COVID-19 and myocardial injury: Targeting elevated biomarkers for potential novel therapies.

BACKGROUND: The prevalence of COVID-19 as the primary diagnosis among hospitalized patients with myocardial injury has increased during the pandemic and targeting elevated oxidant stress and inflammatory biomarkers may offer a potential role for novel therapies to improve outcomes. METHODS: At a single VA Medical Center from January 1 through December 31, 2021, troponin assays from patients being evaluated in the Emergency Room for consideration of admission were analyzed and peak levels from each patient were considered abnormal if exceeding the Upper Reference Limit (URL). Among admitted patients with an elevated troponin level, ICD-10 diagnoses were categorized, biomarker elevations were recorded, and independent predictors of death in patients with COVID-19 were determined at a median of 6-months following admission. RESULTS: Of 998 patients, 399 (40 %) had a negative troponin and were not included in the analysis. Additional patients with an elevated troponin were also excluded, either because they were not admitted (n = 68) or had a final diagnosis of Type 1 MI (n = 117). Of the remaining 414 patients with an elevated peak troponin, COVID-19 was the primary diagnosis in 43 patients (10 %) and was the 4th most common diagnosis of patients admitted with myocardial injury behind congestive heart failure, sepsis, and COPD or pneumonia. At a median of 6-months following admission, 18 (42 %) of the COVID-19 patients had died and independent predictors of death (Odd Ratio: Confidence Intervals) were age (1.18: 1.06‒1.37), Troponin level (Log 10 transformed) (16.54: 2.30‒266.65) and C-Reactive Protein (CRP) (1.30: 1.10‒1.65). CONCLUSIONS: Newly diagnosed COVID-19 during the pandemic was a common cause of elevated troponin in hospitalized patients without a Type 1 MI. Age, peak troponin level and peak CRP level were independent predictors of poor outcomes and suggest a need to target these cardiac biomarkers, potentially with novel antioxidant or anti-inflammatory therapies.

[Analysis of the unicentric registry of the Infarction Code program: retrospective cohort]. / Análisis del registro unicéntrico del programa Código Infarto: cohorte retrospectiva.

Background: Acute coronary syndrome (ACS) is the most serious manifestation of coronary heart disease. The Infarction Code (according to its initialism in Spanish, CI: Código Infarto) program aims to improve the care of these patients. Objective: To describe the clinical presentation and outcomes of CI program in a coronary care unit (CCU). Material and methods: A database of a CCU with 5 years of consecutive records was analyzed. Patients diagnosed with ACS were included. The groups with acute myocardial infarction with and without ST-segment elevation were compared using Student's t, Mann-Whitney U and chi-squared tests. We calculated the relative risk (RR) and 95% confidence intervals (95% CI) of cardiovascular risk factors for mortality. Results: A total of 4678 subjects were analyzed, 78.7% men, mean age 63 years (± 10.7). 80.76% presented acute myocardial infarction with positive ST-segment elevation and fibrinolytic was granted in 60.8% of cases. Percutaneous coronary intervention was performed in 81.4% of patients, which was successful in 82.5% of events. Patients classified as CI presented mortality of 6.8% vs. 11.7%, p = 0.001. Invasive mechanical ventilation had an RR of 26.58 (95% CI: 20.61-34.3) and circulatory shock an RR of 20.86 (95% CI: 16.16-26.93). Conclusions: The CI program decreased mortality by 4.9%. Early fibrinolysis and successful coronary angiography are protective factors for mortality within CCU.

