Clinical significance of early troponin I levels on the prognosis of patients with severe heat stroke / 中华危重病急救医学

OBJECTIVE@#To investigate the clinical significance of early troponin I (TnI) level in the prognosis of severe heat stroke.@*METHODS@#Clinical data of 131 patients with severe heat stroke in the intensive care unit (ICU) of the Affiliated Changzhou NO.2 People's Hospital of Nanjing Medical University (study dataset) and ICU 67 patients with severe heat stroke in Jintan First People's Hospital of Changzhou (validation dataset) were retrospectively analyzed from June 2013 to September 2022. The patients were divided into survival group and death group according to 30-day outcomes. TnI was collected within 24 hours after admission to the emergency department. Cox regression analysis was performed to analyze the risk factors of severe heat stroke death. Spearman correlation test was used to analyze the correlation between TnI and heart rate, and peripheral systolic blood pressure. The receiver operator characteristic curve (ROC curve) was drawn to evaluate the predictive value of TnI for death in patients with severe heat stroke. Decision curve analysis (DCA) was conducted to assess the clinical net benefit rate of TnI prediction. Grouping by TnI cut-off value, Kaplan-Meier survival curve was used to analyze 30-day cumulative survival. Sensitivity analysis included modified Possion regression, E-value, and subgroup forest map was used to evaluate the mortality risk of TnI in different populations. External dataset was used to verify the predictive value of TnI.@*RESULTS@#The death group had significantly higher TnI compared to the survival group [μg/L: 0.623 (0.196, 1.510) vs. 0.084 (0.019, 0.285), P < 0.01]. Multivariate Cox regression analysis after adjusting for confounding factors showed that TnI was an independent risk factor for death [hazard ratio (HR) = 1.885, 95% confidence interval (95%CI) was 1.528-2.325,P < 0.001]. Spearman correlation test showed that TnI was positively correlated with heart rate (r = 0.537, P < 0.001) and negatively correlated with peripheral systolic blood pressure (r = -0.611, P < 0.001). ROC curve showed that the area under the curve (AUC) of the TnI (0.817) was better than that of the acute physiology and chronic health evaluation II (APACHE II, 0.756). The DCA curve showed that the range of clinical net benefit rate of TnI (6.21%-20.00%) was higher than that of APACHE II score (5.14%-20.00%). Kaplan-Meier survival curve showed that patients in the low-risk group (TnI ≤ 0.106) had a significantly higher 30-day survival rate than that in the high-risk group (TnI > 0.106) group (Log-Rank test: χ2 = 17.350, P < 0.001). Modified Possion regression with adjustment for confounding factors showed that TnI was still an independent risk factor for death in patients with severe heat stroke [relative risk (RR) = 1.425, 95%CI was 1.284-1.583, P < 0.001]. The E-value was 2.215. The subgroup forest plot showed that the risk factors of TnI were obvious in male patients and patients ≤ 60 years old (male: HR = 1.731, 95%CI was 1.402-2.138, P < 0.001; ≤ 60 years old: HR = 1.651, 95%CI was 1.362-2.012, P < 0.001). In the validation dataset, ROC curve analysis showed that the AUC (0.836) of TnI predicting the prognosis of severe heat stroke was still higher than the APACHE II score (0.763).@*CONCLUSIONS@#Early elevation of TnI is a high-risk factor for death in patients with severe heat stroke, and it has a good predictive value for death.

Electrocardiographic changes and changes in cardiac lactate and troponin I levels associated with search and rescue physical activity in military dogs / Alterações eletrocardiográficas e nos níveis de lactato e troponina I cardíaca associadas à atividade física de busca e salvamento em cães militares

Rescue and recovery dogs intercalate the activity intensity developed, which also triggers significant metabolic changes in cardiac physiology. Thus, we evaluated the changes that search simulation causes in glucose, lactate, and cardiac troponin I level (cTnI) and the electrocardiographic and heart rate during the activity and recovery phase to predict the physiological adaptation to the exercise. Five healthy adult dogs from the Rescue and Recovery Service of Military Firefighters Corps were submitted to 60 minutes search operation simulation in the woods. They covered a forest area of approximately 50,000 m2. The dogs were loose and accompanied by their driver, and they could perform any physical activity. Were evaluated serum biochemical analysis of glucose, lactate, cardiac troponin I, electrocardiographic, and heart rate (rest, exercise phase, and recovery time). No changes in glucose levels, heart rate, and cardiac rhythm were detected. In comparison to baseline values, there is an increase: in lactate at the end of the exercise phase [EXER] (60'EXER), and in the recovery phase [RCT] at 30'RCT and 60'RCT, and cTnI at 60'RCT, 120'RCT, and 4hRCT. P wave duration was significantly higher at 60'EXER, 15'RCT, and 30'RCT, with no alterations in wave amplitude. QRS interval duration significantly increased at 30'RCT, and the ST segment presented a significant difference at 60'EXER, 15'RCT, and 60'RCT compared to the rest moment. The moderate alterations in lactate and cTnI and few alterations in the electrocardiographic and heart rate maintenance suggest the adaptation of rescue and recovery dogs to the type, intensity, and duration of search operation simulation performed.(AU)

