Immune Checkpoint Inhibitor Cardiotoxicity: Understanding Basic Mechanisms and Clinical Characteristics and Finding a Cure

Insight of immune checkpoint inhibitor related myocarditis

As the understanding of immune-related mechanisms in the development and progression of cancer advances, immunotherapies, notably Immune Checkpoint Inhibitors (ICIs), have become integral in comprehensive cancer treatment strategies. ICIs reactivate T-cell cytotoxicity against tumors by blocking immune suppressive signals on T cells, such as Programmed Death-1 (PD-1) and Cytotoxic T-lymphocyte Antigen-4 (CTLA-4). Despite their beneficial effects, ICIs are associated with immune-related adverse events (irAEs), manifesting as autoimmune side effects across various organ systems. A particularly alarming irAE is life-threatening myocarditis. This rare but severe side effect of ICIs leads to significant long-term cardiac complications, including arrhythmias and heart failure, and has been observed to have a mortality rate of up to 50% in affected patients. This greatly limits the clinical application of ICI-based immunotherapy. In this review, we provide a comprehensive summary of the current knowledge regarding the diagnosis and management of ICI-related myocarditis. We also discuss the utility of preclinical mouse models in understanding and addressing this critical challenge.

Changes in tumor and cardiac metabolism upon immune checkpoint

Cardiovascular disease and cancer are the leading causes of death in the Western world. The associated risk factors are increased by smoking, hypertension, diabetes, sedentary lifestyle, aging, unbalanced diet, and alcohol consumption. Therefore, the study of cellular metabolism has become of increasing importance, with current research focusing on the alterations and adjustments of the metabolism of cancer patients. This may also affect the efficacy and tolerability of anti-cancer therapies such as immune-checkpoint inhibition (ICI). This review will focus on metabolic adaptations and their consequences for various cell types, including cancer cells, cardiac myocytes, and immune cells. Focusing on ICI, we illustrate how anti-cancer therapies interact with metabolism. In addition to the desired tumor response, we highlight that ICI can also lead to a variety of side effects that may impact metabolism or vice versa. With regard to the cardiovascular system, ICI-induced cardiotoxicity is increasingly recognized as one of the most life-threatening adverse events with a mortality of up to 50%. As such, significant efforts are being made to assess the specific interactions and associated metabolic changes associated with ICIs to improve both efficacy and management of side effects.

Atrioventricular Block in the Setting of Immune Myocarditis: A Pragmatic Approach to Diagnosis and Treatment

Immunotherapy has revolutionized cancer treatment in the last decade and has significantly improved patient survival. However, immunotherapy is associated with serious cardiac adverse events including myocarditis and conduction disturbances. In the literature, the mortality rate in patients with immunotherapy-associated myocarditis and complete AV block is reported to be approximately 60%. Current cardio-oncology guidelines provide a series of recommendations for the management of immune myocarditis (IM). However, there is no recommendation on whether or when pacemaker implantation should be performed in the setting of complete AV block associated with myocarditis. This gap in the literature has led to a trend in cardio-oncology practice to implant permanent pacemakers (PPMs) in a significant proportion of patients without waiting for a response to immunosuppressive therapy. However, in a significant proportion of patients undergoing PPM implantation, complete AV block resolves after immunosuppressive therapy. This suggests that in cases of complete AV block in the setting of IM, more robust clues are needed for PPM implantation. This review aims to present algorithms for the management of myocarditis and complete AV block, one of the most lethal complications of immunotherapy, to help fill this gap in the literature.

Relevance of surveillance manual for the early detection of immune checkpoint inhibitor-induced myocarditis: A case series

Objective

The European Cardio-Oncology Guidelines recommend regular electrocardiography and troponin testing during immune checkpoint inhibitors (ICIs) treatment, but their efficacy for monitoring ICI treatment remains unclear. This study aimed to evaluate the effectiveness of a surveillance protocol for early detection of ICI-induced myocarditis.

Methods

Between May 2014 and May 2024, patients who began treatment with ICIs at our hospital and developed ICI-induced myocarditis were included in this study. We created a straightforward management flowchart for myocarditis. The protocol was based on monitoring troponin T levels. We confirmed the efficacy of our surveillance protocol using a case series of ICI-induced myocarditis.

Results

During the observation period, 3481 patients were newly started on ICIs at our hospital. Five patients were previously diagnosed with myocarditis, and five patients were diagnosed with myocarditis after the implementation of the surveillance protocol. The manual enabled the early detection of myocarditis, and the mortality rate for myocarditis at our hospital improved from 60% to 0%. The incidence of conduction system disorders significantly reduced from 100% to 0% (P < 0.01). After the surveillance protocol was initiated, there were no cases of myocarditis requiring immunosuppressive drugs beyond steroids.

Conclusions

This study confirmed the relevance of a troponin-based surveillance protocol for the early detection of ICI-induced myocarditis. The implementation of the surveillance protocol reduced mortality from myocarditis and significantly reduced serious complications of conduction system disorders. Although this study is a small case series of patients who developed myocarditis, we confirm the effectiveness of surveillance for myocarditis.

Cardiotoxicity of Anticancer Drugs: Molecular Mechanisms, Clinical Management and Innovative Treatment

With the continuous refinement of therapeutic measures, the survival rate of tumor patients has been improving year by year, while cardiovascular complications related to cancer therapy have become increasingly prominent. Exploring the mechanism and prevention strategy of cancer therapy-related cardiovascular toxicity (CTR-CVT) remains one of the research hotspots in the field of Cardio-Oncology in recent years. Cardiotoxicity of anticancer drugs involves heart failure, myocarditis, hypertension, arrhythmias and vascular toxicity, mechanistically related to vascular endothelial dysfunction, ferroptosis, mitochondrial dysfunction and oxidative stress. To address the cardiotoxicity induced by different anticancer drugs, various therapeutic measures have been put in place, such as reducing the accumulation of anticancer drugs, shifting to drugs with less cardiotoxicity, using cardioprotective drugs, and early detection. Due to the very limited treatments available to ameliorate anticancer drugs-induced cardiotoxicity, a few innovations are being shifted from animal studies to human studies. Examples include mitochondrial transplantation. Mitochondrial transplantation has been proven to be effective in in vivo and in vitro experiments. Several recent studies have demonstrated that intercellular mitochondrial transfer can ameliorate doxorubicin(DOX)-induced cardiotoxicity, laying the foundation for innovative therapies in anticancer drugs-induced cardiotoxicity. In this review, we will discuss the current status of anticancer drugs-induced cardiotoxicity in terms of the pathogenesis and treatment, with a focus on mitochondrial transplantation, and we hope that this review will bring some inspiration to you.

Identification of key immune-related genes and potential therapeutic targets in immune checkpoint inhibitor-associated myocarditis

BACKGROUND

Immune checkpoint inhibitors (ICIs) are widely used in cancer treatment; however, the emergence of ICI-associated myocarditis (ICI-MC) presents a severe and potentially fatal complication with poorly understood pathophysiological mechanisms. This study aimed to identify crucial immune-related genes in ICI-MC and uncover potential therapeutic targets using bioinformatics.