Introducción: el síndrome coronario agudo (SICA) es la manifestación más grave de la enfermedad coronaria. El programa Código Infarto (CI) tiene como objetivo mejorar la atención de estos pacientes. Objetivo: describir la presentación clínica y los resultados del programa CI de una unidad de cuidados coronarios (UCC). Material y métodos: se analizó una base de datos de una UCC con 5 años de registros consecutivos. Se incluyeron pacientes con diagnóstico de SICA. Se compararon los grupos con infarto agudo de miocardio con y sin elevación del segmento ST mediante las pruebas t de Student, U de Mann-Whitney y chi cuadrada. Se calculó el riesgo relativo (RR) y el intervalo de confianza del 95% (IC 95%) de los factores de riesgo cardiovascular para mortalidad. Resultados: se analizaron 4678 sujetos, 78.7% hombres, con media de edad de 63 años (± 10.7). El 80.76% presentó infarto agudo de miocardio con desnivel positivo del segmento ST y se otorgó fibrinolítico en el 60.8% de los casos. Se realizó intervencionismo coronario percutáneo en el 81.4% de los pacientes, el cual fue exitoso en el 82.5% de los eventos. Los pacientes catalogados como CI presentaron mortalidad del 6.8% frente a 11.7%, p = 0.001. La ventilación mecánica invasiva tuvo una RR de 26.58 (IC 95%: 20.61-34.3) y el choque circulatorio una RR de 20.86 (IC 95%: 16.16-26.93). Conclusiones: el programa CI disminuyó 4.9% la mortalidad. La fibrinólisis temprana y la angiografía coronaria exitosa son factores protectores para mortalidad dentro de la UCC.

Muscle quality and major adverse cardiovascular events in post-acute myocardial infarction: A prospective cohort study.

BACKGROUND & AIMS: Functional muscle quality, as assessed through the muscle quality index (MQI), represents a contemporary method to measure the capacity to generate force. Despite its potential, the prognostic significance of MQI remains uncertain in various clinical conditions, particularly among patients following acute myocardial infarction (AMI). In light of this, our study sought to evaluate the prognostic relevance of MQI concerning major adverse cardiovascular events (MACE) in patients following AMI. METHODS AND RESULTS: This is a secondary analysis of a prospective cohort study that included subjects aged ≥20 years from a Cardiovascular Unit Hospital. Functional muscle quality was estimated using MQI, defined as the ratio of handgrip strength (HGS) to muscle mass (MM) derived from bioelectrical impedance analysis. The outcomes included prolonged length of hospital stay, new adverse cardiovascular events (AMI, stroke and hospital readmission for unstable angina), and cardiovascular mortality. A composite score comprising all adverse events over the 1-year follow-up was calculated and defined as MACE. This study included 163 patients, with a median age of 61 years (IQ: 54-69 years), and the majority consisted of males (76.1%). Individual components of the functional muscle quality (HGS and MM) were not associated with any of the adverse outcomes. Only MQI was associated mortality over the 1-year follow-up. For each increase in MQI, the hazard of mortality decreases: adjusted HR: 0.08 (95% CI 0.01-0.84). CONCLUSION: Functional muscle quality assessed by the MQI may be a valuable clinical predictor of 1-year cardiovascular mortality in patients hospitalized post-AMI.

Mannose Binding Lectin and C3 Serum Levels in Coronary Artery Disease: A Cross-Sectional Study.

BACKGROUND: The process of tissue injury in coronary artery disease (CAD) has been associated with activation of the complement system, partly due to the action of mannose-binding lectin (MBL) and C3, which are expressed in atherosclerotic lesions. OBJECTIVE: The aim of this study was to evaluate the serum levels of MBL and C3 in patients with CAD and to compare them with healthy controls. Additionally, we aim to assess the correlation between MBL and C3 levels and cardiometabolic parameters. METHODS: MBL and C3 serum concentration were determined by ELISA and immunoturbidimetry, respectively, in up to 119 patients undergoing coronary angiography for CAD evaluation, comprising 48 individuals diagnosed with acute myocardial infarction (MI) and 71 without MI. A total of 93 paired healthy controls were included in the study. RESULTS: Individuals with CAD had MBL serum concentration higher than controls (p = .002), regardless of the presence of MI (p = .006). In addition, high concentration of MBL (>2000 ng/mL) was more frequent in patients with CAD (p = .007; OR = 2.6; 95% CI = 1.3-5.1). C3 levels were not significantly associated with any of the patient groups but were positively correlated with cardiometabolic parameters such as body mass index (BMI) and triglycerides levels. CONCLUSIONS: Higher concentrations of MBL were found to be associated with CAD, whereas C3 levels were found to be associated with cardiovascular risk factors.

