Immune Responses in Checkpoint Myocarditis Across Heart, Blood, and Tumor.

Immune checkpoint inhibitors (ICIs) are widely used anti-cancer therapies that can cause morbid and potentially fatal immune-related adverse events (irAEs). ICI-related myocarditis (irMyocarditis) is uncommon but has the highest mortality of any irAE. The pathogenesis of irMyocarditis and its relationship to anti-tumor immunity remain poorly understood. We sought to define immune responses in heart, tumor, and blood during irMyocarditis and identify biomarkers of clinical severity by leveraging single-cell (sc)RNA-seq coupled with T cell receptor (TCR) sequencing, microscopy, and proteomics analysis of 28 irMyocarditis patients and 23 controls. Our analysis of 284,360 cells from heart and blood specimens identified cytotoxic T cells, inflammatory macrophages, conventional dendritic cells (cDCs), and fibroblasts enriched in irMyocarditis heart tissue. Additionally, potentially targetable, pro-inflammatory transcriptional programs were upregulated across multiple cell types. TCR clones enriched in heart and paired tumor tissue were largely non-overlapping, suggesting distinct T cell responses within these tissues. We also identify the presence of cardiac-expanded TCRs in a circulating, cycling CD8 T cell population as a novel peripheral biomarker of fatality. Collectively, these findings highlight critical biology driving irMyocarditis and putative biomarkers for therapeutic intervention.

Mediators and mechanisms of immune checkpoint inhibitor-associated myocarditis: Insights from mouse and human.

The broad application of immune checkpoint inhibitors (ICIs) has led to significant gains in cancer outcomes. By abrogating inhibitory signals, ICIs promote T cell targeting of cancer cells but can frequently trigger autoimmune manifestations, termed immune-related adverse events (irAEs), affecting essentially any organ system. Among cardiovascular irAEs, immune-related myocarditis (irMyocarditis) is the most described and carries the highest morbidity. The currently recommended treatment for irMyocarditis is potent immunosuppression with corticosteroids and other agents, but this has limited evidence basis. The cellular pathophysiology of irMyocarditis remains poorly understood, though mouse models and human data have both implicated effector CD8+ T cells, some of which are specific for the cardiomyocyte protein α-myosin. While the driving molecular signals and transcriptional programs are not well defined, the involvement of chemokine receptors such as CCR5 and CXCR3 has been proposed. Fundamental questions regarding why only approximately 1% of ICI recipients develop irMyocarditis and why irMyocarditis carries a much worse prognosis than other forms of lymphocytic myocarditis remain unanswered. Further work in both murine systems and with human samples are needed to identify better tools for diagnosis, risk-stratification, and treatment.

Serial Measurement of Global Longitudinal Strain Among Women With Breast Cancer Treated With Proton Radiation Therapy: A Prospective Trial for 70 Patients.

PURPOSE: Conventional photon radiation therapy (RT) for breast cancer is associated with a reduction in global longitudinal strain (GLS) and an increase in troponin, N-terminal pro hormone B-type natriuretic peptide (NT-proBNP), and incident heart failure. The cardiac radiation exposure with proton-RT is much reduced and thus may be associated with less cardiotoxicity. The objective was to test the effect of proton-RT on GLS, troponin, and NT-proBNP. METHODS AND MATERIALS: We conducted a prospective, observational, single-center study of 70 women being treated with proton-RT for breast cancer. Serial measurements of GLS, high-sensitivity troponin I, and NT-proBNP were performed at prespecified intervals (before proton-RT, 4 weeks after completion of proton-RT, and again at 2 months after proton-RT). RESULTS: The mean age of the patients was 46 ± 11 years, and the mean body mass index was 25.6 ± 5.2 kg/m2; 32% of patients had hypertension, and the mean radiation doses to the heart and the left ventricle (LV) were 0.44 Gy and 0.12 Gy, respectively. There was no change in left ventricular ejection fraction (65 ± 5 vs 66 ± 5 vs 64 ± 4%; P = .15), global GLS (-21.7 ± 2.7 vs -22.7 ± 2.3 vs -22.8 ± 2.1%; P = .24), or segmental GLS from before to after proton-RT. Similarly, there was no change in either high-sensitivity troponin or NT-proBNP with proton-RT. However, in a post hoc subset analysis, women with hypertension had a greater decrease in GLS after proton-RT compared with women without hypertension (-21.3 ± 3.5 vs -24.0 ± 2.4%; P = .006). CONCLUSIONS: Proton-RT did not affect LV function and was not associated with an increase in biomarkers. These data support the potential cardiac benefits of proton-RT compared with conventional RT.

