/A velocity decrease (MD 0.09, 95% CI 0.00, 0.17; 9 studies), left ventricular end-systolic diameter (LVESD) increase (MD - 0.88, 95% CI, - 2.75,0.99; 6 studies), left ventricular end-diastolic diameter (LVEDD) increase (MD -0.95, 95% CI - 2.67,0.76; 6 studies), and mitral A velocity decrease (MD - 1.42, 95% CI - 3.01,0.17; 4 studies). Heart failure was non-significantly reduced in the cardioprotective arm (OR 0.31, 95% CI 0.06, 1.59; 5 studies). Hypotension was non-significantly increased in the cardioprotective arm (OR 3.91, 95% CI 0.42, 36.46, 3 studies). Cardioprotective drugs reduce anthracycline-induced cardiac damage as assessed by echocardiographic parameters. The clinical relevance of this positive effect is still to be defined.

Electrochemical Aptasensors: Current Status and Future Perspectives

This article reviews the progress of diversity of electrochemical aptasensor for target analytes detection. The immobilization strategies of aptamers on an electrode surface are addressed. The aptasensors are also introduced in compliance with the assay platforms. Many electrochemical aptasensors are nearly identical to conventional immunochemical approaches, sandwich and competition assays using electroactive signaling moieties. Others are "signal-on" and "sign-off" aptasensors credited to the target binding-induced conformational change of aptamers. Label-free aptasensors are also highlighted. Furthermore, the aptasensors applied for clinically important biomarkers are emphasized.

Improving cardiotoxicity prediction in cancer treatment: integration of conventional circulating biomarkers and novel exploratory tools

Early detection strategies and improvements in cancer treatment have dramatically reduced the cancer mortality rate in the United States (US). However, cardiovascular (CV) side effects of cancer therapy are frequent among the 17 million cancer survivors in the US today, and cardiovascular disease (CVD) has become the second leading cause of morbidity and mortality among cancer survivors. Circulating biomarkers are ideal for detecting and monitoring CV side effects of cancer therapy. Here, we summarize the current state of clinical studies on conventional serum and plasma CVD biomarkers to detect and prevent cardiac injury during cancer treatment. We also review how novel exploratory tools such as genetic testing, human stem cell-derived cardiomyocytes, Omics technologies, and artificial intelligence can elucidate underlying molecular and genetic mechanisms of CV injury and to improve predicting cancer therapy-related cardiotoxicity (CTRC). Current regulatory requirements for biomarker qualifications are also addressed. We present generally applicable lessons learned from published studies, particularly on how to improve reproducibility. The combination of conventional circulating biomarkers and novel exploratory tools will pave the way for precision medicine and improve the clinical practice of prediction, detection, and management of CTRC.

Cardiotoxic effects and myocardial injury: the search for a more precise definition of drug cardiotoxicity

Drug-induced cardiotoxicity is a major clinical problem; cardiotoxic drugs may induce both cardiac dysfunction and myocardial injury. Several recent studies reported that cardiac troponins measured with high-sensitivity methods (hs-cTn) can enable the early detection of myocardial injury related to chemotherapy or abuse of drugs that are potentially cardiotoxic. Several authors have some concerns about the standard definition of cardiotoxicity, in particular, regarding the early evaluation of chemotherapy cardiotoxicity in cancer patients. Several recent studies using the hs-cTn assay indicate that myocardial injury may precede by some months or years the diagnosis of heart failure (HF) based on the evaluation of left ventricular ejection fraction (LVEF). Accordingly, hs-cTn assay should considered to be a reliable laboratory test for the early detection of asymptomatic or subclinical cardiotoxic damage in patients undergoing cancer chemotherapy. In accordance with the Fourth Universal Definition of Myocardial Infarction and also taking into account the recent experimental and clinical evidences, the definition of drug-cardiotoxicity should be updated considering the early evaluation of myocardial injury by means of hs-cTn assay. It is conceivable that the combined use of hs-cTn assay and cardiac imaging techniques for the evaluation of cardiotoxicity will significantly increase both diagnostic sensitivity and specificity, and also better prevent chemotherapy-related left ventricular (LV) dysfunction and other adverse cardiac events. However, large randomized clinical trials are needed to evaluate the cost/benefit ratio of standardized protocols for the early detection of cardiotoxicity using hs-cTn assay in patients receiving chemotherapy for malignant diseases.

