Immune Checkpoint Inhibitor Myocarditis Research Articles

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

BackgroundGlobal 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. ObjectivesThis study aimed to detail the role of GCS and GRS in ICI myocarditis. MethodsIn 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. ResultsCases 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). ConclusionsGCS and GRS are lower in ICI myocarditis, and the magnitude of reduction has prognostic significance.

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

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. 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. 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. 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.

Single-cell profiling of human heart and blood in immune checkpoint inhibitor-associated myocarditis.

2507 Background: Myocarditis due to immune checkpoint inhibitors (ICIs) is uncommon; however, myocarditis due to ICIs leads to severe morbidity and even death in 20-40% of cases. The molecular underpinnings of ICI-associated myocarditis are poorly understood, and there is an unmet clinical need to identify therapeutic targets and biomarkers that can aid in disease management. Methods: Heart tissue was obtained through endomyocardial biopsy or autopsy of patients receiving ICIs and was profiled with paired single-cell RNA sequencing (scRNA-seq) and T cell receptor sequencing (TCR) using the 10x Genomics Chromium system. A control dataset was constructed using scRNAseq data of heart tissue from patients receiving ICIs but without myocarditis and a published dataset from healthy patients not receiving ICIs. Peripheral blood mononuclear cells (PBMCs) were collected at the time of myocarditis diagnosis in a larger cohort of patients and analyzed with ICI-treated controls. The CITE-Seq protocol was used to measure paired scRNA-seq, TCR, and surface proteomics in PBMCs, using serial timepoints where available. Results: Heart tissue from 13 patients with myocarditis, including three fatal cases, and seven controls yielded 77,712 single cells. Blood profiling from 27 patients with ICI myocarditis and ICI-treated controls across 54 samples yielded over 230,000 cells. ICI myocarditis tissue demonstrated an increased T cell infiltrate (OR 8.94, FDR = 0.0021). Expression of multiple inflammatory pathways, most notably interferon responses, was up-regulated across multiple immune and non-immune cell types in the setting of myocarditis, providing important pathophysiological insights. T cell clones were also found to be shared between blood and heart, enabling the identification of putative pathogenic T cell subsets. Conclusions: Increased intramyocardial T cells and the activation of interferon response gene networks were seen in the setting of ICI myocarditis. These preliminary findings highlight potential pathological pathways in ICI myocarditis that could serve as biomarkers or therapeutic targets.

Association of early electrical changes with cardiovascular outcomes in immune checkpoint inhibitor myocarditis

Immune-checkpoint inhibitor-associated myocarditis (ICI-myocarditis) often presents with arrhythmias, but the prognostic value of early electrocardiogram findings is unclear. Although ICI-myocarditis and acute cellular rejection (ACR) following cardiac transplantation use similar treatment strategies, differences in arrhythmia burden are unknown. To evaluate the association of electrocardiogram findings in ICI-myocarditis with myocarditis-related mortality and life-threatening arrhythmia. A total of 125 cases of ICI-myocarditis were identified retrospectively across 49 hospitals worldwide; 50 cases of grade 2R or 3R ACR were included as comparators. Two cardiologists blinded to clinical data interpreted electrocardiograms. Associations between electrocardiogram features, myocarditis-related mortality and the composite of myocarditis-related mortality and life-threatening arrhythmias were examined. Adjusted hazard ratios (aHRs) were calculated. The cohort had 78 (62.4%) men; median (interquartile range) age was 67 (58-76) years. At 30 days, myocarditis-related mortality was 20/124 (16.1%), and 28/124 (22.6%) met the composite endpoint. Patients who developed complete heart block (aHR by subdistribution hazards model [aHR(sh)] 3.29, 95% confidence interval [CI] 1.24-8.68; P=0.02) or life-threatening cardiac arrhythmias (aHR(sh) 6.82, 95% CI: 2.87-16.21; P<0.001) had a higher risk of myocarditis-related mortality. Pathological Q waves (aHR(sh) 3.40, 95% CI: 1.38-8.33; P=0.008), low QRS voltage (aHR(sh) 6.05, 95% CI: 2.10-17.39; P<0.001) and Sokolow-Lyon index (aHR(sh)/mV 0.54, 95% CI: 0.30-0.97; P=0.04) on admission electrocardiogram were also associated with increased risk of myocarditis-related mortality. These associations were mirrored in the composite outcome analysis. Compared with ACR, ICI-myocarditis had a higher incidence of life-threatening cardiac arrhythmias (15/125 [12.0%] vs 1/50 [2%]; P=0.04) and third-degree heart block (19/125 [15.2%] vs 0/50 [0%]; P=0.004). Electrocardiograms in ICI-myocarditis with ventricular tachycardias, heart block, low-voltage and pathological Q waves were associated with myocarditis-related mortality and life-threating arrhythmia. Arrhythmia burden in ICI-myocarditis exceeds that of ACR after heart transplant.