METHODS

Using the GSE180045 dataset, which includes three groups-Group A: ICI patients without immune adverse events, Group B: ICI patients with non-myocarditis immune adverse events, and Group C: ICI patients with myocarditis-we analyzed differentially expressed genes (DEGs) between ICI-MC samples (Group C) and non-myocarditis controls (Groups A and B). These DEGs were then cross-referenced with 1796 immune-related genes from the immPort database to identify immune-related DEGs. We conducted functional enrichment analyses (Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, gene set enrichment analysis), constructed a protein-protein interaction network, and identified hub genes. Validation using the GSE4172 dataset led to the identification of optimal feature genes from the overlap between hub genes and DEGs. Predictions of target MicroRNAs (miRNAs) were made, and a competing endogenous RNA (ceRNA) network was constructed. Target drugs for hub genes were predicted using the Connectivity Map database.

RESULTS

We identified 58 DEGs between ICI-MC and controls, which led to the identification of 32 immune-related DEGs after intersection with 1796 immune-related genes. Functional analyses revealed enrichment in cell lysis, CD8+ T-cell receptor, natural killer cell-mediated cytotoxicity, and RAGE signaling. Notably upregulated hub genes included IL7R, PRF1, GNLY, CD3G, NKG7, GZMH, GZMB, KLRB1, KLRK1, and CD247. In the validation dataset, 407 DEGs were uncovered, resulting in the identification of 3 optimal feature genes (KLRB1, NKG7, GZMH). The predicted target miRNAs, lincRNAs, and circRNAs constituted a comprehensive ceRNA network. Among the top 10 drugs with elevated connectivity scores was acetohydroxamic acid, indicating a need for caution in ICI treatment.

CONCLUSION

KG7, GZMH, and KLRB1 were identified as pivotal immune-related genes in ICI-MC. Biological enrichments included pathways involved in cell lysis, the CD8+ T-cell receptor pathway, natural killer cell-mediated cytotoxicity, RAGE signaling, and proinflammatory responses. The ceRNA network illuminated the role of critical molecules and underscored the importance of avoiding drugs such as acetohydroxamic acid in ICI treatment. Key message What is already known on this topic  Myocarditis is recognized as a serious ICI-associated toxicity, seemingly infrequent yet often fulminant and lethal. The underlying mechanisms of ICI-associated myocarditis remain not fully understood. Although the significance of T cells and cytotoxic T lymphocyte-associated protein 4 (CTLA-4) is evident, the inciting antigens, the reasons for their recognition, and the mechanisms causing cardiac cell injury are not well characterized. An improved understanding of ICI-associated myocarditis will provide insights into the equilibrium between the immune and cardiovascular systems. What this study adds  Our study further validates the significance of T cells and CTLA-4 in ICI-associated myocarditis. More importantly, we identified three genes-NKG7, GZMH, and KLRB1-essential for the development of ICI-MC and proposed ceRNA networks involving these three key genes. How this study might affect research, practice or policy  The newly discovered key genes and their intricate molecular interactions offer a comprehensive perspective on the mechanisms underlying ICI-MC. Furthermore, our findings advise caution regarding the use of drugs like acetohydroxamic acid during ICI treatment. As our understanding of these regulatory networks deepens, our study provides valuable insights that could inform future therapeutic strategies for ICI-MC.

Biomarkers associated with immune-related adverse events induced by immune checkpoint inhibitors

Immune checkpoint inhibitors (ICIs) constitute a pivotal class of immunotherapeutic drugs in cancer treatment. However, their widespread clinical application has led to a notable surge in immune-related adverse events (irAEs), significantly affecting the efficacy and survival rates of patients undergoing ICI therapy. While conventional hematological and imaging tests are adept at detecting organ-specific toxicities, distinguishing adverse reactions from those induced by viruses, bacteria, or immune diseases remains a formidable challenge. Consequently, there exists an urgent imperative for reliable biomarkers capable of accurately predicting or diagnosing irAEs. Thus, a thorough review of existing studies on irAEs biomarkers is indispensable. Our review commences by providing a succinct overview of major irAEs, followed by a comprehensive summary of irAEs biomarkers across various dimensions. Furthermore, we delve into innovative methodologies such as machine learning, single-cell RNA sequencing, multiomics analysis, and gut microbiota profiling to identify novel, robust biomarkers that can facilitate precise irAEs diagnosis or prediction. Lastly, this review furnishes a concise exposition of irAEs mechanisms to augment understanding of irAEs prediction, diagnosis, and treatment strategies.

Risk factors and outcomes of pericardial effusion in cancer patients receiving PD-1 inhibitors

BACKGROUND

Programmed cell death 1 (PD-1) inhibitors can induce various adverse reactions associated with immunity, of which cardiotoxicity is a serious complication. Limited research exists on the link between PD-1 inhibitor use and pericardial effusion (PE) occurrence and outcomes.

METHODS

We conducted a retrospective study at the First Affiliated Hospital of Xi'an Jiaotong University from 2017 to 2019, comparing cancer patients who developed PE within 2 years after PD-1 inhibitor therapy to those who did not. Our primary outcome was the all-cause mortality rate at one year. We applied the Kaplan-Meier method for survival analysis. Multivariate logistic regression was utilized to identify PE risk factors, adjusting for potential confounders.

RESULTS

A total of 91 patients were finally included, of whom 39 patients had PE. Compared to non-PE group, one-year all-cause mortality was nearly 5 times higher in PE group (64.10% vs. 13.46%, P < 0.001). Patients who developed PE within 2 years of taking PD-1 inhibitors were significantly associated with increased all-cause mortality compared with those who did not (HR: 6.26, 95%CI: 2.70-14.53, P < 0.001). Multivariable logistic regression showed that use of sintilimab (OR: 14.568, 95%CI: 3.431-61.857, P < 0.001), history of lung cancer (OR: 15.360, 95%CI: 3.276-72.017, P = 0.001), and history of hypocalcemia (OR: 7.076, 95%CI: 1.879-26.649, P = 0.004) were independent risk factors of PE development in patients received PD-1 inhibitors therapy.

CONCLUSIONS

In cancer patients receiving PD-1 inhibitors, PE was associated with higher one-year mortality. Use of sintilimab, and history of lung cancer or hypocalcemia were linked to PE occurrence.

Immune checkpoints in cardiac physiology and pathology: therapeutic targets for heart failure

Immune checkpoint molecules are physiological regulators of the adaptive immune response. Immune checkpoint inhibitors (ICIs), such as monoclonal antibodies targeting programmed cell death protein 1 or cytotoxic T lymphocyte-associated protein 4, have revolutionized cancer treatment and their clinical use is increasing. However, ICIs can cause various immune-related adverse events, including acute and chronic cardiotoxicity. Of these cardiovascular complications, ICI-induced acute fulminant myocarditis is the most studied, although emerging clinical and preclinical data are uncovering the importance of other ICI-related chronic cardiovascular complications, such as accelerated atherosclerosis and non-myocarditis-related heart failure. These complications could be more difficult to diagnose, given that they might only be present alongside other comorbidities. The occurrence of these complications suggests a potential role of immune checkpoint molecules in maintaining cardiovascular homeostasis, and disruption of physiological immune checkpoint signalling might thus lead to cardiac pathologies, including heart failure. Although inflammation is a long-known contributor to the development of heart failure, the therapeutic targeting of pro-inflammatory pathways has not been successful thus far. The increasingly recognized role of immune checkpoint molecules in the failing heart highlights their potential use as immunotherapeutic targets for heart failure. In this Review, we summarize the available data on ICI-induced cardiac dysfunction and heart failure, and discuss how immune checkpoint signalling is altered in the failing heart. Furthermore, we describe how pharmacological targeting of immune checkpoints could be used to treat heart failure.

