Artificial Intelligence to Improve Risk Prediction with Nuclear Cardiac Studies.

PURPOSE OF REVIEW: As machine learning-based artificial intelligence (AI) continues to revolutionize the way in which we analyze data, the field of nuclear cardiology provides fertile ground for the implementation of these complex analytics. This review summarizes and discusses the principles regarding nuclear cardiology techniques and AI, and the current evidence regarding its performance and contribution to the improvement of risk prediction in cardiovascular disease. There is a growing body of evidence on the experimentation with and implementation of machine learning-based AI on nuclear cardiology studies both concerning SPECT and PET technology for the improvement of risk-of-disease (classification of disease) and risk-of-events (prediction of adverse events) estimations. These publications still report objective divergence in methods either utilizing statistical machine learning approaches or deep learning with varying architectures, dataset sizes, and performance. Recent efforts have been placed into bringing standardization and quality to the experimentation and application of machine learning-based AI in cardiovascular imaging to generate standards in data harmonization and analysis through AI. Machine learning-based AI offers the possibility to improve risk evaluation in cardiovascular disease through its implementation on cardiac nuclear studies. AI in improving risk evaluation in nuclear cardiology. * Based on the 2019 ESC guidelines.

Evolución a mediano plazo de pacientes con diagnóstico de cardiopatía amiloidótica por transtiretina / Mid-term Outcome of Patients with Diagnosis of Transthyretin Cardiac Amyloidosis

RESUMEN Introducción: El compromiso cardíaco es la principal causa de morbimortalidad en la amiloidosis, independientemente de la patogenia productora del amiloide subyacente. La amiloidosis por transtiretina (TTR) es una de las variantes más frecuentes, por lo cual el objetivo de este trabajo fue evaluar las características de una cohorte de pacientes con diagnóstico de cardiopatía amiloidótica por TTR (CA-TTR) Material y métodos: Se recabaron datos de los estudios basales, de la metodología diagnóstica y de la evolución de 49 pacientes en seguimiento en la Clínica de Miocardiopatías de nuestra institución. Resultados: La mediana del tiempo de seguimiento fue de 1258 días (410-2004) y la edad promedio de 79 ± 9 años. Al inicio del seguimiento, el 57% de los pacientes estaban en clase funcional I, el 26%, en II y el 16%, en III-IV. El diagnóstico se basó en centellograma con difosfonatos en el 92%; en el 24% requirió biopsia. La mortalidad global fue del 19%, con 15% de muerte cardiovascular. La tasa de internación por insuficiencia cardíaca fue 29%; el 63% de los pacientes empeoró su clase funcional. Conclusiones: El seguimiento de nuestros pacientes con CA-TTR expresa los cambios que ha sufrido el proceso diagnóstico, con una reducción de estudios invasivos y tiempo para la caracterización. El diagnóstico de pacientes en etapas "tempranas" de la enfermedad parece impactar en los resultados a mediano plazo.

ABSTRACT Background: Cardiac involvement is the main cause of morbidity and mortality in amyloidosis, regardless of the underlying pathogenesis of amyloid production, and transthyretin (TTR) amyloidosis is one of the most frequent variants. Objective: The aim of this study was thus to assess the characteristics of a cohort of patients with diagnosis of TTR cardiac amyloidosis (ATTR-CA). Methods: Baseline data and diagnostic and follow-up methodology were collected from 49 patients treated at the cardiomy-opathy clinic of our institution. Results: Median follow-up was 1,258 days (410-2004). Mean age was 79±9 years, and 57% of patients were in functional class (FC) I, 26% in FC II and 16% in FC III-IV at follow-up onset. Diagnosis was made with diphosphonate scintigraphy in 92% of patients and 24% required a biopsy. Overall mortality was 19%, with 15% of cardiovascular death. The rate of hospitalization for heart failure was 29% and 63% of patients worsened their FC. Conclusions: Follow-up of patients with ATTR-CA expresses the changes undergone by the diagnostic process, with a reduction of invasive studies and time to characterization. The diagnosis of patients at "early stages of the disease" seems to have an impact on mid-term outcomes.

