Cooper, Leslie T.

Abstract The immunopathogenesis of autoimmune myocarditis and dilated cardiomyopathy (DCM) in humans is unpredictable and pathogenic mechanisms undefined. The aim was to investigate potential autoimmune mechanisms in human autoimmune myocarditis and heart failure. Our evidence for a Th17 immunophenotype in human myocarditis/DCM(n=40) included reduced CD4+CD25+FoxP3+ Tregulatory cells(0.0006), elevated Th17 cells(0.0008) and increased Th17-promoting cytokines(IL-6 and TGF-beta). Th1(IFNγ+) cells were not significantly elevated(p=0.7184). IL-6(<0.0001), TGF-beta(0.0001), IL-23(0.0003), and GM-CSF+ T cells(0.0006) were significantly elevated. IL-17A+ cells were prevalent in biopsies from human myocarditis, non-recovery associated with persistence of IL-17A cytokines and heart failure associated with elevated Th17 cells in peripheral blood. To identify a potential mechanism to promote a Th17 pro-inflammatory pathogenesis in the heart, novel TLR ligands of human cardiac myosin (HCM) (peptides S2-16 and S2-28) promoted myocarditic PBMCs/CD14+ monocytes to produce Th17 cytokines(IL-23 p=0.0289; IL-6,TGF-beta p<0.0001). TLR ligand stimulation of PBMCs/ monocytes was abrogated by antibodies blocking TLR2, IL-6, IL-17A/23, and GM-CSF. Our translational study suggested human myocarditis/DCM may be controlled by a Th17 phenotype including reduced Treg, elevated Th17 cells, and pro-inflammatory and pro-fibrotic Th17 cytokines triggered by cardiac myosin TLR ligands potentially released from heart.

Abstract An estimated 1 billion people worldwide have deficient or insufficient levels of vitamin D (VitD), while roughly 25% of individuals in the US are reported to have inadequate VitD levels. Considerable evidence indicates that VitD deficiency is associated with an increased risk of cardiovascular disease (CVD), yet it remains unclear whether low VitD is simply a biomarker of CVD or has a true pathologic role. The role of VitD deficiency in the pathogenesis of inflammatory myocarditis is unknown- a disease that is higher in men. We found that only 20% of myocarditis patients had low VitD levels. When we examined VitD receptor (VDR) deficient mice in a model of viral myocarditis, we found that VDR decreased myocarditis in females (p=0.007) but increased inflammation in males (p=0.006). Examination of cytokines in the heart found that VDR-/- male mice had significantly reduced IFN-γ and IL-1β and increased IL-17A, but no significant differences were found in females. Comparison of microarray data during myocarditis to published VitD response element genes revealed around 200 genes associated with proinflammatory (e.g. caspase-1) and profibrotic (e.g. TGF-β1, MMP) responses were increased in WT male mice, which was confirmed by qRT-PCR in VDR-/- mice. Our data confirms that VitD through the VDR promotes myocardial inflammation in males, providing a mechanism for how low VitD levels in men increase myocarditis. This work was funded by NIH R01 HL087033 and HL111938.

Abstract Background The risk of adverse cardiovascular events in patients with acute myocarditis (AM) and desmosomal gene variants (DGV) remains unknown. Purpose To ascertain the risk of death, ventricular arrhythmias, recurrent myocarditis, and heart failure (main endpoint) in patients with AM and pathogenic or likely pathogenetic DGV. Methods In a retrospective international study from 23 hospitals, 97 patients were included: 36 with AM and DGV (DGV(+)), 25 with AM and negative gene testing (DGV(−)), and 36 AM patients without genetics (w/o genetics). All patients had troponin elevation plus findings consistent with AM on histology or at cardiac magnetic resonance imaging (CMRI). In 86 patients CMRI changes in function and structure were re-assessed at follow-up. Results In the DGV(+) AM group (88.9% DSP variants), median age was 24 years, 91.7% presented with chest pain, and median left ventricular (LV) ejection fraction was 56% on CMRI (p=NS vs. the other 2 groups). Kaplan-Meier curves demonstrated a higher risk of the main endpoint in DGV(+) AM compared to DGV(−) and w/o genetics patients (62.3% vs. 17.5% vs. 5.3% at 5 years respectively; p<0.0001), driven by myocarditis recurrence and ventricular arrhythmias (Figure 1A, B). At follow-up CMRI, a higher number of late-gadolinium enhanced segments was found in DGV(+) AM. Conclusions Patients with AM and evidence of DGV have a higher incidence of adverse cardiovascular events compared with AM patients without DGV. Further prospective studies are needed to ascertain if genetic testing might improve risk stratification of patients with AM who are considered at low risk. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): Italian Ministry of Health