Cães de busca e resgate intercalam a intensidade da atividade desenvolvida que desencadeia alterações metabólicas significativas, bem como na fisiologia cardíaca. Assim, foram avaliadas as alterações que a simulação de busca produz nos níveis de glicose, lactato, troponina I cardíaca (cTnI), bem como na frequência cardíaca e atividade eletrocardiográfica durante a fase de atividade e recuperação, a fim de predizer a adaptação fisiológica ao exercício. Cinco cães adultos saudáveis do Serviço de Resgate e Salvamento do Corpo de Bombeiros Militares foram submetidos à simulação de operação de busca de 60 minutos na mata e cobriram uma área florestal de aproximadamente 50.000 m2. Os cães estavam soltos, acompanhados pelo condutor e estavam livres para realizar qualquer tipo de atividade física. Foram avaliados os níveis séricos de glicose, lactato e troponina I cardíaca, atividade eletrocardiográfica e frequência cardíaca em repouso, na fase de exercício e no tempo de recuperação. Não foram detectadas alterações nos níveis de glicose, frequência cardíaca e ritmo cardíaco. Em comparação com os valores basais houve aumento de lactato ao final da fase de exercício [EXER] (60'EXER) e na fase de recuperação [RCT] aos 30'RCT e 60'RCT; e cTnI aos 60'RCT, 120'RCT e 4hRCT. Duração da onda P foi significativamente maior em 60'EXER, 15'RCT e 30'RCT, sem alterações na amplitude da onda. Duração do intervalo QRS teve aumento significativo em 30'RCT e o segmento ST apresentou diferença significativa em 60'EXER, 15'RCT e 60'RCT quando comparado ao basal. As alterações moderadas nos níveis de lactato e cTnI, bem como a pouca alteração na atividade eletrocardiográfica e manutenção da frequência cardíaca sugerem boa adaptação dos cães de busca e resgate ao tipo, intensidade e duração da operação de busca simulada realizada.(AU)

Effect of co-morbid chronic kidney disease on the accuracy of cardiac troponin levels for diagnosis of acute myocardial infarction / 南方医科大学学报

OBJECTIVE@#To evaluate the accuracy of cardiac troponin (cTn) levels in the diagnosis of acute myocardial infarction (AMI) in patients with chronic kidney disease (CKD) and explore a potential strategy for improving the diagnostic accuracy.@*METHODS@#We retrospectively analyzed the data from patients with high-risk chest pain admitted in Zhujiang Hospital from January, 2018 to December, 2020, including 126 patients with and 272 patients without CKD, and 122 patients diagnosed to have AMI and 276 patients without AMI. The baseline clinical data of the patients and blood test results within 12 h after admission were collected.@*RESULTS@#In patients without AMI, cTnT level was significantly higher in those with co-morbid CKD than in those without CKD (P < 0.001), and showed a moderate negative correlation with eGFR (rs=- 0.501, P < 0.001), while cTnI level did not differ significantly between the two groups (P=0.72). In patients with CKD, the optimal cutoff level was 0.177 μg/L for cTnT and 0.415 ng/mL for cTnI for diagnosis of AMI, for which cTnI had a higher specificity than cTnT. The diagnostic model combining both cTnT and cTnI levels [P=eY/(1+ eY), Y=6.928 (cTnT)-0.5 (cTnI)-1.491] had a higher AUC value than cTn level alone.@*CONCLUSION@#In CKD patients, the cutoff level of cTn is increased for diagnosing AMI, and cTnI has a higher diagnostic specificity than cTnT. The combination of cTnT and cTnI levels may further improve diagnostic efficacy for AMI.

Predictive Value of Myocardial injury in Patients with COVID-19 Admitted to a Quaternary Hospital in the City of Rio de Janeiro

Abstract Background In Brazil the factors involved in the risk of death in patients with COVID-19 have not been well established. Objective To analyze whether elevations of high-sensitivity troponin I (hTnI) levels influence the mortality of patients with COVID-19. Methods Clinical and laboratory characteristics of hospitalized patients with COVID-19 were collected upon hospital admission. Univariate and binary logistic regression analyzes were performed to assess the factors that influence mortality. P-value<0.05 was considered significant. Results This study analyzed192 patients who received hospital admission between March 16 and June 2, 2020 and who were discharged or died by July 2, 2020. The mean age was 70±15 years, 80 (41.7%) of whom were women. In comparison to those who were discharged, the 54 (28.1%) who died were older (79±12 vs 66±15years; P=0.004), and with a higher Charlson´s index (5±2 vs 3±2; P=0.027). More patients, aged≥60years (P <0.0001), Charlson´s index>1 (P=0.004), lung injury>50% in chest computed tomography (P=0.011), with previous coronary artery disease (P=0.037), hypertension (P=0.033), stroke (P=0.008), heart failure (P=0.002), lymphocytopenia (P=0.024), high D-dimer (P=0.024), high INR (P=0.003), hTnI (P<0.0001), high creatinine (P<0.0001), invasive mechanical ventilation (P<0.0001), renal replacement therapy (P<0.0001), vasoactive amine (P<0.0001), and transfer to the ICU (P=0.001), died when compared to those who were discharged. In logistic regression analysis, elevated hTnI levels (OR=9.504; 95% CI=1.281-70.528; P=0.028) upon admission, and the need for mechanical ventilation during hospitalization (OR=46.691; 95% CI=2.360-923.706; P=0.012) increased the chance of in-hospital mortality. Conclusion This study suggests that in COVID-19 disease, myocardial injury upon hospital admission is a harbinger of poor prognosis.

