Myocarditis in the Setting of Cancer Therapeutics: Proposed Case Definitions for Emerging Clinical Syndromes in Cardio-Oncology

Myocarditis occurrence with cancer immunotherapy across indications in clinical trial and post-marketing data

Antibodies targeting the PD-1, PD-L1, and CTLA-4 immune checkpoint axis have been used in a variety of tumor types. They achieve anti-tumor activity through activating the patient’s own immune system to target immune response evading cancer cells. However, this unique mechanism of action may cause immune-related adverse events, irAEs. One of these irAEs is myocarditis which is associated with an alarming mortality rate. In this study we presented clinical cases of myocarditis from safety trial datasets submitted to the U.S. Food and Drug Administration, FDA. Additionally, we analyzed over fourteen million FDA Adverse Event Reporting System, FAERS, submissions. The statistical analysis of the FAERS data provided evidence of significantly increased reporting of myocarditis in patients administered immune checkpoint inhibitors alone, in combination with another immune checkpoint inhibitor, the kinase inhibitor axitinib, or chemotherapy, for all cancer types, when compared to patients administered chemotherapy. All combination therapies led to further increased reporting odds ratios of myocarditis. We further analyzed the occurrence of myocarditis by stratifying the reports into sub-cohorts based on specific cancer types and treatment/control groups in major cancer immunotherapy efficacy trials and confirmed the observed trend for each cohort.

Pathophysiology, diagnosis and management of cardiac toxicity induced by immune checkpoint inhibitors and BRAF and MEK inhibitors

Immune checkpoint inhibitors (ICIs) and BRAF and MEK inhibitors (BRAFi/MEKi) have drastically improved the outcome of melanoma patients. ICIs can induce myocarditis, a rare immune related adverse event (irAE) with an estimated lethality of 50%. BRAFi/MEKi may induce left ventricular ejection fraction decrease, hypertension or QT interval prolongation. While the BRAFi/MEKi induced cardiotoxicity is often reversible upon treatment discontinuation or dose adaptation and symptomatic therapy is often sufficient to restore cardiac function, the treatment of ICI-induced myocarditis mainly relies on high dose corticosteroids. There is no established therapy for steroid resistant myocarditis, yet various drugs have been reported to improve outcome. Shared epitopes between melanoma cells and cardiac tissue are thought to underlie the development of ICIs induced myocarditis. The mechanism of BRAFi/MEKi induced cardiotoxicity appears to be related to the Ras-Raf-MEK-ERK pathway in cardiomyocyte repair, survival and proliferation. With the emerging application of ICI-BRAFi/MEKi combinations, so called triplet therapies, differentiating between these two types of cardiotoxicity will become important for appropriate patient management. In this article we provide a summary of the existing literature on the pathophysiology, diagnosis and management of cardiotoxicity of melanoma therapies.

Keeping immune checkpoint inhibitor myocarditis in check: advanced circulatory mechanical support as a bridge to recovery

Immune checkpoint inhibitor (ICI)‐associated myocarditis is a rare, potentially life‐threatening complication of immunotherapy. We report a case of a 60‐year‐old female with a history of colorectal cancer treated with nivolumab immunotherapy who presented with new cardiomyopathy complicated by cardiogenic shock and ventricular arrhythmias. Treatment of ICI‐associated myocarditis requires aggressive immunosuppression and supportive therapy. In this case, the patient required advanced mechanical circulatory support as a bridge to recovery. This case highlights the complexity of diagnosis, haemodynamic management, and treatment of fulminant ICI myocarditis.

Immune Checkpoint Inhibitor-Induced Myocarditis with Myositis/Myasthenia Gravis Overlap Syndrome: A Systematic Review of Cases

BACKGROUND

The development of immune checkpoint inhibitors (ICIs) represents a paradigm shift in the treatment of cancers. Despite showing remarkable efficacy, these agents can be associated with life-threatening immune-related adverse events. In recent years, several cases of myocarditis with myositis and/or myasthenia gravis overlap syndrome (IM3OS) have been reported. However, given the rarity, the clinical features and outcomes of these cases remain poorly understood. We, therefore, attempted to systematically review and summarize all cases of IM3OS reported in the literature.

MATERIALS AND METHODS

Studies reporting IM3OS were identified in Embase and MEDLINE. Only case reports and case series published in journals or presented at conferences were included. We conducted a systematic review according to the PRISMA Harms guidelines.

RESULTS

A total of 60 cases were eligible. The patients' median age was 71 years, and the majority (67%) were males; melanoma was the most common indication for ICIs (38%). The most-reported symptoms were fatigue (80%) and muscle weakness (78%). The median number of doses to the development of IM3OS was one. The average creatine kinase level was 9,645 IU/L. Cardiac arrhythmias occurred in 67% of patients, and 18% had depressed ejection fraction. Initial treatment consisted of immunosuppression with high-dose steroids and supportive therapies. Sixty percent of the patients died in hospital because of acute complications.

CONCLUSION

IM3OS can be associated with significant mortality and morbidity. Prospective studies are needed to understand the optimal approach to diagnose and manage these patients and to develop biomarkers to predict the occurrence and severity of this rare but serious condition.

IMPLICATIONS FOR PRACTICE

Clinicians should suspect coexisting myositis and/or myasthenia gravis in all patients with immune checkpoint inhibitor-induced myocarditis, given their propensity to occur together. Early recognition and prompt treatment with the help of a multidisciplinary team might help improve the outcomes of this life-threatening condition.

Immune checkpoint inhibitor-induced myocarditis in cancer patients: a case report and review of reported cases

BACKGROUND

Immune checkpoint inhibitor (ICI) induced myocarditis is a rare, severe, and often fatal adverse event. Evidence to guide appropriate immunosuppressive therapy is scarce. We present a case of ICI-induced myocarditis and a review of ICI-induced myocarditis cases to determine the most effective immunosuppressive therapeutic strategy for ICI-induced myocarditis.

METHODS

A systematic search of PubMed was carried out for treatment of ICI-induced myocarditis. Reference lists from identified articles were manually reviewed for additional cases.

RESULTS

A total of 87 cases with ICI-induced myocarditis were identified. The majority were melanoma (n = 39), lung cancer (n = 19), renal cell cancer (n = 10), and thymoma cancer patients (n = 4). In 38 (44%) cases, patients received high-dose steroid treatment only. A total of 49 (56%) cases were treated with immunosuppressive agents other than steroid; a total of 13 different immunosuppressive agents were used, including alemtuzumab or abatacept. The median time to onset of symptoms after initiation of ICI was 16 days (range, 1-196 days); cardiotoxic symptoms developed after 2 cycles of ICI (range, 1-13 cycles). A total of 48% of cases were fatal. In cases treated with high-dose steroids only vs. cases treated with other immunosuppressive agents, fatality was 55% and 43% respectively. In 64 out of the 87 cases, tumor control was not described. In patients treated with high-dose steroids only, two patients had stable disease as best tumor response; in patients treated with other immunosuppressive agents, one complete response, one partial response and seven stable disease were noted as best tumor response. Overall, 11 studies were at low risk of bias (12.6%), 38 at moderate risk of bias (43.7%) and 38 at high risk of bias (43.7%).