Global Circumferential and Radial Strain Among Patients With Immune Checkpoint Inhibitor Myocarditis.

BACKGROUND: Global circumferential strain (GCS) and global radial strain (GRS) are reduced with cytotoxic chemotherapy. There are limited data on the effect of immune checkpoint inhibitor (ICI) myocarditis on GCS and GRS. OBJECTIVES: This study aimed to detail the role of GCS and GRS in ICI myocarditis. METHODS: In this retrospective study, GCS and GRS from 75 cases of patients with ICI myocarditis and 50 ICI-treated patients without myocarditis (controls) were compared. Pre-ICI GCS and GRS were available for 12 cases and 50 controls. Measurements were performed in a core laboratory blinded to group and time. Major adverse cardiovascular events (MACEs) were defined as a composite of cardiogenic shock, cardiac arrest, complete heart block, and cardiac death. RESULTS: Cases and controls were similar in age (66 ± 15 years vs 63 ± 12 years; P = 0.20), sex (male: 73% vs 61%; P = 0.20) and cancer type (P = 0.08). Pre-ICI GCS and GRS were also similar (GCS: 22.6% ± 3.4% vs 23.5% ± 3.8%; P = 0.14; GRS: 45.5% ± 6.2% vs 43.6% ± 8.8%; P = 0.24). Overall, 56% (n = 42) of patients with myocarditis presented with preserved left ventricular ejection fraction (LVEF). GCS and GRS were lower in myocarditis compared with on-ICI controls (GCS: 17.5% ± 4.2% vs 23.6% ± 3.0%; P < 0.001; GRS: 28.6% ± 6.7% vs 47.0% ± 7.4%; P < 0.001). Over a median follow-up of 30 days, 28 cardiovascular events occurred. A GCS (HR: 4.9 [95% CI: 1.6-15.0]; P = 0.005) and GRS (HR: 3.9 [95% CI: 1.4-10.8]; P = 0.008) below the median was associated with an increased event rate. In receiver-operating characteristic (ROC) curves, GCS (AUC: 0.80 [95% CI: 0.70-0.91]) and GRS (AUC: 0.76 [95% CI: 0.64-0.88]) showed better performance than cardiac troponin T (cTnT) (AUC: 0.70 [95% CI: 0.58-0.82]), LVEF (AUC: 0.69 [95% CI: 0.56-0.81]), and age (AUC: 0.54 [95% CI: 0.40-0.68]). Net reclassification index and integrated discrimination improvement demonstrated incremental prognostic utility of GRS over LVEF (P = 0.04) and GCS over cTnT (P = 0.002). CONCLUSIONS: GCS and GRS are lower in ICI myocarditis, and the magnitude of reduction has prognostic significance.

Hemodynamic and Clinical Performance of Hearts Donated After Circulatory Death.

BACKGROUND: Donor organ demand continues to outpace supply in heart transplantation. Utilization of donation after circulatory death (DCD) hearts could significantly increase heart donor availability for patients with advanced heart failure. OBJECTIVES: The purpose of this study was to describe hemodynamic and clinical profiles of DCD hearts in comparison to standard of care (SOC) hearts donated after brain death (DBD). METHODS: This single-center retrospective cohort study of consecutive heart transplant recipients analyzed right heart catheterization measurements, inotrope scores, echocardiograms, and clinical outcomes between DCD and DBD heart recipients. RESULTS: Between April 2016 and February 2022, 47 DCD and 166 SOC hearts were transplanted. Median time from DCD consent to transplant was significantly shorter compared with SOC waiting list time (17 days [6-28 days] vs 70 days [23-240 days]; P < 0.001). Right heart function was significantly impaired in DCD recipients compared with SOC recipients 1 week post-transplant (higher median right atrial pressure (10 mm Hg [8-13 mm Hg] vs 7 mm Hg [5-11 mm Hg]; P < 0.001), higher right atrial pressure to pulmonary capillary wedge pressure ratio (0.64 [0.54-0.82] vs 0.57 [0.43-0.73]; P = 0.016), and lower pulmonary arterial pulsatility index (1.66 [1.27-2.50] vs 2.52 [1.63-3.82]; P < 0.001), but was similar between groups by 3 weeks post-transplant. DCD and SOC recipient mortality was similar at 30 days (DCD 0 vs SOC 2%; P = 0.29) and 1 year post-transplant (DCD 3% vs SOC 8%; P = 0.16). CONCLUSIONS: DCD heart utilization is associated with transient post-transplant right heart dysfunction and short-term clinical outcomes otherwise similar to transplantation using DBD hearts.