[Positron emission tomography in infective endocarditis associated with intracardiac devices and prosthetic valves]. / Tomografía por emisión de positrones en endocarditis infecciosa asociada a dispositivos y válvulas protésicas.

Infective endocarditis (IE) is a serious and potentially lethal condition. The diagnostic capacity of the modified Duke criteria is high for native valves, but it declines in the case of EI of prosthetic valves or EI associated with devices. Echocardiography and microbiological findings are essential for diagnosis but may be insufficient in this group of patients. Our objective was to evaluate the usefulness of positron emission tomography and fusion with computed tomography (PET / CT) in patients with suspected IE, carriers of prosthetic valves or intracardiac devices; 32 patients were studied, who underwent PET / CT with 18F-Fluorine deoxyglucose (18F-FDG). Those with intense focal and/or heterogeneous uptake with a Standard Uptake Value SUV) cut-off point greater than or equal to 3.7 were considered suggestive of infection. The initial diagnoses according to the modified Duke criteria were compared with the final diagnosis established by the Institutional Endocarditis Unit. The addition of PET / CT to these criteria, provided a conclusive diagnosis in 22 of the 32 initial cases reclassifying 11 cases in definitive EI; another 5 cases were negative for that diagnosis. EI continues to be a serious clinical problem. In those cases where the Duke criteria are not sufficient to establish the diagnosis and clinical suspicion persists, PET / CT can be a useful complementary tool to increase the diagnostic sensitivity.

La endocarditis infecciosa (EI) es una enfermedad grave y potencialmente letal. La capacidad diagnóstica de los criterios de Duke modificados es alta para válvulas nativas, pero decae en el caso de EI de válvulas protésicas o EI asociadas a dispositivos. El ecocardiograma y los hallazgos microbiológicos son fundamentales para el diagnóstico, pero pueden resultar insuficientes en este grupo de pacientes. Nuestro objetivo fue evaluar la utilidad de la tomografía por emisión de positrones y fusión con tomografía computarizada (PET/TC) en pacientes con sospecha de EI, portadores de válvulas protésicas o dispositivos intracardiacos. Se estudiaron 32 pacientes, a los cuales se les realizó un PET/CT con 18F-Flúor desoxiglucosa (18F-FDG). Se consideraron sugestivos de infección aquellos con captación intensa de tipo focal y/o heterogénea con un punto de corte de Standard Uptake Value (SUV) mayor o igual a 3.7. Los diagnósticos iniciales según los criterios de Duke modificados, se compararon con el diagnóstico final establecido por la Unidad de Endocarditis institucional. El agregado del PET/CT a esos criterios, proporcionó un diagnóstico concluyente en 22 de los 32 casos iniciales, reclasificando a 11 casos en EI definitivas y a otros 5 casos como negativos para ese diagnóstico. La EI continúa siendo un grave problema clínico. En aquellos casos donde los criterios de Duke no son suficientes para establecer el diagnóstico y la sospecha clínica persiste, el PET/CT puede ser una herramienta complementaria útil para aumentar la sensibilidad diagnóstica.

Tomografía por emisión de positrones en endocarditis infecciosa asociada a dispositivos y válvulas protésicas / Positron emission tomography in infective endocarditis associated with intracardiac devices and prosthetic valves

La endocarditis infecciosa (EI) es una enfermedad grave y potencialmente letal. La capacidad diagnóstica de los criterios de Duke modificados es alta para válvulas nativas, pero decae en el caso de EI de válvulas protésicas o EI asociadas a dispositivos. El ecocardiograma y los hallazgos microbiológicos son fundamentales para el diagnóstico, pero pueden resultar insuficientes en este grupo de pacientes. Nuestro objetivo fue evaluar la utilidad de la tomografía por emisión de positrones y fusión con tomografía computarizada (PET/TC) en pacientes con sospecha de EI, portadores de válvulas protésicas o dispositivos intracardiacos. Se estudiaron 32 pacientes, a los cuales se les realizó un PET/CT con 18F-Flúor desoxiglucosa (18F-FDG). Se consideraron sugestivos de infección aquellos con captación intensa de tipo focal y/o heterogénea con un punto de corte de Standard Uptake Value (SUV) mayor o igual a 3.7. Los diagnósticos iniciales según los criterios de Duke modificados, se compararon con el diagnóstico final establecido por la Unidad de Endocarditis institucional. El agregado del PET/CT a esos criterios, proporcionó un diagnóstico concluyente en 22 de los 32 casos iniciales, reclasificando a 11 casos en EI definitivas y a otros 5 casos como negativos para ese diagnóstico. La EI continúa siendo un grave problema clínico. En aquellos casos donde los criterios de Duke no son suficientes para establecer el diagnóstico y la sospecha clínica persiste, el PET/CT puede ser una herramienta complementaria útil para aumentar la sensibilidad diagnóstica.