Infarto agudo al miocardio con arterias coronarias sin lesiones obstructivas (MINOCA): características clínicas de pacientes / Myocardial infarction without obstructive coronary artery disease: clinical characteristics in patients hospitalized in a coronary care unit

Introducción: El término MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries) ha cobrado relevancia como diagnóstico de trabajo en el contexto de pacientes con sospecha de isquemia miocárdica y estudio coronario sin lesiones obstructivas. Objetivos: Describir las distintas etiologías y variables clínicas de pacientes con MINOCA hospitalizados en la unidad coronaria de nuestro centro (Hospital de la P Universalidad de Chile) Métodos: Estudio observacional retrospectivo en el que se realizó un análisis descriptivo de las variables estudiadas. Además, se analizó el uso de los métodos de imágenes complementarios y otras variables pronósticas. El seguimiento se realizó dentro del primer año posterior al evento. Resultados: El diagnóstico etiológico más frecuente de los pacientes con MINOCA fue el de miocardiopatía por estrés (MCE). Se incluyeron 55 pacientes, 55% de ellos mujeres. La edad promedio fue 57 años y la frecuencia de factores de riesgo cardiovascular clásicos (FRCV) fue baja. En los pacientes con MCE se observó menores niveles de troponina ultrasensible; mayores niveles de NT-proBNP y mayor mortalidad en comparación a otras etiologías. Conclusiones: El perfil de pacientes con MINOCA hospitalizados en nuestro centro correspondió predominantemente a mujeres postmenopáusicas con baja frecuencia de FRCV. La mortalidad de los pacientes con MINOCA se concentró en el grupo con MCE.

Background: MINOCA (acronym for "Myocardial Infarction with Non-Obstructive Coronary Arteries") is relevant as a working guide in the diagnosis of patients with suspicion of ischemia and absence of obstructive coronary artery disease. Aim: to describe the different causes and clinical variables in patients with MINOCA admitted to a coronary care unit of a University hospital in Santiago, Chile. Methods: this is an observational retrospective analysis of relevant clinical variables in 55 patients finally diagnosed as having MINOCA. Use of image based studies and characteristics related to prognosis were also analyzed. Follow up extended for one year after the event. Results: 55 patients were included, 55% of them women. Mean age was 57 years; presence of traditional risk factors for myocardial infarction was low. The most common eventual etiologic diagnosis was Stress Cardiomyopathy (SCM) in which lower levels of ultrasensitive troponin and higher levels of NT-proBNP were observed. Mortality in SCM was higher than that observed in other etiologies. Conclusion: MINOCA was more frequent in post menopausal women. Mortality was greater in patients with SMC.

Adapting an Intervention to Improve Acute Myocardial Infarction Care in Tanzania: Co-Design of the MIMIC Intervention.

Background: Uptake of evidence-based care for acute myocardial infarction (AMI) is suboptimal in Tanzania, but there are currently no published interventions to improve AMI care in sub-Saharan Africa. Objectives: Co-design a quality improvement intervention for AMI care tailored to local contextual factors. Methods: An interdisciplinary design team consisting of 20 physicians, nurses, implementation scientists, and administrators met from June 2022 through August 2023. Half of the design team consisted of representatives from the target audience, emergency department physicians and nurses at a referral hospital in northern Tanzania. The design team reviewed multiple published quality improvement interventions focusing on ED-based AMI care. After selecting a multicomponent intervention to improve AMI care in Brazil (BRIDGE-ACS), the design team used the ADAPT-ITT framework to adapt the intervention to the local context. Findings: The design team audited current AMI care processes at the study hospital and reviewed qualitative data regarding barriers to care. Multiple adaptations were made to the original BRIDGE-ACS intervention to suit the local context, including re-designing the physician reminder system and adding patient educational materials. Additional feedback was sought from topical experts, including patients with AMI. Draft intervention materials were iteratively refined in response to feedback from experts and the design team. The finalized intervention, Multicomponent Intervention to Improve Myocardial Infarction Care in Tanzania (MIMIC), consisted of five core components: physician reminders, pocket cards, champions, provider training, and patient education. Conclusion: MIMIC is the first locally tailored intervention to improve AMI care in sub-Saharan Africa. Future studies will evaluate implementation outcomes and efficacy.

