Interpretation of elevated baseline concentrations and serial changes of high-sensitivity cardiac troponin T in confirmed muscular dystrophies.

AIMS: Concentrations of high-sensitivity cardiac troponin T (hs-cTnT) are frequently elevated in stable patients with confirmed muscle dystrophies. However, sparse information is available on the interpretation of serial concentration changes. METHODS: Hs-cTnT was collected in 35 stable outpatients with confirmed skeletal muscle dystrophies at 0 and 1 h and after 6-12 months during scheduled outpatient visits. We simulated the effectiveness of the European Society of Cardiology (ESC) 0/1 h algorithm and assessed biological variation at 6-12 months using two established methods: reference change value (RCV) and minimal important difference (MID). RESULTS: Median baseline hs-cTnT concentrations were 34.4 ng/L [inter-quartile range (IQR): 17.5-46.2], and values > 99th percentile upper limit of normal were present in 34 of 35 patients. All patients were stable without cardiovascular adverse events during a follow-up of 6.6 months (IQR: 6-7). Median concentration change was 1.9 ng/L (IQR: 0.7-3.2) and 0.8 ng/L (IQR: 0-7.0) at 60 min and 6-9 months, respectively. Applying the criteria of the ESC 0/1 h algorithm for triage of suspected acute coronary syndrome (ACS) showed poor overall effectiveness of baseline hs-cTnT values. No patient would qualify for rule-out based on hs-cTnT less than the limit of detection, whereas five cases would qualify for rule-in based on hs-cTnT ≥ 52 ng/L. Biological variabilities at 6-12 months per MID and RCV were 1.2 ng/L [95% confidence interval (CI): 0.7-2.1] and 28.6% (95% CI: 27.9-29.6), respectively. A total of 8 (22.9%) and 25 (71.4%) cases exceeded the biological variation range, suggesting some additional myocardial damage. CONCLUSIONS: The high prevalence of elevated hs-cTnT could negatively impact the effectiveness of rule-out and rule-in strategies based on a single hs-cTnT value. Knowledge of the physiological and biological variation of hs-cTnT after 6-12 months is helpful to detect the progression of cardiac involvement or to search for cardiac complications including but not limited to arrhythmias that may trigger acute or chronic myocardial damage.

Optimizing resource allocation: Cost-effectiveness of specified D-dimer cut-offs in cancer patients with suspected venous thromboembolism.

An accurate diagnosis of venous thromboembolism (VTE) is crucial, given the potential for high mortality in undetected cases. Strategic D-dimer testing may aid in identifying low-risk patients, preventing overdiagnosis and reducing imaging costs. We conducted a retrospective, comparative analysis to assess the potential cost savings that could be achieved by adopting different approaches to determine the most effective D-dimer cut-off value in cancer patients with suspected VTE, compared to the commonly used rule-out cut-off level of 0.5 mg/L. The study included 526 patients (median age 65, IQR 55-75) with a confirmed cancer diagnosis who underwent D-dimer testing. Among these patients, the VTE prevalence was 29% (n = 152). Each diagnostic strategy's sensitivity, specificity, negative likelihood ratio (NLR), as well as positive likelihood ratio (PLR), and the proportion of patients exhibiting a negative D-dimer test result, were calculated. The diagnostic strategy that demonstrated the best balance between specificity, sensitivity, NLR, and PLR, utilized an inverse age-specific cut-off level for D-dimer [0.5 + (66-age) × 0.01 mg/L]. This method yielded a PLR of 2.9 at a very low NLR for the exclusion of VTE. We observed a significant cost reduction of 4.6% and 1.0% for PE and DVT, respectively. The utilization of an age-adjusted cut-off [patient's age × 0.01 mg/L] resulted in the highest cost savings, reaching 8.1% for PE and 3.4% for DVT. Using specified D-dimer cut-offs in the diagnosis of VTE could improve economics, considering the limited occurrence of confirmed cases among patients with suspected VTE.