Sodium-Glucose Co-Transporter-2 Inhibitors and Cardiac Outcomes Among Patients Treated With Anthracyclines.

BACKGROUND: Sodium-glucose co-transporter-2 (SGLT2) inhibitors improve outcomes among patients with established heart failure. Despite supportive basic science studies, there are no data on the value of SGLT2 inhibitors among patients treated with anthracyclines. OBJECTIVES: This study sought to test the cardiac efficacy and overall safety of SGLT2 inhibitors in patients treated with anthracyclines. METHODS: This study identified 3,033 patients with diabetes mellitus (DM) and cancer who were treated with anthracyclines. Cases were patients with cancer and DM who were on SGLT2 inhibitor therapy during anthracycline treatment (n = 32). Control participants (n = 96) were patients with cancer and DM who were also treated with anthracyclines, but were not on an SGLT2 inhibitor. The primary cardiac outcome was a composite of cardiac events (heart failure incidence, heart failure admissions, new cardiomyopathy [>10% decline in ejection fraction to <53%], and clinically significant arrhythmias). The primary safety outcome was overall mortality. RESULTS: Age, sex, ethnicity, cancer type, cancer stage, and other cardiac risk factors were similar between groups. There were 20 cardiac events over a median follow-up period of 1.5 years. The cardiac event incidence was lower among case patients in comparison to control participants (3% vs 20%; P = 0.025). Case patients also experienced lower overall mortality when compared with control participants (9% vs 43%; P < 0.001) and a lower composite of sepsis and neutropenic fever (16% vs 40%; P = 0.013). CONCLUSIONS: SGLT2 inhibitors were associated with lower rate of cardiac events among patients with cancer and DM who were treated with anthracyclines. Additionally, SGLT2 inhibitors appeared to be safe. These data support the conducting of a randomized clinical trial testing SGLT2 inhibitors in patients at high cardiac risk treated with anthracyclines.

Renin-angiotensin-aldosterone system inhibitors and survival in patients with hypertension treated with immune checkpoint inhibitors.

BACKGROUND: Preclinical studies indicate that the concurrent use of inhibitors of the renin-angiotensin-aldosterone system (RAAS) may improve outcomes in broad groups of patients with cancer. There are limited data on the association between the use of RAAS inhibitors and outcomes among patients treated with immune checkpoint inhibitors (ICIs). METHODS: We performed a retrospective study of all patients treated with an ICI in a single academic network. Of 10,903 patients, 5910 were on any anti-hypertensive medication. Of those on anti-hypertensive therapy, 3426 were prescribed a RAAS inhibitor during ICI treatment, and 2484 were prescribed other anti-hypertensive medications. The primary outcome was overall survival in the entire cohort and in sub-groups by cancer types. RESULTS: Thoracic cancer (34%) and melanoma (16%) were the most common types of cancer. Those prescribed a RAAS inhibitor were older, more frequently male, and had more cardiovascular risk factors. In a Cox proportional hazard model, the concurrent use of RAAS inhibitors was associated with better overall survival (hazard ratio (HR):0.92, [95% Confidence Interval (CI):0.85-0.99], P = .032). Patients with gastrointestinal (HR:0.82, [95% CI: 0.67-1.01], P = .057) and genitourinary cancer (HR:0.81, [95% CI:0.64-1.01], P = .067) had a non-statistically significant better overall survival. CONCLUSIONS: In this large retrospective study, patients with hypertension who were concomitantly taking a RAAS inhibitor during ICI therapy had better overall survival. This benefit was primarily noted among patients with gastrointestinal and genitourinary cancers. Prospective randomized trials are warranted to further evaluate and specify the benefit of RAAS inhibitors in patients with cancer who receive ICI therapy.

Pre-Existing Autoimmune Disease Increases the Risk of Cardiovascular and Noncardiovascular Events After Immunotherapy.