[Relationship between the systolic-diastolic shock index and mortality in myocardial infarction]. / Relación del índice de choque sistólico-diastólico con mortalidad en el infarto miocárdico.

Background: In the emergency room, the shock index was applied to determine the prognosis in various pathologies, such as acute infarction. The shock index is the re-sult of dividing heart rate by the systolic blood pressure. Objective: To determine the relationship between the systolic shock index and the di-astolic shock index as prognostic factors for mortality in acute myocardial infarction with ST segment elevation prior to admission to the Hemodynamics Room. Material and methods: A prolective analytical cross-sectional study was carried out in patients who were admitted to the Hemodynamics Room for cardiac catheterization within a period of 5 months in 2022. The systolic shock index and diastolic shock index were included as independent variables and mortality was the dependent variable. SPSS, version 25, was used and Pearson's chi-square test was used as statistical test, with a p value < 0.05 being significant. Results: 162 patients were analyzed and showed a diastolic shock index > 1.2143 with a sensitivity of 62.5% and a specificity of 77.4% with a p < 0.05. Their systolic shock in-dex was > 0.8908 with a sensitivity of 45.8% and specificity of 91.2%, with a p < 0.05. Conclusion: It was determined that both shock indices are related as mortality prognos-tic factors in acute myocardial infarction with ST elevation prior to admission to the He-modynamic Room.

Introducción: en el Servicio de Urgencias, se implementó el índice de choque para determinar el pronóstico de forma rápida en diversas patologías, como en el infarto agudo al miocardio. El índice de choque es el resultado de dividir la frecuencia cardia-ca entre la presión arterial. Objetivo: determinar la relación entre el índice de choque sistólico y el índice de choque diastólico como factores pronósticos de mortalidad en el infarto agudo al mio-cardio con elevación del segmento ST previo al ingreso al Área de Hemodinamia. Material y métodos: estudio transversal analítico prolectivo en pacientes que ingresa-ron al Área de Hemodinamia para cateterismo cardiaco en un plazo de cinco meses en el 2022. Tuvo como variables independientes el índice de choque sistólico y el índice de choque diastólico y como variable dependiente la mortalidad. Se utilizó el paquete estadístico SPSS, versión 25, y como prueba estadística la prueba chi cuadrada de Pearson, con una p < 0.05 como estadísticamente significativa. Resultados: se analizaron 162 pacientes que tuvieron un índice de choque diastólico > 1.2143, con una sensibilidad de 62.5% y una especificidad de 77.4%, con una p < 0.05. Y presentaron un índice de choque sistólico > 0.8908, con una sensibilidad de 45.8% y una especificidad de 91.2%, con una p < 0.05. Conclusión: se determinó que ambos índices de choque tienen relación como factores pronósticos de mortalidad en el infarto agudo al miocardio con elevación del segmento ST antes de su ingreso al Área de Hemodinamia.

Theoretical analysis of immunochromatographic assay and consideration of its operating parameters for efficient designing of high-sensitivity cardiac troponin I (hs-cTnI) detection.

Troponin is the American College of Cardiology and American Heart Association preferred biomarker for diagnosing acute myocardial infarction (MI). We provide a modeling framework for high sensitivity cardiac Troponin I (hs-cTnI) detection in chromatographic immunoassays (flow displacement mode) with an analytical limit of detection, i.e., LOD < 10 ng/L. We show that each of the various control parameters exert a significant influence over the design requirements to reach the desired LOD. Additionally, the design implications in a multiplexed fluidic network, as in the case of Simple Plex™ Ella instrument, are significantly affected by the choice of the number of channels or partitions in the network. We also provide an upgrade on the existing LOD equation to evaluate the necessary minimum volume to detect a particular concentration by considering the effects of stochastics and directly incorporating the target number of copies in each of the partitions in case of multiplexed networks. Even though a special case of cTnI has been considered in this study, the model and analysis are analyte agnostic and may be applied to a wide class of chromatographic immunoassays. We believe that this contribution will lead to more efficient designing of the immunochromatographic assays.

Clinical value of combined plasma brain natriuretic peptide and serum cystatin C measurement on the prediction of heart failure in patients after acute myocardial infarction.

