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(1) Background: The CT-based attenuation correction of SPECT images is essential for obtaining accurate quantitative images in cardiovascular imaging. However, there are still many SPECT cameras without associated CT scanners throughout the world, especially in developing countries. Performing additional CT scans implies troublesome planning logistics and larger radiation doses for patients, making it a suboptimal solution. Deep learning (DL) offers a revolutionary way to generate complementary images for individual patients at a large scale. Hence, we aimed to generate linear attenuation coefficient maps from SPECT emission images reconstructed without attenuation correction using deep learning. (2) Methods: A total of 384 SPECT myocardial perfusion studies that used 99mTc-sestamibi were included. A DL model based on a 2D U-Net architecture was trained using information from 312 patients. The quality of the generated synthetic attenuation correction maps (ACMs) and reconstructed emission values were evaluated using three metrics and compared to standard-of-care data using Bland-Altman plots. Finally, a quantitative evaluation of myocardial uptake was performed, followed by a semi-quantitative evaluation of myocardial perfusion. (3) Results: In a test set of 66 test patients, the ACM quality metrics were MSSIM = 0.97 ± 0.001 and NMAE = 3.08 ± 1.26 (%), and the reconstructed emission quality metrics were MSSIM = 0.99 ± 0.003 and NMAE = 0.23 ± 0.13 (%). The 95% limits of agreement (LoAs) at the voxel level for reconstructed SPECT images were: [-9.04; 9.00]%, and for the segment level, they were [-11; 10]%. The 95% LoAs for the Summed Stress Score values between the images reconstructed were [-2.8, 3.0]. When global perfusion scores were assessed, only 2 out of 66 patients showed changes in perfusion categories. (4) Conclusion: Deep learning can generate accurate attenuation correction maps from non-attenuation-corrected cardiac SPECT images. These high-quality attenuation maps are suitable for attenuation correction in myocardial perfusion SPECT imaging and could obviate the need for additional imaging in standalone SPECT scanners.
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Glycoprotein IIb/IIIa inhibitors are an adjuvant therapy for the treatment of patients with acute coronary syndromes. The main adverse reactions are bleeding and thrombocytopenia in 1-2% of cases. A 66-year-old woman arrived at the emergency department with ST-elevation MI. The catheterisation lab was busy, so she received thrombolytic therapy. Coronary angiography revealed a 90% stenosis in the middle segment of the left anterior descending artery and Thrombolysis in MI 2 flow. Subsequent percutaneous coronary intervention showed abundant thrombus and a coronary dissection and it was necessary to insert five drug-eluting stents. Non-fractionated heparin and a tirofiban infusion were used. After the percutaneous coronary intervention, she developed severe thrombocytopenia, haematuria and gingivorrhagia, for which infusion of tirofiban was suspended. In follow-up, no major bleeding or subsequent haemorrhagic complications were identified. It is crucial to distinguish between heparin-induced thrombocytopenia and thrombocytopenia caused by other drugs. A high level of suspicion should be employed in these cases.
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BACKGROUND: OSA conveys worse clinical outcomes in patients with coronary artery disease. The STOP-BANG score is a simple tool that evaluates the risk of OSA and can be added to the large number of clinical variables and scores that are obtained during the management of patients with myocardial infarction (MI). Currently, machine learning (ML) is able to select and integrate numerous variables to optimize prediction tasks. RESEARCH QUESTION: Can the integration of STOP-BANG score with clinical data and scores through ML better identify patients who experienced an in-hospital cardiovascular event after acute MI? STUDY DESIGN AND METHODS: This is a prospective observational cohort study of 124 patients with acute MI of whom the STOP-BANG score classified 34 as low (27.4%), 30 as intermediate (24.2%), and 60 as high (48.4%) OSA-risk patients who were followed during hospitalization. ML implemented feature selection and integration across 47 variables (including STOP-BANG score, Killip class, GRACE score, and left ventricular ejection fraction) to identify those patients who experienced an in-hospital cardiovascular event (ie, death, ventricular arrhythmias, atrial fibrillation, recurrent angina, reinfarction, stroke, worsening heart failure, or cardiogenic shock) after definitive MI treatment. Receiver operating characteristic curves were used to compare ML performance against STOP-BANG score, Killip class, GRACE score, and left ventricular ejection fraction, independently. RESULTS: There were an increasing proportion of cardiovascular events across the low, intermediate, and high OSA risk groups (P = .005). ML selected 7 accessible variables (ie, Killip class, leukocytes, GRACE score, c reactive protein, oxygen saturation, STOP-BANG score, and N-terminal prohormone of B-type natriuretic peptide); their integration outperformed all comparators (area under the curve, 0.83 [95% CI, 0.74-0.90]; P < .01). INTERPRETATION: The integration of the STOP-BANG score into clinical evaluation (considering Killip class, GRACE score, and simple laboratory values) of subjects who were admitted for an acute MI because of ML can significantly optimize the identification of patients who will experience an in-hospital cardiovascular event.