Infective endocarditis (IE) is a serious and potentially lethal condition. The diagnostic capacity of the modified Duke criteria is high for native valves, but it declines in the case of EI of prosthetic valves or EI associated with devices. Echocardiography and microbiological findings are essential for diagnosis but may be insufficient in this group of patients. Our objective was to evaluate the usefulness of positron emission tomography and fusion with computed tomography (PET / CT) in patients with suspected IE, carriers of prosthetic valves or intracardiac devices; 32 patients were studied, who underwent PET / CT with 18F-Fluorine deoxyglucose (18F-FDG). Those with intense focal and/or heterogeneous uptake with a Standard Uptake Value (SUV) cut-off point greater than or equal to 3.7 were considered suggestive of infection. The initial diagnoses according to the modified Duke criteria were compared with the final diagnosis established by the Institutional Endocarditis Unit. The addition of PET / CT to these criteria, provided a conclusive diagnosis in 22 of the 32 initial cases reclassifying 11 cases in definitive EI; another 5 cases were negative for that diagnosis. EI continues to be a serious clinical problem. In those cases where the Duke criteria are not sufficient to establish the diagnosis and clinical suspicion persists, PET / CT can be a useful complementary tool to increase the diagnostic sensitivity.

[Bone seeking tracers' scintigraphy for the diagnosis of transthyretin cardiac amyloidosis]. / Centellografía con fosfonatos para el diagnóstico de la amiloidosis cardíaca por transtirretina.

Transthyretin cardiac amyloidosis (ATTR) is a restrictive cardiomyopathy that leads to heart failure in considerable number of patients. Early diagnosis allows specific treatment options. However, ATTR diagnosis is complex and requires invasive procedures. The utility of 99mTc-phosphate tracers for non-invasive diagnosis is well-known but the experience in Argentina is insufficient. The aim of this work was to assess the utility of 99m Tc-phosphate tracers for the diagnosis of ATTR. A total of 46 scintigraphies for detection of cardiac amyloidosis performed between September 2016 and January 2018 were analyzed. Cardiac retention after one hour was assessed in relation to bone uptake using two methods: A semi-quantitative visual score (grade 0 = absent, I = low II = moderate-III = high) and a quantitative method (heart/lung ratio). The final diagnosis and the amyloidosis subtype were carried out by our institution cardiomyopathy team according to international guidelines. The positive and negative predictive values for Grade ≥ II were 96% and 100% respectively for diagnosis of ATTR. Using 1.38 as cut-off value for heart/lung ratio the sensitivity and the specificity were 96% and 100%, respectively for differentiating transthyretin cardiac amyloidosis from light-chain cardiac amyloidosis and other cardiopathies. Scintigraphy with 99m Tc-phosphate tracers enable noninvasive diagnosis and subtype classification of cardiac amyloidosis. The use of this non-invasive, inexpensive and widely available tool will result in better patient management.

Centellografía con fosfonatos para el diagnóstico de la amiloidosis cardíaca por transtirretina / Bone seeking tracers' scintigraphy for the diagnosis of transthyretin cardiac amyloidosis