PET Radiopharmaceuticals for Imaging Chemotherapy-Induced Cardiotoxicity

Purpose of Review

Currently, cardiotoxicity is monitored through echocardiography or multigated acquisition scanning and is defined as 10% or higher LVEF reduction. The latter stage may represent irreversible myocardium injury and limits modification of therapeutic paradigms at earliest stages. To stratify patients for anthracycline-related heart failure, highly sensitive and molecularly specific probes capable of interrogating cardiac damage at the subcellular levels have been sought.

Recent Findings

PET tracers may provide noninvasive assessment of earliest changes within myocardium. These tracers are at nascent stages of development and belong primarily to (a) mitochondrial potential-targeted and (b) general ROS (reactive oxygen species)-targeted radiotracers. Given that electrochemical gradient changes at the mitochondrial membrane represent an upstream, and earliest event before triggering the production of the ROS and caspase activity in a biochemical cascade, the former category might offer interrogation of cardiotoxicity at earliest stages exemplified by PET imaging, using ¹⁸F-Mitophos and ⁶⁸Ga-Galmydar in rodent models.

Summary

Both categories of radiotracers may provide tools for monitoring chemotherapy-induced cardiotoxicity and interrogating therapeutic efficacy of cardio-protectants.

A Doxorubicin-Glucuronide Prodrug Released from Nanogels Activated by High-Intensity Focused Ultrasound Liberated β-Glucuronidase

The poor pharmacokinetics and selectivity of low-molecular-weight anticancer drugs contribute to the relatively low effectiveness of chemotherapy treatments. To improve the pharmacokinetics and selectivity of these treatments, the combination of a doxorubicin-glucuronide prodrug (DOX-propGA3) nanogel formulation and the liberation of endogenous β-glucuronidase from cells exposed to high-intensity focused ultrasound (HIFU) were investigated in vitro. First, a DOX-propGA3-polymer was synthesized. Subsequently, DOX-propGA3-nanogels were formed from this polymer dissolved in water using inverse mini-emulsion photopolymerization. In the presence of bovine β-glucuronidase, the DOX-propGA3 in the nanogels was quantitatively converted into the chemotherapeutic drug doxorubicin. Exposure of cells to HIFU efficiently induced liberation of endogenous β-glucuronidase, which in turn converted the prodrug released from the DOX-propGA3-nanogels into doxorubicin. β-glucuronidase liberated from cells exposed to HIFU increased the cytotoxicity of DOX-propGA3-nanogels to a similar extend as bovine β-glucuronidase, whereas in the absence of either bovine β-glucuronidase or β-glucuronidase liberated from cells exposed to HIFU, the DOX-propGA3-nanogels hardly showed cytotoxicity. Overall, DOX-propGA3-nanogels systems might help to further improve the outcome of HIFU-related anticancer therapy.

Cardiac Biomarkers in Patients with Cancer: Considerations, Clinical Implications, and Future Avenues

PURPOSE OF THE REVIEW

As the number of cancer survivors increases due to early screening and modern (antineoplastic) treatments, cancer treatment associated cardiotoxicity (CTAC) is becoming an increasing health burden that affects survival and quality of life among cancer survivors. Thus, clinicians need to identify adverse events early, in an effort to take suitable measures before the occurrence of permanent or irreversible cardiac dysfunction.

RECENT FINDINGS

Cardiac troponin (cTn) and B-type natriuretic peptide (BNP) have been proven to detect subclinical cardiotoxicity during antineoplastic treatment. As such, these cardio-specific biomarkers could predict which patients are at risk of developing CTAC even before the start of therapy. Nevertheless, there are inconsistent data from published studies, and the recommendations regarding the use of these biomarkers and their validity are mostly based on expert consensus opinion. In this review, we summarize available literature that evaluates biomarkers of CTAC, and we encourage strategies that integrate circulating biomarkers and cardiac imaging in identifying cancer patients that are at high risk.