Valor Prognóstico de Níveis Elevados de Troponina I Isolados em Pacientes sem Síndrome Coronariana Aguda Admitidos no Serviço de Emergência / Prognostic Value of Isolated Elevated Troponin I Levels in Patients without Acute Coronary Syndrome Admitted to the Emergency Department

Resumo Fundamento: Embora a elevação não isquêmica da troponina seja frequentemente observada em pacientes admitidos no pronto-socorro (PS), não há consenso quanto ao seu manejo. Objetivos: Este estudo teve como objetivo caracterizar os pacientes admitidos no PS com elevação da troponina não-isquêmica e identificar potenciais preditores de mortalidade nessa população. Métodos: Este estudo observacional retrospectivo incluiu pacientes do PS com resultado positivo no teste da troponina entre junho e julho de 2015. Pacientes com diagnóstico clínico de síndrome coronariana aguda (SCA) foram excluídos. Os dados demográficos dos pacientes e as variáveis clínicas e laboratoriais foram extraídos dos prontuários médicos. Os dados do seguimento foram obtidos por 16 meses ou até a ocorrência de morte. O nível de significância estatística foi de 5%. Resultados: A elevação da troponina sem SCA foi encontrada em 153 pacientes no PS. A mediana (IIQ) de idade dos pacientes foi de 78 (19) anos, 80 (52,3%) eram do sexo feminino e 59 (38,6%) morreram durante o seguimento. A mediana do período de seguimento (IIQ) foi de 477 (316) dias. Os sobreviventes eram significativamente mais jovens 76 (24) vs. 84 (13) anos; p=0,004) e apresentaram uma maior proporção de elevação da troponina isolada (sem elevação da creatina quinase ou mioglobina) em duas avaliações consecutivas: 48 (53,9%) vs. 8 (17,4%), p<0,001. Os sobreviventes também apresentaram menor taxa de tratamento antiplaquetário e internação no mesmo dia. Na regressão logística multivariada com ajuste para variáveis significativas na análise univariada, a elevação isolada da troponina em duas avaliações consecutivas mostrou hazard ratio = 0,43 (IC95% 0,17-0,96, p=0,039); hospitalização, tratamento antiplaquetário anterior e idade permaneceram independentemente associados à mortalidade. Conclusões: A elevação isolada da troponina em duas medidas consecutivas foi um forte preditor de sobrevida em pacientes no PS com elevação da troponina, mas sem SCA.

Abstract Background: Although non-ischemic troponin elevation is frequently seen in patients admitted to the emergency department (ED), consensus regarding its management is lacking. Objectives: This study aimed to characterize patients admitted to the ED with non-ischemic troponin elevation and to identify potential mortality predictors in this population. Methods: This retrospective observational study included ED patients with a positive troponin test result between June and July of 2015. Patients with a clinical diagnosis of acute coronary syndrome (ACS) were excluded. Data on patient demographics and clinical and laboratory variables were extracted from medical records. Follow-up data were obtained for 16 months or until death occurred. The statistical significance level was 5%. Results: Troponin elevation without ACS was found in 153 ED patients. The median (IQR) patient age was 78 (19) years, 80 (52.3%) were female and 59(38.6%) died during follow-up. The median (IQR) follow-up period was 477(316) days. Survivors were significantly younger 76 (24) vs. 84 (13) years; p=0.004) and featured a higher proportion of isolated troponin elevation (without creatine kinase or myoglobin elevation) in two consecutive evaluations: 48 (53.9%) vs. 8 (17.4%), p<0.001. Survivors also presented a lower rate of antiplatelet treatment and same-day hospitalization. In the multivariate logistic regression with adjustment for significant variables in the univariate analysis, isolated troponin elevation in two consecutive evaluations showed a hazard ratio= 0.43 (95%CI 0.17-0.96, p=0.039); hospitalization, previous antiplatelet treatment and age remained independently associated with mortality. Conclusions: Isolated troponin elevation in two consecutive measurements was a strong predictor of survival in ED patients with troponin elevation but without ACS.

Associação entre o índice de massa corporal e a gravidade e complexidade das lesões coronarianas em pacientes pós-infarto / Association of body mass index and coronary lesions severity and complexity in post-myocardial infarction patients

Objetivo: Avaliar a associação entre o índice de massa corporal e a gravidade das lesões coronarianas em pacientes com infarto agudo do miocárdio. Métodos: Coorte aninhada ao Catarina Heart Study que avaliou 350 indivíduos durante o primeiro evento de infarto agudo do miocárdio e o 30º dia pós-infarto. As variáveis qualitativas foram analisadas pelo teste do qui-quadrado. Após o resultado da distribuição, a avaliação de variáveis quantitativas foi feita pelo teste de t de Student, pela correlação de Pearson, pelo teste de Mann-Whitney e pela correlação de Spearman. Resultados: Indivíduos com obesidade G2 (15,4%) tiveram maior probabilidade de trombose em 30 dias em comparação a indivíduos com índice de massa corporal normal (1,1%), com p=0,005. Indivíduos com obesidade grau 1 (6,0%) e obesidade grau 2 (7,7%) tiveram mais eventos de infarto agudo do miocárdio em 30 dias em comparação a indivíduos com índice de massa corporal normal (0,0%), com p=0,019 e p=0,009, respectivamente. Nenhuma associação significativa foi encontrada em termos de fração de ejeção do ventrículo esquerdo, mortalidade e complexidade das lesões coronarianas (escore SYNTAX e TIMI frame count). Conclusão: A obesidade em diversos graus está diretamente associada a fatores de risco para doença cardiovascular, como hipertensão arterial sistêmica, dislipidemia e tabagismo. Não houve associação entre o índice de massa corporal com a gravidade das lesões coronarianas ou a fração de ejeção do ventrículo esquerdo. Não houve diferença na mortalidade comparando-se indivíduos com índice de massa corporal elevado a pacientes com índice de massa corporal normal. Pacientes com obesidade tiveram mais desfechos cardiovasculares, como trombose e novo evento de infarto agudo do miocárdio em 30 dias, ao serem comparados a pacientes com índice de massa corporal normal. Outros desfechos de seguimento em 30 dias não estiveram associados ao índice de massa corporal.