This research investigated the predictive value of combined detection of brain natriuretic peptide (BNP) and cystatin C (Cys C) in heart failure after percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI). Sixty-five AMI patients complicated by heart failure (HF) after PCI and 79 non-heart failure (non-HF) patients were involved in this research. The levels of Cys C and BNP were measured. Risk factors for heart failure in AMI patients after PCI were analyzed by multivariate logistic regression analysis. Efficacy of BNP and Cys C on predicting heart failure were analyzed by receiver operating characteristic (ROC) curve. Cys C and BNP levels were significantly higher in the HF group than in the non-HF group. BNP and Cys C levels were the independent influencing factors causing heart failure within one year after PCI. The area under the predicted curve (AUC) of Cys C, BNP, and combined Cys C and BNP were 0.763, 0.829, and 0.893, respectively. The combined detection of Cys C and BNP was highly valuable in predicting heart failure in AMI patients after PCI, which can be regarded as the serum markers for diagnosis and treatment of heart failure.

Long-term outcomes among stable post-acute myocardial infarction patients living in rural versus urban areas: insights from the prospective, observational TIGRIS registry.

BACKGROUND: Insights on the differences in clinical outcomes, quality of life (QoL) and health resource utilisation (HRU) with different levels of care available to post-acute myocardial infarction (AMI) populations in rural and urban settings are limited. METHODS: The long-Term rIsk, clinical manaGement, and healthcare Resource utilisation of stable coronary artery dISease (TIGRIS), a prospective, observational registry, enrolled 8452 patients aged ≥50 years 1-3 years post-AMI from June 2013 to November 2014 from 24 countries in Asia Pacific/Australia, Europe, North America and South America. Differences in QoL (measured using the EuroQol Research Foundation instrument) and HRU between patients in rural and urban settings were evaluated in this post hoc analysis. The incidence of clinical endpoints (cardiovascular (CV) death, AMI, unstable angina with urgent revascularisation and stroke; bleeding; and all-cause mortality) was analysed. Data were collected at baseline and every 6 months for 24 months. RESULTS: There were fewer hospitalisations and visits to general practitioners (GPs) and cardiologists in the rural versus urban populations (adjusted event rate ratio (ERR)=0.90 (95% CI, 0.82 to 1.00, p=0.04); ERR=0.84 (95% CI, 0.78 to 0.92, p<0.001); ERR=0.86 (95% CI, 0.81 to 0.92, p<0.001), respectively). No statistically significant differences were observed between rural and urban populations in all-cause death, AMI, unstable angina with urgent revascularisation, CV death, stroke, major bleeding events and health-related QoL. The adjusted incidence rate ratio was 0.92 (95% CI, 0.74 to 1.15) for the composite of CV death, AMI and stroke. CONCLUSIONS: Living in rural areas was associated with fewer GP/cardiologist visits and hospitalisations; no significant differences in clinical outcomes and QoL were observed. TRIAL REGISTRATION NUMBER: NCT01866904.

Potential performance of a 0 h/1 h algorithm and a single cut-off measure of high-sensitivity troponin T in a diverse population: main results of the IN-HOPE study.