Aims: We developed an international registry to examine cardiovascular complications of COVID-19. Methods: A REDCap form was created in March 2020 at Mayo Clinic in collaboration with the International Society of Cardiomyopathy, Myocarditis and Heart Failure (ISCMF) and data were entered from April 2020 through April 2021. Results: Of the 696 patients in the COVID-19 Registry, 411 (59.2%) were male and 283 (40.8%) were female, with a sex ratio of 1.5:1 male to female. In total, 95.5% of the patients were from Japan. The average age was 52 years with 31.5% being >65 years of age. COVID-19 patients with a history of cardiovascular disease (CVD) had more pre-existing conditions including type II diabetes (p < 0.0001), cancer (p = 0.0003), obesity (p = 0.001), and kidney disease (p = 0.001). They also had a greater mortality of 10.1% compared to 1.7% in those without a history of CVD (p < 0.0001). The most common cardiovascular conditions in patients with a history of CVD were hypertension (33.7%), stroke (5.7%) and arrhythmias (5.1%). We found that troponin T, troponin I, brain natriuretic peptide (BNP), N-terminal pro-BNP (NT-proBNP), C-reactive protein (CRP), IL-6 and lambda immunoglobulin free light chains (Ig FLC) were elevated above reference levels in patients with COVID-19. Myocarditis is known to occur mainly in adults under the age of 50, and when we examined biomarkers in patients that were ≤50 years of age and had no history of CVD we found that a majority of patients had elevated levels of troponin T (71.4%), IL-6 (59.5%), creatine kinase/CK-MB (57.1%), D-dimer (57.8%), kappa Ig FLC (75.0%), and lambda Ig FLC (71.4%) suggesting myocardial injury and possible myocarditis. Conclusions: We report the first findings to our knowledge of cardiovascular complications from COVID-19 in the first year of the pandemic in a predominantly Japanese population. Mortality was increased by a history of CVD and pre-existing conditions including type II diabetes, cancer, obesity, and kidney disease. Our findings indicate that even in cases where no abnormalities are found in ECG or ultrasound cardiography that myocardial damage may occur, and cardiovascular and inflammatory biomarkers may be useful for the diagnosis.

The National Heart, Lung, and Blood Institute (NHLBI) convened a workshop of international experts to discuss new research opportunities for the prevention, detection, and intervention of myocarditis in May 2021. These experts reviewed the current state of science and identified key gaps and opportunities in basic, diagnostic, translational, and therapeutic frontiers to guide future research in myocarditis. In addition to addressing community-acquired myocarditis, the workshop also focused on emerging causes of myocarditis including immune checkpoint inhibitors and SARS-CoV-2 related myocardial injuries and considered the use of systems biology and artificial intelligence methodologies to define workflows to identify novel mechanisms of disease and new therapeutic targets. A new priority is the investigation of the relationship between social determinants of health (SDoH), including race and economic status, and inflammatory response and outcomes in myocarditis. The result is a proposal for the reclassification of myocarditis that integrates the latest knowledge of immunological pathogenesis to refine estimates of prognosis and target pathway-specific treatments.