Increase of Cardiac Autoantibodies Against Beta-2-adrenergic Receptor During Acute Cellular Heart Transplant Rejection.

BACKGROUND: Acute cellular rejection (ACR) in heart transplant (HTx) recipients may be accompanied by cardiac cell damage with subsequent exposure to cardiac autoantigens and the production of cardiac autoantibodies (aABs). This study aimed to evaluate a peptide array screening approach for cardiac aABs in HTx recipients during ACR (ACR-HTx). METHODS: In this retrospective single-center observational study, sera from 37 HTx recipients, as well as age and sex-matched healthy subjects were screened for a total of 130 cardiac aABs of partially overlapping peptide sequences directed against structural proteins using a peptide array approach. RESULTS: In ACR-HTx, troponin I (TnI) serum levels were found to be elevated. Here, we could identify aABs against beta-2-adrenergic receptor (ß-2AR: EAINCYANETCCDFFTNQAY) to be upregulated in ACR-HTx (intensities: 0.80 versus 1.31, P = 0.0413). Likewise, patients positive for ß-2AR aABs showed higher TnI serum levels during ACR compared with aAB negative patients (10.0 versus 30.0 ng/L, P = 0.0375). Surprisingly, aABs against a sequence of troponin I (TnI: QKIFDLRGKFKRPTLRRV) were found to be downregulated in ACR-HTx (intensities: 3.49 versus 1.13, P = 0.0025). A comparison in healthy subjects showed the same TnI sequence to be upregulated in non-ACR-HTx (intensities: 2.19 versus 3.49, P = 0.0205), whereas the majority of aABs were suppressed in non-ACR-HTx. CONCLUSIONS: Our study served as a feasibility analysis for a peptide array screening approach in HTx recipients during ACR and identified 2 different regulated aABs in ACR-HTx. Hence, further multicenter studies are needed to evaluate the prognostic implications of aAB testing and diagnostic or therapeutic consequences.

Design, Rationale and Initial Findings From HERA-FIB on 10 222 Patients With Atrial Fibrillation Presenting to an Emergency Department Over An 11-Year Period.

BACKGROUND: For the majority of patients with atrial fibrillation (AF), disease management has improved in recent years. However, there are still populations underrepresented or excluded in current registries and randomized controlled trials. HERA-FIB (Heidelberg Registry of Atrial Fibrillation) was planned to assess real-world evidence for the prevalence, demographic characteristics and management of patients with the diagnosis of AF presenting consecutively to a chest pain unit. METHODS AND RESULTS: HERA-FIB is a retrospective, observational, single-center study on patients with a diagnosis of AF presenting to a chest pain unit from June 2009 until March 2020. This article describes the structure, governance, outcome assessment, quality and data collection processes of the registry. Additionally, characteristics of populations of special interest are described. The study consecutively enrolled 10 222 patients presenting with AF to the chest pain unit of the University Hospital of Heidelberg. Clinical parameters and patient characteristics were assessed retrospectively. Outcome parameters included rates for all-cause death, stroke, myocardial infarction and major bleedings. We were able to investigate patient cohorts of special interest such as advanced chronic kidney disease, octogenarians, and those with acute coronary syndrome who are often underrepresented in current studies and randomized controlled trials. CONCLUSIONS: HERA-FIB is one of the largest real-world single-center retrospective registries on patients with AF, which captures the era of transition from vitamin K antagonists to non-vitamin K oral anticoagulation regimens in clinical practice and offers the possibility to investigate patient populations usually underrepresented or excluded in current available randomized controlled trials and registries. REGISTRATION: URL: https://www.clinicaltrials.gov; unique identifier: NCT05995561.

Comparison of the clinical chemistry score to other biomarker algorithms for rapid rule-out of acute myocardial infarction and risk stratification in patients with suspected acute coronary syndrome.