CONCLUSION

Immune checkpoint inhibitor induced myocarditis is a serious and often fatal adverse event. High-dose prednisolone, alemtuzumab or abatacept are all possible treatments options for ICI-induced myocarditis, whereas infliximab increases the risk of death from cardiovascular causes, and should be avoided. Further research is needed.

Update on acute myocarditis

Acute myocarditis (AM), a recent-onset inflammation of the heart, has heterogeneous clinical presentations, varying from minor symptoms to high-risk cardiac conditions with severe heart failure, refractory arrhythmias, and cardiogenic shock. AM is moving from being a definitive diagnosis based on histological evidence of inflammatory infiltrates on cardiac tissue to a working diagnosis supported by high sensitivity troponin increase in association with specific cardiac magnetic resonance imaging (CMRI) findings. Though experts still diverge between those advocating for histological definition versus those supporting a mainly clinical definition of myocarditis, in the real-world practice the diagnosis of AM has undoubtedly shifted from being mainly biopsy-based to solely CMRI-based in most of clinical scenarios. It is thus important to clearly define selected settings where EMB is a must, as information derived from histology is essential for an optimal management. As in other medical conditions, a risk-based approach should be promoted in order to identify the most severe AM cases requiring appropriate bundles of care, including early recognition, transfer to tertiary centers, aggressive circulatory supports with inotropes and mechanical devices, histologic confirmation and eventual immunosuppressive therapy. Despite improvements in recognition and treatment of AM, including a broader use of promising mechanical circulatory supports, severe forms of AM are still burdened by dismal outcomes. This review is focused on recent clinical studies and registries that shed new insights on AM. Attention will be paid to contemporary outcomes and predictors of prognosis, the emerging entity of immune checkpoint inhibitors-associated myocarditis, updated CMRI diagnostic criteria, new data on the use of temporary mechanical circulatory supports in fulminant myocarditis. The role of viruses as etiologic agents will be reviewed and a brief update on pediatric AM is also provided. Finally, we summarize a risk-based approach to AM, based on available evidence and clinical experience.

Clinical implications of isolated troponinemia following immune checkpoint inhibitor therapy

Cardiovascular adverse events induced by immune checkpoint inhibitors (ICIs) have gained significant interest over the past decade due to their impact on short- and long-term outcomes. They were initially thought to be rare, but the increasing use of ICIs in the treatment of both advanced and early stages of various malignancies has resulted in a substantial increase in their incidence. Different guidelines have proposed screening measures for ICI-induced myocarditis by incorporating troponin measurements at baseline and during the first few weeks of treatment. However, no specific guidelines have been developed yet regarding the interpretation of an asymptomatic rise in troponins. This state-of-the art review aims to provide an overview of the clinical relevance of elevated troponins during checkpoint inhibition and recommendations on how to manage elevated troponin levels during ICI therapy.

Immune checkpoint inhibitor cardiotoxicity: Breaking barriers in the cardiovascular immune landscape

Immune checkpoint inhibitors (ICI) have changed the landscape of cancer therapy, but their use carries a high risk of cardiac immune related adverse events (iRAEs). With the expanding utilization of ICI therapy, there is a growing need to understand the underlying mechanisms behind their anti-tumor activity as well as their immune-mediated toxicities. In this review, we will focus on clinical characteristics and immune pathways of ICI cardiotoxicity, with an emphasis on single-cell technologies used to gain insights in this field. We will focus on three key areas of ICI-mediated immune pathways, including the anti-tumor immune response, the augmentation of the immune response by ICIs, and the pathologic "autoimmune" response in some individuals leading to immune-mediated toxicity, as well as local factors in the myocardial immune environment predisposing to autoimmunity. Discerning the underlying mechanisms of these immune pathways is necessary to inform the development of targeted therapies for ICI cardiotoxicities and reduce treatment related morbidity and mortality.

Cardiovascular toxicity of angiogenesis inhibitors and immune checkpoint inhibitors: synergistic anti-tumour effects at the cost of increased cardiovascular risk?

In the past two decades, treatment outcomes for a wide range of malignancies have improved remarkably due to the development of novel anti-cancer therapies, including vascular endothelial growth factor inhibitors (VEGFIs) and immune checkpoint inhibitors (ICIs). Despite their unprecedented anti-tumour effects, it is becoming increasingly clear that both types of agents are associated with specific cardiovascular toxicity, including hypertension, congestive heart failure, myocarditis and acceleration of atherosclerosis. Currently, VEGFI and ICI combination therapy is recommended for the treatment of advanced renal cell carcinoma (RCC) and has shown promising treatment efficacy in other tumour types as well. Consequently, VEGFI and ICI combination therapy will most likely become an important therapeutic strategy for various malignancies. However, this combinatory approach is expected to be accompanied by a substantial increase in cardiovascular risk, as both types of agents could act synergistically to induce cardiovascular sequelae. Therefore, a comprehensive baseline assessment and adequate monitoring by specialised cardio-oncology teams is essential in case these agents are used in combination, particularly in high-risk patients. This review summarises the mechanisms of action and treatment indications for currently registered VEGFIs and ICIs, and discusses their main vascular and cardiac toxicity. Subsequently, we provide the biological rationales for the observed promising synergistic anti-tumour effects of combined VEGFI/ICI administration. Lastly, we speculate on the increased risk for cardiovascular toxicity in case these agents are used in combination and its implications and future directions for the clinical situation.

Cardiotoxicity associated with immune checkpoint inhibitors and CAR T-cell therapy

INTRODUCTION

The expanding use of immunotherapy and the growing population of patients with cancer has led to an increase in the reporting of immune related adverse events (irAEs). The emergency clinician should be aware of these emerging toxicities, some of which can be fatal. In this review we discuss the cardiotoxic side effects of immune checkpoint inhibitors (ICIs) and chimeric antigen receptor T-cell (CAR T-cell) therapy.

DISCUSSION

Recognizing the possible presentations of cardiotoxic irAEs is of utmost important as the diagnosis of cardiotoxicity associated with ICI and CAR T-cell can be difficult to make in the emergency department. The emergency clinician will have to presume the diagnosis and treat it without final confirmation in most cases. For this reason, if the diagnosis is suspected, early involvement of the cardiologist and oncologist is important to help guide management. Most irAEs will be treated with glucocorticoids, but in the case of CAR T-cell cardiotoxicity, Tocilizumab should be used as first line.

CONCLUSION

Although cardiotoxicity is rare, it is often life-threatening. Treatment should be initiated as soon as the diagnosis is suspected, and early involvement of the cardiologist and oncologist is imperative for optimal treatment.

Immune Myocarditis Overlapping With Myasthenia Gravis Due to Anti-PD-1 Treatment for a Chordoma Patient: A Case Report and Literature Review

Immunotherapy begins to be widely used due to the increasing exploration and gratifying effects in multiple cancers. Chordoma, as a rare bone malignant tumor, often recurs and metastasizes after undergoing surgery and radiotherapy. Therefore, immunotherapy can be explored as an emerging, potentially effective treatment to improve the survival rate and clinical benefit of patients. However, a variety of immune-related adverse events (irAEs) cannot be avoided completely. And the immunotherapy-induced myocarditis, as a rare but fatal irAE, has been increasingly reported. Understanding the mechanism involved in irAEs can inform best practices for side effects management. Here, we firstly reported a case of immune myocarditis and subsequent myasthenia gravis (MG) following anti-PD-1 treatment for chordoma.