54-Year-Old Man With Acute Dyspnea on Exertion

54-Year-Old Man With Acute Dyspnea on Exertion

Sex-Specific Cardiovascular Risks of Cancer and Its Therapies.

In both cardiovascular disease and cancer, there are established sex-based differences in prevalence and outcomes. Males and females may also differ in terms of risk of cardiotoxicity following cancer therapy, including heart failure, cardiomyopathy, atherosclerosis, thromboembolism, arrhythmias, and myocarditis. Here, we describe sex-based differences in the epidemiology and pathophysiology of cardiotoxicity associated with anthracyclines, hematopoietic stem cell transplant (HCT), hormone therapy and immune therapy. Relative to males, the risk of anthracycline-induced cardiotoxicity is higher in prepubertal females, lower in premenopausal females, and similar in postmenopausal females. For autologous hematopoietic cell transplant, several studies suggest an increased risk of late heart failure in female lymphoma patients, but sex-based differences have not been shown for allogeneic hematopoietic cell transplant. Hormone therapies including GnRH (gonadotropin-releasing hormone) modulators, androgen receptor antagonists, selective estrogen receptor modulators, and aromatase inhibitors are associated with cardiotoxicity, including arrhythmia and venous thromboembolism. However, sex-based differences have not yet been elucidated. Evaluation of sex differences in cardiotoxicity related to immune therapy is limited, in part, due to low participation of females in relevant clinical trials. However, some studies suggest that females are at increased risk of immune checkpoint inhibitor myocarditis, although this has not been consistently demonstrated. For each of the aforementioned cancer therapies, we consider sex-based differences according to cardiotoxicity management. We identify knowledge gaps to guide future mechanistic and prospective clinical studies. Furthering our understanding of sex-based differences in cancer therapy cardiotoxicity can advance the development of targeted preventive and therapeutic cardioprotective strategies.

Correction to: Electrocardiographic Manifestations of Immune Checkpoint Inhibitor Myocarditis.

Correction to: Electrocardiographic Manifestations of Immune Checkpoint Inhibitor Myocarditis.

Abstract 12876: Identification of Pathogenic Immune Cell Subsets in Immunotherapy-Induced Myocarditis

Introduction: 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 (irAE) 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 pathologic immune subsets and molecular changes in ICI myocarditis are unknown. Hypothesis: We hypothesize that ICI myocarditis is associated with significant quantitative and molecular changes in pathogenic immune cell subsets. Methods: To identify immune subset(s) associated with ICI myocarditis, we performed time-of-flight mass cytometry (CyTOF) on peripheral blood mononuclear cells from 40 patients and controls with autoimmune adverse events (irAE) on ICI including four patients with ICI myocarditis. We also profiled 15 patients/controls using single cell T-cell receptor (TCR) sequencing and RNA sequencing (scRNA-seq) with feature barcoding for surface marker expression confirmation. Results: With both methods, we found expansion of cytotoxic CD8+ T effector cells re-expressing CD45RA (Temra CD8+ cells) in ICI myocarditis patients compared to controls. Using TCR sequencing, these CD8+ Temra cells were clonally expanded in myocarditis patients. Transcriptomic analysis of these Temra CD8+ clones confirmed a highly activated and cytotoxic phenotype with expression of granzyme/perforin. Longitudinal study demonstrated progression of these Temra CD8+ cells into an exhausted phenotype two months after treatment with glucocorticoids. Differential expression of proinflammatory chemokines (CCL4/CCL4L2/CCL5) was uncovered in clonally expanded Temra CD8+ cells, and ligand-receptor analysis implicated their regulation of other inflammatory cells such as monocytes and NK cells. Conclusions: Clonal cytotoxic Temra CD8+ cells are significantly increased in patients with ICI myocarditis, and have unique transcriptional changes, including upregulation of chemokines CCL4/CCL4L2/CCL5, which may serve as attractive diagnostic/therapeutic targets.