La amiloidosis cardíaca del subtipo transtirretina (ATTR) es una cardiopatía restrictiva que causa insuficiencia cardíaca en un número considerable de pacientes. Su identificación temprana permitiría brindar tratamientos específicos. Sin embargo, el diagnóstico de ATTR es complejo y requiere métodos invasivos. Los fosfonatos marcados con 99mTecnecio han demostrado ser útiles para el diagnóstico, aunque en Argentina la experiencia es escasa. Nuestro objetivo fue evaluar la utilidad de este método para diagnosticar de forma no invasiva la ATTR. Se estudiaron 46 pacientes entre septiembre de 2016 y enero de 2018 por sospecha de amiloidosis cardíaca. Se evaluó el grado de captación cardíaca con relación al tejido óseo, a la hora, mediante dos métodos: semi-cuantitativo y cuantitativo. El diagnóstico definitivo de amiloidosis y el subtipo específico fue asignado por el centro de miocardiopatías de nuestra institución siguiendo recomendaciones internacionales. Una captación ≥ grado II presentó un valor predictivo positivo del 96% y negativo del 100% para el diagnóstico de amiloidosis cardíaca ATTR. El valor de corte de 1.38 en la relación corazón/pulmón presentó una sensibilidad del 96% y una especificidad del 100% para discriminar entre pacientes con ATTR de aquellos con amiloidosis por cadenas livianas u otras afecciones (área bajo la curva relación corazón/pulmón = 0.95 p < 0.001). La centellografía con fosfonatos marcados demostró ser un método no invasivo útil para diagnosticar ATTR. Dado que además de ser no invasiva, es una herramienta de bajo costo y ampliamente disponible en nuestro medio, su aplicación puede redundar en un beneficio clínico para muchos pacientes.

Transthyretin cardiac amyloidosis (ATTR) is a restrictive cardiomyopathy that leads to heart failure in considerable number of patients. Early diagnosis allows specific treatment options. However, ATTR diagnosis is complex and requires invasive procedures. The utility of 99mTc-phosphate tracers for non-invasive diagnosis is well-known but the experience in Argentina is insufficient. The aim of this work was to assess the utility of 99mTc-phosphate tracers for the diagnosis of ATTR. A total of 46 scintigraphies for detection of cardiac amyloidosis performed between September 2016 and January 2018 were analyzed. Cardiac retention after one hour was assessed in relation to bone uptake using two methods: A semi-quantitative visual score (grade 0 = absent, I = low II = moderate-III = high) and a quantitative method (heart/lung ratio). The final diagnosis and the amyloidosis subtype were carried out by our institution cardiomyopathy team according to international guidelines. The positive and negative predictive values for Grade ≥ II were 96% and 100% respectively for diagnosis of ATTR. Using 1.38 as cut-off value for heart/lung ratio the sensitivity and the specificity were 96% and 100%, respectively for differentiating transthyretin cardiac amyloidosis from light-chain cardiac amyloidosis and other cardiopathies. Scintigraphy with 99mTc-phosphate tracers enable noninvasive diagnosis and subtype classification of cardiac amyloidosis. The use of this non-invasive, inexpensive and widely available tool will result in better patient management.

Actual impact of screening for myocardial ischemia with single-photon emission tomography among patients undergoing peripheral vascular interventions.

The present study provides actual data with regard to the prevalence of myocardial ischemia among patients under contemporary cardiovascular prevention strategies undergoing peripheral vascular interventions. We included a total of 200 consecutive patients who underwent gated single-photon emission computed tomography myocardial perfusion study between January 2012 and January 2014 as preoperative evaluation for peripheral vascular interventions at our institution. The baseline medical treatment comprised aspirin (81%), statins (79%), and ß-blockers (54%). Thirty-two (16%) patients underwent carotid revascularization; 69 (34.5%) patients underwent lower limb revascularization, and 99 patients underwent aortic interventions. Twenty-six (13%) patients showed evidence of myocardial ischemia, with an extensive ischemic burden identified in seven (3.5%) patients. Within the group of patients with peripheral vasculopathy, those with lower limb arteriopathy had a higher prevalence of ischemia. According to the results of the myocardial perfusion study, the cardiology in charge indicated invasive coronary angiography in 11/26 (42%) patients with evidence of myocardial ischemia. Seven of the 11 (64%) patients who had coronary angiography were revascularized. After a mean follow-up of 24 months, no cardiovascular adverse events were detected.

Impact of a hybrid decision support system to improve the adherence to implantable cardioverter defibrillator therapy guidelines for primary prevention of sudden cardiac death.