Background: Acute myocarditis is an inflammatory condition that may herald the onset of dilated cardiomyopathy (DCM) or arrhythmogenic cardiomyopathy (ACM). We investigated the frequency and clinical consequences of DCM and ACM genetic variants in a population-based cohort of patients with acute myocarditis. Methods: This was a population-based cohort of 336 consecutive patients with acute myocarditis enrolled in London and Maastricht. All participants underwent targeted DNA sequencing for well-characterized cardiomyopathy-associated genes with comparison to healthy controls (n=1053) sequenced on the same platform. Case ascertainment in England was assessed against national hospital admission data. The primary outcome was all-cause mortality. Results: Variants that would be considered pathogenic if found in a patient with DCM or ACM were identified in 8% of myocarditis cases compared with <1% of healthy controls ( P =0.0097). In the London cohort (n=230; median age, 33 years; 84% men), patients were representative of national myocarditis admissions (median age, 32 years; 71% men; 66% case ascertainment), and there was enrichment of rare truncating variants (tv) in ACM-associated genes (3.1% of cases versus 0.4% of controls; odds ratio, 8.2; P =0.001). This was driven predominantly by DSP -tv in patients with normal LV ejection fraction and ventricular arrhythmia. In Maastricht (n=106; median age, 54 years; 61% men), there was enrichment of rare truncating variants in DCM-associated genes, particularly TTN -tv, found in 7% (all with left ventricular ejection fraction <50%) compared with 1% in controls (odds ratio, 3.6; P =0.0116). Across both cohorts over a median of 5.0 years (interquartile range, 3.9–7.8 years), all-cause mortality was 5.4%. Two-thirds of deaths were cardiovascular, attributable to worsening heart failure (92%) or sudden cardiac death (8%). The 5-year mortality risk was 3.3% in genotype-negative patients versus 11.1% for genotype-positive patients ( P adjusted =0.08). Conclusions: We identified DCM- or ACM-associated genetic variants in 8% of patients with acute myocarditis. This was dominated by the identification of DSP -tv in those with normal left ventricular ejection fraction and TTN -tv in those with reduced left ventricular ejection fraction. Despite differences between cohorts, these variants have clinical implications for treatment, risk stratification, and family screening. Genetic counseling and testing should be considered in patients with acute myocarditis to help reassure the majority while improving the management of those with an underlying genetic variant.

Abstract Over 10 million doses of COVID-19 vaccines based on RNA technology, viral vectors, recombinant protein, and inactivated virus have been administered worldwide. Although generally very safe, post-vaccine myocarditis can result from adaptive humoral and cellular, cardiac-specific inflammation within days and weeks of vaccination. Rates of vaccine-associated myocarditis vary by age and sex with the highest rates in males between 12 and 39 years. The clinical course is generally mild with rare cases of left ventricular dysfunction, heart failure and arrhythmias. Mild cases are likely underdiagnosed as cardiac magnetic resonance imaging (CMR) is not commonly performed even in suspected cases and not at all in asymptomatic and mildly symptomatic patients. Hospitalization of symptomatic patients with electrocardiographic changes and increased plasma troponin levels is considered necessary in the acute phase to monitor for arrhythmias and potential decline in left ventricular function. In addition to evaluation for symptoms, electrocardiographic changes and elevated troponin levels, CMR is the best non-invasive diagnostic tool with endomyocardial biopsy being restricted to severe cases with heart failure and/or arrhythmias. The management beyond guideline-directed treatment of heart failure and arrhythmias includes non-specific measures to control pain. Anti-inflammatory drugs such as non-steroidal anti-inflammatory drugs, and corticosteroids have been used in more severe cases, with only anecdotal evidence for their effectiveness. In all age groups studied, the overall risks of SARS-CoV-2 infection-related hospitalization and death are hugely greater than the risks from post-vaccine myocarditis. This consensus statement serves as a practical resource for physicians in their clinical practice, to understand, diagnose, and manage affected patients. Furthermore, it is intended to stimulate research in this area.