Clinical Strategy for the Diagnosis and Treatment of Immune Checkpoint Inhibitor-Associated Myocarditis: A Narrative Review

Importance

In the last decade, immune checkpoint inhibitors (ICIs) have been approved for the treatment of many cancer types. Immune checkpoint inhibitor-associated myocarditis has emerged as a significant and potentially fatal adverse effect. Recognizing, diagnosing, and treating ICI-associated myocarditis poses new challenges for the practicing clinician. Here, the current literature on ICI-associated myocarditis is reviewed.

Observations

Clinical presentation and cardiac pathological findings are highly variable in patients with ICI-associated myocarditis. Although endomyocardial biopsy is the criterion standard diagnostic test, a combination of clinical suspicion, cardiac biomarkers (specifically troponin), and cardiac imaging, in addition to biopsy, is often needed to support the diagnosis. Importantly, the combination of a cytotoxic T-lymphocyte-associated protein 4 inhibitor with a programmed cell death protein 1 or programmed death-ligand 1 inhibitor increases the risk of developing ICI-associated myocarditis.

Conclusion and Relevance

This review aims to provide a standardized diagnostic and therapeutic approach for patients with suspected ICI-associated myocarditis. A complete history of recent cancer treatments and physical examination in combination with cardiac biomarkers, cardiac imaging, and endomyocardial biopsy represent a pragmatic diagnostic approach for most cases of ICI-associated myocarditis. The addition of novel biomarkers or imaging modalities is an area of active research and should be evaluated in larger cohorts.

Diagnosis, treatment and predictors of prognosis of myocarditis. A narrative review

Although it has been recognized for almost two centuries, myocarditis is still a challenging diagnosis due to the wide heterogeneity of its clinical manifestations and evolution. Moreover, the diagnostic gold standard, endomyocardial biopsy (EMB), is infrequently used, making hard to determine the exact incidence of myocarditis. Clinical presentation includes a wide range of symptoms, ranging from asymptomatic or subclinical disease with mild dyspnea and chest pain to sudden death, due to cardiogenic shock or malignant ventricular arrhythmias. Equally, the evolution of myocarditis largely varies: albeit short-term prognosis is usually good, with complete or partial recovery, dilated cardiomyopathy with chronic heart failure is the major long-term consequence of myocarditis, developing often several years after the acute onset. This narrative review aims to summarize the current knowledge about myocarditis, with a particular attention to predictors of short- and long-term prognosis, in order to provide a rational and practical approach to the diagnosis, evaluation and treatment of suspected myocarditis.

Clinical characteristics, time course, treatment and outcomes of patients with immune checkpoint inhibitor-associated myocarditis

Background

Immune checkpoint inhibitors (ICI) have emerged as a front-line therapy for a variety of solid tumors. With the widespread use of these agents, immune-associated toxicities are increasingly being recognized, including fatal myocarditis. There are limited data on the outcomes and prognostic utility of biomarkers associated with ICI-associated myocarditis. Our objective was to examine the associations between clinical biomarkers of cardiomyocyte damage and mortality in patients with cancer treated with ICIs.

Methods

We retrospectively studied 23 patients who developed symptomatic and asymptomatic troponin elevations while receiving ICI therapy at a National Cancer Institute-designated comprehensive cancer center. We obtained serial ECGs, troponin I, and creatine kinase-MD (CK-MB), in addition to other conventional clinical biomarkers, and compared covariates between survivors and non-survivors.

Results

Among patients with myocarditis, higher troponin I (p=0.037) and CK-MB (p=0.034) levels on presentation correlated with progression to severe myocarditis. Higher troponin I (p=0.016), CK (p=0.013), and CK-MB (p=0.034) levels were associated with increased mortality, while the presence of advanced atrioventricular block on presentation (p=0.088) trended toward increased mortality. Weekly troponin monitoring lead to earlier hospitalization for potential myocarditis (p=0.022) and was associated with decreased time to steroid initiation (p=0.053) and improved outcomes.

Conclusions

Routine troponin surveillance may be helpful in predicting mortality in ICI-treated patients with cancer in the early phase of ICI therapy initiation. Early detection of troponin elevation is associated with earlier intervention and improved outcomes in ICI-associated myocarditis. The recommended assessment and diagnostic studies guiding treatment decisions are presented.

Immune checkpoint inhibitor myocarditis: elucidating the spectrum of disease through endomyocardial biopsy

AIMS

Although immune checkpoint inhibitor (ICI) myocarditis carries a high reported mortality, increasing reports of smoldering myocarditis suggest a clinical spectrum of disease. Endomyocardial biopsy (EMB) remains the gold standard for diagnosis of ICI myocarditis, but different pathologic diagnostic criteria exist. The objective of this study was to classify the spectrum of ICI myocarditis and myocardial inflammation by pathology findings on EMB and correlate this with clinical outcomes.

METHODS AND RESULTS

All patients who had EMB at MD Anderson Cancer Center between January 2018 and August 2019 for suspected ICI myocarditis were retrospectively reviewed. A grading system (Grades 0-2) based on the degree of inflammatory infiltrate was developed by pathologists. Cardiovascular outcomes and treatment were compared between grades of pathology. We identified 28 patients who had EMB for suspected ICI myocarditis, of which 18 were positive for myocarditis/inflammation. There were four deaths (two in Grade 2 and two in Grade 1), but only one was attributable to myocarditis. Grade 2 patients had no myocarditis-associated deaths despite having the highest troponin T values (median 2063 pg/mL). Four patients with Grade 1 myocardial inflammation continued ICI without any immunomodulation, and all were alive without adverse cardiovascular events at follow-up.

CONCLUSION

We defined an EMB grading system for ICI myocarditis encompassing a spectrum of histologic findings of inflammatory infiltrates. A subset of low-grade myocardial inflammation patients were able to continue ICI without immunosuppressive therapy. Further studies are needed to identify low-risk patients who can be safely treated with ICI.

Cardiovascular Complications Associated with Contemporary Lung Cancer Treatments

OPINION STATEMENT

Lung cancer is the most common form of cancer in humans and the leading cause of cancer-related death worldwide. Traditionally, lung cancer has been diagnosed as either small cell lung cancer (SCLC) or non-small cell lung cancer (NSCLC). However, recent developments in molecular pathology have revolutionized the diagnosis and treatment of the disease, thus improving patient prognosis and increasing the number of survivors. In advanced NSCLC cases, molecularly targeted drugs for patients with positive driver gene mutation/rearrangement, and immune checkpoint inhibitors for those with a positive biomarker, have changed the standard of care. SCLC is a highly malignant entity. In addition to the chemotherapy and radiotherapy, immune checkpoint inhibitors have recently provided some hope for extended-stage SCLC. Smoking cessation is related to decreased morbidity. However, early metastasis remains a significant challenge. Recently, cancer therapy-related cardiovascular disease (CTRCD) has emerged as diverse pathophysiology, including fulminant myocarditis, fatal arrhythmia, pericarditis, hypertension, and thrombosis, that emerged with modern lung cancer therapies. Cardio-oncology is a new interdisciplinary collaboration to develop methodologies to manage cardiovascular risk factors and CTRCDs with the common goal of minimizing unnecessary interruption of cancer treatment and maximizing outcomes of lung cancer survivors.