AIMS: Chest pain is a major cause of medical evaluation at emergency department (ED) and demands observation to exclude the diagnosis of acute myocardial infarction (AMI). High-sensitivity cardiac troponin assays used as isolated measure and by 0- and 1-h algorithms are accepted as a rule-in/rule-out strategy, but there is a lack of validation in specific populations. METHODS AND RESULTS: The IN-HOspital Program to systematizE Chest Pain Protocol (IN-HOPE study) is a multicentre study that prospectively included patients admitted to the ED due to suspected symptoms of AMI at 16 sites in Brazil. Medical decisions of all patients followed the standard approach of 0 h/3 h protocol, but, in addition, blood samples were also collected at 0 and 1 h and sent to a central laboratory (core lab) to measure high-sensitivity cardiac troponin T (hs-cTnT). To assess the theoretical performance of 0 h/1 h algorithm, troponin < 12 ng/L with a delta < 3 was considered rule-out while a value ≥ 52 or a delta ≥ 5 was considered a rule-in criterion (the remaining were considered as observation group). The main objective of the study was to assess, in a population managed by the 0 h/3 h protocol, the accuracy of 0 h/1 h algorithm overall and in groups with a higher probability of AMI. All patients were followed up for 30 days, and potential events were adjudicated. In addition to the prospective cohort, a retrospective analysis was performed assessing all patients with hs-cTnT measured during the year of 2021 but not included in the prospective cohort, regardless of the indication of the test. A total of 5.497 patients were included (583 in the prospective and 4.914 in the retrospective analysis). The prospective cohort had a mean age of 57.3 (± 14.8) and 45.6% of females with a mean HEART score of 4.0 ± 2.2. By the core lab analysis, 74.4% would be eligible for a rule-out approach (45.3% of them with a HEART score > 3) while 7.3% would fit the rule-in criteria. In this rule-out group, the negative predictive value for index AMI was 100% (99.1-100) overall and regardless of clinical scores. At 30 days, no death or AMI occurred in the rule-out group of both 0/1 and 0/3 h algorithms while 52.4% of the patients in the rule-in group (0 h/1 h) were considered as AMI by adjudication. In the observation group (grey zone) of 0 h/1 h algorithm, GRACE discriminated the risk of these patients better than HEART score. In the retrospective analysis, 1.091 patients had a troponin value of <5 ng/L and there were no cardiovascular deaths at 30 days in this group. Among all 4.914 patients, the 30-day risk of AMI or cardiovascular death increased according to the level of troponin: 0% in the group < 5 ng/L, 0.6% between 5 and 14 ng/L, 2.2% between 14 and 42 ng/L, 6.3% between 42 and 90 ng/L, and 7.7% in the level ≥ 90 ng/L. CONCLUSION: In this large multicentre study, a 0 h/1 h algorithm had the potential to classify as rule-in or rule-out in almost 80% of the patients. The rule-out protocol had high negative predictive value regardless of clinical risk scores. Categories of levels of hs-cTn T also showed good accuracy in discriminating risk of the patients with a very favourable prognosis for cardiovascular death in the group with value < 5 ng/L. CLINICALTRIALS.GOV: NCT04756362.

Biodegradable and Flexible Thermoplastic Composite Graphite Electrodes: A Promising Platform for Inexpensive and Sensitive Electrochemical Detection of Creatine Kinase at the Point-of-Care.

Acute myocardial infarction (AMI) is the main cause of death worldwide, and the time of diagnosis is decisive for the effectiveness of the treatment of patients with AMI. Creatine kinase-myocardial band (CK-MB) has a predominance and high affinity with myocardial tissue, making it considered one of the main biomarkers for the diagnosis of AMI. In this work, we report a novel biodegradable composite material based on a polymer blend of Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) and Poly(butylene adipate-co-terephthalate) (PHBV:Ecoflex) and graphite microparticles for sensitive and selective electrochemical detection of CK-MB. The morphological and physicochemical characterizations of the thermoplastic composite material revealed a homogeneous and synergistic distribution of the graphite microparticles through the blend structure, providing low defects and high electrical conductivity with high electron transfer kinetics (k0 = 3.54 × 10-3 cm s-1) features with adequate flexibility for point-of-care applications. The portable and disposable devices were applied to detect CK-MB using the electrochemical impedance spectroscopy (EIS) technique in a relevant clinical concentration ranging from 5.0 ng mL-1 to 100.0 ng mL-1 and presented a limit of detection of 0.26 ng mL-1 CK-MB. The selectivity of the sensor was confirmed by testing the potential interference of major biomolecules found in biofluids and other relevant macromolecules. The accuracy and robustness were assessed by addition and recovery protocol in urine and saliva samples without sample pretreatment and demonstrated the potential of our method for rapid and decentralized tests of AMI. In addition, the study of the thermal, biological, and photodegradation of the devices after being used was also carried out, aiming at the disposal of the material more sustainably.