Abstract 9923: Global Circumferential Strain and Cardiovascular Events in Patients with Myocarditis Related to Immune Checkpoint Inhibitors

Introduction: Myocarditis is a rare but highly morbid complication of immune-checkpoint inhibitors (ICI) use. Improved methods for detection and risk stratification are needed. Cytotoxic chemotherapy associates with reduced global circumferential strain (GCS) but no data is available on the utility of GCS in ICI myocarditis. Hypothesis: We hypothesized that GCS by echocardiography would be reduced in ICI myocarditis and the magnitude of reduction would have prognostic implications. Methods: In this retrospective cohort, GCS from 75 patients with ICI myocarditis (cases) and 49 ICI treated patients without myocarditis (controls) was compared. Pre-ICI GCS values were available for 10 cases and 39 controls. Measurements were performed by a reader blinded to group and time (TomTec, Germany). Major adverse cardiac event was defined as a composite of cardiogenic shock, cardiac arrest, complete heart block, and cardiac death. Results: Cases and controls had similar age (66±15 vs. 63±12 years; p=0.19), sex (male: 55% vs. 66%; p=0.22) and cancer type (p=0.08). Pre-ICI GCS values were lower in cases (n=10) than in controls (n=39) (-21.7±2.0 vs. -23.5±2.9, p=0.04), but within normal range. Overall, 56% (n=42) of cases had left ventricular ejection fraction (LVEF) &gt;50% at presentation. The GCS was lower in cases than in controls (-17.5±4.2 vs. -23.5±3.0, p&lt;0.001) in the entire cohort and in both preserved (-19.7±3.8 vs. -23.6±3.0, p&lt;0.001) and reduced EF (-14.6±2.7 vs. -20.9±2.3, p&lt;0.001) strata. Over a median follow-up of 30 days, 28 events occurred. An absolute GCS value &lt; the median (17.1%) was associated with an increased rate of events (HR: 4.9, 95% CI: 1.6-15.0, p=0.005, Figure), adjusted for age and LVEF. The association was also noted when GCS is treated as continuous (HR: 1.18, 95% CI: 1.03-1.35, p=0.02). Conclusions: Global circumferential strain is lower in patients with ICI-myocarditis and the magnitude of the reduction in GCS has prognostic significance.

Abstract 9361: The Effect of Immune Checkpoint Inhibitors on the Right Ventricle and Pulmonary Vasculature: Autopsy/Biopsy and Echocardiographic Data

Introduction: Immune checkpoint inhibitors (ICI) have revolutionized cancer treatment but can lead to cardiovascular toxicities including myocarditis which can present as left ventricular dysfunction. Little is known about the effect of ICIs on the right ventricle (RV) and pulmonary vasculature. Methods: We identified six patients at our institution with ICI-induced myocarditis and right ventricular dysfunction. We also compared pulmonary pressure estimates or tricuspid regurgitant velocity measurements in two independent cohorts of patients who had pre- and post-ICI treatment echocardiography (echo) data. The first cohort included 13 unselected patients with renal cell carcinoma (RCC) or melanoma treated with an ICI at this institution. The second cohort included 31 patients from an international registry who met European Society of Cardiology criteria for ICI myocarditis. Echo parameters pre- and post-ICI were compared using the Wilcoxon signed rank test. Results: Biopsy and autopsy results from the six patient case series revealed lymphocytic myocarditis affecting the interventricular septum and right ventricle (Table 1). All patients with autopsies had RV dilation, and five of the six patients had RV dysfunction on imaging during their hospitalization. In the melanoma/RCC cohort, tricuspid regurgitation velocity was significantly increased post-ICI versus pre-ICI [mean 2.42, SD 0.51 m/s vs. mean 2.16, SD 0.48 m/s, p=0.03]. Right ventricular systolic pressure (RVSP) pre-ICI [mean 24.00, SD 8.26 mmHg] was decreased compared to post-ICI [mean 31.93, SD 12.93 mmHg, p=0.05]. In the second cohort, RVSP was significantly increased post-ICI [median: 30.5, IQR: 26.7-38] as compared to pre-ICI [median: 27.5, IQR: 24.6-35, p=0.03]. Conclusion: ICIs may negatively affect RV and pulmonary circulatory function. More research is needed to understand whether ICIs increase the risk of RV dysfunction and pulmonary vascular disease.