BACKGROUND: The clinical chemistry score (CCS) comprising high-sensitivity cardiac troponins (hs-cTn), glucose and estimated glomerular filtration rate has been previously validated with superior accuracy for detection and risk stratification of acute myocardial infarction (AMI) compared to hs-cTn alone. METHODS: The CCS was compared to other biomarker-based algorithms for rapid rule-out and prognostication of AMI including the hs-cTnT limit-of-blank (LOB, <3 ng/L) or limit-of-detection (LOD, <5 ng/L) and a dual marker strategy (DMS) (copeptin <10 pmol/L and hs-cTnT ≤14 ng/L) in 1506 emergency department (ED) patients with symptoms suggestive of acute coronary syndrome. Negative predictive values (NPV) and sensitivities for AMI rule-out, and 12-month combined endpoint rates encompassing mortality, myocardial re-infarction, as well as stroke were assessed. RESULTS: NPVs of 100% (95% CI: 98.3-100%) were observed for CCS = 0, hs-cTnT LoB and hs-cTnT LoD with rule-out efficacies of 11.1%, 7.6% and 18.3% as well as specificities of 13.0% (95% CI: 9.9-16.6%), 8.8% (95% CI: 7.3-10.5%) and 21.4% (95% CI: 19.2-23.8%), respectively. A CCS ≤ 1 achieved a rule-out in 32.2% of all patients with a NPV of 99.6% (95% CI: 98.4-99.9%) and specificity of 37.4% (95% CI: 34.2-40.5%) compared to a rule-out efficacy of 51.2%, NPV of 99.0 (95% CI: 98.0-99.5) and specificity of 59.7% (95% CI: 57.0-62.4%) for the DMS. Rates of the combined end-point of death/AMI within 30 days ranged between 0.0% and 0.7% for all fast-rule-out protocols. CONCLUSIONS: The CCS ensures reliable AMI rule-out with low short and long-term outcome rates for a specific ED patient subset. However, compared to a single or dual biomarker strategy, the CCS displays reduced efficacy and specificity, limiting its clinical utility.

Real-World Evidence on Disparities on the Initiation of Ticagrelor Versus Prasugrel in Patients With Acute Coronary Syndrome.

Background Management of patients with non-ST-segment-elevation acute coronary syndrome (NSTE-ACS) is based on 2020 European Society of Cardiology guidelines, which recommend the preferential use of prasugrel over ticagrelor. Because the selection of the respective P2Y12 inhibitor has to consider label restrictions, we sought to evaluate the proportion of patients qualifying for either ticagrelor or prasugrel and reasons for noneligibility in an unselected cohort of patients with acute coronary syndrome. Methods and Results In this retrospective observational study, patients with ST-segment-elevation myocardial infarction (STEMI) or NSTE-ACS presenting consecutively during a 24-month period were enrolled. The eligibility of patients for a dual antiplatelet therapy option was assessed retrospectively. A total of 1502 patients had confirmed acute coronary syndrome (287 STEMI and 1215 NSTE-ACS). Eligibility for ticagrelor and full-dose prasugrel differed significantly for STEMI and NSTE-ACS (93% versus 51%, P<0.0001 versus 80% versus 31%, P<0.0001). Eligibility remained significantly lower (STEMI 78% versus NSTE-ACS 52%) if low-dose prasugrel was considered. Patients eligible for full-dose prasugrel had lower ischemic risk per GRACE (Global Registry of Acute Coronary Events) score (109 points [90-129 points] versus 121 points [98-146 points], P<0.0001) and lower bleeding risk (14 points [13-15 points] versus 20 points [12-29 points], P<0.0001) per PRECISE-DAPT (Predicting Bleeding Complications in Patients Undergoing Stent Implantation and Subsequent Dual Antiplatelet Therapy) score. Conclusions In real life, eligibility for prasugrel in patients requiring dual antiplatelet therapy is considerably lower than for ticagrelor, even in a cohort with high rates of coronary angiography and percutaneous coronary interventions. The recommended use of prasugrel over ticagrelor in current acute coronary syndrome guidelines contrasts with our observations of a substantial disparity on the eligibility. This important aspect has not received appropriate attention yet. Registration URL: https://www.clinicaltrials.gov; Unique identifier: NCT05774431.