Objective: To evaluate the association between body mass index and severity of coronary lesions in patients with acute myocardial infarction. Methods: A cohort nested to Catarina Heart Study, which evaluated 350 individuals during the first event of myocardial infarction and the 30th day post-infarction. Qualitative variables were analyzed using the Chi-square test. After the distribution result, the evaluation of quantitative variables was done through Student's t-test, Pearson's correlation, Mann Whitney's test, and Spearman's correlation. Results: Individuals with G2 obesity (15.4%) had a greater probability of having thrombosis in 30 days compared to individuals with normal body mass index (1.1%), p=0.005. Individuals with G1 obesity (6.0%) and G2 obesity (7.7%) had more events of myocardial infarction in 30 days compared to individuals with normal body mass index (0.0%), with p=0.019 and p=0.009, respectively. No significant association was found in terms of left ventricle ejection fraction, mortality, and complexity of coronary lesions (SYNTAX score and TIMI frame count). Conclusion: Obesity in several degrees is directly associated with risk factors for cardiovascular disease, such as hypertension, dyslipidemia, and smoking. There was no association between the body mass index and the severity of coronary lesions or left ventricle ejection fraction. There was no difference in mortality comparing individuals with high body mass index to patients with normal body mass index. Patients with obesity had more cardiovascular outcomes, such as thrombosis and a new event of myocardial infarction in 30 days when compared to patients with normal body mass index. Other follow-up outcomes in 30 days were not associated with body mass index

Behavior of acute myocardial infarctions in an intensive care unit of a medium-size city over a one-year span / Comportamiento del infarto agudo de miocardio en una unidad de cuidado intensivo de una ciudad intermedia durante un año

Abstract Objectives: to identify the clinical and paraclinical behavior of myocardial infarctions in an intensive care unit of a medium-size city during 2017. Methods: a descriptive, cross-sectional study which included 99 medical records with a diagnosis of myocardial infarction on ICU discharge. The variables were described and analysis of variance and Chi2tests were performed, using a p-value less than 0.05 for statistically significant differences. Results: the prevalence of myocardial infarction in the ICU was 11.8%. The average age was 66.8 years. Chest pain was present in 82.8% with an average duration of 335 minutes. The pain most often radiated to the left arm (13.1%). Non-ST segment elevation myocardial infarction was the most frequent (50.5%), and the electrocardiogram located the infarctions on the inferior surface in 28.2%. The average ultrasensitive troponin I was 28.2 ng/mL. A total of 54.5% had complications. Mortality was 14.1%. Hospital stay was 6.5 and critical care stay was three days. There was a statistically significant relationship between chest pain and ST segment elevation (p<0.001) and between troponin I plus hospital stay and ST segment elevation (p=0.007 and p=0.003, respectively). Conclusion: the study showed that 11.8% of patients admitted to ICU are admitted for myocardial infarction, and there is a statistically significant relationship between chest pain and an elevated ST segment and between increased troponin I plus a longer hospital stay and ST segment elevation. (Acta Med Colomb 2020; 45. DOI:https://doi.org/10.36104/amc.2020.1498).

Resumen Identificar el comportamiento clínico y paraclínico del infarto de miocardio en una unidad de cuidados intensivos de una ciudad intermedia durante el 2017. Métodos: estudio descriptivo de corte transversal, incluyó 99 registros con diagnóstico de infarto del miocardio al egreso de UCI. Se describieron las variables y se realizaron análisis de varianza y chi2y se consideró un valor de p<0.05 para diferencias estadísticamente significativas. Resultados: la prevalencia de infarto del miocardio fue 11.8% en UCI. La edad promedio fue 66.8 años. El dolor precordial estuvo presente en 82.8% con una duración promedio de 335 minutos. La irradiación del dolor fue más frecuente a miembro superior izquierdo (13.1%). El infarto sin elevación del complejo ST fue más frecuente (50.5%). Y la localización electrocardiográfica fue en la cara inferior en 28.2%. El promedio de troponina I ultrasensible fue de 28.2 ng/mL. Presentaron complicaciones el 54.5%. La mortalidad fue de 14.1%. La estancia hospitalaria fue 6.5 y la estancia en cuidados críticos tres días. Se encontró relación estadísticamente significativa entre dolor precordial y elevación del segmento ST (p<0.001) y entre troponina I con estancia hospitalaria y elevación del segmento ST (p=0.007 y p=0.003 respectivamente). Conclusión: se identificó que 11.8% de los pacientes que ingresan a la UCI, lo hacen por infarto del miocardio, y una relación estadísticamente significativa entre dolor precordial con elevación del segmento ST y entre el aumento de troponina I con mayor estancia hospitalaria y elevación del segmento ST.(Acta Med Colomb 2020; 45. DOI:https://doi.org/10.36104/amc.2020.1498).