Ventricular arrhythmias in patients with immune checkpoint inhibitor myocarditis

Abstract Background Immune checkpoint inhibitor (ICI)-associated myocarditis is associated with a markedly increased risk of morbidity and mortality. The occurrence of ventricular arrhythmias (VA) in patients with ICI-associated myocarditis has not been well characterized. Purpose The aim of this study was to determine the characteristics and risk factors for severe VA in patients with ICI myocarditis. Methods The cohort consisted of 202 patients with ICI myocarditis. Ventricular arrhythmias were defined as a composite of sustained ventricular tachycardia and ventricular fibrillation. We used a multivariable logistic regression model to test the association between clinical variables and the development of VA. Results From a cohort of 202 patients with ICI myocarditis (67±13 years, 35% female, 60% hypertension, 23% diabetes mellitus), 41 (20.3%) developed VA, of which, 33 had VT and 8 had VF. The median time from admission to VF was 144 hours and to VT was 72 hours. A VA occurred in 17.5% of patients with a normal LVEF, and 25% of patients with reduced LVEF. On univariate analysis, a QRS duration &amp;gt;110ms (OR 2.88, 95% CI 1.40 to 6.16, P=0.005) and a QTc duration &amp;gt;470ms were associated with an increased probability of VA (OR 2.58, 95% CI 1.23, 5.41, P=0.012). The association remained significant after adjustment for age and gender. Additionally, a longer time from admission to initiation of corticosteroids was associated with a higher probability of VA (OR 1.06, 95% CI 1.01 to 1.13, P=0.027). The association between the time from admission to administration of corticosteroids and probability of VA remained significant after adjustment for age, gender, and LVEF on admission (OR, 1.06, 95% CI 1.00, 1.13, P=0.037) where each 6-hour delay in the initiation of corticosteroids was associated with a 4% increase in the risk for VA. Conclusions Ventricular arrhythmias are common in the setting of ICI myocarditis and are observed in patients presenting with both a preserved and a reduced LVEF. Wider QRS and longer QT at presentation and longer time from admission to initiation of corticosteroids were associated with an increased risk of VA. Funding Acknowledgement Type of funding sources: None.

The role of endomyocardial biopsy in suspected myocarditis in the contemporary era: a 10-year National Transplant Centre experience

BackgroundDiagnostic endomyocardial biopsy (EMB) in patients with suspected myocarditis helps to direct therapy and guide prognosis. This study aimed to investigate the correlation between the 2007 clinical guideline indications for EMB and the presence of a diagnostic biopsy result and associated outcomes in patients with suspected myocarditis in a national quaternary referral center in a contemporary cohort. MethodsAll cases of suspected myocarditis referred to the National Cardiac Transplant Centre who underwent EMB between 2009 and 2019 were identified retrospectively through pathology records. Outcomes including subsequent need for inotrope and/or mechanical circulatory support (MCS), heart transplantation and in-hospital mortality were recorded. ResultsIn total, 25 (68% male, mean age of 45 ± 15 years) EMBs were performed for this indication across this time period, 64% (n = 16) of which demonstrated diagnostic results, the majority (75%, n = 12) identifying acute lymphocytic myocarditis, 13% (n = 2) giant cell, one patient (6.3%) eosinophilic and one (6.3%) an immune checkpoint inhibitor myocarditis. The majority of those with histologically confirmed myocarditis had a Class I or IIa guideline indication for EMB (n = 12, 75%). The remaining 4 patients (25%), either met Class IIb criteria (n = 2) or would not have been accounted for in this guideline. The majority of patients requiring inotropes and/or MCS (n = 9/11), and/or heart transplant (n = 3/4), or who later died (n = 4/5) were in the diagnostic biopsy group. ConclusionsIn this 10-year National referral sample, 75% of patients with histologically confirmed myocarditis had a Class I or IIa indication for EMB, reinforcing the usefulness of traditional guidelines in this contemporary era. However, 25% of patients with a subsequent confirmed histological diagnosis had either none or a less well-established indication for EMB, highlighting the need for clinical suspicion outside of accepted clinical scenarios.