LNA oligonucleotide mediates an anti-inflammatory effect in autoimmune myocarditis via targeting lactate dehydrogenase B.

Treatment of myocarditis is often limited to symptomatic treatment due to unknown pathomechanisms. In order to identify new therapeutic approaches, the contribution of locked nucleic acid antisense oligonucleotides (LNA ASOs) in autoimmune myocarditis was investigated. Hence, A/J mice were immunized with cardiac troponin I (TnI) to induce experimental autoimmune myocarditis (EAM) and treated with LNA ASOs. The results showed an unexpected anti-inflammatory effect for one administered LNA ASO MB_1114 by reducing cardiac inflammation and fibrosis. The target sequence of MB_1114 was identified as lactate dehydrogenase B (mLDHB). For further analysis, mice received mLdhb-specific GapmeR during induction of EAM. Here, mice receiving the mLdhb-specific GapmeR showed increased protein levels of cardiac mLDHB and a reduced cardiac inflammation and fibrosis. The effect of increased cardiac mLDHB protein level was associated with a downregulation of genes of reactive oxygen species (ROS)-associated proteins, indicating a reduction in ROS. Here, the suppression of murine pro-apoptotic Bcl-2-associated X protein (mBax) was also observed. In our study, an unexpected anti-inflammatory effect of LNA ASO MB_1114 and mLdhb-specific GapmeR during induction of EAM could be demonstrated in vivo. This effect was associated with increased protein levels of cardiac mLDHB, mBax suppression and reduced ROS activation. Thus, LDHB and LNA ASOs may be considered as a promising target for directed therapy of myocarditis. Nevertheless, further investigations are necessary to clarify the mechanism of action of anti-inflammatory LDHB-triggered effects.

Prognostic value of circulating microRNAs compared to high-sensitivity troponin T in patients presenting with suspected acute coronary syndrome to the emergency department.

BACKGROUND: To evaluate the prognostic value of eleven microRNAs (miRNAs) compared to high-sensitivity Troponin T (hs-cTnT) in patients presenting with suspected acute coronary syndrome (ACS) to the emergency department (ED). METHODS: 1,042 patients presenting between August 2014 and April 2017 were included. Expression levels of eleven microRNAs (miR-21-5p, miR-22-3p, miR-29a-3p, miR-92a-3p, miR-122-5p, miR-126-3p, miR-132-3p, miR-133a-3p, miR-134-5p, miR-191-3p, and miR-423-5p) were determined using RT-qPCR. All-cause mortality (ACM) and a composite of ACM, acute myocardial infarction (AMI) and stroke were defined as endpoints. RESULTS: During a median follow-up of 399 (P25-P75: 381-525) days 58 patients (5.6%) died. The composite endpoint occurred in 86 patients (8.3%). Different expression levels of miR-21-5p (median, P25-P75: 5.28 [5.14-5.51] vs. 5.16 [4.97-5.35], p = 0.0033) and miR-122-5p (median, P25-P75: 5.17 [4.81-5.49] vs. 5.35 [5.01-5.69], p = 0.0184) were observed in patients who died compared to survivors. ROC-optimized cutoff of miR-21-5p (HR, P25-P75: 3.3 [1.2-9.4], p = 0.0239), but not miR-122-5p (HR, P25-P75: 0.4 [0.2-0.8], p = 0.0116), was predictive for all-cause mortality, even after adjustment in a multivariate model. Nevertheless, addition of miR-21-5p and miR-122-5p decreased prognostic accuracy of hs-cTnT for all-cause mortality (△AUC: 0.112, p = 0.0159). Hs-cTnT admission values had a high prognostic value for ACM (AUC [95%CI] = 0.794 [0.751-0.837]) and the composite of ACM, AMI and stroke (AUC [95%CI] = 0.745 [0.695-0.794]). CONCLUSIONS: Despite a different expression depending on outcomes miR-21-5p and miR-122-5p do not add prognostic information to hs-cTnT in patients presenting with suspected ACS to the ED.

