Cardiac troponins: Mechanisms of release and role in healthy and diseased subjects.

The cardiac troponins (cTns), cardiac troponin C (cTnC), cTnT, and cTnI are key elements of myocardial apparatus, fixed as protein complex on the thin filament of sarcomere and are involved in the regulation of excitation-contraction coupling of cardiomyocytes in the presence of Ca2+ . Circulating cTnT and cTnI (cTns) increase following cardiac tissue necrosis, and they are consolidated biomarkers of acute myocardial infarction (AMI). However, the use of high sensitivity (hs)-immunoassay tests for cTnT and cTnI has made it possible to identify a multitude of other clinical conditions associated with increased circulating levels of cTns. cTns can be measured also in the peripheral circulation of healthy subjects or athletes, suggesting that different mechanisms are involved in the release of cTns in the blood independently of cardiac cell necrosis. In this review, the molecular/cellular mechanisms involved in cTns release in blood and the exploitation of cTnI and cTnT as biomarkers of cardiac adverse events, in addition to cardiac necrosis, are discussed.

Normal high-sensitivity cardiac troponin for ruling-out inpatient mortality in acute COVID-19.

INTRODUCTION: Assessment of inpatient mortality risk in COVID-19 patients is important for guiding clinical decision-making. High sensitivity cardiac troponin T (hs-cTnT) is a biomarker of cardiac injury associated with a worse prognosis in COVID-19. We explored how hs-cTnT could potentially be used in clinical practice for ruling in and ruling out mortality in COVID-19. METHOD: We tested the diagnostic value of hs-cTnT in laboratory-confirmed COVID-19 patients (≥18 years old) admitted to the Royal Berkshire Hospital (UK) between 1st March and 10th May 2020. A normal hs-cTnT was defined as a value within the 99th percentile of healthy individuals (≤14 ng/L), and an elevated hs-cTnT was defined as >14 ng/L. Adverse clinical outcome was defined as inpatient mortality related to COVID-19. RESULTS: A total of 191 COVID-19 patients (62% male; age 66±16 years) had hs-cTnT measured on admission. Of these patients, 124 (65%) had elevated hs-cTnT and 67 (35%) had normal hs-cTnT. On a group level, patients with elevated hs-cTnT had worse inpatient survival (p = 0.0014; Kaplan-Meier analysis) and higher risk of inpatient mortality (HR 5.84 [95% CI 1.29-26.4]; p = 0.02; Cox multivariate regression) compared to patients with normal hs-cTnT. On a per-patient level, a normal hs-cTnT had a negative predictive value of 94% (95% CI: 85-98%) for ruling out mortality, whilst an elevated hs-cTnT had a low positive predictive value of 38% (95% CI: 39-47%) for ruling in mortality. CONCLUSIONS: In this study cohort of COVID-19 patients, the potential clinical utility of hs-cTnT appears to rest in ruling out inpatient mortality. This finding, if prospectively validated in a larger study, may allow hs-cTnT to become an important biomarker to facilitate admission-avoidance and early safe discharge.

Implementation of high-sensitivity troponin with a rapid diagnostic algorithm reduces emergency department length of stay for discharged patients.

INTRODUCTION: High sensitivity troponin (hs-cTn) and diagnostic algorithms are used to rapidly triage patients with symptoms of acute myocardial infarction in emergency departments (ED). However, few studies have evaluated the impact of simultaneously implementing hs-cTn and a rapid rule-out algorithm on length of stay (LOS). METHODS: We assessed the impact of transitioning from contemporary cTnI to hs-cTnI in 59,232 ED encounters over three years. hs-cTnI was implemented with an orderable series that included baseline, two-, four-, and six-hour specimens collected at provider discretion and operationalized with an algorithm to calculate the change in hs-cTnI from baseline and provide interpretations of "insignificant", "significant," or "equivocal." Patient demographics, results, chief complaint, disposition, and ED LOS were captured from the electronic medical record. RESULTS: cTnI was ordered for 31,875 encounters prior to hs-cTnI implementation and 27,357 after. The proportion of cTnI results above the 99th percentile upper reference limit decreased from 35.0% to 27.0% for men and increased from 27.8% to 34.8% for women. Among discharged patients, the median LOS decreased by 0.6 h (0.5-0.7). LOS among discharged patients with a chief complaint of chest pain decreased by 1.0 h (0.8-1.1) and further decreased by 1.2 h (1.0-1.3) if the initial hs-cTnI was below the limit of quantitation. The rate of acute coronary syndrome upon re-presentation within 30 days did not change post-implementation (0.10% versus 0.07%). CONCLUSION: Implementation of an hs-cTnI assay with a rapid rule-out algorithm decreased ED LOS among discharged patients, particularly among those with a chief complaint of chest pain.