Efficacy and safety of immune checkpoint inhibitors in solid tumor patients combined with chronic coronary syndromes or its risk factor: a nationwide multicenter cohort study

BACKGROUND

Although, immune checkpoint inhibitors (ICIs) have been widely applied in the therapy of malignant tumors, the efficacy and safety of ICIs in patients with tumors and pre-existing CAD, especially chronic coronary syndromes (CCS) or their risk factors (CRF), is not well identified.

METHODS

This was a nationwide multicenter observational study that enrolled participants who diagnosed with solid tumors and received ICIs therapy. The main efficacy indicators were progression-free survival (PFS) and overall survival (OS), followed by objective response rate (ORR) and disease control rate (DCR). Safety was assessed by describing treatment-related adverse events (TRAEs) during ICIs therapy evaluated by the Common Terminology Criteria for Adverse Events 5.0 (CTCAE 5.0).

RESULTS

In the current research, we retrospectively analyzed the data of 551 patients diagnosed with solid tumors and received ICIs therapy, and these patients were divided into CCS/CRF group and non-CCS/CRF group. Patients with CCS/CRF had more favorable PFS and OS than patients without CCS/CRF (P < 0.001) and the pre-existing CCS/CRF was a protective factor for survival. The ORR (51.8% vs. 39.1%) and DCR (95.8% vs. 89.2%) were higher in CCS/CRF group than in non-CCS/CRF group (P = 0.003, P = 0.006). In this study, there was no significant difference in treatment-related adverse events (TRAEs), including immune-related adverse events (irAEs), between the two groups.

CONCLUSIONS

We concluded that ICIs appear to have better efficacy in malignant solid tumor patients with pre-existing CCS/CRF and are not accompanied by more serious irAEs.

The Emerging Field of Cardioimmunology: Past, Present and Foreseeable Future

Over the past 30 years, the field of cardioimmunology has moved from being dismissed as a field that was chasing an epiphenomenon of little biological consequence to a scientific discipline that is providing important new insights into the immunologic basis for hypertension, atherosclerosis, myocarditis, pericarditis, autoimmune heart disease, and heart failure. In this article, we will review the conceptual insights and technical breakthroughs that have allowed the field to move forward, as well as the clinical trials in the cardioimmunology space, to provide a historical context for the articles that will appear in the compendium that is focused on the interface between cardioimmunology, myocardial function, and disease.

Immune checkpoint inhibitor-associated cardiovascular toxicities: A review

Immune checkpoint inhibitors (ICIs) have revolutionary effects on therapeutic strategies for multiple malignancies. Their efficacy depends on their ability to reactivate the host immune system to fight cancer cells. However, adverse reactions to ICIs are common and involve several organs, limiting their use in clinical practice. Although the incidence of cardiovascular toxicity is relatively low, it is associated with serious consequences and high mortality rates. The primary cardiovascular toxicities include myocarditis, pericarditis, Takotsubo syndrome, arrhythmia, vasculitis, acute coronary syndrome, and venous thromboembolism. Currently, the mechanism underlying ICI-associated cardiovascular toxicity remains unclear and underexplored. The diagnosis and monitoring of ICI-associated cardiovascular toxicities mainly include the following indicators: symptoms, signs, laboratory examination, electrocardiography, imaging, and pathology. Treatments are based on the grade of cardiovascular toxicity and mainly include drug withdrawal, corticosteroid therapy, immunosuppressants, and conventional cardiac treatment. This review focuses on the incidence, underlying mechanisms, clinical manifestations, diagnoses, and treatment strategies.

The role of circulating biomarkers in predicting the 30-day mortality of immune checkpoint inhibitors-related myocarditis: a retrospective cohort study

Immune checkpoint inhibitors-related myocarditis (ICIs-M) is a rare and highly lethal immune-related adverse events (irAEs) in common irAEs. This study aims to find circulating biomarkers that can reflect disease state and prognosis accurately. 48 patients with ICIs-M were enrolled according to the diagnostic criteria for ICIs-related myocarditis. For all enrolled patients, valuable information was extracted retrospectively from the medical system, mainly including demographic information, tumor information and laboratory examination. The follow-up period was defined as 30 days after the first diagnosis of ICIs-M. In this study, the 30-day mortality rate of ICIs-M was 24.4%. After adjusting for potential confounding factors using multivariate analysis tools, we demonstrated the excellent performance of biomarkers in predicting 30-day mortality in patients with ICIs-M, including PLT (hazard ratio (HR), 1.07; 95% confidence interval (95%CI), 1.01-1.14; p = 0.028), ALT (HR, 1.23; 95%CI, 1.06-1.41; p = 0.005), AST(HR, 1.06; 95%CI, 1.01-1.10; p = 0.015), LDH (HR, 1.15; 95%CI, 1.04-1.26; p = 0.004), troponin I(HR, 1.44; 95%CI, 1.09-1.89; p = 0.009), PLR (blood plate/lymphocyte) (HR, 1.04; 95% CI, 1.01-1.07; p = 0.024), LAR (lactate dehydrogenase/albumin) (HR, 1.05; 95%CI, 1.01-1.09; p = 0.012), and AAR (aspartate transaminase/albumin) (HR, 1.18; 95%CI, 1.00-1.39; p = 0.048). The analysis of the receiver operating characteristic showed that biomarkers with area under curve (AUC) greater than or equal to 0.80 were LDH (cutoff value, 724.5; AUC, 0.86; 95%CI, 0.75-0.97), LAR (cutoff value, 18.11; AUC, 0.87; 95%CI, 0.76-0.97), troponin I (cutoff value, 0.87; AUC, 0.80; 95%CI, 0.62-0.99), and AAR(cutoff value, 1.52; AUC, 0.80; 95%CI, 0.61-0.98). LDH, LAR, troponin I, and AAR are a group of promising biomarkers that demonstrate excellent predictive ability in predicting the 30-day mortality rate of immune-related myocarditis.

Immune checkpoint inhibitors associated cardiovascular immune-related adverse events

Immune checkpoint inhibitors (ICIs) are specialized monoclonal antibodies (mAbs) that target immune checkpoints and their ligands, counteracting cancer cell-induced T-cell suppression. Approved ICIs like cytotoxic T-lymphocyte antigen-4 (CTLA-4), programmed death-1 (PD-1), its ligand PD-L1, and lymphocyte activation gene-3 (LAG-3) have improved cancer patient outcomes by enhancing anti-tumor responses. However, some patients are unresponsive, and others experience immune-related adverse events (irAEs), affecting organs like the lung, liver, intestine, skin and now the cardiovascular system. These cardiac irAEs include conditions like myocarditis, atherosclerosis, pericarditis, arrhythmias, and cardiomyopathy. Ongoing clinical trials investigate promising alternative co-inhibitory receptor targets, including T cell immunoglobulin and mucin domain-containing protein 3 (Tim-3) and T cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT). This review delves into the mechanisms of approved ICIs (CTLA-4, PD-1, PD-L1, and LAG-3) and upcoming options like Tim-3 and TIGIT. It explores the use of ICIs in cancer treatment, supported by both preclinical and clinical data. Additionally, it examines the mechanisms behind cardiac toxic irAEs, focusing on ICI-associated myocarditis and atherosclerosis. These insights are vital as ICIs continue to revolutionize cancer therapy, offering hope to patients, while also necessitating careful monitoring and management of potential side effects, including emerging cardiac complications.