Potential Gene Association Studies of Chemotherapy-Induced Cardiotoxicity: A Systematic Review and Meta-Analysis

Chemotherapy is widely used in the treatment of cancer patients, but the cardiotoxicity induced by chemotherapy is still a major concern to most clinicians. Currently, genetic methods have been used to detect patients with high risk of chemotherapy-induced cardiotoxicity (CIC), and our study evaluated the correlation between genomic variants and CIC. The systematic literature search was performed in the PubMed, Cochrane Central Register of Controlled Trials (CENTRAL), China Biology Medicine disc (CBMdisc), the Embase database, China National Knowledge Internet (CNKI) and Wanfang database from inception until June 2020. Forty-one studies were identified that examined the relationship between genetic variations and CIC. And these studies examined 88 different genes and 154 single nucleotide polymorphisms (SNPs). Our study indicated 6 variants obviously associated with the increased risk for CIC, including CYBA rs4673 (pooled odds ratio, 1.93; 95% CI, 1.13–3.30), RAC2 rs13058338 (2.05; 1.11–3.78), CYP3A5 rs776746 (2.15; 1.00–4.62) ABCC1 rs45511401 (1.46; 1.05–2.01), ABCC2 rs8187710 (2.19; 1.38–3.48), and HER2-Ile655Val rs1136201 (2.48; 1.53–4.02). Although further studies are required to validate the diagnostic and prognostic roles of these 6 variants in predicting CIC, our study emphasizes the promising benefits of pharmacogenomic screening before chemotherapy to minimize the CIC.

Mogamulizumab-Associated Acute Myocarditis in a Patient With T-Cell Lymphoma

A 62-year-old woman with human T-lymphotropic virus type 1 cell lymphoma developed heart failure after mogamulizumab, an immunotherapy agent. Clinical presentation and cardiac magnetic resonance imaging were consistent with myocarditis, and a recurrence of heart failure occurred after rechallenge with the therapy. (Level of Difficulty: Advanced.).

Cancer Therapeutics-related Cardiac Dysfunction in Patients Treated With Immune Checkpoint Inhibitors: An Understudied Manifestation

The widespread use of immune checkpoint inhibitors (ICI) has become a mainstay of care for a variety of malignancies. However, these therapies portend a range of adverse effects, including a potentially fatal form of cardiotoxicity which to date has not been elucidated. We aimed to evaluate the baseline characteristics of ICI-mediated cardiotoxicity. We performed a retrospective study evaluating patients treated with ICI who performed at least 2 echocardiography examinations, before and after the initiation of ICI. Cardiotoxicity was defined as Cancer Therapeutics-related Cardiac Dysfunction (CTRCD) development, with an absolute left ventricular ejection fraction reduction of >10%, to a value <53%. Fifty-two patients were included with a male preponderance (65%) and a mean age of 66 (±12) years. Twelve (23%) patients developed CTRCD, of which 2 patients were diagnosed with myocarditis. Among the CTRCD group, patients tended to be older and more likely to have baseline diastolic dysfunction: lower e' septal (P=0.026), higher E/e' septal (P=0.035), and a trend of E/e' average (P=0.076). All-cause and cardiovascular hospitalizations were significantly more common among the CTRCD group (P=0.028 and 0.001, respectively). Higher prevalence of cardiovascular mortality was observed among the CTRCD group (25% vs. 2%, P=0.034). We evaluated the development of CTRCD among patients treated with ICI therapies. Our findings suggest that baseline diastolic parameters may be associated with CTRCD development assisting in the early diagnosis of ICI-induced cardiac injury.

A retrospective analysis of cardiovascular adverse events associated with immune checkpoint inhibitors

Background

Modern therapies in oncology have increased cancer survivorship, as well as the incidence of cardiovascular adverse events. While immune checkpoint inhibitors have shown significant clinical impact in several cancer types, the incidence of immune-related cardiovascular (CV) adverse events poses an additional health concern and has been reported.

Methods

We performed a retrospective analysis of the FDA Adverse Event Reporting System data of suspect product reports for immunotherapy and classical chemotherapy from January 2010–March 2020. We identified 90,740 total adverse event reports related to immune checkpoint inhibitors and classical chemotherapy.

Results

We found that myocarditis was significantly associated with patients receiving anti-program cell death protein 1 (PD-1) or anti-program death ligand 1 (PD-L1), odds ratio (OR) = 23.86 (95% confidence interval [CI] 11.76–48.42, (adjusted p-value) q <  0.001), and combination immunotherapy, OR = 7.29 (95% CI 1.03–51.89, q = 0.047). Heart failure was significantly associated in chemotherapy compared to PD-(L)1, OR = 0.50 (95% CI 0.37–0.69, q <  0.001), CTLA4, OR = 0.08 (95% CI 0.03–0.20, q <  0.001), and combination immunotherapy, OR = 0.25 (95% CI 0.13–0.48, q <  0.001). Additionally, we observe a sex-specificity towards males in cardiac adverse reports for arrhythmias, OR = 0.81 (95% CI 0.75–0.87, q <  0.001), coronary artery disease, 0.63 (95% CI 0.53–0.76, q <  0.001), myocardial infarction, OR = 0.60 (95% CI 0.53–0.67, q <  0.001), myocarditis, OR = 0.59 (95% CI 0.47–0.75, q <  0.001) and pericarditis, OR = 0.5 (95% CI 0.35–0.73, q <  0.001).

Conclusion

Our study provides the current risk estimates of cardiac adverse events in patients treated with immunotherapy compared to conventional chemotherapy. Understanding the clinical risk factors that predispose immunotherapy-treated cancer patients to often fatal CV adverse events will be crucial in Cardio-Oncology management.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40959-021-00106-x.

What the Cardiologist Needs to Know About Cancer Immunotherapies and Complications

OPINION STATEMENT

Immunotherapies have transformed the current landscape for cancer treatment and demonstrated unparalleled improvements in survival rates. Now, a third of cancer patients are eligible for treatment with the most widely used class of immunotherapy, immune checkpoint inhibitors (ICIs). As more patients are treated with these novel agents, it is critical for both oncologists and subspecialists to establish a better understanding of the adverse events which can occur. The incidence of myocarditis associated with ICI therapy has been reported to be between 0.27 and 1.14%, 5 times that of myocarditis from other cancer therapies, and, of those patients, 20-50% develop a fulminant form. However, because of unclear risk factors, a broad clinical spectrum, and lack of specific noninvasive studies for diagnosis, the care of patients with ICI-associated cardiotoxicity can be challenging. Here, we have provided a brief overview of the current immunotherapy agents with a focus on the emerging evidence regarding diagnosis and management of cardiac adverse events.