COVID-19 and cardiovascular manifestations.

OBJECTIVE: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19, a viral outbreak that started in December 2019, eventually lead to a worldwide pandemic. COVID-19 usually presents with flu-like symptoms, such as headaches, dry cough, fever, fatigue, myalgia, shortness of breath, diarrhea and loss of smell or taste. However, it can also have major effects on the cardiovascular system. Based on the available relevant literature, we aimed to elaborate the possible mechanisms influencing cardiovascular damage, myocardial injury and thromboembolic disease process in particular. MATERIALS AND METHODS: After considering our inclusion and exclusion criteria, the systematic review included 8 studies in total. RESULTS: In general, underlying cardiovascular diseases were associated with poorer clinical outcomes. This may be due to immunological dysregulation. The disease outcomes were also positively correlated with the severity of the disease, especially with myocardial injury. Thus, cardiac biomarkers, such as Troponin T, CK-MB and myoglobin could be utilized in prediction algorithms for deciphering the clinical outcome in COVID-19 patients. CONCLUSIONS: Venous thromboembolisms were commonly encountered complications despite the administration of thromboprophylaxis, and they mostly presented as pulmonary embolisms, warranting the need for relevant investigations in hemodynamically unstable patients. However, more studies need to be conducted to better understand the mechanisms at play and the ensuing complications, to better treat COVID-19 patients.

Management of cardiovascular symptoms after Pfizer-BioNTech COVID-19 vaccine in teenagers in the emergency department.

BACKGROUND: Cardiovascular complications after Pfizer-BioNTech COVID-19 (BNT) vaccination are a concern, especially in adolescents. We analyzed the risk factors for myocarditis after BNT vaccination. METHODS: We used a special evaluation protocol for all patients aged 12-18 years who presented to our emergency department with cardiovascular symptoms after BNT vaccination. RESULTS: A total of 195 patients (109 boys and 86 girls) were enrolled. Eleven (5.6%) patients presented with arrhythmia (arrhythmia group), 14 (7.2%) had a diagnosis of pericarditis/myocarditis (the peri/myocarditis group), and the remaining 170 were controls (no cardiac involvement). Chest pain (77.6%) was the most common symptom. The median time from vaccination to symptom onset was 3 days. In the peri/myocarditis group (13 myocarditis and 1 pericarditis), the median time to the peak troponin T level was 5 days after vaccination. Abnormal electrocardiographic changes, including ST-T changes and conduction blocks, were more commonly detected in the peri/myocarditis group (85.7% vs. 12.4% in the control group, p < 0.01). Echocardiography revealed normal ventricular function in all patients. Symptoms were resolved before discharge in all, with the median duration of hospital stay being 4 days. The electrocardiography was the most appropriate screening tool for myocarditis, with a sensitivity and specificity of 85.7% and 87.6%, respectively. CONCLUSION: Pericarditis or myocarditis was diagnosed in 7.2% of adolescents presenting to the emergency department with cardiovascular symptoms after BNT vaccination. In addition to the troponin T level, ECG change listed above can be used as a screening tool for vaccine-induced cardiac complications.

Cardiac function in relation to functional status and fatigue in patients with post-COVID syndrome.