Background: The use of immune checkpoint inhibitors (ICI) is associated with cardiovascular (CV) events, and patients with pre-existing autoimmune disease are at increased CV risk. Objectives: The aim of this study was to characterize the risk for CV events in patients with pre-existing autoimmune disease post-ICI. Methods: This was a retrospective study of 6,683 patients treated with ICIs within an academic network. Autoimmune disease prior to ICI was confirmed by chart review. Baseline characteristics and risk for CV and non-CV immune-related adverse events were compared with a matched control group (1:1 ratio) of ICI patients without autoimmune disease. Matching was based on age, sex, history of coronary artery disease, history of heart failure, and diabetes mellitus. CV events were a composite of myocardial infarction, percutaneous coronary intervention, coronary artery bypass graft, stroke, transient ischemic attack, deep venous thrombosis, pulmonary embolism, or myocarditis. Univariable and multivariable Cox proportional hazards models were used to determine the association between autoimmune disease and CV events. Results: Among 502 patients treated with ICIs, 251 patients with and 251 patients without autoimmune disease were studied. During a median follow-up period of 205 days, there were 45 CV events among patients with autoimmune disease and 22 CV events among control subjects (adjusted HR: 1.77; 95% CI: 1.04-3.03; P = 0.0364). Of the non-CV immune-related adverse events, there were increased rates of psoriasis (11.2% vs 0.4%; P < 0.001) and colitis (24.3% vs 16.7%; P = 0.045) in patients with autoimmune disease. Conclusions: Patients with autoimmune disease have an increased risk for CV and non-CV events post-ICI.

Immune checkpoint inhibitors for cancer and venous thromboembolic events.

BACKGROUND: Immune checkpoint inhibitors (ICIs) are widely used cancer treatments. There are limited data on the risk for developing venous thromboembolism (VTE) among patients on an ICI. METHODS: This was a retrospective study of 2854 patients who received ICIs at a single academic centre. VTE events, defined as a composite of deep vein thrombosis or pulmonary embolism, were identified by individual chart review and blindly adjudicated using standard imaging criteria. A self-controlled risk-interval design was applied with an 'at-risk period' defined as the two-year period after and the 'control period', defined as the two-year before treatment. The hazard ratio (HR) was calculated using a fixed-effect proportional hazards model. RESULTS: Of the 2854 patients, 1640 (57.5%) were men; the mean age was 64 ± 13 years. The risk for VTE was 7.4% at 6 months and 13.8% at 1 year after starting an ICI. The rate of VTE was > 4-fold higher after starting an ICI (HR 4.98, 95% CI 3.65-8.59, p < 0.001). There was a 5.7-fold higher risk for deep vein thrombosis (HR 5.70, 95% CI 3.79-8.59, p < 0.001) and a 4.75-fold higher risk for pulmonary embolism (HR 4.75, 95% CI 3.20-7.10, p < 0.001). Comparing patients with and without a VTE event, a history of melanoma and older age predicted lower risk of VTE, while a higher Khorana risk score, history of hypertension and history of VTE predicted higher risk. CONCLUSIONS: The rate of VTE among patients on an ICI is high and increases after starting an ICI.

Rationale and design of the preserved versus reduced ejection fraction biomarker registry and precision medicine database for ambulatory patients with heart failure (PREFER-HF) study.

INTRODUCTION: Patients with heart failure (HF) are classically categorised by left ventricular ejection fraction (LVEF). Efforts to predict outcomes and response to specific therapy among LVEF-based groups may be suboptimal, in part due to the underlying heterogeneity within clinical HF phenotypes. A multidimensional characterisation of ambulatory patients with and without HF across LVEF groups is needed to better understand and manage patients with HF in a more precise manner. METHODS AND ANALYSIS: To date, the first cohort of 1313 out of total planned 3000 patients with and without HF has been enroled in this single-centre, longitudinal observational cohort study. Baseline and 1-year follow-up blood samples and clinical characteristics, the presence and duration of comorbidities, serial laboratory, echocardiographic data and images and therapy information will be obtained. HF diagnosis, aetiology of disease, symptom onset and clinical outcomes at 1 and 5 years will be adjudicated by a team of clinicians. Clinical outcomes of interest include all-cause mortality, cardiovascular mortality, all-cause hospitalisation, cardiovascular hospitalisation, HF hospitalisation, right-sided HF and acute kidney injury. Results from the Preserved versus Reduced Ejection Fraction Biomarker Registry and Precision Medicine Database for Ambulatory Patients with Heart Failure (PREFER-HF) trial will examine longitudinal clinical characteristics, proteomic, metabolomic, genomic and imaging data to better understand HF phenotypes, with the ultimate goal of improving precision medicine and clinical outcomes for patients with HF. ETHICS AND DISSEMINATION: Information gathered in this research will be published in peer-reviewed journals. Written informed consent for PREFER-HF was obtained from all participants. All study procedures were approved by the Mass General Brigham Institutional Review Board in Boston, Massachusetts and performed in accordance with the Declaration of Helsinki (Protocol Number: 2016P000339). TRIAL REGISTRATION NUMBER: PREFER-HF ClinicalTrials.gov identifier: NCT03480633.