OBJECTIVES: Despite the well-documented benefit of implantable cardioverter defibrillator (ICD) in patients with severe left ventricular dysfunction, there is a large number of patients who had not been offered this therapy. The aim of this study is to evaluate the utility of a hybrid decision support system (hCDSS) to improve the adherence to indicate ICD therapy in our institution. METHODS: We conducted a retrospective, observational and single-center study. An hCDSS focused on patients with severe deterioration of the left ventricular function was implemented, creating a mandatory field containing the value of left ejection fraction and three options to choose: >35%, ≤ 35% or unknown. When the option ≤ 35% is checked, an email is automatically sent to the electrophysiology section where the staff can contact the treating physician to discuss the indication of ICD therapy. We measured the number of ICDs implanted before the alert (month 1-21), immediate post and late post alert (month 22-27 and 28-48 months respectively) RESULTS: The rate of ICD implantation increased from 1.76% per month in the pre-intervention period to 4.48% after the intervention (p < 0.001). This increase in the rate of ICD implantation remained stable between the immediate and late post-intervention period (4.6 vs. 4.4; p = .8) CONCLUSION: The implementation of a hybrid decision support system was associated with improved adherence to clinical guidelines for prevention of sudden cardiac death, as evidenced by a rapid and sustained increase in the number of ICD implants in patients with severe left ventricular dysfunction.

Proyecto de mejora de calidad para reducir errores de prescripción en pacientes internados por patologías cardiovasculares / Quality Improvement Project to Reduce Prescription Errors in Patients Hospitalized due to Cardiovascular Diseases

Introducción: Los errores de prescripción son un problema frecuente que amenaza la seguridad de los pacientes internados, especialmente en áreas de cuidados críticos. Objetivo: Evaluar la efectividad de un proyecto de mejora de la calidad para reducir errores de prescripción en pacientes internados por patologías de origen cardiovascular. Material y métodos: Se implementó un proyecto de mejora de la calidad destinado a reducir errores de prescripción intrahos-pitalaria. Los tres componentes principales del proyecto fueron: supervisión obligatoria de las indicaciones, utilización de un software que ordena las indicaciones por sistemas biológicos e implementación de una norma de formato universal de prescripción de medicamentos, que incluyó un diccionario de abreviaturas y de diluciones normalizadas. Con anterioridad a la implementación de estos cambios se midió la cantidad de errores de prescripción semanales, estratificados por área de internación. Se analizó el impacto del proyecto dividiendo las muestras en cuatro períodos consecutivos de 9 semanas cada uno (un período preintervención y tres posintervención) y se comparó luego la cantidad de errores detectados en cada uno de ellos. En cada período se evaluaron de manera aleatoria las indicaciones de 180 pacientes. Resultados: Se analizaron en total 720 prescripciones. La implementación del proyecto de mejora logró reducir la cantidad de errores de manera rápida y sostenida en el tiempo (mediana preintervención de 85, RIC 70-95 y mediana final de 26, RIC 21-37; p = 0,0004). Conclusión: El proyecto de mejora de la calidad implementado permitió reducir significativamente la cantidad de errores de prescripción en pacientes internados por patologías cardiovasculares.

High-sensitivity troponin and right ventricular function in acute pulmonary embolism.

INTRODUCTION: Right ventricular (RV) dysfunction has proved to be an important predictor of morbidity and mortality in patients with pulmonary embolism (PE). Tricuspid annular plane systolic excursion (TAPSE) is one of the parameters that have been validated as predictor of outcomes. The aim of our study was to evaluate the performance (sensitivity and specificity) of high-sensitivity cardiac troponin T (hs-cTnT) to predict RV dysfunction defined as TAPSE <16 mm. METHODS: We conducted a single-center retrospective analysis of 40 patients prospectively included. Median age was 66 years (59-76) and PESI score was 81 (67-100). RESULTS: Right ventricular dysfunction was present in 30% of the patients and was associated with higher median troponin values (33.5 ng/L vs 16 ng/L; P= .03). A logarithmic relation was observed between hs-cTnT and lower TAPSE values (r(2)= 0.36; P< .0001). The area under the ROC curve of hs-cTnT to predict RV dysfunction was 0.77 (0.63-0.92). CONCLUSION: hs-cTnT is a biomarker with good performance to identify RV dysfunction in PE.