Immune checkpoint inhibitors and cardiovascular toxicity

Cardiotoxicity of Immune Checkpoint Inhibitors

PURPOSE OF REVIEW

Immunotherapies, particularly immune checkpoint inhibitors (ICI), are revolutionary cancer therapies being increasingly applied to a broader range of cancers. Our understanding of the mechanism, epidemiology, diagnosis, and treatment of cardiotoxicity related to immunotherapies remains limited. We aim to synthesize the limited current literature on cardiotoxicity of ICIs and to share our opinions on the diagnosis and treatment of this condition.

RECENT FINDINGS

The incidence of ICI-associated myocarditis ranges from 0.1 to 1%. Patients with ICI-associated myocarditis often have a fulminant course with a case fatality rate of 25-50%. The diagnosis of this condition poses many challenges because independently a normal electrocardiogram, biomarkers, or a preserved left ventricular function do not rule out ICI-associated myocarditis. Endomyocardial biopsy should be pursued when clinical suspicion remains despite normal non-invasive tests. Data on optimal screening and surveillance tools are lacking. Cessation of ICIs, combined with high dose corticosteroids and other immunosuppressant approaches are the cornerstones of the treatment of ICI-associated myocarditis. This condition may recur when patients are re-challenged with these agents and the decision to resume ICIs should be made through a multidisciplinary discussion. Immunotherapies have changed the landscape of cancer treatment. Recognizing and managing cardiotoxicity related to ICIs is of critical importance. Our understanding of ICI-cardiotoxicity has improved, but large information gaps remain for further research. Due to the high case fatality rate, any type of cardiac symptoms or signs in a patient who has recently started an ICI should prompt consideration of ICI-cardiotoxicity.

Clinical experience of patients referred to a multidisciplinary cardio-oncology clinic: an observational cohort study

Introduction

Cardiovascular disease is the 2nd leading cause of long-term morbidity and mortality in cancer survivors. Cardio-oncology clinics (cocs) have emerged to address the issue; however, there is a paucity of data about the demographics and clinical outcomes of patients seen in the coc setting.

Methods

Cancer patients referred to The Ottawa Hospital coc were included in this retrospective observational study. Data collected were patient demographics, cancer type and stage, reason for referral, cardiac risk factors, cardiac assessments and treatment, and clinical outcomes.

Results

Between 2008 and 2015, 779 patients (516 women, 66%; 263 men, 34%) were referred to the coc. Median age of the patients at cancer diagnosis was 60 years (range: 18-90 years). The most frequent reasons for referral were decreased left ventricular ejection fraction (33%), pre-chemotherapy assessment (14%), and arrhythmia (14%). Treatment with cardiac medication was given in 322 patients (41%), 181 (56%) of whom received more than 2 cardiac medications, with 57 (18%) receiving an angiotensin-converting enzyme inhibitor (acei), 46 (14%) receiving an acei and a beta-blocker, and 38 (12%) receiving a beta-blocker. Of 163 breast cancer patients, 129 (79%) were able to complete targeted therapy with coc co-management. Most of the 779 patients (n = 643, 83%) were alive at the time of the last data collection.

Conclusions

This cohort study is one of the largest to report characteristics and clinical outcomes of patients referred to a coc. Collaboration between oncologists and cardiologists resulted in completion of cancer therapy in most patients. Ongoing analysis of referral patterns, management plans, and patient outcomes will help to guide the cardiac care of oncology patients, ultimately optimizing cancer and cardiac outcomes alike.

Heart Failure and Cancer: Mechanisms of Old and New Cardiotoxic Drugs in Cancer Patients

Although there have been many improvements in prognosis for patients with cancer, anticancer therapies are burdened by the risk of cardiovascular toxicity. Heart failure is one of the most dramatic clinical expressions of cardiotoxicity, and it may occur acutely or appear years after treatment. This article reviews the main mechanisms and clinical presentations of left ventricular dysfunction induced by some old and new cardiotoxic drugs in cancer patients, referring to the most recent advances in the field. The authors describe the mechanisms of cardiotoxicity induced by anthracyclines, which can lead to cardiovascular problems in up to 48% of patients who take them. The authors also describe mechanisms of cardiotoxicity induced by biological drugs that produce left ventricular dysfunction through secondary mechanisms. They outline the recent advances in immunotherapies, which have revolutionised anticancer therapies.