Desenvolvimento e aplicação de uma rede neural artificial para identificação de fibrilação atrial no eletrocardiograma: uma nova ferramenta para otimização diagnóstica / Development and application of an artificial neural network to identify atrial fibrillation on the electrocardiogram: a new tool for diagnostic optimization

INTRODUÇÃO: A fibrilação atrial (FA) é a arritmia cardíaca sustentada mais comum no mundo e está associada a alta morbidade e mortalidade. O diagnóstico precoce da FA é parte fundamental para o controle bem sucedido da carga global da doença e, infelizmente, muitos casos não são diagnosticados devido à dificuldade de identificação da arritmia por profissionais de saúde não especializados. Nesse contexto, o uso de inovações tecnológicas como a inteligência artificial no processo de investigação diagnóstica surge como uma potencial intervenção disruptiva. OBJETIVO: O objetivo do presente estudo foi desenvolver um modelo de redes neurais artificiais (RNAs) com utilização de imagens de eletrocardiograma (ECG) e extração de sinais com alta sensibilidade e especificidade em relação a laudos médicos. MÉTODOS: O modelo foi treinado com dados de 11.029 ECGs de janeiro a dezembro de 2022, que totalizaram 100.108 derivações para treinamento da rede neural, uma ResNet unidimensional, utilizada com uma camada de convolução inicial, quatro blocos de camadas residuais e um bloco de densa camada para classificação binária. A extração foi individual de acordo com a disposição e tamanho das derivações na imagem do ECG, que foram então transformadas em um sinal unidimensional. A partir dos dados brutos em forma de sinal, foi realizada uma reamostragem, padronizando todos os fabricantes para 300hz. Em seguida, os ruídos do sinal foram removidos por meio do filtro Savitzky-Golay. Em seguida, o sinal foi padronizado para ter mediana = 0 e desvio padrão = 1. Foi adicionado um padding para ter um tamanho padrão de 2048. O padding utilizado foi um valor constante igual a zero. Realizamos padronização e preenchimento no sinal original (não filtrado) para obter 2 dados de uma única derivação. RESULTADOS: O modelo apresentou, ao final, uma sensibilidade de 100% e uma especificidade de 94,5% para a identificação de FA no ECG. Esse resultado foi um ganho para a utilização de redes neurais, pois a tecnologia utilizada anteriormente, com apenas a extração de métricas de onda, apresentava uma precisão menor. CONCLUSÃO: Concluímos que modelos de RNA, que extraem sinais de imagens e os transformam em predições para tomada de decisão por médicos especialistas, podem ser incluídos no arsenal de métodos preditivos para triagem com alta sensibilidade e trazer laudos médicos mais rápidos e confiáveis.

Photoelectrochemical Determination of Cardiac Troponin I as a Biomarker of Myocardial Infarction Using a Bi2S3 Film Electrodeposited on a BiVO4-Coated Fluorine-Doped Tin Oxide Electrode.

A sensitive and selective label-free photoelectrochemical (PEC) immunosensor was designed for the detection of cardiac troponin I (cTnI). The platform was based on a fluorine-doped tin oxide (FTO)-coated glass photoelectrode modified with bismuth vanadate (BiVO4) and sensitized by an electrodeposited bismuth sulfide (Bi2S3) film. The PEC response of the Bi2S3/BiVO4/FTO platform for the ascorbic acid (AA) donor molecule was approximately 1.6-fold higher than the response observed in the absence of Bi2S3. The cTnI antibodies (anti-cTnI) were immobilized on the Bi2S3/BiVO4/FTO platform surface to produce the anti-cTnI/Bi2S3/BiVO4/FTO immunosensor, which was incubated in cTnI solution to inhibit the AA photocurrent. The photocurrent obtained by the proposed immunosensor presented a linear relationship with the logarithm of the cTnI concentration, ranging from 1 pg mL-1 to 1000 ng mL-1. The immunosensor was successfully employed in artificial blood plasma samples for the detection of cTnI, with recovery values ranging from 98.0% to 98.5%.

Determinants of the clinical presentation of acute coronary syndromes.