Interpretation of myocardial injury subtypes in COVID-19 disease per fourth version of Universal Definition of Myocardial Infarction.

BACKGROUND: Application of the 4th version of Universal Definition of Myocardial Infarction (UDMI) to characterize rates and prognostic relevance of myocardial injury in COVID-19 disease. METHODS: This retrospective, single-centre observational study enrolled 104 patients hospitalized with SARS-CoV-2 infection. Kaplan-Meier analysis and multivariate Cox regression were used to identify influence of acute or chronic myocardial injury on a composite primary (mortality, incident acute respiratory distress syndrome, incident mechanical ventilation) and secondary endpoint (mortality, incident acute myocardial injury during hospitalization, incident venous thrombosis, pulmonary embolism or stroke). RESULTS: A total of 27 (26.0%) patients presented with chronic myocardial injury, and 19 (18.3%) with acute myocardial injury. 42 patients(40.4%) developed an incident myocardial injury during hospitalization. The presence of acute or chronic myocardial injury on admission and incident myocardial injury during hospitalization were associated with higher rates of endpoints. Independent predictors for the primary endpoint were higher severity stages according to Siddiqi et al. classification system and history of dyslipidaemia. Maximal hs-cTnT and D-dimer concentrations during hospitalization showed an association (r = 0.61). CONCLUSIONS: Objective description of myocardial injury according to the 4th UDMI in the current COVID-19 pandemic is crucial in order to discriminate patients with acute myocardial infarction and acute, chronic or incident myocardial injury.

Validation of two severity scores as predictors for outcome in Coronavirus Disease 2019 (COVID-19).

BACKGROUND: An established objective and standardized reporting of clinical severity and disease progression in COVID-19 is still not established. We validated and compared the usefulness of two classification systems reported earlier-a severity grading proposed by Siddiqi and a system from the National Australian COVID-19 guideline. Both had not been validated externally and were now tested for their ability to predict complications. METHODS: In this retrospective, single-centre observational study, patients hospitalized with confirmed COVID-19 across all severity stages were enrolled. The clinical severity was graded at admission and during hospitalization. Multivariate Cox regression was used to identify independent risk factors for mortality, a composite primary (mortality, incident acute respiratory distress syndrome, incident mechanical ventilation), a secondary endpoint (mortality, incident acute myocardial injury, incident venous thrombosis, pulmonary embolism or stroke) and progression of severity grades. RESULTS: Of 109 patients 17 died, 31 and 48 developed the primary and secondary endpoint, respectively. Worsening of the severity grade by at least one stage occurred in 27 and 28 patients, respectively. Siddiqi and Australian classification were identified as independent predictors for the primary endpoint (adjusted hazard ratio (aHR) 2.30, p<0.001 and aHR 2.08, p<0.001), for the secondary endpoint (aHR 2.12, p<0.001 and aHR 1.79, p<0.001) and mortality (aHR 2.30, p = 0.071 and aHR 1.98, p = 0.017). Both classification systems showed very good agreement regarding initial grading and good agreement regarding progression of severity stages. CONCLUSIONS: Standardized and objective severity grading is useful to unequivocally stratify patients presenting with COVID-19 for their individual risk of complications.

[Cardiac biomarkers and COVID-19 - Phenotypes and Interpretation]. / Kardiale Biomarker und COVID-19-Phänotypen und Interpretation.