Protective effect of low-intensity pulsed ultrasound on immune checkpoint inhibitor-related myocarditis via fine-tuning CD4+ T-cell differentiation

PURPOSE

Immune checkpoint inhibitors (ICIs) have transformed traditional cancer treatments. Specifically, ICI-related myocarditis is an immune-related adverse event (irAE) with high mortality. ICIs activate CD4+ T-lymphocyte reprogramming, causing an imbalance between Th17 and Treg cell differentiation, ultimately leading to myocardial inflammatory damage. Low-intensity pulsed ultrasound (LIPUS) can limit inflammatory responses, with positive therapeutic effects across various cardiovascular inflammatory diseases; however, its role in the pathogenesis of ICI-related myocarditis and CD4+ T-cell dysfunction remains unclear. Accordingly, this study investigated whether LIPUS can alleviate ICI-related myocarditis inflammatory damage and, if so, aimed to elucidate the beneficial effects of LIPUS and its underlying molecular mechanisms.

METHODS

An in vivo model of ICI-related myocarditis was obtained by intraperitonially injecting male A/J mice with an InVivoPlus anti-mouse PD-1 inhibitor. LIPUS treatment was performed via an ultrasound-guided application to the heart via the chest wall. The echocardiographic parameters were observed and cardiac function was assessed using an in vivo imaging system. The expression of core components of the HIPPO pathway was analyzed via western blotting.

RESULTS

LIPUS treatment reduced cardiac immune responses and inflammatory cardiac injury. Further, LIPUS treatment alleviated the inflammatory response in mice with ICI-related myocarditis. Mechanistically, in the HIPPO pathway, the activation of Mst1-TAZ axis improved autoimmune inflammation by altering the interaction between the transcription factors FOXP3 and RORγt and regulating the differentiation of Treg and Th17 cells.

CONCLUSION

LIPUS therapy was shown to reduce ICI-related myocarditis inflammatory damage and improve cardiac function, representing an exciting finding for irAEs treatment.

Immunotherapy-Associated Atherosclerosis: A Comprehensive Review of Recent Findings and Implications for Future Research

Purpose of the Review

Even as immune checkpoint inhibitors (ICIs) have transformed the lifespan of many patients, they may also trigger acceleration of long-term cardiovascular disease. Our review aims to examine the current landscape of research on ICI-mediated atherosclerosis and address key questions regarding its pathogenesis and impact on patient management.

Recent Findings

Preclinical mouse models suggest that T cell dysregulation and proatherogenic cytokine production are key contributors to plaque development after checkpoint inhibition. Clinical data also highlight the significant burden of atherosclerotic cardiovascular disease (ASCVD) in patients on immunotherapy, although the value of proactively preventing and treating ASCVD in this population remains an open area of inquiry. Current treatment options include dietary/lifestyle modification and traditional medications to manage hypertension, hyperlipidemia, and diabetes risk factors; no current targeted therapies exist.

Summary

Early identification of high-risk patients is crucial for effective preventive strategies and timely intervention. Future research should focus on refining screening tools, elucidating targetable mechanisms driving ICI atherosclerosis, and evaluating long-term cardiovascular outcomes in cancer survivors who received immunotherapy. Moreover, close collaboration between oncologists and cardiologists is essential to optimize patient outcomes.

Tolerated Re-Challenge of Immunotherapy in a Patient with ICI Associated Myocarditis: A Case Report and Literature Review

Many different types of cancer can be treated with immunotherapy drugs called immune checkpoint inhibitors (ICIs). These drugs have altered the landscape of cancer treatment options since they function by triggering a stronger immune response to malignancy. As expected, ICIs' modification of immune regulatory controls leads to a wide range of organ/gland-specific immune-related side effects. These adverse effects are uncommonly deadly and typically improve by discontinuing treatment or administering corticosteroid drugs. As a result of a number of factors-including a lack of specificity in the clinical presentation, the possibility of overlap with other cardiovascular and general medical illnesses, difficulties in diagnosis, and a general lack of awareness-the true incidence of ICI-associated myocarditis is likely underestimated. Currently, protocols for the surveillance, diagnosis, or treatment of this condition are unclear. Several questions remain unanswered, such as how to best screen for this rare toxin, what tests should be run on patients who are suspected of having it, how to treat myocarditis once it has developed, and who is at most risk. In this article, we provide a case study of ICI-associated myocarditis and explain its key characteristics and treatment options.

Cardiomuscular Biomarkers in the Diagnosis and Prognostication of Immune Checkpoint Inhibitor Myocarditis

BACKGROUND

Immune checkpoint inhibitors (ICIs) are approved for multiple cancers but can result in ICI-associated myocarditis, an infrequent but life-threatening condition. Elevations in cardiac biomarkers, specifically troponin-I (cTnI), troponin-T (cTnT), and creatine kinase (CK), are used for diagnosis. However, the association between temporal elevations of these biomarkers with disease trajectory and outcomes has not been established.

METHODS

We analyzed the diagnostic accuracy and prognostic performances of cTnI, cTnT, and CK in patients with ICI myocarditis (n=60) through 1-year follow-up in 2 cardio-oncology units (APHP Sorbonne, Paris, France and Heidelberg, Germany). A total of 1751 (1 cTnT assay type), 920 (4 cTnI assay types), and 1191 CK sampling time points were available. Major adverse cardiomyotoxic events (MACE) were defined as heart failure, ventricular arrhythmia, atrioventricular or sinus block requiring pacemaker, respiratory muscle failure requiring mechanical ventilation, and sudden cardiac death. Diagnostic performance of cTnI and cTnT was also assessed in an international ICI myocarditis registry.

RESULTS

Within 72 hours of admission, cTnT, cTnI, and CK were increased compared with upper reference limits (URLs) in 56 of 57 (98%), 37 of 42 ([88%] P=0.03 versus cTnT), and 43 of 57 ([75%] P<0.001 versus cTnT), respectively. This increased rate of positivity for cTnT (93%) versus cTnI ([64%] P<0.001) on admission was confirmed in 87 independent cases from an international registry. In the Franco-German cohort, 24 of 60 (40%) patients developed ≥1 MACE (total, 52; median time to first MACE, 5 [interquartile range, 2-16] days). The highest value of cTnT:URL within the first 72 hours of admission performed best in terms of association with MACE within 90 days (area under the curve, 0.84) than CK:URL (area under the curve, 0.70). A cTnT:URL ≥32 within 72 hours of admission was the best cut-off associated with MACE within 90 days (hazard ratio, 11.1 [95% CI, 3.2-38.0]; P<0.001), after adjustment for age and sex. cTnT was increased in all patients within 72 hours of the first MACE (23 of 23 [100%]), whereas cTnI and CK values were less than the URL in 2 of 19 (11%) and 6 of 22 (27%) of patients (P<0.001), respectively.

CONCLUSIONS

cTnT is associated with MACE and is sensitive for diagnosis and surveillance in patients with ICI myocarditis. A cTnT:URL ratio <32 within 72 hours of diagnosis is associated with a subgroup at low risk for MACE. Potential differences in diagnostic and prognostic performances between cTnT and cTnI as a function of the assays used deserve further evaluation in ICI myocarditis.