Patients with Post-COVID syndrome (PCS) are frequently referred for cardiologic evaluation. We assessed cardiac function and biomarkers in relation to functional status and fatigue in patients with PCS. This prospective single-center cohort study included 227 patients with persisting symptoms after COVID-19 infection. Most frequent complaints were fatigue (70%), dyspnea (56%), neurocognitive symptoms (34%) and chest pain (28%). Standardized questionnaires were used to assess Post-COVID-Functional-Scale (PCFS) and fatigue (MFI-20). The fatigue severity was inversely related to age and did not correlate with cardiovascular diseases, echocardiographic findings, or biomarkers. Similarly, mild to moderate functional impairment (PCFS 1-3) did not correlate with cardiovascular alterations. However, the subgroup of patients with significant functional impairment (PCFS = 4) had more frequent cardiovascular comorbidities, biomarkers and impaired global longitudinal strain (GLS). Patients with elevated troponin T showed abnormal GLS, reduced left ventricular ejection fraction and impaired tricuspid annular plane systolic excursion. The majority of patients with PCS shows a normal cardiac function. Only the small subgroup of patients with severe functional impairment and patients with elevated troponin T is at risk for impaired cardiac function and likely to benefit from specialized care by a cardiologist.

Admission high-sensitivity cardiac troponin levels as a prognostic indicator for in-hospital mortality rates in the elderly and very elderly COVID-19 patients.

BACKGROUND: Elevation of cardiac troponin (cTn) is associated with the worst prognosis not only in cardiovascular disease but also in non-cardiovascular disease. The aim of this study is to verify if cTn has a prognostic role in elderly and very elderly coronavirus disease 2019 (COVID-19) patients. METHODS: This study enrolled consecutive COVID-19 elderly patients hospitalized at INRCA hospital, with available admission high sensitivity cardiac troponin T (HS-cTnT) level. Patients were divided into three groups based on HS-cTnT level: group A (Hs-cTnT ≤ 40 pg/ml), group B (Hs-cTnT 41-100 pg/ml), and group C (Hs-cTnT ≥ 101 pg/ml). The correlation between HS-cTnT levels and mortality rates was analyzed. RESULTS: 461 patients (mean age 86 years; 59% female) were divided into group A (261 patients), group B (129 patients), and group C (71 patients). Group C resulted significantly older, more affected by heart failure, chronic obstructive pulmonary disease, chronic kidney disease, and dementia, and with higher levels of creatinine, C-reactive protein, pro-calcitonin, interleukin-6, ferritin, NT-proBNP, D-dimer then group A and group B. Mortality rate increased significantly across groups (group A: 18.4%; group B: 36.4%; group C: 62.0%; p<0.001). Group C had a significant increase in mortality risk compared to group A, both univariate analysis (HR 3.78) and multivariate analysis (model 2 HR 3.10; model 3 HR 3.59; model 4 HR 1.72). CONCLUSION: HS-cTnT has demonstrated a prognostic role in elderly and very elderly COVID-19 patients. HS-cTnT is a simple and inexpensive laboratory exam that gives clinicians important information on mortality risk stratification.

Acute Perimyocarditis in an Adolescent Japanese Male after a Booster Dose of the BNT162b2 COVID-19 Vaccine.

Perimyocarditis is a rare and serious cardiac complication following COVID-19 vaccination. Young males are most at risk after the second dose. With the introduction of the booster (third) dose, some reports have focused on the risk of perimyocarditis after a booster dose. However, no currently available report in Japan has comprehensively described this phenomenon. A healthy 14-year-old Japanese male, who had completed a two-dose primary series of the BNT162b2 (Pfizer-BioNTech) vaccine six months prior, developed fever and chest pain within 24 hours after a homologous booster dose. He was transferred to our institute because of worsening chest pain. A multiplex PCR test showed no evidence of active viral infections, including SARS-CoV-2. Electrocardiography revealed ST-segment elevation in almost all leads, suggesting pericarditis. Echocardiography showed normal systolic function. Laboratory data demonstrated C-reactive protein levels of 8.8 mg/dL and elevated cardiac damage markers (troponin T, 1.9 ng/mL; creatine phosphokinase, 1527 U/L; MB isoenzyme, 120 U/L), suggesting myocarditis. He was diagnosed with perimyocarditis associated with the booster dose, which was confirmed by cardiac magnetic resonance imaging four days after initial symptoms. Chest pain improved spontaneously along with a resolution of electrocardiographic findings and laboratory data within several days. He was discharged eight days after admission. Perimyocarditis is less frequent after a booster dose than after primary doses. In this case, the patient with booster-dose-associated perimyocarditis showed favorable clinical course without severe sequelae. The patient's clinical course was consistent with findings on previous large-scale reports on primary-dose-associated perimyocarditis and case series on booster-dose-associated perimyocarditis.