Background Sarcoidosis is an inflammatory, noncaseating, granulomatous disorder of unknown cause that can affect any body system and is associated with cardiovascular disease including sudden cardiac death (SCD). Cardiac involvement in sarcoidosis is associated with higher risk of SCD, but the SCD risk in the general sarcoidosis population is unknown. We aimed to determine the risk of SCD in people with sarcoidosis versus the matched general population. Methods and Results A population‐based cohort of sarcoidosis and age‐ and sex‐matched comparators from January 1, 1976 to December 31, 2013 was used; presence of other comorbidities in the comparator group was not an exclusion criterion. Mortality, including time, place, and cause of death were measured and manually adjudicated for SCD events. Incidence rates are reported per 100 000 person‐years, and Cox models were used for group comparisons. Of the 345 incident cases of sarcoidosis (171 men; 50%) there were 58 reported deaths; 10 were definite/probable SCD versus 57 all‐cause and 9 SCDs in comparators. Median follow‐up was 12.9 years (interquartile range, 6.0–23.4 years) . Incidence rate of SCD in sarcoidosis was 192 (95% CI, 92–352) versus 155 (95% CI, 71–294) in comparators (hazard ratio [HR], 1.28 (95% CI, 0.52–3.17). Nocturnal deaths were more frequent in sarcoidosis 57 (95% CI, 12–168) versus 17 (95% CI, 0.4–95) (HR, 3.76 [95% CI, 0.39–36.47]). No significant differences were detected between the groups by sex, age, calendar year of diagnosis, or disease duration. Conclusions In a population‐based cohort of patients with sarcoidosis, the risk for SCD compared with matched comparators was not increased. There were more nocturnal deaths among patients with sarcoidosis, yet this was statistically insignificant.

Abstract Funding Acknowledgements Type of funding sources: None. Background Etiology identification and risk stratification represent major issues for patients presenting with undefined left ventricular arrhythmogenic cardiomyopathy (ULVACM). Purpose To investigate the role of genetics and histology for ULVACM classification, management, and risk assessment. Methods We retrospectively analyzed a multicenter cohort of patients (screened n=1037) with ULVACM defined by ventricular arrhythmia (VA) onset, nonischemic late gadolinium enhancement (LGE) limited to the LV, and no severe dilated cardiomyopathy (LVEF≥40%). We selected patients undergoing both next generation sequencing (NGS) screening and endomyocardial biopsy (EMB) for etiology definition. When feasible, immunosuppressive therapy (IST) was used to target active myocardial inflammation (AMI). The study endpoint was a composite of cardiac death, heart transplantation and malignant VAs (VT, VF, appropriate ICD treatment). Results The study cohort is composed by 135 ULVACM patients (age 43±14 years, 63% males, LVEF 55±7 %). NGS identified pathogenic or likely-pathogenic variants (PVs/LPVs) consistent with ACM in 21 cases (16%), whereas EMB showed AMI in 78 patients (58%), including 13/21 PVs/LPVs+ (62%). After reclassification of 86 patients (64%), only 49 (36%) remained ULVACM. IST was started in 41/78 AMI patients (53%), including 9/13 PVs/LPVs+ (69%). Twenty patients (15%) met the study endpoint by 12 months, and 36 (27%) by the end of the study (60±27 months). Beyond malignant VT onset, AMI was the only predictor of events by 12 months (HR 5.0, 95%CI 1.4-18.1, p=0.007). No prognostic role was found for PVs/LPVs, except for the subgroup (n=77) with nonsustained VT onset. Among AMI patients, those treated by IST had a significantly lower occurrence of events, both by 12-months (1/41 vs. 16/37, p&lt;0.001) and later (HR 0.05, 95%CI 0.01-0.21, p&lt;0.001). Results were independently confirmed in PVs/LPVs+ and PVs/LPVs- cases. Excluding the IST population, the association of multiple factors among VT onset, PVs/LPVs, and AMI, resulted in an improved discrimination of arrhythmic risk profiles. Conclusion The combined genetic and histological workup allowed reclassification of up to 64% ULVACM patients, and substantially contributed into prognostic assessment. Furthermore, EMB identified suitable candidates for IST, who showed better outcomes irrespectively of their genotype.