Clinical and Research Tools for the Study of Cardiovascular Effects of Cancer Therapy

The expansion of cancer therapeutics has paved the way for improved cancer-related outcomes. Cardiotoxicity from cancer therapy occurs in a small but significant subset of patients, is often poorly understood, and contributes to adverse outcomes at all stages of cancer treatment. Given the often-idiopathic occurrence of cardiotoxicity, novel strategies are needed for risk-stratification and early identification of cancer patients experiencing cardiotoxicity. Clinical and research tools extending from imaging to blood-based biomarkers and pluripotent stem cells are being explored as methods to study the cardiovascular impact of various cancer treatments. Here we provide an overview of tools currently available for evaluation of cardiotoxicity and highlight novel techniques in development aimed at understanding underlying pathophysiologic mechanisms.

High-sensitivity cardiac troponin I and T methods for the early detection of myocardial injury in patients on chemotherapy

Important advances achieved in pharmacological cancer treatment have led progressively to a reduction in mortality from many forms of cancer, and increasing numbers of previously incurable patients can now hope to become cancer-free. Yet, to achieve these improved outcomes a high price has been paid in terms of untoward side effects associated with treatment, cardio-toxicity in particular. Several recent studies have reported that cardiac troponin assay using high-sensitivity methods (hs-cTn) can enable the early detection of myocardial injury related to chemotherapy or abuse of drugs that are potentially cardiotoxic. Several authors have recently suggested that changes in hs-cTn values enable the early diagnosis of cardiac injury from chemotherapy, thus potentially benefitting cancer patients with increased troponin values by initiating early cardioprotective therapy. However, large randomised clinical trials are needed in order to evaluate the cost/benefit ratio of standardised protocols for the early detection of cardiotoxicity using the hs-cTn assay in patients treated with chemotherapy.

Emerging Challenges of Radiation-Associated Cardiovascular Dysfunction (RACVD) in Modern Radiation Oncology: Clinical Practice, Bench Investigation, and Multidisciplinary Care

Radiotherapy (RT) is a crucial treatment modality in managing cancer patients. However, irradiation dose sprinkling to tumor-adjacent normal tissues is unavoidable, generating treatment toxicities, such as radiation-associated cardiovascular dysfunction (RACVD), particularly for those patients with combined therapies or pre-existing adverse features/comorbidities. Radiation oncologists implement several efforts to decrease heart dose for reducing the risk of RACVD. Even applying the deep-inspiration breath-hold (DIBH) technique, the risk of RACVD is though reduced but still substantial. Besides, available clinical methods are limited for early detecting and managing RACVD. The present study reviewed emerging challenges of RACVD in modern radiation oncology, in terms of clinical practice, bench investigation, and multidisciplinary care. Several molecules are potential for serving as biomarkers and therapeutic targets. Of these, miRNAs, endogenous small non-coding RNAs that function in regulating gene expression, are of particular interest because low-dose irradiation, i.e., 200 mGy (one-tenth of conventional RT daily dose) induces early changes of pro-RACVD miRNA expression. Moreover, several miRNAs, e.g., miR-15b and miR21, involve in the development of RACVD, further demonstrating the potential bio-application in RACVD. Remarkably, many RACVDs are late RT sequelae, characterizing highly irreversible and progressively worse. Thus, multidisciplinary care from oncologists and cardiologists is crucial. Combined managements with commodities control (such as hypertension, hypercholesterolemia, and diabetes), smoking cessation, and close monitoring are recommended. Some agents show abilities for preventing and managing RACVD, such as statins and angiotensin-converting enzyme inhibitors (ACEIs); however, their real roles should be confirmed by further prospective trials.

Proceedings From the Global Cardio-Oncology Summit: The Top 10 Priorities to Actualize for CardioOncology

The discipline of cardio-oncology has expanded at a remarkable pace. Recent developments and challenges to clinicians who practice cardio-oncology were presented at the Global Cardio-Oncology Summit on October 3 to 4, 2019, in São Paulo, Brazil. Here, we present the top 10 priorities for our field that were discussed at the meeting, and also detail a potential path forward to address these challenges. Defining robust predictors of cardiotoxicity, clarifying the role of cardioprotection, managing and preventing thromboembolism, improving hematopoietic stem cell transplant outcomes, personalizing cardiac interventions, building the cardio-oncology community, detecting and treating cardiovascular events associated with immunotherapy, understanding tyrosine kinase inhibitor cardiotoxicity, and enhancing survivorship care are all priorities for the field. The path forward requires a commitment to research, education, and excellence in clinical care to improve our patients' lives.