Elevación persistente de troponina I / Persistent elevation of troponin I

Resumen La troponina cardiaca es el marcador bioquímico más sensible y específico de daño/necrosis miocárdica, de ahí que desempeñe un papel crucial en el diagnóstico del síndrome coronario agudo. Sin embargo, en ocasiones, como en el caso clínico que se describirá, la elevación anormal de troponina no siempre obedece a un síndrome coronario agudo trombótico, sino a causa cardiaca sin enfermedad coronaria significativa, causa extracardiaca o alteración analítica (verdaderos falsos positivos). El interés de este caso radica en que siempre debería tenerse en mente la posibilidad de que se produzca un falso positivo de troponina por causa analítica, en especial en situaciones clínicas sin una razón obvia de daño miocárdico y cuando no sea evidente la confirmación de daño miocárdico mediante pruebas complementarias.

Abstract Cardiac troponin is the most sensitive and specific biochemical marker for myocardial damage / necrosis, and thus has a crucial role in the diagnosis of acute coronary syndrome. However, occasionally, as in the clinical case that will be described, the abnormal elevation of troponin does not always obey that of an acute coronary syndrome, but also to a cardiac cause with no significant coronary disease, extra-cardiac cause, or analytical change (true false positives). The interest in this case lies in that it should always be borne in mind that a false positive troponin can be produced due to an analytical cause. This can be the case in clinical situations with no obvious reason for myocardial damage and when the confirmation of myocardial damage may not be evident using complementary tests.

Evaluation of perioperative high-sensitive cardiac troponin i as a predictive biomarker of major adverse cardiovascular events after noncardiac surgery

ABSTRACT Background: Various studies suggest that perioperative concentrations of high-sensitivity troponins are incremental and predictive factors of a major adverse cardiac event (MACE) and all-cause mortality. Objective: The objective of the study was to evaluate the predictive value of high-sensitivity cardiac troponin I (hs-cTnI) in the development of MACE and all-cause mortality, within 30-days and 1-year follow-up after noncardiac surgery. Methods: In this prospective cohort study, we included men ≥ 45 years and women ≥ 55 years with ≥ 2 cardiovascular risk factors and undergoing intermediate or high-risk noncardiac surgery. Demographic and clinical information was collected from clinical charts. We measured baseline hs-cTnI 24 h before surgery, and its post-operative concentration 24 h after surgery. Results: In the entire sample, 8 patients (8.6%) developed MACE at 30-days follow-up (4 deaths), 12 (12.9%) within the 1st year (7 deaths), and 17 (18.2%) after complete post-surgical follow-up (10 deaths). We observed higher baseline and post-operative concentrations in patients who presented MACE (12 pg/ml vs. 3.5 pg/ml; p = 0.001 and 18.3 pg/ml vs. 5.45 pg/ml; p = 0.009, respectively). The hazard ratios (HRs) calculated by Cox regression analysis between the hs-cTnI baseline concentration and the post-operative development of MACE at 30-days and 1-year were 5.70 (95% confidence interval [CI], 1.10-29.40) with hs-cTnI > 6.2 pg/ml and 12.86 (95% CI, 1.42-116.34) with hs-cTnI > 3.3 pg/ml, respectively. The estimated post-operative HR death risk at 1-year was 14.43 (95% CI, 1.37-151.61) with hs-cTnI > 4.5 pg/ml. Conclusions: Pre-operative hs-cTnI was an independent predictive risk factor for MACE at 30-days and 1-year after noncardiac surgery and for all-cause mortality at 1-year after noncardiac surgery.

Irisin and troponin I expression in dialysis patients submitted to remote ischemic preconditioning: a pilot study / Expressão de irisina e troponina I em pacientes em diálise submetidos a pré-condicionamento isquêmico remoto: um estudo piloto

ABSTRACT Background: Renal replacement therapy continues to be related to high hospitalization rates and poor quality of life. All-cause morbidity and mortality in renal replacement therapy in greater than 20% per year, being 44 times greater when diabetes is present, and over 10 times that of the general population. Regardless of treatment, the 5-year survival is 40%, surpassing many types of cancers. Irisin is a hormone that converts white adipose tissue into beige adipose tissue, aggregating positive effects like fat mass control, glucose tolerance, insulin resistance, prevention of muscle loss, and reduction in systemic inflammation. Objectives: To determine the serum levels of troponin I in hemodialysis patients submitted to remote ischemic preconditioning (RIPC) associated with irisin expression. Methods: This was a prospective, randomized, double-blind clinical trial with patients with chronic kidney disease submitted to hemodialysis for a 6-month period. Troponin I, IL-6, urea, TNF-α, and creatinine levels were determined from blood samples. The expressions of irisin, thioredoxin, Nf-kb, GPX4, selenoprotein and GADPH were also evaluated by RT-PCR. Results: Samples from 14 hypertensive patients were analyzed, 9 (64.3%) of whom were type 2 diabetics, aged 44-64 years, and 50% of each sex. The difference between pre- and post-intervention levels of troponin I was not significant. No differences were verified between the RIPC and control groups, except for IL-6, although a significant correlation was observed between irisin and troponin I. Conclusion: Remote ischemic preconditioning did not modify irisin or troponin I expression, independent of the time of collection.