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Doenças Cardiovasculares/etiologia , Aprendizado de Máquina , Infarto do Miocárdio/complicações , Medição de Risco/métodos , Idoso , Doenças Cardiovasculares/epidemiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Apneia Obstrutiva do Sono/complicaçõesRESUMO
BACKGROUND: Ventricular tachycardia (VT) is one of the main predictors of mortality in Chagas cardiomyopathy (CC). Although the substrate of sustained and nonsustained-VT (NS-VT) seems to be the same, little is known about the distribution of late enhancement (LE). Our aim was to compare the clinical findings and the amount and patterns of LE in Chagas disease according to the presence and type of VT. METHODS AND RESULTS: Magnetic resonance imaging was performed in 54 Chagas seropositive patients: 8 indeterminate and 46 with CC of whom 15 were without VT, 13 with NS-VT, and 18 with sustained-VT (S-VT). There were 31 males (57%), mean age was 55.9 ± 12.2 years. LE was found in 87% of all patients and in 50%, 80%, and 100% of the indeterminate, without VT and VT groups, respectively. The percentage of LE increased progressively in the indeterminate, CC without VT, and CC with VT groups; without a significant difference between NS-VT and S-VT (0.93%, 15.2%, 23.2%, and 21.4%, respectively). The amount of LE increased with the functional class. LE in the basal and mid lateral wall was more frequent in VT, without difference between S-VT and NS-VT. The only predictor of VT was the percentage of LE, odds ratio (OR), 6.2; (95% confidence interval [CI], 3.7-28.4; P = .01) with a cutoff of Odds Ratio 17.1%. CONCLUSIONS: The amount of LE increases in relation to the clinical stage of the disease and its functional class in Chagas seropositive patients. The amount of LE was the main predictor of VT, without difference between S-VT and NS-VT.
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Cardiomiopatia Chagásica/diagnóstico por imagem , Eletrocardiografia , Imagem Cinética por Ressonância Magnética , Taquicardia Ventricular/diagnóstico , Potenciais de Ação , Adulto , Idoso , Cardiomiopatia Chagásica/complicações , Cardiomiopatia Chagásica/fisiopatologia , Meios de Contraste/administração & dosagem , Feminino , Gadolínio DTPA/administração & dosagem , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Fatores de Risco , Volume Sistólico , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/fisiopatologia , Fatores de Tempo , Função Ventricular Esquerda , Função Ventricular DireitaRESUMO
BACKGROUND: While 18F-fluorodeoxyglucose and 18F-sodium fluoride with positron emission tomography relate with inflammation and calcification, their role in the assessment of patients with Takayasu arteritis has not yet been studied. METHODS: We present 5 patients with suspected active metabolic disease who underwent PET with 18F-fluorodeoxyglucose and 18F-sodium fluoride in order to explore the locations and correlations of 18F-fluorodeoxyglucose and 18F-sodium fluoride uptakes. Diagnosis of metabolic active disease was based on 18F-fluorodeoxyglucose uptake. RESULTS: We studied 3 female patients and 2 male patients. Median age was 29 years (min: 19 max: 63). In areas with atherosclerotic plaques, we found a negative correlation between 18F-sodium fluoride and 18F-fluorodeoxyglucose uptakes (r = -0.78) (P = .001). Meanwhile, in areas with only metabolic active disease, we found a positive correlation between 18F-sodium fluoride and 18F-fluorodeoxyglucose uptakes (r = 0.94) (P = .019). CONCLUSIONS: In Takayasu arteritis, 18F-sodium fluoride uptake can document different stages of metabolic disease, even in the absence of active metabolic disease or symptoms.