Germline genetic variants are associated with development of insulin-dependent diabetes in cancer patients treated with immune checkpoint inhibitors

BACKGROUND

Immune checkpoint inhibitors (ICIs) have dramatically improved survival in patients with cancer but are often accompanied by severe immune-related adverse events (irAEs), which can sometimes be irreversible. Insulin-dependent diabetes is a rare, but life-altering irAE. Our purpose was to determine whether recurrent somatic or germline mutations are observed in patients who develop insulin-dependent diabetes as an irAE.

METHODS

We performed RNA and whole exome sequencing on tumors from 13 patients who developed diabetes due to ICI exposure (ICI-induced diabetes mellitus, ICI-DM) compared with control patients who did not develop diabetes.

RESULTS

In tumors from ICI-DM patients, we did not find differences in expression of conventional type 1 diabetes autoantigens, but we did observe significant overexpression of ORM1, PLG, and G6PC, all of which have been implicated in type 1 diabetes or are related to pancreas and islet cell function. Interestingly, we observed a missense mutation in NLRC5 in tumors of 9 of the 13 ICI-DM patients that was not observed in the control patients treated with the same drugs for the same cancers. Germline DNA from the ICI-DM patients was sequenced; all NLRC5 mutations were germline. The prevalence of NLRC5 germline variants was significantly greater than the general population (p=5.98×10^-6). Although NLRC5 is implicated in development of type 1 diabetes, germline NLRC5 mutations were not found in public databases from patients with type 1 diabetes, suggesting a different mechanism of insulin-dependent diabetes in immunotherapy-treated patients with cancer.

CONCLUSIONS

Validation of the NLRC5 mutation as a potential predictive biomarker is warranted, as it might improve patient selection for treatment regimens. Furthermore, this genetic alteration suggests potential mechanisms of islet cell destruction in the setting of checkpoint inhibitor therapy.

Advances in immune checkpoint inhibitors induced-cardiotoxicity

Immune checkpoint inhibitors (ICIs) are approved as the first-line drug for treating many cancers and has shown significant survival benefits; however, it also causes immune-related adverse events (irAEs) while activating the immune system, involving multiple organs. Among them, cardiovascular immune-related adverse events (CV-irAE) are rare, but common causes of death in ICIs treated cancer patients, which manifest as myocardial, pericardial, vascular and other cardiovascular toxicities. Therefore, it is important that irAEs, especially CV-irAE should be carefully recognized and monitored during the whole ICIs treatment because early detection and treatment of CV-irAE can significantly reduce the mortality of such patients. Consequently, it is urgent to fully understand the mechanism and management strategies of CV-irAE. The effects of ICIs are multifaceted and the exact mechanism of CV-irAE is still elusive. Generally, T cells identify tumor cell antigens as well as antigen in cardiomyocytes that are the same as or homologous to those on tumor cells, thus causing myocardial damage. In addition, ICIs promote formation of cardiac troponin I (cTnI) that induces cardiac dysfunction and myocardial dilatation; moreover, ICIs also increase the production of cytokines, which promote infiltration of inflammation-linked molecules into off-target tissues. Currently, the management and treatment of cardiovascular toxicity are largely dependent on glucocorticoids, more strategies for prevention and treatment of CV-irAE, such as predictive markers are being explored. This review discusses risk factors, potential pathophysiological mechanisms, clinical manifestations, and management and treatment of CV-irAE, guiding the development of more effective prevention, treatment and management strategies in the future.

The Role of Single-Cell Profiling and Deep Immunophenotyping in Understanding Immune Therapy Cardiotoxicity

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ICIs used in cancer therapy can cause serious cardiac immune-related side effects.

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Single-cell multi-omics are powerful tools in understanding cell subsets/phenotypes.

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Multi-omics technology can elucidate disease mechanisms in ICI-induced myocarditis.

Advances in therapeutic targeting of immune checkpoints receptors within the CD96-TIGIT axis: clinical implications and future perspectives

INTRODUCTION

The development of therapeutic antibodies targeting immune checkpoint molecules (ICMs) that induce long-term remissions in cancer patients has revolutionized cancer immunotherapy. However, a major drawback is that relapse after an initial response may be attributed to innate and acquired resistance. Additionally, these treatments are not beneficial to all patients. Therefore, the discovery and targeting of novel ICMs and their combination with other immunotherapeutics are urgently needed.

AREAS COVERED

There has been increasing evidence of the CD96-TIGIT axis as ICMs in cancer immunotherapy in the last five years. This review will highlight and discuss the current knowledge about the role of CD96 and TIGIT in hematological and solid tumor immunotherapy in the context of empirical studies and clinical trials, and provide a comprehensive list of ongoing cancer clinical trials on the blockade of these ICMs, as well as the rationale behind combinational therapies with anti-PD-1/PD-L1 agents, chemotherapy drugs, and radiotherapy. Moreover, we share our perspectives on anti-CD96/TIGIT-related combination therapies.

EXPERT OPINION

CD96-TIGIT axis regulates anti-tumor immune responses. Thus, the receptors within this axis are the potential candidates for cancer immunotherapy. Combining the inhibition of CD96-TIGIT with anti-PD-1/PD-L1 mAbs and chemotherapy drugs has shown relatively effective results in the context of preclinical studies and tumor models.

Incidence of immune checkpoint inhibitor mediated cardiovascular toxicity: A systematic review and meta-analysis

BACKGROUND

Immune checkpoint inhibitors (ICI) are a novel class of anti-cancer therapy becoming increasingly associated with fatal cardiovascular toxicities (CVTs). The aim is to determine the incidence of CVTs in cohorts treated with ICIs as sole anti-cancer therapy.

METHODS

A systematic literature search of scientific and medical databases was performed using PRISMA principles to identify relevant cohorts (PROSPERO registration CRD42021272470). Data for specific CVTs (pericardial disease, myocarditis, heart failure, arrhythmia, myocardial infarction/ischaemia and angina), CVT-related death and CV risk factors were extracted. Presence of CVTs in ICI-monotherapy versus combination-ICI therapy, and programmed death 1/programmed death ligand 1- (PD1/PDL1-) versus cytotoxic T-lymphocyte-associated protein 4- (CTLA4-) inhibitor groups were dichotomised and meta-analysed using random-effect models.

RESULTS

Forty-eight studies (11,207 patients) were identified, from which 146 CVTs were observed (incidence 1.30%). ICI-monotherapy led to more CVTs than combination therapy (119/9009; 1.32% vs. 18/2086; 0.86%). Across monotherapies, PD1/PDL1-inhibitors had lower incidence of CVTs compared to CTLA4-inhibitors (62/6950; 0.89% vs. 57/2059; 2.77%). Based on eight studies that were meta-analysed, no significant difference was observed comparing monotherapy versus combination-ICI therapy (RR-0.69, 95% CI -1.47 to 0.09) for all CVTs, or PD1/PDL1- to CTLA4-inhibitors (RR-0.27, 95% CI -2.06 to 1.53), for all CVTs including CVT-death. CV risk factors could not be attributed to an ICI group as data was population based rather than individual based.

CONCLUSION

ICI-mediated CVTs are rare and potentially fatal. The role of CV risk factors in their development remains unclear.