An Emergent Form of Cardiotoxicity: Acute Myocarditis Induced by Immune Checkpoint Inhibitors

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies that activate the immune system, aiming at enhancing antitumor immunity. ICIs have shown great promise in the treatment of several advanced malignancies. However, therapy with these immunomodulatory antibodies may lead to a wide spectrum of immune-related adverse events in any organ and any tissue. Cardiologic immune-related events include pericarditis, pericardial effusion, various types of arrhythmias including the occurrence of complete atrioventricular block, myocardial infarction, heart failure, and myocarditis. Although relatively rare, myocarditis is associated with a very high reported mortality in comparison to other adverse events. Myocarditis often presents significant diagnostic complexity and may be under-recognized. When confronted with an unexpected change in the clinical picture, the physician must differentiate between immune-related adverse events, cancer worsening, or other causes unrelated to the cancer or its therapy. However, this is not always easy. Therefore, with the increasing use of checkpoint inhibitors in cancer, all providers who care for patients with cancer should be made aware of this rare, but potentially fatal, cardiologic immune-related adverse event, and able to recognize when prompt consultation with a cardiologist specialist is indicated. In this review, we evaluate currently available scientific evidence and discuss clinical manifestations and new potential approaches to the diagnosis and therapy of acute myocarditis induced by ICIs. Temporary or permanent discontinuation of the ICIs and high-dose steroids have been administered to treat myocarditis, but symptoms may worsen in some patients despite therapy.

Comparative Transcriptomics of Immune Checkpoint Inhibitor Myocarditis Identifies Guanylate Binding Protein 5 and 6 Dysregulation

Immune checkpoint inhibitors (ICIs) are revolutionizing cancer treatment. Nevertheless, their increasing use leads to an increase of immune-related adverse events (irAEs). Among them, ICI-associated myocarditis (ICIM) is a rare irAE with a high mortality rate. We aimed to characterize the transcriptional changes of ICIM myocardial biopsies and their possible implications. Patients suspected for ICIM were assessed in the cardio-oncology units of University Hospitals Heidelberg and Kiel. Via RNA sequencing of myocardial biopsies, we compared transcriptional changes of ICIM (n = 9) with samples from dilated cardiomyopathy (DCM, n = 11), virus-induced myocarditis (VIM, n = 5), and with samples of patients receiving ICIs without any evidence of myocarditis (n = 4). Patients with ICIM (n = 19) showed an inconsistent clinical presentation, e.g., asymptomatic elevation of cardiac biomarkers (hs-cTnT, NT-proBNP, CK), a drop in left ventricular ejection fraction, or late gadolinium enhancement in cMRI. We found 3784 upregulated genes in ICIM (FDR < 0.05). In the overrepresented pathway 'response to interferon-gamma', we found guanylate binding protein 5 and 6 (compared with VIM: GBP5 (log2 fc 3.21), GBP6 (log2 fc 5.37)) to be significantly increased in ICIM on RNA- and protein-level. We conclude that interferon-gamma and inflammasome-regulating proteins, such as GBP5, may be of unrecognized significance in the pathophysiology of ICIM.

Classification, prevalence, and outcomes of anticancer therapy-induced cardiotoxicity: the CARDIOTOX registry

AIM

Cardiotoxicity (CTox) is a major side effect of cancer therapies, but uniform diagnostic criteria to guide clinical and research practices are lacking.

METHODS AND RESULTS

We prospectively studied 865 patients, aged 54.7 ± 13.9; 16.3% men, scheduled for anticancer therapy related with moderate/high CTox risk. Four groups of progressive myocardial damage/dysfunction were considered according to current guidelines: normal, normal biomarkers (high-sensitivity troponin T and N-terminal natriuretic pro-peptide), and left ventricular (LV) function; mild, abnormal biomarkers, and/or LV dysfunction (LVD) maintaining an LV ejection fraction (LVEF) ≥50%; moderate, LVD with LVEF 40-49%; and severe, LVD with LVEF ≤40% or symptomatic heart failure. Cardiotoxicity was defined as new or worsening of myocardial damage/ventricular function from baseline during follow-up. Patients were followed for a median of 24 months. Cardiotoxicity was identified in 37.5% patients during follow-up [95% confidence interval (CI) 34.22-40.8%], 31.6% with mild, 2.8% moderate, and 3.1% with severe myocardial damage/dysfunction. The mortality rate in the severe CTox group was 22.9 deaths per 100 patients-year vs. 2.3 deaths per 100 patients-year in the rest of groups, hazard ratio of 10.2 (95% CI 5.5-19.2) (P < 0.001).

CONCLUSIONS

The majority of patients present objective data of myocardial injury/dysfunction during or after cancer therapy. Nevertheless, severe CTox, with a strong prognostic relationship, was comparatively rare. This should be reflected in protocols for clinical and research practices.

Role of Cardiac Imaging in the Diagnosis of Immune Checkpoints Inhibitors Related Myocarditis

Immune checkpoint inhibitors (ICI) have constituted a paradigm shift in the management of patients with cancer. Their administration is associated with a new spectrum of immune-related toxicities that can affect any organ. In patients treated with ICI, cardiovascular toxicities, particularly myocarditis, occur with a low incidence (<1%) but with a high fatality rate (30-50%). ICI-related myocarditis has been attributed to an immune infiltration, comprising of T-cells that are positive for CD3+, CD4+, CD8+, and macrophages that are positive for CD68. The diagnosis remains challenging and is made based on clinical syndrome, an electrocardiogram (ECG), biomarker data, and imaging criteria. In most clinical scenarios, endomyocardial biopsy plays a pivotal role in diagnosis, while cardiac magnetic resonance imaging (cMRI) has limitations that should be acknowledged. In this review, we discuss the role of medical imaging in optimizing the management of ICI related myocarditis, including diagnosis, prognostication, and treatment decisions.

Role of cardiovascular magnetic resonance in early detection and treatment of cardiac dysfunction in oncology patients

The purpose of this review is to provide an overview of the essential role that cardiovascular magnetic resonance (CMR) has in the field of cardio-oncology. Recent findings: CMR has been increasingly used for early identification of cancer therapy related cardiac dysfunction (CTRCD) due to its precision in detecting subtle changes in cardiac function and for myocardial tissue characterization. Summary: CMR is able to identify subclinical CTRCD in patients receiving potentially cardiotoxic chemotherapy and guide initiation of cardio protective therapy. Multiparametric analysis with myocardial strain, tissue characterization play a critical role in understanding important clinical questions in cardio-oncology.