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

Although immune checkpoint inhibitor (ICI) myocarditis carries a high reported mortality, increasing reports of smoldering myocarditis suggest a clinical spectrum of disease. Endomyocardial biopsy (EMB) remains the gold standard for diagnosis of ICI myocarditis, but different pathologic diagnostic criteria exist. The objective of this study was to classify the spectrum of ICI myocarditis and myocardial inflammation by pathology findings on EMB and correlate this with clinical outcomes. All patients who had EMB at MD Anderson Cancer Center between January 2018 and August 2019 for suspected ICI myocarditis were retrospectively reviewed. A grading system (Grades 0-2) based on the degree of inflammatory infiltrate was developed by pathologists. Cardiovascular outcomes and treatment were compared between grades of pathology. We identified 28 patients who had EMB for suspected ICI myocarditis, of which 18 were positive for myocarditis/inflammation. There were four deaths (two in Grade 2 and two in Grade 1), but only one was attributable to myocarditis. Grade 2 patients had no myocarditis-associated deaths despite having the highest troponin T values (median 2063 pg/mL). Four patients with Grade 1 myocardial inflammation continued ICI without any immunomodulation, and all were alive without adverse cardiovascular events at follow-up. We defined an EMB grading system for ICI myocarditis encompassing a spectrum of histologic findings of inflammatory infiltrates. A subset of low-grade myocardial inflammation patients were able to continue ICI without immunosuppressive therapy. Further studies are needed to identify low-risk patients who can be safely treated with ICI.

Management of immune checkpoint inhibitor myocarditis: a serial cardiovascular magnetic resonance T2 mapping approach.

Management of immune checkpoint inhibitor myocarditis: a serial cardiovascular magnetic resonance T2 mapping approach.

Myocarditis as a rare, yet serious adverse event associated with immune checkpoint inhibitors in patients with non-small cell lung cancer: Case series from a large community-based cancer center.

e21047 Background: Patients (pts) with lung cancer and other cancers treated with immune checkpoint inhibitors (ICI) may experience immune related adverse events (irAE). These can present with variable severity and with single- or multi-organ involvement including pneumonitis, colitis, hepatitis, and myocarditis/pericarditis. The incidence of myocarditis has been reported between 0.06% and 2.4% and is associated with a high mortality (25% to 50%). This retrospective review of real-world data (RWD) investigates myocarditis as a high-grade adverse event in pts with lung cancer treated with ICIs. Methods: Pts were identified and characterized using RWD in the Syapse Learning Health Network platform from 2010 to 2020 at Advocate Aurora Health Care. Eligible pts included: ≥18 years old; histologically confirmed NSCLC; and myocarditis diagnosis by ICD codes. Additional chart review was performed to confirm timing of ICI treatment and myocarditis. All pts identification and review were performed after IRB review. Results: 12,686 pts with non-small cell lung cancer were eligible for review. The median age at diagnosis was 70; 54% were female; 86% were White and 12% were Black; 1,975 (15.6%) were treated with an ICI and of those 4 cases (0.2%) of myocarditis were identified. All 4 pts were White females, ages 46, 59, 65, and 74 years. Pathology included lung adenocarcinoma (3) and an undifferentiated lung carcinoma (1). All pts had metastatic disease, and none had a prior history of cardiac disease. ICIs were pembrolizumab (2), durvalumab (1), and nivolumab (1). Median time from initial dose of ICI to diagnosis of myocarditis was 62 days [range: 42-185]. All 4 pts presented with chest pain and elevated troponin T [median 0.07 ng/ml (range: 0.06-0.08)]. All pts had echocardiography at the time of diagnosis, and 2 pts had cardiac MRI that confirmed myocarditis. 3 pts were treated with a prednisone taper. 1 pt died of recurrent congestive heart failure and ventricular tachycardia despite rescue attempt with high dose corticosteroids. 2 pts had additional concomitant irAEs of hypothyroidism/colitis, and thyroiditis/pneumonitis, respectively. Conclusions: Many irAEs are reversible. This RWD analysis confirms that clinically evident myocarditis is a rare but serious adverse event of ICI therapy. Early consideration, diagnosis, and intervention may help prevent poor outcomes. Termination of ICI therapy along with initiation of corticosteroids constitute the current standard of management. Further research is warranted to better identify high risk groups, surveillance measures, and improved management of ICI associated myocarditis.