Diagnostic Yield of Cardiac Biomarker Testing in Predicting Cardiac Disease and Multisystem Inflammatory Syndrome in Children in the Pandemic Era.

OBJECTIVES: This study aimed to assess whether elevations in cardiac biomarkers are associated with pediatric cardiac diagnoses in the era of COVID-19 and multisystem inflammatory syndrome in children (MIS-C). STUDY DESIGN: This single-center retrospective study analyzed children with a troponin drawn in the emergency department or inpatient unit between April 21 and December 31, 2020. The primary outcome was the presence of a cardiac diagnosis or MIS-C. Relationships among demographics, complaint, cardiac diagnostics, and cardiac biomarkers were analyzed. RESULTS: Four hundred eighty-six patients (mean ± SD; age 13.1 ± 7.8 years; 46.7% women) met inclusion criteria, for whom a cardiac diagnosis (excluding MIS-C) was made in 27 (5.6%) patients, with MIS-C diagnosed in 14 (2.9%) patients. The sensitivity and specificity of an elevated initial high-sensitivity troponin T (hsTropT) value (>14 ng/L) in predicting the composite outcome of a cardiac diagnosis or MIS-C were 54% and 89%, respectively. Four percent of patients with negative initial troponin values were found to have a cardiac diagnosis or MIS-C. Multivariable regression analysis demonstrated that elevated hsTropT (>14 ng/L; odds ratio [OR] [95% confidence interval]: 4.9 [1.70-14.0]) and elevated N-terminal pro B-type natriuretic peptide values (>500 pg/mL; 6.4 [2.01-20.1]) were associated with increased odds of a cardiac diagnosis or MIS-C. CONCLUSIONS: Children with elevated cardiac biomarkers have increased odds of a cardiac diagnosis or MIS-C and warrant workup regardless of indication for testing. Although a negative hsTropT may reassure providers, further investigation is critical in developing algorithms to reliably exclude cardiac disease.

Biomarkers Predictive for In-Hospital Mortality in Patients with Diabetes Mellitus and Prediabetes Hospitalized for COVID-19 in Austria: An Analysis of COVID-19 in Diabetes Registry.

BACKGROUND: This study assessed the predictive performance of inflammatory, hepatic, coagulation, and cardiac biomarkers in patients with prediabetes and diabetes mellitus hospitalized for COVID-19 in Austria. METHODS: This was an analysis of a multicenter cohort study of 747 patients with diabetes mellitus or prediabetes hospitalized for COVID-19 in 11 hospitals in Austria. The primary outcome of this study was in-hospital mortality. The predictor variables included demographic characteristics, clinical parameters, comorbidities, use of medication, disease severity, and laboratory measurements of biomarkers. The association between biomarkers and in-hospital mortality was assessed using simple and multiple logistic regression analyses. The predictive performance of biomarkers was assessed using discrimination and calibration. RESULTS: In our analysis, 70.8% had type 2 diabetes mellitus, 5.8% had type 1 diabetes mellitus, 14.9% had prediabetes, and 8.6% had other types of diabetes mellitus. The mean age was 70.3 ± 13.3 years, and 69.3% of patients were men. A total of 19.0% of patients died in the hospital. In multiple logistic regression analysis, LDH, CRP, IL-6, PCT, AST-ALT ratio, NT-proBNP, and Troponin T were significantly associated with in-hospital mortality. The discrimination of NT-proBNP was 74%, and that of Troponin T was 81%. The calibration of NT-proBNP was adequate (p = 0.302), while it was inadequate for Troponin T (p = 0.010). CONCLUSION: Troponin T showed excellent predictive performance, while NT-proBNP showed good predictive performance for assessing in-hospital mortality in patients with diabetes mellitus hospitalized with COVID-19. Therefore, these cardiac biomarkers may be used for prognostication of COVID-19 patients.

Evaluation of cardiac injury with biomarkers and echocardiography after COVID-19 infection.