Cardiovascular Care of the Oncology Patient During COVID-19: An Expert Consensus Document From the ACC Cardio-Oncology and Imaging Councils

In response to the coronavirus disease 2019 (COVID-19) pandemic, the Cardio-Oncology and Imaging Councils of the American College of Cardiology offers recommendations to clinicians regarding the cardiovascular care of cardio-oncology patients in this expert consensus statement. Cardio-oncology patients-individuals with an active or prior cancer history and with or at risk of cardiovascular disease-are a rapidly growing population who are at increased risk of infection, and experiencing severe and/or lethal complications by COVID-19. Recommendations for optimizing screening and monitoring visits to detect cardiac dysfunction are discussed. In addition, judicious use of multimodality imaging and biomarkers are proposed to identify myocardial, valvular, vascular, and pericardial involvement in cancer patients. The difficulties of diagnosing the etiology of cardiovascular complications in patients with cancer and COVID-19 are outlined, along with weighing the advantages against risks of exposure, with the modification of existing cardiovascular treatments and cardiotoxicity surveillance in patients with cancer during the COVID-19 pandemic.

Circulating Biomarkers for Cardiotoxicity Risk Prediction

OPINION STATEMENT

Improvements in cancer survival have led to the emergence of cardiovascular disease as an important determinant of adverse outcome in survivors. Cancer therapeutics-related cardiac dysfunction is the most well-known form of cardiotoxicity. However, newer cancer therapies bring a broader range of cardiotoxicities. The optimal method to identify patients at risk of these complications is unclear, but circulating biomarkers comprise one possible approach. Troponins and natriuretic peptides have garnered the broadest evidence base for cardiotoxicity risk prediction, but other markers are being investigated. In this review, we explore evidence for circulating biomarkers in cardiotoxicity prediction associated with cancer therapies.

Mechanisms and Management of Immune Checkpoint Inhibitor-Related Cardiac Adverse Events

Onco-cardiology recently emerged as a novel discipline to provide effective cardioprotective care against cancer therapeutics-related cardiac adverse events (CAEs) and support the continuity of optimal cancer treatment. Immune checkpoint inhibitors (ICIs) have revolutionized cancer therapy and dramatically improved outcomes in patients with advanced or refractory cancers. However, ICIs intrinsically stimulate systemic immune responses and can potentially induce a spectrum of immune-related adverse events (irAEs), which can affect any organs of the body. The manifestation of cardiac irAEs includes myocarditis, arrhythmias and conduction abnormalities, and pericardial diseases. Takotsubo-like cardiomyopathy is also included as a manifestation of ICI-related CAEs, but the pathophysiological relevance is unclear. Although the incidence is rare, ICI-related CAEs are life-threatening and potentially fatal. Elucidating pathophysiology and establishing management measures of ICI-related CAEs are one of the most urgent challenges in the field of onco-cardiology.

Paraneoplastic Neurological Syndromes and Beyond Emerging With the Introduction of Immune Checkpoint Inhibitor Cancer Immunotherapy

Paraneoplastic neurological syndromes are more commonly seen with malignancies such as small cell lung cancer, thymoma, gynecological malignancies, and breast cancer as well as seminoma. With the introduction of immune checkpoint inhibitor (ICI) cancer immunotherapy we see an increase of autoimmune neurological complications in patients with malignancies not traditionally associated with paraneoplastic neurological syndromes, such as melanoma and renal cell carcinoma. Immune checkpoint inhibitors enhance antitumor immune responses resulting often in immune-related adverse effects that can affect any organ, including the central and peripheral nervous system, neuromuscular junction and muscle. Neurological complications are rare; neuromuscular complications are more common than central nervous system ones but multifocal neurological presentations are often encountered. The vast majority of neurological complications appear within 3 months of ICI initiation, but have been described even after ICI cessation. Neural autoantibody testing reveals autoantibodies in approximately half of the patients with CNS complications. Early suspicion and diagnosis is critical to avoid worsening and improve outcomes. Therapeutic strategies depend on the severity of the symptoms and initially typically involve discontinuation of ICI and high dose steroids. Further immunosuppression might be necessary. Outcomes are dependent on patient's characteristics and clinical presentations.

Temporal Relation Between Second Dose BNT162b2 mRNA Covid-19 Vaccine and Cardiac involvement in a Patient with Previous SARS-COV-2 Infection

The Publisher regrets that this article is an accidental duplication of an article that has already been published, https://doi.org/10.1016/j.ijcha.2021.100774 . The duplicate article has therefore been withdrawn.

The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal

Inflammatory Myositis in Cancer Patients Receiving Immune Checkpoint Inhibitors

OBJECTIVE

To estimate the incidence of immune checkpoint inhibitor-related myositis (ICI-myositis) in cancer patients receiving ICIs, and to report associated clinical manifestations, patterns of care, and outcomes.

METHODS

We identified a retrospective cohort of patients receiving ICIs between 2016 and 2019 seen at the University of Texas MD Anderson Cancer Center. Cases of ICI-myositis were identified using International Classification of Disease codes and confirmed by reviewing medical records and pathology, as available.

RESULTS

A total of 9,088 patients received an ICI. Thirty-six patients (0.40%) were identified as having ICI-myositis: 17 patients (47%) with ICI-myositis alone and 19 (53%) with overlap manifestations (5 patients with myocarditis, 5 with myasthenia gravis, and 9 with both). The incidence of ICI-myositis was 0.31% in those receiving ICI monotherapy and 0.94% in those receiving combination ICI therapy (relative risk 3.1 [95% confidence interval 1.5-6.1]). Twenty-five patients (69%) received ≥1 treatment in addition to glucocorticoids: plasmapheresis in 17 patients (47%), intravenous immunoglobulin in 12 (33%), and biologics in 11 (31%). Patients with overlap conditions had worse outcomes than those with myositis alone, and 79% of them developed respiratory failure. Eight patients died as a result of ICI-myositis, and all had overlap syndrome with myasthenia gravis or myocarditis (P < 0.05); 75% of these patients had a concomitant infection.

CONCLUSION

ICI-myositis is a rare but severe adverse event. More than half of the patients presented with overlap manifestations and had deleterious outcomes, including respiratory failure and death. None of the patients with ICI-myositis alone died as a result of adverse events. Optimal treatment strategies have yet to be determined.

CYP1B1 as a therapeutic target in cardio-oncology

Cardiovascular complications have been frequently reported in cancer patients and survivors, mainly because of various cardiotoxic cancer treatments. Despite the known cardiovascular toxic effects of these treatments, they are still clinically used because of their effectiveness as anti-cancer agents. In this review, we discuss the growing body of evidence suggesting that inhibition of the cytochrome P450 1B1 enzyme (CYP1B1) can be a promising therapeutic strategy that has the potential to prevent cancer treatment-induced cardiovascular complications without reducing their anti-cancer effects. CYP1B1 is an extrahepatic enzyme that is expressed in cardiovascular tissues and overexpressed in different types of cancers. A growing body of evidence is demonstrating a detrimental role of CYP1B1 in both cardiovascular diseases and cancer, via perturbed metabolism of endogenous compounds, production of carcinogenic metabolites, DNA adduct formation, and generation of reactive oxygen species (ROS). Several chemotherapeutic agents have been shown to induce CYP1B1 in cardiovascular and cancer cells, possibly via activating the Aryl hydrocarbon Receptor (AhR), ROS generation, and inflammatory cytokines. Induction of CYP1B1 is detrimental in many ways. First, it can induce or exacerbate cancer treatment-induced cardiovascular complications. Second, it may lead to significant chemo/radio-resistance, undermining both the safety and effectiveness of cancer treatments. Therefore, numerous preclinical studies demonstrate that inhibition of CYP1B1 protects against chemotherapy-induced cardiotoxicity and prevents chemo- and radio-resistance. Most of these studies have utilized phytochemicals to inhibit CYP1B1. Since phytochemicals have multiple targets, future studies are needed to discern the specific contribution of CYP1B1 to the cardioprotective and chemo/radio-sensitizing effects of these phytochemicals.