RESUMO Introdução: A terapia de substituição renal continua associada a altas taxas de hospitalização e baixa qualidade de vida. A morbimortalidade por todas as causas na terapia de substituição renal é superior a 20% ao ano, sendo 44 vezes maior quando a diabetes está presente e mais de 10 vezes a da população em geral. Independentemente do tratamento, a sobrevida em 5 anos é de 40%, superando muitos tipos de câncer. A irisina é um hormônio que converte tecido adiposo branco em tecido adiposo bege, agregando efeitos positivos como o controle de massa gorda, tolerância à glicose, resistência à insulina, prevenção de perda muscular e redução da inflamação sistêmica. Objetivos: Determinar os níveis séricos de troponina I em pacientes em hemodiálise submetidos ao pré-condicionamento isquêmico remoto (PCIR) associado à expressão da irisina. Métodos: Estudo clínico prospectivo, randomizado, duplo-cego, com pacientes com doença renal crônica submetidos à hemodiálise por um período de 6 meses. Os níveis de troponina I, IL-6, uréia, TNF-α e creatinina foram determinados a partir de amostras de sangue. As expressões de irisina, tioredoxina, Nf-kb, GPX4, selenoproteína e GADPH foram também avaliadas por RT-PCR. Resultados: Foram analisadas amostras de 14 pacientes hipertensos, 9 (64,3%) dos quais eram diabéticos tipo 2, com idades entre 44 e 64 anos e 50% de cada gênero. A diferença entre os níveis pré e pós-intervenção de troponina I não foi significativa. Não houve diferenças entre os grupos PCIR e controle, exceto pela IL-6, embora tenha sido observada correlação significativa entre irisina e troponina I. Conclusão: O pré-condicionamento isquêmico remoto não modificou a expressão de irisina ou troponina I, independentemente do tempo de coleta.

Analysis of myocardial injury in patients with COVID-19 and association between concomitant cardiovascular diseases and severity of COVID-19 / 中华心血管病杂志

Objective: To evaluate the cardiovascular damage of patients with COVID-19, and determine the correlation of serum N-terminal pro B-type natriuretic peptide (NT-proBNP） and cardiac troponin-I (cTnI） with the severity of COVID-19, and the impact of concomitant cardiovascular disease on severity of COVID-19 was also evaluated. Methods: A cross-sectional study was designed on 150 consecutive patients with COVID-19 in the fever clinic of Tongji Hospital in Wuhan from January 19 to February 13 in 2020, including 126 mild cases and 24 cases in critical care. Both univariate and multivariate logistic regression were used to analyze the correlation of past medical history including hypertension, diabetes and coronary heart disease (CHD）, as well as the levels of serum NT-proBNP and cTnI to the disease severity of COVID-19 patients. Results: Age, hypersensitive C-reactive protein(hs-CRP) and serum creatinine levels of the patients were higher in critical care cases than in mild cases(all P<0.05). Prevalence of male, elevated NT-proBNP and cTnI, hypertension and coronary heart disease were significantly higher in critical cases care patients than in the mild cases(all P<0.05). Univariate logistic regression analysis showed that age, male, elevated NT-proBNP, elevated cTnI, elevated hs-CRP, elevated serum creatinine, hypertension, and CHD were significantly correlated with critical disease status(all P<0.05). Multivariate logistic regression analysis showed that elevated cTnI(OR=26.909，95%CI 4.086-177.226，P=0.001) and CHD (OR=16.609，95%CI 2.288-120.577，P=0.005) were the independent risk factors of critical disease status. Conclusions: COVID-19 can significantly affect the heart function and lead to myocardial injury. The past medical history of CHD and increased level of cTnI are 2 independent determinants of clinical disease status in patients with COVID-19.

Performance of Copeptin for Early Diagnosis of Acute Myocardial Infarction in an Emergency Department Setting

BACKGROUND: Rapid and accurate diagnosis of acute myocardial infarction (AMI) is critical for initiating effective treatment and achieving better prognosis. We investigated the performance of copeptin for early diagnosis of AMI, in comparison with creatine kinase myocardial band (CK-MB) and troponin I (TnI). METHODS: We prospectively enrolled 271 patients presenting with chest pain (within six hours of onset), suggestive of acute coronary syndrome, at an emergency department (ED). Serum CK-MB, TnI, and copeptin levels were measured. The diagnostic performance of CK-MB, TnI, and copeptin, alone and in combination, for AMI was assessed by ROC curve analysis by comparing the area under the curve (AUC). Sensitivity, specificity, negative predictive value, and positive predictive value of each marker were obtained, and the characteristics of each marker were analyzed. RESULTS: The patients were diagnosed as having ST elevation myocardial infarction (STEMI; N=43), non-ST elevation myocardial infarction (NSTEMI; N=25), unstable angina (N=78), or other diseases (N=125). AUC comparisons showed copeptin had significantly better diagnostic performance than TnI in patients with chest pain within two hours of onset (AMI: P=0.022, ≤1 hour; STEMI: P=0.017, ≤1 hour and P=0.010, ≤2 hours). In addition, TnI and copeptin in combination exhibited significantly better diagnostic performance than CK-MB plus TnI in AMI and STEMI patients. CONCLUSIONS: The combination of TnI and copeptin improves AMI diagnostic performance in patients with early-onset chest pain in an ED setting.