Cardiac myosin-specific autoimmune T cells contribute to immune-checkpoint-inhibitor-associated myocarditis

Immune checkpoint inhibitors (ICIs) are an effective therapy for various cancers; however, they can induce immune-related adverse events (irAEs) as a side effect. Myocarditis is an uncommon, but fatal, irAE caused after ICI treatments. Currently, the mechanism of ICI-associated myocarditis is unclear. Here, we show the development of myocarditis in A/J mice induced by anti-PD-1 monoclonal antibody (mAb) administration alone without tumor cell inoculation, immunization, or viral infection. Mice with myocarditis have increased cardiac infiltration, elevated cardiac troponin levels, and arrhythmia. Anti-PD-1 mAb treatment also causes irAEs in other organs. Autoimmune T cells recognizing cardiac myosin are activated and increased in mice with myocarditis. Notably, cardiac myosin-specific T cells are present in naive mice, showing a phenotype of antigen-experienced T cells. Collectively, we establish a clinically relevant mouse model for ICI-associated myocarditis and find a contribution of cardiac myosin-specific T cells to ICI-associated myocarditis development and pathogenesis.

A Retrospective, Single-Institution Experience of Bullous Pemphigoid as an Adverse Effect of Immune Checkpoint Inhibitors

Immune checkpoint inhibitors are a class of cancer treatment drugs that stimulate the immune system's ability to fight tumor cells. These drugs are monoclonal antibodies targeting im-mune-inhibiting proteins on cancer cells, such as CTLA-4 and PD-1/PD-L1. Immune checkpoint inhibitors cause many immune-related adverse events. Cutaneous toxicities are of the most common adverse effects and occur with a range of severity. Bullous Pemphigoid is a rare adverse event with a high impact on quality of life that may occur after immune checkpoint inhibitor treatment. In this article, we investigate current research on immune checkpoint inhibitors, cutaneous adverse events, and common presentations and treatments, with a specific focus on Bullous Pemphigoid, its characteristics, onset timing, and treatment. Significant findings include a negative skew in the onset of presentation. Furthermore, we describe exclusive cases.

Immune myocarditis related to sintilimab treatment in a patient with advanced lung adenocarcinoma: A case report

Immune checkpoint inhibitors (ICI) have improved clinical outcomes of patients with advanced lung cancer, but may lead to fatal cardiac injury. We describe a 66-year-old man with advanced lung adenocarcinoma who presented with chest pain and dyspnea 3 weeks after the first dose of sintilimab. The initial electrocardiogram (ECG) demonstrated ST-elevation in leads V5-V9, and a high-sensitivity troponin level was significantly elevated. However, coronary angiography did not reveal any significant stenosis. The patient was successfully treated with methylprednisolone and immunoglobulin. Cardiac MRI was carried out before discharge and late gadolinium enhancement (LGE) was found to be in the mid layer of the septal segment and the subepicardial layer of the inferolateral wall. Due to the high fatality, ICI-related myocarditis requires close surveillance, prompt management and long-term follow-up.

Cardiotoxicity associated with immune checkpoint inhibitors: Current status and future challenges

Immune checkpoint inhibitors (ICIs) are the most notable breakthrough in tumor treatment. ICIs has been widely used in tumor patients, but its wide range of immune-related adverse events (irAEs) should not be ignored. irAEs can be involved in any organ system, including immune-related cardiotoxicity. Although the cardiotoxicity induced by immune checkpoint inhibitors is rare, it is extremely lethal and has attracted increasing attention. PD-1 and PD-L1 are expressed in human cardiomyocytes, so the application of PD-1/PDL-1 inhibitors can cause many adverse reactions to the cardiovascular system. This review summarizes the latest epidemiological evidence on the cardiovascular toxicity of programmed cell death protein-1(PD-1)/programmed cell death ligand-1(PD-L1) inhibitors and the clinical manifestations, as well as the potential pathological mechanisms. These updates may provide a novel perspective for monitoring early toxicity and establishing appropriate treatment for patients with ICI-related cardiotoxicity.

Identification of Pathogenic Immune Cell Subsets Associated With Checkpoint Inhibitor-Induced Myocarditis

BACKGROUND

Immune checkpoint inhibitors (ICIs) are monoclonal antibodies used to activate the immune system against tumor cells. Despite therapeutic benefits, ICIs have the potential to cause immune-related adverse events such as myocarditis, a rare but serious side effect with up to 50% mortality in affected patients. Histologically, patients with ICI myocarditis have lymphocytic infiltrates in the heart, implicating T cell-mediated mechanisms. However, the precise pathological immune subsets and molecular changes in ICI myocarditis are unknown.

METHODS

To identify immune subset(s) associated with ICI myocarditis, we performed time-of-flight mass cytometry on peripheral blood mononuclear cells from 52 individuals: 29 patients with autoimmune adverse events (immune-related adverse events) on ICI, including 8 patients with ICI myocarditis, and 23 healthy control subjects. We also used multiomics single-cell technology to immunophenotype 30 patients/control subjects using single-cell RNA sequencing, single-cell T-cell receptor sequencing, and cellular indexing of transcriptomes and epitopes by sequencing with feature barcoding for surface marker expression confirmation. To correlate between the blood and the heart, we performed single-cell RNA sequencing/T-cell receptor sequencing/cellular indexing of transcriptomes and epitopes by sequencing on MRL/Pdcd1^-/- (Murphy Roths large/programmed death-1-deficient) mice with spontaneous myocarditis.

RESULTS

Using these complementary approaches, we found an expansion of cytotoxic CD8⁺ T effector cells re-expressing CD45RA (Temra CD8⁺ cells) in patients with ICI myocarditis compared with control subjects. T-cell receptor sequencing demonstrated that these CD8⁺ Temra cells were clonally expanded in patients with myocarditis compared with control subjects. Transcriptomic analysis of these Temra CD8⁺ clones confirmed a highly activated and cytotoxic phenotype. Longitudinal study demonstrated progression of these Temra CD8⁺ cells into an exhausted phenotype 2 months after treatment with glucocorticoids. Differential expression analysis demonstrated elevated expression levels of proinflammatory chemokines (CCL5/CCL4/CCL4L2) in the clonally expanded Temra CD8⁺ cells, and ligand receptor analysis demonstrated their interactions with innate immune cells, including monocytes/macrophages, dendritic cells, and neutrophils, as well as the absence of key anti-inflammatory signals. To complement the human study, we performed single-cell RNA sequencing/T-cell receptor sequencing/cellular indexing of transcriptomes and epitopes by sequencing in Pdcd1^-/- mice with spontaneous myocarditis and found analogous expansions of cytotoxic clonal effector CD8⁺ cells in both blood and hearts of such mice compared with controls.

CONCLUSIONS

Clonal cytotoxic Temra CD8⁺ cells are significantly increased in the blood of patients with ICI myocarditis, corresponding to an analogous increase in effector cytotoxic CD8⁺ cells in the blood/hearts of Pdcd1^-/- mice with myocarditis. These expanded effector CD8⁺ cells have unique transcriptional changes, including upregulation of chemokines CCL5/CCL4/CCL4L2, which may serve as attractive diagnostic/therapeutic targets for reducing life-threatening cardiac immune-related adverse events in ICI-treated patients with cancer.