Current pandemic caused by SARS-CoV-2 inducing viral COVID-19 pneumonia, is categorized in 3 stages. Some biomarkers could be assigned to one of these stages, showing a correlation to mortality in COVID-19 patients. Laboratory findings in COVID-19, especially when serially evaluated, may represent individual disease severity and prognosis. These may help planning and controlling therapeutic interventions. Biomarkers for myocardial injury (high sensitive cardiac troponin, hsTn) or hemodynamic stress (NTproBNP) may occur in COVID-19 pneumonia such as in other pneumonias, correlating with severity and prognosis of the underlying disease. In hospitalized COVID-19 patients' mild increases of hsTn or NTproBNP may be explained by cardiovascular comorbidities and direct or indirect cardiac damage or stress caused by or during COVID-19 pneumonia. In case of suspected NSTE-ACS and COVID-19, indications for echocardiography or reperfusion strategy should be carefully considered against the risk of contamination.

Heart-Specific Immune Responses in an Animal Model of Autoimmune-Related Myocarditis Mitigated by an Immunoproteasome Inhibitor and Genetic Ablation.

BACKGROUND: Immune checkpoint inhibitor (ICI) therapy is often accompanied by immune-related pathology, with an increasing occurrence of high-risk ICI-related myocarditis. Understanding the mechanisms involved in this side effect could enable the development of management strategies. In mouse models, immune checkpoints, such as PD-1 (programmed cell death protein 1), control the threshold of self-antigen responses directed against cardiac TnI (troponin I). We aimed to identify how the immunoproteasome, the main proteolytic machinery in immune cells harboring 3 distinct protease activities in the LMP2 (low-molecular-weight protein 2), LMP7 (low-molecular-weight protein 7), and MECL1 (multicatalytic endopeptidase complex subunit 1) subunit, affects TnI-directed autoimmune pathology of the heart. METHODS: TnI-directed autoimmune myocarditis (TnI-AM), a CD4+ T-cell-mediated disease, was induced in mice lacking all 3 immunoproteasome subunits (triple-ip-/-) or lacking either the gene encoding LMP2 and LMP7 by immunization with a cardiac TnI peptide. Alternatively, before induction of TnI-AM or after establishment of autoimmune myocarditis, mice were treated with the immunoproteasome inhibitor ONX 0914. Immune parameters defining heart-specific autoimmunity were investigated in experimental TnI-AM and in 2 cases of ICI-related myocarditis. RESULTS: All immunoproteasome-deficient strains showed mitigated autoimmune-related cardiac pathology with less inflammation, lower proinflammatory and chemotactic cytokines, less interleukin-17 production, and reduced fibrosis formation. Protection from TnI-directed autoimmune heart pathology with improved cardiac function in LMP7-/- mice involved a changed balance between effector and regulatory CD4+ T cells in the spleen, with CD4+ T cells from LMP7-/- mice showing a higher expression of inhibitory PD-1 molecules. Blocked immunoproteasome proteolysis, by treatment of TLR2 (Toll-like receptor 2)-engaged and TLR7 (Toll-like receptor 7)/TLR8 (Toll-like receptor 8)-engaged CD14+ monocytes with ONX 0914, diminished proinflammatory cytokine responses, thereby reducing the boost for the expansion of self-reactive CD4+ T cells. Correspondingly, in mice, ONX 0914 treatment reversed cardiac autoimmune pathology, preventing the induction and progression of TnI-AM when self-reactive CD4+ T cells were primed. The autoimmune signature during experimental TnI-AM, with high immunoproteasome expression, immunoglobulin G deposition, interleukin-17 production in heart tissue, and TnI-directed humoral autoimmune responses, was also present in 2 cases of ICI-related myocarditis, demonstrating the activation of heart-specific autoimmune reactions by ICI therapy. CONCLUSIONS: By reversing heart-specific autoimmune responses, immunoproteasome inhibitors applied to a mouse model demonstrate their potential to aid in the management of autoimmune myocarditis in humans, possibly including patients with ICI-related heart-specific autoimmunity.