The effect of high-dose vitamin c on biochemical markers of myocardial injury in coronary artery bypass surgery

Abstract Objective: To evaluate the effect of high-dose vitamin C on cardiac reperfusion injury and plasma levels of creatine kinase-muscle/brain (CK-MB), troponin I, and lactate dehydrogenase (LDH) in patients undergoing coronary artery bypass grafting (CABG). Methods: This is a double-blind randomized clinical trial study. Fifty patients (50-80 years old) who had CABG surgery were selected. The intervention group received 5 g of intravenous vitamin C before anesthesia induction and 5 g of vitamin C in cardioplegic solution. The control group received the same amount of placebo (normal saline). Arterial blood samples were taken to determine the serum levels of CK-MB, troponin I, and LDH enzymes. Left ventricular ejection fraction was measured and hemodynamic parameters were recorded at intervals. Results: High doses of vitamin C in the treatment group led to improvement of ventricular function (ejection fraction [EF]) and low Intensive Care Unit (ICU) stay. The cardiac enzymes level in the vitamin C group was lower than in the control group. These changes were not significant between the groups in different time intervals (anesthesia induction, end of bypass, 6 h after surgery, and 24 h after surgery) for CK-MB, LDH, and troponin I. Hemodynamic parameters, hematocrit, potassium, urinary output, blood transfusion, arrhythmia, and inotropic support showed no significant difference between the groups. Conclusion: Vitamin C has significantly improved the patients' ventricular function (EF) 72 h after surgery and reduced the length of ICU stay. No significant changes in cardiac biomarkers, including CK-MB, troponin I, and LDH, were seen over time in each group. IRCT code: IRCT2016053019470N33

Desafios na interpretação dos ensaios de troponina ultrassensível em terapia intensiva / Challenges in high-sensitive troponin assay interpretation for intensive therapy

RESUMO As troponinas cardíacas T e I são marcadores considerados altamente sensíveis e específicos para o diagnóstico de infarto agudo do miocárdio. Atualmente, com o advento dos ensaios ultrassensíveis, uma série de anormalidades não primariamente cardíacas pode se manifestar por meio da elevação destes ensaios. A redução de seu limiar de detecção promoveu maior precocidade no diagnóstico e na utilização de medidas terapêuticas baseadas em evidência, no entanto, esta característica aumentou o espectro de doenças cardíacas não coronarianas detectáveis, trazendo desafios para a caracterização das síndromes coronarianas agudas e um novo papel para estes testes nas desordens conhecidas no ambiente das unidades de tratamento intensivo, em especial na sepse. A abordagem de pacientes por meio de um maior entendimento do comportamento destes marcadores deve ser redimensionada para sua correta interpretação.

ABSTRACT Cardiac troponins T and I are considered highly sensitive and specific markers for the diagnosis of acute myocardial infarction. Currently, a series of nonprimary cardiac abnormalities may manifest as an elevation in high-sensitive assays. The reduction in their detection limits has allowed earlier diagnosis and the use of evidence-based therapeutic measures; however, this characteristic has increased the spectrum of detectable noncoronary heart diseases, which poses challenges for characterizing acute coronary syndromes and creates a new role for these tests in known disorders in intensive care units, especially sepsis. Management of patients through a greater understanding of how these markers behave should be re-evaluated to ensure their correct interpretation.

Elevated High-Sensitivity Troponin I in the Stabilized Phase after an Acute Coronary Syndrome Predicts All-Cause and Cardiovascular Mortality in a Highly Admixed Population: A 7-Year Cohort / A Troponina I de Alta Sensibilidade Elevada na Fase Estabilizada após Síndrome Coronariana Aguda Prevê Mortalidade por Todas as Causas e Mortalidade Cardiovascular em uma População Altamente Miscigenada: Uma Coorte de 7 Anos

Abstract Background: High-sensitivity cardiac troponin I (hs-cTnI) has played an important role in the risk stratification of patients during the in-hospital phase of acute coronary syndrome (ACS), but few studies have determined its role as a long-term prognostic marker in the outpatient setting. Objective: To investigate the association between levels of hs-cTnI measured in the subacute phase after an ACS event and long-term prognosis in a highly admixed population. Methods: We measured levels of hs-cTnI in 525 patients 25 to 90 days after admission for an ACS event; these patients were then divided into tertiles according to hs-cTnI levels and followed for up to 7 years. We compared all-cause and cardiovascular mortality using Cox proportional hazards models and adopting a significance level of 5%. Results: After a median follow-up of 51 months, patients in the highest tertile had a greater hazard ratio (HR) for all-cause mortality after adjustment for age, sex, known cardiovascular risk factors, medication use, and demographic factors (HR: 3.84, 95% CI: 1.92-8.12). These findings persisted after further adjustment for estimated glomerular filtration rate < 60 ml/min/1.73 m2 and left ventricular ejection fraction < 0.40 (HR: 6.53, 95% CI: 2.12-20.14). Cardiovascular mortality was significantly higher in the highest tertile after adjustment for age and sex (HR: 5.65, 95% CI: 1.94-16.47) and both in the first (HR: 4.90, 95% CI: 1.35-17.82) and second models of multivariate adjustment (HR: 5.89, 95% CI: 1.08-32.27). Conclusions: Elevated hs-cTnI levels measured in the stabilized phase after an ACS event are independent predictors of all-cause and cardiovascular mortality in a highly admixed population.