Sequential Blockade of PD-1 and PD-L1 Causes Fulminant Cardiotoxicity-From Case Report to Mouse Model Validation

The combined administration of programmed cell death 1 (PD-1) and programmed cell death ligand 1 (PD-L1) inhibitors might be considered as a treatment for poorly responsive cancer. We report a patient with brain metastatic lung adenocarcinoma in whom fatal myocarditis developed after sequential use of PD-1 and PD-L1 inhibitors. This finding was validated in syngeneic tumor-bearing mice. The mice bearing lung metastases of CT26 colon cancer cells treated with PD-1 and/or PD-L1 inhibitors showed that the combination of anti-PD-1 and anti-PD-L1, either sequentially or simultaneously administered, caused myocarditis lesions with myocyte injury and patchy mononuclear infiltrates in the myocardium. A significant increase of infiltrating neutrophils in myocytes was noted only in mice with sequential blockade, implying a role for the pathogenesis of myocarditis. Among circulating leukocytes, concurrent and subsequent treatment of PD-1 and PD-L1 inhibitors led to sustained suppression of neutrophils. Among tumor-infiltrating leukocytes, combinatorial blockade increased CD8⁺ T cells and NKG2D⁺ T cells, and reduced tumor-associated macrophages, neutrophils, and natural killer (NK) cells in the lung metastatic microenvironment. The combinatorial treatments exhibited better control and anti-PD-L1 followed by anti-PD-1 was the most effective. In conclusion, the combinatory use of PD-1 and PD-L1 blockade, either sequentially or concurrently, may cause fulminant cardiotoxicity, although it gives better tumor control, and such usage should be cautionary.

Managing cardiotoxicity associated with immune checkpoint inhibitors

Immuno-oncology is a fast evolving field of cancer therapy and immune checkpoint inhibitors (ICIs) are clearly a breakthrough in this field. Cardiotoxicity with conventional anti-cancer therapies has been well studied in the past and clear guidelines for management of these side effects are available in the literature. However, cardiotoxicity with novel agents such as ICIs has been fairly under-reported and/or underestimated and we are yet to formulate clear guidelines for management of these rare side effects. In the last few years, there has been an overall increase in the number of cases of cardiotoxicity related to ICIs. In this literature review, we describe the mechanism of action of the most widely used ICIs and their related cardiotoxicities. The increase in number of case reports about the potential of cardiotoxicities with these novel agents clearly indicates the need for a new insight into the field of cardio-immuno-oncology.

Cardio-oncology - strategies for management of cancer-therapy related cardiovascular disease

Current therapy of advanced cancers is based on several modalities including radiotherapy, cytotoxic chemotherapy, molecularly targeted inhibitors and antibodies targeting immune checkpoints. All of those these modalities can negatively impact the cardiovascular system, and there is considerable experience in relation to radiotherapy and chemotherapy. In contrast, the knowledge base on cardiovascular toxicities of novel agents targeting signal transduction pathways and immune regulation is quite limited. In particular, potential late effects are of concern as cardiovascular pathology can negatively impact quality of life and prognosis in cancer survivors, particularly when additional cardiovascular risk factors are present. Treatment-associated adverse events include hypertension, venous thromboembolism, coronary artery disease, valvular heart disease, heart failure and arrhythmias. Early diagnosis of subclinical cardiotoxic effects of cancer therapies remains challenging. Integrated care, as provided by multidisciplinary cardio-oncology teams is the best option for prevention, diagnosis and treatment of cardiovascular diseases associated with cancer therapy. This review considers the cardiotoxic effects of specific cancer therapies and discusses novel diagnostic and therapeutic approaches as a reference for optimizing the care of cancer patients receiving novel cancer therapies.

Arterial events in cancer patients-the case of acute coronary thrombosis

Patients with cancer are at high risk for both venous and arterial thrombotic complications. A variety of factors account for the greater thrombotic risk, including the underlying malignancy and numerous cancer-directed therapies. The occurrence of an acute thrombotic event in patients with cancer is associated with substantial morbidity and mortality. Acute coronary syndrome (ACS) represents a particularly important cardiovascular complication in cancer patients. With cardio-vascular risk factors becoming more prevalent in an aging cancer population that is surviving longer, questions pertaining to the appropriate management of vascular toxicity are likely to assume even greater value in the coming years. In this article, we review the current understanding of ACS in patients with cancer. The predisposition to thrombosis in a malignant host and the cancer treatments most commonly associated with vascular toxicity are reviewed. Risk prediction and management strategies are discussed, and discrepancies in the clinical evidence are highlighted.