Mechanisms and clinical manifestations of cardiovascular toxicities associated with immune checkpoint inhibitors

Immunotherapies have greatly expanded the armamentarium of cancer-directed therapies in the past decade, allowing the immune system to recognize and fight cancer. Immune checkpoint inhibitors (ICIs), in particular, have revolutionized cancer treatment and have demonstrated survival benefit in numerous types of cancer. These monoclonal antibodies increase anti-cancer immunity by blocking down-regulators of adaptive immunity, including cytotoxic T lymphocyte-associated protein 4 (CTLA-4), programmed cell death protein 1 (PD-1), and its ligand (PD-L1), resulting in anti-tumor activity. As ICIs increase immune system activation, they can cause a wide range of inflammatory side effects, termed immune-released adverse events. Though these toxicities can affect nearly any organ, the most fatal toxicity is myocarditis. Here, we discuss the diverse spectrum of cardiovascular toxicities associated with ICI use. In addition, we provide insight and future directions on mechanisms and treatments for immune-related adverse events (irAEs) involving the myocardium, pericardium, vasculature, and conduction system.

Human induced pluripotent stem cell (iPSC)-derived cardiomyocytes as an in vitro model in toxicology: strengths and weaknesses for hazard identification and risk characterization

INTRODUCTION

Human induced pluripotent stem cell (iPSC)-derived cardiomyocytes is one of the most widely used cell-based models that resulted from the discovery of how non-embryonic stem cells can be differentiated into multiple cell types. In just one decade, iPSC-derived cardiomyocytes went from a research lab to widespread use in biomedical research and preclinical safety evaluation for drugs and other chemicals.

AREAS COVERED

This manuscript reviews data on toxicology applications of human iPSC-derived cardiomyocytes. We detail the outcome of a systematic literature search on their use (i) in hazard assessment for cardiotoxicity liabilities, (ii) for risk characterization, (iii) as models for population variability, and (iv) in studies of personalized medicine and disease.

EXPERT OPINION

iPSC-derived cardiomyocytes are useful to increase the accuracy, precision, and efficiency of cardiotoxicity hazard identification for both drugs and non-pharmaceuticals, with recent efforts beginning to demonstrate their utility for risk characterization. Notable limitations include the needs to improve the maturation of cells in culture, to better understand their potential use identifying structural cardiotoxicity, and for additional case studies involving population-wide and disease-specific risk characterization. Ultimately, the greatest future benefits are likely for non-pharmaceutical chemicals, filling a critical gap where no routine testing for cardiotoxicity is currently performed.

Concepts in cardiac oncology

Cardiac oncology is a subspecialty of cardiology engaging cardiologists and oncologists alike, in order to provide the best possible oncologic treatment for patients at high cardiovascular risk or developing cardio-toxicity during the course of their treatment, thus avoiding discontinuing it, and aiming at improving survival and quality of life. Early diagnosis and the effectiveness of the newer cancer treatments delivered an increasing number of long-term survivors (presently almost 30 million worldwide), at high risk of developing cardiovascular diseases. This predisposition has been correlated not only to the toxic side effects of the oncologic treatment but also to a real vulnerability to the risk factors in this patients population. For decades, the concept of cardio-toxicity in cardiac oncology has been restricted to ventricular dysfunction, but during the last few years the Food and Drug Administration has approved hundreds of new molecules and cardiac oncology has escalated its complexity. The introduction of new target therapy, proteasome inhibitors, immuno-modulators, and inhibitors of the immunitary checkpoint, magnified the concept of cardio-toxicity to a wider definition of ‘cardiovascular toxicity’ incorporating arterial hypertension, ischaemia, cardiomyopathy, myocarditis, arrhythmic complications, long QT, and arterial and venous thrombosis. We are still lacking guidelines on the new and varied forms of toxicity, as well as monitoring strategies in the short- and long-term follow-up.

Myocardial T1 and T2 Mapping by Magnetic Resonance in Patients With Immune Checkpoint Inhibitor-Associated Myocarditis

BACKGROUND

Myocarditis is a potentially fatal complication of immune checkpoint inhibitor (ICI) therapy. Data on the utility of cardiovascular magnetic resonance (CMR) T1 and T2 mapping in ICI myocarditis are limited.

OBJECTIVES

This study sought to assess the value of CMR T1 and T2 mapping in patients with ICI myocarditis.

METHODS

In this retrospective study from an international registry of patients with ICI myocarditis, clinical and CMR findings (including T1 and T2 maps) were collected. Abnormal T1 and T2 were defined as 2 SD above site (vendor/field strength specific) reference values and a z-score was calculated for each patient. Major adverse cardiovascular events (MACE) were a composite of cardiovascular death, cardiogenic shock, cardiac arrest, and complete heart block.

RESULTS

Of 136 patients with ICI myocarditis with a CMR, 86 (63%) had T1 maps and 79 (58%) also had T2 maps. Among the 86 patients (66.3 ± 13.1 years of age), 36 (41.9%) had a left ventricular ejection fraction <55%. Across all patients, mean z-scores for T1 and T2 values were 2.9 ± 1.9 (p < 0.001) and 2.2 ± 2.1 (p < 0.001), respectively. On Siemens 1.5-T scanner (n = 67), native T1 (1,079.0 ± 55.5 ms vs. 1,000.3 ± 22.1 ms; p < 0.001) and T2 (56.2 ± 4.9 ms vs. 49.8 ± 2.2 ms; p < 0.001) values were elevated compared with reference values. Abnormal T1 and T2 values were seen in 78% and 43% of the patients, respectively. Applying the modified Lake Louise Criteria, 95% met the nonischemic myocardial injury criteria and 53% met the myocardial edema criteria. Native T1 values had excellent discriminatory value for subsequent MACE, with an area under the curve of 0.91 (95% confidence interval: 0.84 to 0.98). Native T1 values (for every 1-unit increase in z-score, hazard ratio: 1.44; 95% confidence interval: 1.12 to 1.84; p = 0.004) but not T2 values were independently associated with subsequent MACE.

CONCLUSIONS

The use of T1 mapping and application of the modified Lake Louise Criteria provides important diagnostic value, and T1 mapping provides prognostic value in patients with ICI myocarditis.