Coronavirus disease 2019 (COVID-19) causes cardiovascular damage in the acute period. Knowledge regarding cardiovascular damage after COVID-19 infection and during longer-term follow-up is currently limited. In our study, we aimed to compare cardiac and inflammatory markers and echocardiographic parameters between patients who had recovered from COVID-19 and control group. A total of 224 individuals were included, comprising 126 patients with a history of COVID-19 and 98 healthy controls. The demographic characteristics of the two groups were similar. Complete blood count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), N-terminal pro-B type natriuretic peptide (NT-ProBNP), D-dimer, haemoglobin A1C, troponin T and creatine kinase myocardial band (CK-MB) levels were compared between both groups. The mean follow-up period of the COVID-19 group was 58.39 ± 39.1 days (range:10 - 180 days post-COVID-19). Red cell distribution width (RDW), ESR, CRP, NT-ProBNP, D-dimer and troponin T values were significantly higher in the COVID-19 group compared to the control group. Left ventricular ejection fraction (LVEF) was significantly lower in the COVID-19 group. Left ventricular diastolic diameter (LVDD) and incidence of pericardial effusion were higher in the COVID-19 group. For multivariate analysis, possible factors identified by univariate analysis were subjected to multivariate logistic regression analysis to determine independent predictors of COVID-19. Among these factors, RDW, CRP and LVEF were independently higher in the COVID-19 group than in the control group. We conclude that although the clinical and prognostic significance of cardiac and other inflammatory markers in the acute phase of COVID-19 is known, we found that these biomarkers and echocardiography parameters can also be used in the follow-up of cardiac injury for a mid-term period post-infection.

[Troponin-T and n-terminal pro-brain type natriuretic peptide plasma levels and its relationship with mortality in COVID-19]. / Niveles plasmáticos de troponina T y de la fracción aminoterminal del propéptido natriurético cerebral y su relación con mortalidad en COVID-19.

INTRODUCTION: Cardiovascular compromise in coronavirus disease 2019 (COVID-19) does not necessarily present with the classic symptoms described in myocarditis. There is growing evidence demonstrating subclinical cardiovascular compromise in the context of the intense inflammation unleashed, the cytokine storm involved, the baseline prothrombotic state, and the consequent endothelial dysfunction. We set out to analyse whether Troponin-T (TT) and the amino-terminal fraction of pro-brain natriuretic peptide (NT-proBNP) determined at hospital admission, are related to mortality during the hospitalization of these patients. MATERIAL AND METHODS: Analytical, observational, retrospective cohort and cross-sectional study. It included subjects with COVID-19 hospitalized for moderate-severe illness, from 20/03/20 to 15/11/20. The TT and NT-proBNP obtained in the first 24 hours from admission were analysed. Altered TT was considered if ≥.014 ng/dl and altered NT-proBNP if ≥300 pg/ml. RESULTS: One hundred and eight subjects were included, 63.2% men, age 51.5 years (59-43), 28% were admitted to the Critical Unit and 25% died. The group with elevated TT presented higher mortality (OR = 3.1; 95%CI = 1.10-8.85; p = .02). The group with elevated NT-proBNP also show higher mortality (OR = 3.47; 95%CI = 1.21-9.97; p = .01). On multivariate analysis, only NT-proBNP ≥300 pg/ml remained an independent risk factor. CONCLUSIONS: NT-proBNP levels ≥300 pg/ml at admission in patients with moderate-severe COVID-19 were associated with higher mortality.

Serial Assessment of Myocardial Injury Markers in Mechanically Ventilated Patients With SARS-CoV-2 (from the Prospective MaastrICCht Cohort).