Association between incidental statin use and skeletal myopathies in patients treated with immune checkpoint inhibitors.

OBJECTIVES: Skeletal myopathies are highly morbid, and in rare cases even fatal, immune-related adverse events (irAE) associated with immune checkpoint inhibitors (ICI). Skeletal myopathies are also a recognized statin-associated side effect. It is unknown whether concurrent use of statins and ICIs increases the risk of skeletal myopathies. METHODS: This was a retrospective cohort study of all patients who were treated with an ICI at a single academic institution (Massachusetts General Hospital, Boston, MA, USA). The primary outcome of interest was the development of a skeletal myopathy. The secondary outcome of interest was an elevated creatine kinase level (above the upper limit of normal). RESULTS: Among 2757 patients, 861 (31.2%) were treated with a statin at the time of ICI start. Statin users were older, more likely to be male and had a higher prevalence of cardiovascular and non-cardiovascular co-morbidities. During a median follow-up of 194 days (inter quartile range 65-410), a skeletal myopathy occurred in 33 patients (1.2%) and was more common among statin users (2.7 vs. 0.9%, P < 0.001). Creatine kinase (CK) elevation was present in 16.3% (114/699) and was higher among statin users (20.0 vs. 14.3%, P = 0.067). In a multivariable Cox model, statin therapy was associated with a >2-fold higher risk for skeletal myopathy (HR, 2.19; 95% confidence interval, 1.07-4.50; P = 0.033). CONCLUSION: In this large cohort of ICI-treated patients, a higher risk was observed for skeletal myopathies and elevation in CK levels in patients undergoing concurrent statin therapy. Prospective observational studies are warranted to further elucidate the potential association between statin use and ICI-associated myopathies.

Effect of a multidisciplinary Severe Immunotherapy Complications Service on outcomes for patients receiving immune checkpoint inhibitor therapy for cancer.

BACKGROUND: In 2017, Massachusetts General Hospital implemented the Severe Immunotherapy Complications (SIC) Service, a multidisciplinary care team for patients hospitalized with immune-related adverse events (irAEs), a unique spectrum of toxicities associated with immune checkpoint inhibitors (ICIs). This study's objectives were to evaluate the intervention's (1) effect on patient outcomes and healthcare utilization, and (2) ability to collect biological samples via a central infrastructure, in order to study the mechanisms responsible for irAEs. METHODS: A hospital database was used to identify patients who received ICIs for a malignancy and were hospitalized with severe irAEs, before (April 2, 2016-October 3, 2017) and after (October 3, 2017-October 24, 2018) SIC Service initiation. The primary outcome was readmission rate after index hospitalization. Secondary outcomes included length of stay (LOS) for admissions, corticosteroid and non-steroidal second-line immunosuppression use, ICI discontinuation, and inpatient mortality. RESULTS: In the pre-SIC period, 127 of 1169 patients treated with ICIs were hospitalized for irAEs; in the post-SIC period, 122 of 1159. After SIC service initiation, reductions were observed in irAE readmission rate (14.8% post-SIC vs 25.9% pre-SIC; OR 0.46; 95% CI 0.22 to 0.95; p=0.036) and readmission LOS (median 6 days post-SIC vs 7 days pre-SIC; 95% CI -16.03 to -0.14; p=0.046). No significant pre-initiation and post-initiation differences were detected in corticosteroid use, second-line immunosuppression, ICI discontinuation, or inpatient mortality rates. The SIC Service collected 789 blood and tissue samples from 234 patients with suspected irAEs. CONCLUSIONS: This is the first study to report that establishing a highly subspecialized care team focused on irAEs is associated with improved patient outcomes and reduced healthcare utilization. Furthermore, the SIC Service successfully integrated blood and tissue collection safety into routine care.