Resumo Fundamento: A troponina cardíaca de alta sensibilidade I (TnI-as) tem desempenhado um papel importante na estratificação de risco dos pacientes durante a fase intra-hospitalar da síndrome coronariana aguda (SCA), mas poucos estudos determinaram seu papel como marcador prognóstico de longo prazo no ambiente ambulatorial. Objetivo: Investigar a associação entre os níveis de TnI-as medidos na fase subaguda após um evento de SCA e o prognóstico a longo prazo, em uma população altamente miscigenada. Métodos: Medimos os níveis de TnI-as em 525 pacientes em um período de 25 a 90 dias após a entrada em hospital por um evento de SCA; esses pacientes foram então divididos em tercis conforme os níveis de TnI-as, e acompanhados por até 7 anos. Comparamos as mortalidades por todas as causas e cardiovascular através de modelos de riscos proporcionais de Cox e adotando um nível de significância de 5%. Resultados: Após um acompanhamento médio de 51 meses, os pacientes no tercil mais alto apresentaram uma taxa de risco (HR) maior para mortalidade por todas as causas, após ajustes para idade, sexo, fatores de risco cardiovascular conhecidos, uso de medicação e fatores demográficos (HR: 3,84 IC 95%: 1,92-8,12). Esses achados persistiram após um ajuste adicional para uma taxa de filtração glomerular (TFG) estimada < 60 ml/min/1,73 m2 e uma fração de ejeção do ventrículo esquerdo < 0,40 (HR: 6,53; IC95%: 2,12-20,14). A mortalidade cardiovascular foi significativamente maior no tercil mais alto, após ajustes para idade e sexo (RR: 5,65; IC95%: 1,94-16,47) e tanto no primeiro modelo de ajuste multivariado (HR: 4,90; IC 95%: 1,35-17,82) quanto no segundo (HR: 5,89; IC95%: 1,08-32,27). Conclusões: Níveis elevados de TnI-as, medidos na fase estabilizada após um evento de SCA, são preditores independentes de mortalidade por todas as causas e de mortalidade cardiovascular em uma população altamente miscigenada.

Potential predictors for mental stress-induced myocardial ischemia in patients with coronary artery disease / 中华医学杂志(英文版)

BACKGROUND@#Mental stress-induced myocardial ischemia (MSIMI) is closely associated with adverse cardiac events in patients with coronary artery disease (CAD) and we aimed to determine whether biomarkers and blood pressure could be potential predictors of MSIMI.@*METHODS@#This study enrolled 82 patients with documented CAD between June 1, 2017 and November 9, 2017. Patient blood samples were obtained at resting period and at the end of mental arithmetic. Then, patients were assigned to MSIMI positive group and MSIMI negative group. The main statistical methods included linear regression, receiver operating characteristic (ROC) curves, and logistic regression.@*RESULTS@#Patients with CAD with MSIMI had significantly greater median resting N-terminal pro-brain natriuretic peptide (NT-proBNP, 141.02 [45.85-202.76] pg/mL vs. 57.95 [27.06-117.64] pg/mL; Z = -2.23, P = 0.03) and mean systolic blood pressure (SBP) (145.56 ± 16.87 mmHg vs. 134.92 ± 18.16 mmHg, Z = -2.13, P = 0.04) when compared with those without MSIMI. After 5-min mental stress task, those who developed MSIMI presented higher elevation of median post-stressor high sensitivity cardiac troponin I (hs-cTnI, 0.020 [0.009-0.100] ng/mL vs. 0.009 [0.009-0.010] ng/mL; Z = -2.45, P = 0.01), post-stressor NT-proBNP (138.96 [39.93-201.56] pg/mL vs. 61.55 [25.66-86.50] pg/mL; Z = -2.15, P = 0.03) compared with those without MSIMI. Using the ROC curves, and after the adjustment for basic characteristics, the multiple logistic regression analysis showed that patients presenting a post-stressor hs-cTnI ≥ 0.015 ng/mL had seven-fold increase in the risk of developing MSIMI (odds ratio [OR]: 7.09; 95% confidence interval [CI]: 1.65-30.48; P = 0.009), a rest NT-proBNP ≥ 80.51 pg/mL had nearly eight-fold increase (OR: 7.85; 95% CI: 1.51-40.82; P = 0.014), a post-stressor NT-proBNP ≥ 98.80 pg/mL had 35-fold increase (OR: 34.96; 95% CI: 3.72-328.50; P = 0.002), a rest SBP ≥ 129.50 mmHg had 11-fold increase (OR: 11.42; 95% CI: 1.21-108.17; P = 0.034).@*CONCLUSIONS@#The present study shows that CAD patients with higher hs-cTnI level, and/or greater NT-proBNP and/or SBP are at higher risk of suffering from MSIMI when compared with those without MSIMI, indicating that hs-cTnI, NT-proBNP, SBP might be potential predictors of MSIMI.