Cyclin-dependent kinase inhibition and its intersection with immunotherapy in breast cancer: more than CDK4/6 inhibition

INTRODUCTION

Cyclin-dependent kinase (CDK) 4/6 inhibitors (CDK4/6i) have had clinical success in treating hormone receptor-positive, human epidermal growth factor receptor 2-negative metastatic breast cancer. Notably, CDK4/6i have expanded to the neoadjuvant setting for early breast cancer and other cancer types and potently synergize with immunotherapy. Other CDKs, including CDK7, CDK9, and CDK12/13, mainly function in transcriptional processes as well as cell cycle regulation, RNA splicing, and DNA damage response. Inhibiting these CDKs aids in suppressing tumors, reversing drug resistance, increasing drug sensitivity, and enhancing anti-tumor immunity in breast cancer.

AREAS COVERED

We reviewed the applications of CDK4/6i, CDK7i, CDK9i and CDK12/13i for various breast cancer subtypes and their potentials for combination with immunotherapy. A literature search of PubMed, Embase, and Web of Science was conducted in April 2022.

EXPERT OPINION

The use of CDK4/6i represents a major milestone in breast cancer treatment. Moreover, transcription-related CDKs play critical roles in tumor development and are promising therapeutic targets for breast cancer. Some relevant clinical studies are underway. More specific and efficient CDKis will undoubtedly be developed and clinically tested. Characterization of their immune-priming effects will promote the development of combination therapies consisting of CDKi and immunotherapy.

Clinical Manifestations, Monitoring, and Prognosis: A Review of Cardiotoxicity After Antitumor Strategy

The development of various antitumor drugs has significantly improved the survival of patients with cancer. Many first-line chemotherapy drugs are cytotoxic and the cardiotoxicity is one of the most significant effects that could leads to poor prognosis and decreased survival rate. Cancer treatment include traditional anthracycline drugs, as well as some new targeted drugs such as trastuzumab and ICIs. These drugs may directly or indirectly cause cardiovascular injury through different mechanisms, and lead to increasing the risk of cardiovascular disease or accelerating the development of cardiovascular disease. Cardiotoxicity is clinically manifested by arrhythmia, decreased cardiac function, or even sudden death. The cardiotoxicity caused by traditional chemotherapy drugs such as anthracyclines are significantly known. The cardiotoxicity of some new antitumor drugs such like immune checkpoint inhibitors (ICIs) is also relatively clear and requiring further observation and verification. This review is focused on major three drugs with relatively high incidence of cardiotoxicity and poor prognosis and intended to provide an update on the clinical complications and outcomes of these drugs, and we innovatively summarize the monitoring status of survivors using these drugs and discuss the biomarkers and non-invasive imaging features to identify early cardiotoxicity. Finally, we summarize the prevention that decreasing antitumor drugs-induced cardiotoxicity.

Cardiovascular toxicities associated with immune checkpoint inhibitors: An updated comprehensive disproportionality analysis of the FDA adverse event reporting system

WHAT IS KNOWN AND OBJECTIVE

Immune checkpoint inhibitors (ICIs) have significantly improved clinical outcomes for a wide range of cancers but can also lead to cardiovascular toxicities. This study was to scientifically and systematically explore the association between cardiovascular toxicities and immune checkpoint inhibitors (ICIs) and also to characterize the main features of ICI-related cardiovascular toxicities.

METHODS

From January 2012 to December 2020, data in the Food and Drug Administration Adverse Event Reporting System (FAERS) database were retrieved for disproportionality analysis. The definition of adverse events (AEs) relied on the Medical Dictionary for Regulatory Activities (MedDRA). We used the reporting odds ratio (ROR) with 95% confidence intervals (CIs) to evaluate the association between ICIs and cardiovascular AEs. Clinical characteristics of patients with ICI-associated cardiovascular toxicities were collected, and the time to onset following different ICI regimens was further investigated.

RESULTS AND DISCUSSION

We identified a total of 13,713 ICI-associated cardiovascular toxicities which appeared to influence more men (56.90%) than women (36.79%), with a median age of 67 (interquartile range [IQR] 58-74) years. ICI-associated cardiovascular AEs were most frequently reported in lung, pleura, thymus and heart cancer patients (34.49%). Compared with the full database, ICI therapies were detected with pharmacovigilance of myocardial disorders (ROR: 2.64; 95% CI: 2.55-2.75) and pericardial disorders (ROR: 4.51; 95% CI: 4.30-4.74). Concerning myocardial and pericardial disorders, a significant increased ROR was found for all anti-PD-1 and anti-PD-L1 monotherapies, with the exception of anti-CTLA-4 monotherapies. Regarding cardiac arrhythmias, only tremelimumab among ICI monotherapies was associated with an increased ROR (1.92, 1.09-4.72; 4 cases). Compared with ICI monotherapy, ICI combination therapy detected an increase in cardiovascular toxicity spectrum, but did not prolong the onset time.

WHAT IS NEW AND CONCLUSION

We observed that the spectrum and risk of ICI-associated cardiovascular AEs differed between therapeutic regimens. The poor clinical outcome and early onset of these events should attract clinical attention.

Plasma Exchange for Severe Immune-Related Adverse Events from Checkpoint Inhibitors: An Early Window of Opportunity?

Immune checkpoint inhibitors (ICIs) have revolutionized the treatment of several advanced malignancies leading to durable remission in a subset of patients. Their rapidly expanding use has led to an increased frequency of immune-related adverse events (irAEs). The pathogenesis of irAEs is poorly understood but may involve aberrant activation of T cells leading to inflammatory cytokine release or production of pathogenic antibodies leading to organ damage. Severe irAEs can be extremely debilitating and, in some cases, life threatening. IrAEs may not always be corticosteroid responsive or may require excessively high, often toxic, corticosteroid doses. Therapeutic plasma exchange (PLEX) is a treatment modality that has shown promising results for the management of certain severe irAEs, including irAEs that are not mentioned in current treatment guidelines. PLEX may attenuate ongoing irAEs and prevent delayed irAEs by accelerating clearance of the ICI, or by acutely removing pathogenic antibodies, cytokines, and chemokines. Here, we summarize examples from the literature in which PLEX was successfully used for the treatment of irAEs. We posit that timing may be a critical factor and that earlier utilization of PLEX for life-threatening irAEs may result in more favorable outcomes. In individuals at high risk for irAEs, the availability of PLEX as a potential therapeutic mitigation strategy may encourage life-saving ICI use or rechallenge. Future research will be critical to better define which indications are most amenable to PLEX, particularly to establish the optimal place in the sequence of irAE therapies and to assess the ramifications of ICI removal on cancer outcomes.

Cardio-Oncology Drug Interactions: A Scientific Statement From the American Heart Association

In the cardio-oncology population, drug interactions are of particular importance given the complex pharmacological profile, narrow therapeutic index, and inherent risk of therapies used to manage cardiovascular disease and cancer. Drug interactions may be beneficial or detrimental to the desired therapeutic effect. Clinicians in both cardiology and oncology should be cognizant of these potential drug-drug interactions that may reduce the efficacy or safety of either cardiovascular or cancer therapies. These risks can be mitigated through increased recognition of potential drug-drug interaction, use of alternative medications when possible, and careful monitoring. This scientific statement provides clinicians with an overview of pharmacodynamic and pharmacokinetic drug-drug interactions in patients with cancer exposed to common cardiovascular and cancer medications.