Myocardial injury in COVID-19 is associated with in-hospital mortality. However, the development of myocardial injury over time and whether myocardial injury in patients with COVID-19 at the intensive care unit is associated with outcome is unclear. This study prospectively investigates myocardial injury with serial measurements over the full course of intensive care unit admission in mechanically ventilated patients with COVID-19. As part of the prospective Maastricht Intensive Care COVID cohort, predefined myocardial injury markers, including high-sensitivity cardiac troponin T (hs-cTnT), N-terminal pro-B-type natriuretic peptide (NT-proBNP), and electrocardiographic characteristics were serially collected in mechanically ventilated patients with COVID-19. Linear mixed-effects regression was used to compare survivors with nonsurvivors, adjusting for gender, age, APACHE-II score, daily creatinine concentration, hypertension, diabetes mellitus, and obesity. In 90 patients, 57 (63%) were survivors and 33 (37%) nonsurvivors, and a total of 628 serial electrocardiograms, 1,565 hs-cTnT, and 1,559 NT-proBNP concentrations were assessed. Log-hs-cTnT was lower in survivors compared with nonsurvivors at day 1 (ß -0.93 [-1.37; -0.49], p <0.001) and did not change over time. Log-NT-proBNP did not differ at day 1 between both groups but decreased over time in the survivor group (ß -0.08 [-0.11; -0.04] p <0.001) compared with nonsurvivors. Many electrocardiographic abnormalities were present in the whole population, without significant differences between both groups. In conclusion, baseline hs-cTnT and change in NT-proBNP were strongly associated with mortality. Two-thirds of patients with COVID-19 showed electrocardiographic abnormalities. Our serial assessment suggests that myocardial injury is common in mechanically ventilated patients with COVID-19 and is associated with outcome.

Cardiac MRI in Suspected Acute Myocarditis After COVID-19 mRNA Vaccination.

PURPOSE: To evaluate cardiac MRI characteristics in patients with suspected hypersensitivity myocarditis following mRNA COVID-19 vaccination. MATERIALS AND METHODS: Patients clinically suspected of acute myocarditis after COVID-19 vaccination were retrospectively analyzed and compared against a healthy control group. Cardiac MRI protocol included parameters such as T1 and T2 relaxation times, extracellular volume (ECV), T2 signal intensity ratio, and late gadolinium enhancement (LGE). Lymph node size was assessed in the patient group on the injection side. Student t-test, analyses of variance (ANOVA) with Tukey post-hoc test, and χ2 test were used for statistical analysis. RESULTS: 20 patients with clinically suspected post-vaccine myocarditis (28 ±â€Š12 years; 12 men) and 40 controls (31 ±â€Š11 years; 25 men) were evaluated. According to the 2018 Lake Louise criteria (LLC), patients with clinically suspected myocarditis were further subdivided into an LLC-positive group (n = 9) and an LLC-negative group (n = 11). The mean time of symptom onset after vaccination was 1.1 ±â€Š1.2 days (LLC-positive) and 6.5 ±â€Š9.2 days (LLC-negative). Group differences in inflammatory variables between myocarditis patients and control subjects were more pronounced in the LLC-positive group (e. g., T1 relaxation time: 1041 ±â€Š61 ms [LLC positive] vs. 1008 ±â€Š79 ms [LLC-negative] vs. 970 ±â€Š25 ms [control]; p <.001; or T2 signal intensity ratio 2.0 ±â€Š0.3 vs. 1.6 ±â€Š0.3 [LLC-negative] and vs. 1.6 ±â€Š0.3 [control], p = .012). LLC-positive patients were significantly faster in receiving an MRI after initial symptom onset (8.8 ±â€Š6.1 days vs. 52.7 ±â€Š33.4 days; p = .001) and had higher troponin T levels (3938 ±â€Š5850 ng/l vs. 9 ±â€Š11 ng/l; p <.001). LGE lesions were predominantly located at the subepicardium of the lateral wall. Axillary lymphadenopathy was more frequent in the LLC-positive group compared to the LLC-negative group (8/9 [89 %] vs. 0/11 [0 %], p < 0.001). CONCLUSION: Vaccine-induced myocarditis should be considered in patients with acute symptom onset after mRNA vaccination, especially if elevated serum troponin T is observed. Imaging findings of vaccine-induced myocarditis are similar to virus-induced myocarditis, allowing for the use of the Lake Louise Criteria for diagnostic purposes. KEY POINTS: · Vaccine-induced hypersensitivity myocarditis can be confirmed with cardiac MRI. · Especially patients with sudden onset of symptoms and elevated serum troponin T had positive cardiac MRI findings. · Cardiac MRI characteristics of vaccine-induced myocarditis are similar to those in virus-induced myocarditis. CITATION FORMAT: · Kravchenko D, Isaak A, Mesropyan N et al. Cardiac MRI in Suspected Acute Myocarditis After COVID-19 mRNA Vaccination. Fortschr Röntgenstr 2022; 194: 1003 - 1011.