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.

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.

Electrocardiographic features of immune checkpoint inhibitor associated myocarditis.

BACKGROUND: Myocarditis is a highly morbid complication of immune checkpoint inhibitor (ICI) use that remains inadequately characterized. The QRS duration and the QTc interval are standardized electrocardiographic measures that are prolonged in other cardiac conditions; however, there are no data on their utility in ICI myocarditis. METHODS: From an international registry, ECG parameters were compared between 140 myocarditis cases and 179 controls across multiple time points (pre-ICI, on ICI prior to myocarditis, and at the time of myocarditis). The association between ECG values and major adverse cardiac events (MACE) was also tested. RESULTS: Both the QRS duration and QTc interval were similar between cases and controls prior to myocarditis. When compared with controls on an ICI (93±19 ms) or to baseline prior to myocarditis (97±19 ms), the QRS duration prolonged with myocarditis (110±22 ms, p<0.001 and p=0.009, respectively). In contrast, the QTc interval at the time of myocarditis (435±39 ms) was not increased compared with pre-myocarditis baseline (422±27 ms, p=0.42). A prolonged QRS duration conferred an increased risk of subsequent MACE (HR 3.28, 95% CI 1.98 to 5.62, p<0.001). After adjustment, each 10 ms increase in the QRS duration conferred a 1.3-fold increase in the odds of MACE (95% CI 1.07 to 1.61, p=0.011). Conversely, there was no association between the QTc interval and MACE among men (HR 1.33, 95% CI 0.70 to 2.53, p=0.38) or women (HR 1.48, 95% CI 0.61 to 3.58, p=0.39). CONCLUSIONS: The QRS duration is increased in ICI myocarditis and is associated with increased MACE risk. Use of this widely available ECG parameter may aid in ICI myocarditis diagnosis and risk-stratification.

Temporal Trends and Outcomes Among Patients Admitted for Immune-Related Adverse Events: A Single-Center Retrospective Cohort Study from 2011 to 2018.

BACKGROUND: The aim of this study was to characterize severe immune-related adverse events (irAEs) seen among hospitalized patients and to examine risk factors for irAE admissions and clinically relevant outcomes, including length of stay, immune checkpoint inhibitor (ICI) discontinuation, readmission, and death. METHODS: Patients who received ICI therapy (ipilimumab, pembrolizumab, nivolumab, atezolizumab, durvalumab, avelumab, or any ICI combination) at Massachusetts General Hospital (MGH) and were hospitalized at MGH following ICI initiation between January 1, 2011, and October 24, 2018, were identified using pharmacy and hospital admission databases. Medical records of all irAE admissions were reviewed, and specialist review with defined criteria was performed. Demographic data, relevant clinical history (malignancy type and most recent ICI regimen), and key admission characteristics, including dates of admission and discharge, immunosuppressive management, ICI discontinuation, readmission, and death, were collected. RESULTS: In total, 450 admissions were classified as irAE admissions and represent the study's cohort. Alongside the increasing use of ICIs at our institution, the number of patients admitted to MGH for irAEs has gradually increased every year from 9 in 2011 to 92 in 2018. The hospitalization rate per ICI recipient has declined over that same time period (25.0% in 2011 to 8.5% in 2018). The most common toxicities leading to hospitalization in our cohort were gastrointestinal (30.7%; n = 138), pulmonary (15.8%; n = 71), hepatic (14.2%; n = 64), endocrine (12.2%; n = 55), neurologic (8.4%; n = 38), cardiac (6.7%; n = 30), and dermatologic (4.4%; n = 20). Multivariable logistic regression revealed statistically significant increases in irAE admission risk for CTLA-4 monotherapy recipients (odds ratio [OR], 2.02; p < .001) and CTLA-4 plus PD-1 combination therapy recipients (OR, 1.88; p < .001), relative to PD-1/PD-L1 monotherapy recipients, and patients with multiple toxicity had a 5-fold increase in inpatient mortality. CONCLUSION: This study illustrates that cancer centers must be prepared to manage a wide variety of irAE types and that CTLA-4 and combination ICI regimens are more likely to cause irAE admissions, and earlier. In addition, admissions for patients with multi-organ involvement is common and those patients are at highest risk of inpatient mortality. IMPLICATIONS FOR PRACTICE: The number of patients admitted to Massachusetts General Hospital for immune-related adverse events (irAEs) has gradually increased every year and the most common admissions are for gastrointestinal (30.7%), pulmonary (15/8%), and hepatic (14.2%) events. Readmission rates are high (29% at 30 days, 49% at 180 days) and 64.2% have to permanently discontinue immune checkpoint inhibitor therapy. Importantly, multiple concurrent toxicities were seen in 21.6% (97/450) of irAE admissions and these patients have a fivefold increased risk of inpatient death.