Case Series of Steroid-Resistant Immune Checkpoint Inhibitor Associated Myocarditis: A Comparative Analysis of Corticosteroid and Tofacitinib Treatment

Background: Immune checkpoint inhibitor (ICI)–associated myocarditis is an uncommon and potentially fatal immune-related adverse event (irAE). Although corticosteroids are recommended as the first-line treatment by current guidelines, patients still have variable responses to it, and the guidelines vary significantly in terms of treatment strategies.

Objectives: In this study, we performed a retrospective analysis of ICI-associated myocarditis in our hospital to propose a new comparative analysis to aid individualized treatment.

Methods: We reviewed detailed records of 24 patients with confirmed ICI-associated myocarditis in our hospital from July 1, 2019, to April 1, 2021. Although all the cases in our study received recommended initial corticosteroid treatment according to the guidelines, different responses to corticosteroid were observed during the process of subsequent corticosteroid tapering. Basing on troponin cardiac troponin T rebound during corticosteroid tapering, we propose a new classification analysis of ICI-associated myocarditis that included two subgroups: corticosteroid-sensitive (n = 8) and corticosteroid-resistant group (n = 16).

Results: Compared with corticosteroid-sensitive patients, larger doses of corticosteroid, longer period of treatment, and higher mortality rate were found in corticosteroid-resistant patients. Corticosteroid-resistant patients were characterized by more prominent ptosis, muscle weakness, elevated cardiac biomarkers, creatine kinase, and hepatic enzymes levels than that in the corticosteroid-sensitive patients. Tofacitinib (5 mg twice a day) was used in 11 corticosteroid-resistant patients, with seven patients recovered from ICI-associated myocarditis, showing a promising therapeutic effect.

Conclusion: Our group analysis of corticosteroid responsiveness in patients with ICI-associated myocarditis may help clinicians to apply individualized treatment in this high-risk cohort. In addition, tofacitinib could provide clinical benefits when used early in the corticosteroid-resistant patients and may provide a new option for the treatment of ICI-associated myocarditis.

Pathogenic mitochondrial dysfunction and metabolic abnormalities

Herein we trace links between biochemical pathways, pathogenesis, and metabolic diseases to set the stage for new therapeutic advances. Cellular and acellular microorganisms including bacteria and viruses are primary pathogenic drivers that cause disease. Missing from this statement are subcellular compartments, importantly mitochondria, which can be pathogenic by themselves, also serving as key metabolic disease intermediaries. The breakdown of food molecules provides chemical energy to power cellular processes, with mitochondria as powerhouses and ATP as the principal energy carrying molecule. Most animal cell ATP is produced by mitochondrial synthase; its central role in metabolism has been known for >80 years. Metabolic disorders involving many organ systems are prevalent in all age groups. Progressive pathogenic mitochondrial dysfunction is a hallmark of genetic mitochondrial diseases, the most common phenotypic expression of inherited metabolic disorders. Confluent genetic, metabolic, and mitochondrial axes surface in diabetes, heart failure, neurodegenerative disease, and even in the ongoing coronavirus pandemic.

Cardiac Toxicity Associated with Immune Checkpoint Inhibitors: A Systematic Review

Immune checkpoint inhibitors are immune stimulatory drugs used to treat many types of cancer. These drugs are antibodies against inhibitory proteins, such as CTLA-4 and PD-1/PD-L1, that are expressed on immune cells. When bound, they allow for increased stimulation of T cells to fight tumor cells. However, immune checkpoint inhibitors have several immune-related adverse effects. Many cases have come to light recently of cardiotoxicity as a result of treatment with these drugs. Cardiotoxicity from immune checkpoint inhibitors is unique due to its rarity and high mortality rate. Patients with this toxicity may present with myocarditis, pericarditis, Takotsubo cardiomyopathy, conduction disorders, and others within just a few weeks of starting immune checkpoint inhibitors. We present here a review of the current research on immune checkpoint inhibitors, their associated cardiotoxicities, the timing of presentation of these conditions, lab tests and histology for each condition, and finally the treatment of patients with cardiotoxicity. We observe a positive skew in the onset of presentation, which is significant for the treating physician.

Introduction to the Theme "Old and New Toxicology: Interfaces with Pharmacology"

The theme of Volume 61 is "Old and New Toxicology: Interfaces with Pharmacology." Old toxicology is exemplified by the authors of the autobiographical articles: B.M. Olivera's work on toxins and venoms from cone snails and P. Taylor's studies of acetylcholinesterase and the nicotinic cholinergic receptor, which serve as sites of action for numerous pesticides and venoms. Other articles in this volume focus on new understanding and new types of toxicology, including (a) arsenic toxicity, which is an ancient poison that, through evolution, has caused most multicellular organisms to express an active arsenic methyltransferase to methylate arsenite, which accelerates the excretion of arsenic from the body; (b) small molecules that react with lipid dicarbonyls, which are now considered the most toxic oxidative stress end products; (c) immune checkpoint inhibitors (ICIs), which have revolutionized cancer therapy but have numerous immune-related adverse events, including cardiovascular complications; (d) autoimmunity caused by the environment; (e) idiosyncratic drug-induced liver disease, which together with the toxicity of ICIs represents new toxicology interfacing with pharmacology; and (f) sex differences in the development of cardiovascular disease, with men more susceptible than women to vascular inflammation that initiates and perpetuates disease. These articles and others in Volume 61 reflect the interface and close integration of pharmacology and toxicology that began long ago but continues today.

Cardiooncology-dealing with modern drug treatment, long-term complications, and cancer survivorship

Modern treatment strategies have improved prognosis and survival of patients with malignant diseases. The key components of tumor treatment are conventional chemotherapy, radiotherapy, targeted therapies, and immunotherapy. Cardiovascular side-effects may occur in the early phase of tumor therapy or even decades later. Therefore, knowledge and awareness of acute and long-lasting cardiac side effects of anti-cancer therapies are essential. Cardiotoxicity impairs quality of life and overall survival. The new cardiologic subspecialty 'cardio-oncology' deals with the different cardiovascular problems arising from tumor treatment and the relationship between cancer and heart diseases. Early detection and treatment of cardiotoxicity is of crucial importance. A detailed cardiac assessment of patients prior to administration of cardiotoxic agents, during and after treatment should be performed in all patients. The current review focusses on acute and long-term cardiotoxic side effects of classical cytotoxic and selected modern drug treatments such as immune checkpoint inhibitors and discusses strategies for the diagnosis of treatment-related adverse cardiovascular effects in cancer patients.

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.

Mechanisms of Cardiovascular Toxicities Associated With Immunotherapies

Immune-based therapies have revolutionized cancer treatments. Cardiovascular sequelae from these treatments, however, have emerged as critical complications, representing new challenges in cardio-oncology. Immune therapies include a broad range of novel drugs, from antibodies and other biologics, including immune checkpoint inhibitors and bispecific T-cell engagers, to cell-based therapies, such as chimeric-antigen receptor T-cell therapies. The recognition of immunotherapy-associated cardiovascular side effects has also catapulted new research questions revolving around the interactions between the immune and cardiovascular systems, and the signaling cascades affected by T cell activation, cytokine release, and immune system dysregulation. Here, we review the specific mechanisms of immune activation from immunotherapies and the resulting cardiovascular toxicities associated with immune activation and excess cytokine production.

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.