INTRODUCTION: Two clinical presentations of acute coronary syndrome (ACS) have been defined: ST- segment elevation ACS (STEACS) or non-ST-segment elevation ACS (NSTEACS). The mechanism that determines the clinical presentation of ACS is not clearly understood. The aim of this study was to define the association between cardiovascular risk factors and other clinical variables with the clinical presentation of ACS as STEACS or NSTEACS. METHODS: We analyzed data of patients prospectively included in the Epi-Cardio Registry with a diagnosis of ACS from April 2006 to April 2018. A total of 10 019 patients were included in the study. RESULTS: In the multivariate analysis, male sex (OR 1.5) and active smoking (OR 1.71) were positively associated with STEACS presentation. Conversely, hypertension (OR 0.71), dyslipidemia (OR 0.74), age (OR 0.97 per quintile), history of myocardial infarction (OR 0.57), chronic angina (OR 0.44), presence of comorbidities (OR 0.64), and extension of coronary heart disease (OR 0.84) were negatively associated with STEACS. Women differed from men by presenting a higher incidence of NSTEACS, due to a greater proportion of ACS without obstructive coronary heart disease. CONCLUSION: Some cardiovascular risk factors and other clinical variables are independently associated with the presentation of ACS as ST EACS or NSTEACS. These findings confirm the influence of risk factors and clinical history on the pathophysiology, clinical and electrocardiographic presentation of ACS.

Introducción: Existen dos formas de presentación clínica de los síndromes coronarios agudos (SCA): con elevación del segmento ST (SCACEST) y sin elevación (SCASEST). Los mecanismos que determinan ambas presentaciones no se conocen completamente. El objetivo del estudio fue definir la asociación entre factores de riesgo cardiovascular y otras variables clínicas con la presentación de los SCA como SCACEST o SCASEST. Métodos: Analizamos información de pacientes incluidos prospectivamente en el Registro Epi-Cardio con diagnóstico de SCA desde abril de 2006 a abril de 2018.Se incluyeron un total de 10 019 pacientes. Resultados: En el análisis multivariado, el sexo masculino (OR 1.5) y el tabaquismo activo (OR 1.71) se asociaron positivamente con el SCACEST. Contrariamente, la hipertensión (OR 0.71), las dislipidemias (OR 0.74), la edad (OR 0.97 por quintilo), historia de infarto (OR 0.57), angina crónica (OR 0.44), presencia de comorbilidades (OR 0.64), y la extensión de enfermedad coronaria (OR 0.84) se asociaron negativamente con el SCACEST. Las mujeres presentaron mayor incidencia de SCASEST, debido a una mayor proporción de SCA sin obstrucción coronaria significativa. Conclusión: Concluimos que algunos factores de riesgo cardiovascular y otras variables clínicas se asociaron independientemente con la presentación clínica como SCACEST o SCASEST, confirmando su influencia en la fisiopatología y en la presentación clínica y electrocardiográfica de los SCA.

COVID-19's influence on cardiac function: a machine learning perspective on ECG analysis.

In December 2019, the spread of the SARS-CoV-2 virus to the world gave rise to probably the biggest public health problem in the world: the COVID-19 pandemic. Initially seen only as a disease of the respiratory system, COVID-19 is actually a blood disease with effects on the respiratory tract. Considering its influence on hematological parameters, how does COVID-19 affect cardiac function? Is it possible to support the clinical diagnosis of COVID-19 from the automatic analysis of electrocardiography? In this work, we sought to investigate how COVID-19 affects cardiac function using a machine learning approach to analyze electrocardiography (ECG) signals. We used a public database of ECG signals expressed as photographs of printed signals, obtained in the context of emergency care. This database has signals associated with abnormal heartbeat, myocardial infarction, history of myocardial infarction, COVID-19, and healthy heartbeat. We propose a system to support the diagnosis of COVID-19 based on hybrid deep architectures composed of pre-trained convolutional neural networks for feature extraction and Random Forests for classification. We investigated the LeNet, ResNet, and VGG16 networks. The best results were obtained with the VGG16 and Random Forest network with 100 trees, with attribute selection using particle swarm optimization. The instance size has been reduced from 4096 to 773 attributes. In the validation step, we obtained an accuracy of 94%, kappa index of 0.91, and sensitivity, specificity, and area under the ROC curve of 100%. This work showed that the influence of COVID-19 on cardiac function is quite considerable: COVID-19 did not present confusion with any heart disease, nor with signs of healthy individuals. It is also possible to build a solution to support the clinical diagnosis of COVID-19 in the context of emergency care from a non-invasive and technologically scalable solution, based on hybrid deep learning architectures.