Decreased Absolute Lymphocyte Count and Increased Neutrophil/Lymphocyte Ratio With Immune Checkpoint Inhibitor-Associated Myocarditis.

Background Myocarditis attributable to immune checkpoint inhibitor (ICI) therapy is a potentially fatal immune-related adverse event. Limited data have suggested an association between baseline and on-treatment absolute lymphocyte count (ALC) and neutrophil/lymphocyte ratio (NLR) and the development of other immune-related adverse events; there are no data characterizing the role of ALC and NLR in ICI-associated myocarditis. Methods and Results This was a case control study of 55 patients with ICI myocarditis and 55 controls without any post-ICI immune-related adverse events. We leveraged clinical testing, where patients underwent routine serial blood counts before and with each ICI cycle to compare the baseline and change in ALC and NLR between cases and controls. The association between the change in these parameters with clinical variables and major adverse cardiac events was also tested. In cases, there was a statistically significant decrease in ALC with myocarditis from baseline (1.6 thousands per cubic milliliter (K/µL); interquartile range, 1.1-1.9 K/µL) to admission (1.1 K/µL; interquartile range, 0.7-1.3 K/µL; P<0.001). Similarly, there was an increase in NLR from baseline (3.5; interquartile range, 2.3-5.4) to admission (6.6; interquartile range, 4.5-14.1; P<0.001). There was no statistically significant change in controls. In follow-up, there were 20 events; larger decreases in ALC (44.6% versus 18.2%; P<0.001) or increases in NLR (156.5% versus 65.1%; P=0.019) were associated with major adverse cardiac events. Conclusions A reduction in ALC and an increase in NLR was seen with ICI myocarditis. A greater decrease in ALC or increase in NLR was associated with subsequent major adverse cardiac events.

Association Between Immune Checkpoint Inhibitors With Cardiovascular Events and Atherosclerotic Plaque.

BACKGROUND: Immune checkpoint inhibitors (ICIs) treat an expanding range of cancers. Consistent basic data suggest that these same checkpoints are critical negative regulators of atherosclerosis. Therefore, our objectives were to test whether ICIs were associated with accelerated atherosclerosis and a higher risk of atherosclerosis-related cardiovascular events. METHODS: The study was situated in a single academic medical center. The primary analysis evaluated whether exposure to an ICI was associated with atherosclerotic cardiovascular events in 2842 patients and 2842 controls matched by age, a history of cardiovascular events, and cancer type. In a second design, a case-crossover analysis was performed with an at-risk period defined as the 2-year period after and the control period as the 2-year period before treatment. The primary outcome was a composite of atherosclerotic cardiovascular events (myocardial infarction, coronary revascularization, and ischemic stroke). Secondary outcomes included the individual components of the primary outcome. In addition, in an imaging substudy (n=40), the rate of atherosclerotic plaque progression was compared from before to after the ICI was started. All study measures and outcomes were blindly adjudicated. RESULTS: In the matched cohort study, there was a 3-fold higher risk for cardiovascular events after starting an ICI (hazard ratio, 3.3 [95% CI, 2.0-5.5]; P<0.001). There was a similar increase in each of the individual components of the primary outcome. In the case-crossover, there was also an increase in cardiovascular events from 1.37 to 6.55 per 100 person-years at 2 years (adjusted hazard ratio, 4.8 [95% CI, 3.5-6.5]; P<0.001). In the imaging study, the rate of progression of total aortic plaque volume was >3-fold higher with ICIs (from 2.1%/y before 6.7%/y after). This association between ICI use and increased atherosclerotic plaque progression was attenuated with concomitant use of statins or corticosteroids. CONCLUSIONS: Cardiovascular events were higher after initiation of ICIs, potentially mediated by accelerated progression of atherosclerosis. Optimization of cardiovascular risk factors and increased awareness of cardiovascular risk before, during, and after treatment should be considered among patients on an ICI.