The Evolving Immunotherapy Landscape and the Epidemiology, Diagnosis, and Management of Cardiotoxicity: JACC: CardioOncology Primer

Immune checkpoint inhibitors (ICIs) are newer therapies being applied to an increasing number of patients with cancer. Data suggest that up to 36% of cancer patients may be eligible for immunotherapy and, in late 2019, there were more than 3,362 clinical trials initiated to evaluate the effectiveness of immunotherapy, either as single agents or in combination with other immunotherapy, targeted therapies, or traditional cytotoxic or radiation therapy. With the combination of both immune and non-immune treatment approaches, the complexity in making the diagnosis of cardiotoxicity related to an ICI will increase substantially. Here, we summarize the published data on the epidemiology, diagnosis, and management of cardiotoxicity of ICIs. This is a rapidly evolving field, and as our understanding continues to evolve, previously considered hypotheses may not prove to be entirely correct. Research and continued collaborations are urgently needed to provide evidence-based cardiovascular care for this rapidly expanding and vulnerable cohort of patients. (J Am Coll Cardiol CardioOnc 2021;3:35-47) © 2021 The Authors. Published by Elsevier on behalf of the American College of Cardiology Foundation. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Immune checkpoint inhibitor-associated myocarditis: manifestations and mechanisms

Immune checkpoint inhibitors (ICIs) have transformed the treatment of various cancers, including malignancies once considered untreatable. These agents, however, are associated with inflammation and tissue damage in multiple organs. Myocarditis has emerged as a serious ICI-associated toxicity, because, while seemingly infrequent, it is often fulminant and lethal. The underlying basis of ICI-associated myocarditis is not completely understood. While the importance of T cells is clear, the inciting antigens, why they are recognized, and the mechanisms leading to cardiac cell injury remain poorly characterized. These issues underscore the need for basic and clinical studies to define pathogenesis, identify predictive biomarkers, improve diagnostic strategies, and develop effective treatments. An improved understanding of ICI-associated myocarditis will provide insights into the equilibrium between the immune and cardiovascular systems.

Early Detection of Checkpoint Inhibitor-Associated Myocarditis Using 68Ga-FAPI PET/CT

Objective: Checkpoint inhibitors (ICIs) have gained importance in recent years regarding the treatment of a variety of oncologic diseases. The possibilities of diagnosing cardiac adverse autoimmune effects of ICIs are still limited. We aimed to implement FAPI PET/CT imaging in detecting ICI-associated myocarditis.

Methods: In a retrospective study, FAPI PET/CT scans of 26 patients who received ICIs from 01/2017 to 10/2019 were analyzed. We compared tracer enrichment in the heart of patients without any signs of a cardiac disease (n = 23) to three patients with suspected ICI-associated myocarditis. To exclude any significant coronary heart disease, cardiac catherization was performed. All three patients' myocardial biopsies were examined for inflammatory cells.

Results: Three patients showed clinical manifestations of an ICI syndrome including myocarditis with elevated levels of hsTnT (175 pg/ml, 1,771 pg/ml, 157 pg/ml). Further cardiological assessments revealed ECG abnormalities, lymphocyte infiltration of the myocardium in the biopsies or wall motion abnormalities in echocardiography. These patients' FAPI PET/CTs showed cardiac enrichment of the marker which was less distinct or absent in patients receiving ICIs without any signs of immunological adverse effects or cardiac impairment (n = 23) [Median SUV myocarditis patients: 1.79 (IQR: 1.65, 1.85), median SUV non-myocarditis patients: 1.15 (IQR: 0.955, 1.52)].

Conclusions: Apart from the successful implementation of ICIs in oncological treatments, ICI-associated myocarditis is still a challenging adverse effect. FAPI PET/CT may be used in order to identify affected patients at an early stage. Moreover, when integrated into cancer stage diagnostics, it contributes to cardiac risk stratification besides biomarker, ECG and echocardiography.

Left ventricular myocardial strain and tissue characterization by cardiac magnetic resonance imaging in immune checkpoint inhibitor associated cardiotoxicity

Background

Immune checkpoint inhibitors (ICIs) are highly effective in treating cancer; however, cardiotoxicity can occur, including myocarditis. Cardiac magnetic resonance (CMR) imaging is useful for evaluation of myocarditis, although it has not been well studied in ICI cardiotoxicity.

Methods

We identified patients referred for CMR evaluation of ICI cardiotoxicity from September 2015 through September 2019. We assessed structural and functional parameters, feature tracking (FT) left ventricular and atrial strain, T2- weighted ratios and quantitative late gadolinium enhancement (LGE). We also applied the Updated Lake Louise Criteria for diagnosis of myocarditis.

Results

Of the 20 patients referred, the median left ventricular ejection fraction (LVEF) was 52.5% ± 19.1 and 50% had a normal LVEF (≥53%). FT strain analysis revealed an average abnormal global longitudinal strain (GLS) of −9.8%± 4.2%. In patients with a normal LVEF, the average GLS remained depressed at −12.3%± 2.4%. In all patients, GLS demonstrated a significant negative correlation with LVEF (r_s = −0.64, p 0.002). Sixteen patients (80%) had presence of LGE (14 non-ischemic pattern and 2 ischemic). Percent LGE did not correlate with any CMR parameters and notably did not correlate with LVEF (r_s = −0.29, p = 0.22) or GLS (r_s = 0.10, p = 0.67), highlighting the value of tissue characterization beyond functional assessment. Nine patients (45%) met full Updated Lake Louise Criteria and 85% met at least one criterion, suggestive of myocarditis in the correct clinical context. Thirteen patients (65%) were treated for ICI-associated myocarditis and, of these, 54% (n = 7) had recovery of LVEF to normal. There was no correlation between LVEF (p = 0.47), GLS (0.89), or % LGE (0.15) and recovery of LVEF with treatment.

Conclusion

In patients with suspected ICI cardiotoxicity, CMR is an important diagnostic tool, even in the absence of overt left ventricular dysfunction, as abnormalities in left ventricular strain, T2 signal and LGE can identifying disease.

Asymptomatic Immune Checkpoint Inhibitor-associated Myocarditis

We herein report the case of a 75-year-old man with asymptomatic immune checkpoint inhibitor (ICI)-associated myocarditis diagnosed on the basis of elevated levels of creatine kinase (CK), CK-myocardial band and troponin I (TNI). He was suspected of being complicated with myasthenia gravis (MG). High-dose prednisolone (PSL) is associated with a risk of MG exacerbation; therefore, PSL therapy was gradually increased from 5 mg/day to 20 mg/day, which resulted in the normalization of the TNI level, and no PSL-related side effects occurred. MG easily complicates myocarditis as an immune-related adverse event; thus, the treatment plan should be carefully considered.

The Cytokine Expression in Patients with Cardiac Complication after Immune Checkpoint Inhibitor Therapy

We herein report the cytokine expression at different stages for three patients who developed cardiac complications after immune checkpoint inhibitor (ICI) therapy. Case 1 with biopsy-proven myocarditis showed increased levels of interleukin (IL)-8, monocyte chemotactic and activating factor, and granulocyte macrophage colony-stimulating factor (GM-CSF) when he developed Takotsubo cardiomyopathy. Case 2 with subclinical myocarditis showed predominant activation of IL-8 during the progressive clinical course. Case 3 with cytokine-releasing syndrome showed substantial activations of IL-6, IL-8, GM-CSF, and interferon-γ. Our data suggest the development of unique cytokine activation in individual patients with cardiac complications after ICI therapy.