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Radioisótopos de Flúor/farmacocinética , Tomografia por Emissão de Pósitrons , Fluoreto de Sódio/farmacocinética , Arterite de Takayasu/diagnóstico por imagem , Adulto , Aorta/diagnóstico por imagem , Calcinose/diagnóstico por imagem , Feminino , Fluordesoxiglucose F18/farmacocinética , Humanos , Inflamação , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
INTRODUCTION: Determination of antinuclear antibodies (ANA) by indirect immunofluorescence (IIF) is usually the initial test for the diagnosis of systemic rheumatic diseases (SRD). Assigning predictive values to positive and negative results of the test is vital because lack of knowledge about ANAs and their usefulness in classification criteria of SRD leads to inappropriate use. METHODS: Retrospective study, ANA tests requested by different specialties, correlation to patients' final diagnosis. RESULTS: The prevalence of autoimmune disease was relatively low in our population yielding a low PPV and a high NPV for the ANA test. 40% of the patients had no clinical criteria applied prior to test. Coexistence of two or more autoimmune disorders affects prevalence and predictive values. CONCLUSION: Application of the test after careful evaluation for clinical criteria remarkably improves the positive likelihood ratio for the diagnosis.
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Nowadays, there is a wide array of imaging studies available for the evaluation of coronary artery disease, each with its particular indications and strengths. Cardiac single photon emission tomography is mostly used to evaluate myocardial perfusion, having experienced recent marked improvements in image acquisition. Cardiac PET has its main utility in perfusion imaging, atherosclerosis and endothelial function evaluation, and viability assessment. Cardiovascular computed tomography has long been used as a reference test for non-invasive evaluation of coronary lesions and anatomic characterization. Cardiovascular magnetic resonance is currently the reference standard for non-invasive ventricular function evaluation and myocardial scarring delineation. These specific strengths have been enhanced with the advent of hybrid equipment, offering a true integration of different imaging modalities into a single, simultaneous and comprehensive study.
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Doença da Artéria Coronariana/diagnóstico , Imagem Multimodal/métodos , Doença da Artéria Coronariana/fisiopatologia , Humanos , Imageamento por Ressonância Magnética/métodos , Tomografia por Emissão de Pósitrons/métodos , Tomografia Computadorizada de Emissão de Fóton Único/métodos , Tomografia Computadorizada por Raios X/métodosRESUMO
Resumen La endocarditis infecciosa es una patología que requiere un diagnóstico y tratamiento oportuno para prevenir sus graves complicaciones y, ante todo, evitar la muerte del paciente. En el presente artículo, documentamos el abordaje diagnóstico y terapéutico de un caso de endocarditis, en el escenario de una cardiopatía congénita, válvula aórtica bicúspide, atendida en el Instituto Nacional de Cardiología "Ignacio Chávez".
Abstract Infective endocarditis is a condition that requires an early diagnosis and treatment to prevent its severe complications and, above all, avoid death. In this article we document the diagnosis and therapeutics of a case of infective endocarditis in the setting of a congenital heart disease, bicuspid aortic valve, referred to the National Institute of Cardiology "Ignacio Chávez".
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BACKGROUND AND AIMS: The pathogenesis of coronary artery ectasia (CE) is poorly understood. An underlying inflammatory process is suspected; current therapy aims to prevent thrombotic events. Presently, there is no evidence to support an anti-inflammatory approach for CE patients. We undertook this study to determine the presence and levels of adhesion molecules as well as other inflammation-related markers and evaluate their invasive angiography findings to compare between patients with CE or atherosclerotic coronary artery disease (CAD). METHODS: We included 23 patients with CE alone and 23 patients with CAD alone reported by diagnostic angiography. The two groups were paired according to gender and age. Clinical variables, angiographic findings (STEMI, NSTEMI, previous coronary stenting and previous CABG), serum VCAM, ICAM, C-reactive protein (CRP), IL-6 and adiponectin were compared between groups. RESULTS: In patients with CE, median for serum VCAM was 1700 ng/mL with a range from 900-4050 and for serum ICAM was 550 ng/mL (370-1530); in contrast to the obstructive lesions group where we found a median for VCAM of 1150 ng/mL (650-2000) and for ICAM of 370 ng/mL (150-480). Both measurements achieved statistical significance with a p value = 0.0001. There was no important variation between patients measured at different times from diagnosis. CONCLUSION: Plasma soluble adhesion molecules in CE are elevated in comparison to CAD. The presence of high levels of these molecules, along with not uncommon multivessel and extensive coronary affection suggest the participation of subclinical inflammation, which may have an important role in the development of CE.