Myosin specific TRM cells mediate increased severity of immune checkpoint inhibitor myocarditis

Abstract Immune checkpoint blockade has revolutionized the field of cancer immunotherapy; however, it has been also associated with immune-related adverse events (IRAE). Immune checkpoint inhibitor (ICI)-myocarditis occurs in approximately 1% of patients, however, it has a high fatality rate of up to 50%. To prevent life-threatening toxicities, it is imperative to understand what predisposes patients to ICI-myocarditis. We examined if previous cardiac injury increases an individual’s susceptibility to develop ICI-myocarditis. We demonstrated that ischemic injury substantially changes the phenotype of cardiac lymphocytes, causing them to upregulate the well-characterized tissue resident markers such as CD69 and CD103. We were excited to find that these cardiac tissue resident T (TRM) cells express prominent levels of the checkpoint molecule PD-1 and have high TCR specificity for cardiac myosin. TRM cells have been described in the literature to establish residency in non-lymphoid organs where they provide a rapid functional response more efficiently than circulating memory T cells. To investigate the role that cardiac TRM cells play in the occurrence of ICI-myocarditis, we developed a novel two-hit model. In this model cardiac injury is induced through ischemic injury (first hit), mice are allowed to recover before we begin the administration of immune checkpoint antibodies (second hit). Our data suggest that after the administration of PD-1 blocking antibodies, mice with myosin specific TRM cells are more susceptible to ICI-myocarditis. Further characterization of cardiac TRM cells could provide insight into why checkpoint mediated cardiac toxicities are particularly rapid and have high fatality rates.

Slow bidirectional ventricular tachycardia as a manifestation of immune checkpoint inhibitor myocarditis

Slow bidirectional ventricular tachycardia as a manifestation of immune checkpoint inhibitor myocarditis

Treatment of corticosteroid refractory immune checkpoint inhibitor myocarditis with Infliximab: a case series

BackgroundGlucocorticoid treatment remains the cornerstone of therapy for immune checkpoint inhibitor (ICI) myocarditis, but data supporting the use of additional immunotherapy for steroid refractory cases remains limited. We investigate the safety and efficacy of infliximab in patients with ICI myocarditis who are refractory to corticosteroids. Additionally, we highlight the importance of a multi-disciplinary approach in the care for these complex patients.MethodsWe retrospectively identified consecutive patients who developed ICI myocarditis at our institution between January 2017 and January 2020. Baseline characteristics, laboratory data and clinical outcomes were compared between patients who received infliximab and those who did not.ResultsOf a total of 11 patients who developed ICI myocarditis, 4 were treated with infliximab. Aside from age, there were no significant differences in baseline patient characteristics between the two groups including total number of ICI doses received and duration from initial ICI dose to onset of symptoms. The time to troponin normalization was 58 vs. 151.5 days (p = 0.25). The duration of prednisone taper was longer in the infliximab group (90 vs. 150 days p = 0.32). All patients survived initial hospital admission. Over a median follow-up period of 287 days, two of the 4 patients died from sepsis 2 and 3 months after initial treatment of their myocarditis; one of these patients was on a steroid taper and the other patient had just completed a steroid taper.ConclusionsInfliximab, despite its black box warning in patients with heart failure, may be a safe and effective treatment for ICI myocarditis.

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

BackgroundMyocarditis 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. ObjectivesThis study sought to assess the value of CMR T1 and T2 mapping in patients with ICI myocarditis. MethodsIn 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. ResultsOf 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. ConclusionsThe 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

BackgroundMyocarditis 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...