Comparación pronóstica entre scores de riesgo y la aplicación de redes neuronales para la predicción de la mortalidad a corto y mediano plazo en pacientes con insuficiencia cardíaca / Prognostic Comparison between Risk Scores and Neural Networks to Predict Short- and Mid-Term Mortality in Acute Heart Failure

RESUMEN Introducción: En el contexto de la insuficiencia cardíaca (IC) existen scores de riesgo para evaluar la mortalidad por cualquier causa durante el primer año, con áreas bajo la curva ROC que oscilan entre 0,59 y 0,80. Objetivo: Desarrollar y validar un modelo basado en algoritmos de redes neuronales (RN) destinado a mejorar el rendimiento de los modelos tradicionales para predecir mortalidad a corto y mediano plazo de pacientes con IC aguda. Material y métodos: Se analizó una base de datos con 181 variables de 483 pacientes con IC aguda en un hospital de comunidad de la Ciudad de Buenos Aires (junio de 2005-junio de 2019). Se utilizaron 25 variables para calcular 5 modelos de riesgo validados para predecir la mortalidad a 30 días, 6 meses y un año: EFFECT, ADHERE, GWTG-HF, 3C-HF y ACUTE-HF. Resultados: La edad media fue 78 ± 11,1años, 58% eran varones, el 35% de las IC eran de etiología isquémico necrótica, y la fracción de eyección media fue 52% (35-60). En término de discriminación a 30 días, fueron mejores el score EFFECT (ROC: 0,68) y el 3C-HF (ROC: 0,67) que el ACUTE- HF (ROC: 0,54). A los 6 meses y al año, el score EFFECT (ROC: 0,69 y 0,69) superó al ADHERE (ROC: 0,53 y 0,56) (p=0,011 y p = 0,003, respectivamente), y los scores EFFECT GWRG-HF (ROC: 0,68 y 0,66) y 3C-HF (ROC: 0,67 y 0,67) superaron al score ACUTE-HF (ROC: 0,53 y 0,56). De los algoritmos de RN los mejores resultados se obtuvieron con un perceptrón multicapa (PMC) con dos capas ocultas. Se usó una RN de arquitectura de capas 24-9-7-2 con los siguientes resultados: ROC: 0,82, valor predictivo negativo (VPN) 93,2% y valor predictivo positivo (VPP) 66,7% para mortalidad a 30 días; ROC: 0,87, VPN: 89,1% y VPP: 78,6% para mortalidad a 6 meses; y ROC: 0,85, VPN: 85,6% y VPP: 78,9% para mortalidad al año. En términos de discriminación, los algoritmos de RN superaron a los scores tradicionales ( p <0,001). Los factores que obtuvieron ≥50% de importancia estandarizada para predecir la mortalidad a los 30 días fueron en orden descendente la creatinina sérica, la hemoglobina, la frecuencia respiratoria, la urea, el sodio, la edad y la presión arterial sistólica. Agregaron capacidad pronóstica la clase III-IV NYHA y la demencia para mortalidad a 6 meses, y la frecuencia cardíaca y la disfunción renal crónica para mortalidad al año. Conclusiones: Los modelos con algoritmos de RN fueron significativamente superiores a los scores de riesgo tradicionales en nuestros pacientes con IC. Estos hallazgos constituyen una hipótesis de trabajo a validar con una mayor muestra de casos y en forma multicéntrica.

ABSTRACT Background: Heart failure (HF) risk scores to assess all-cause mortality during the first year have areas under the ROC curve (AUC) ranging between 0.59 and 0.80 Objective: To develop and validate a neural network (NN) algorithm-based model to improve traditional scores' performance for predicting short- and mid-term mortality of patients with acute HF. Methods: A prospective clinical database was analyzed including 483 patients admitted with diagnosis of acute HF in a coronary care unit community hospital of Buenos Aires, between June 2005 and June 2019. Among 181 demographic, laboratory, treatment and follow-up variables, only 25 were selected to calculate five acute heart failure risk scores aimed to predict 30-day, 6-month and 1-year mortality: EFFECT, ADHERE, GWTG-HF, 3C-HF, and ACUTE-HF. Results: Mean age was 78 ± 11.1 years, 58% were men, 35% had ischemic necrotic HF and median left ventricular ejection fraction was 52% (35-60). At 30 days, the EFFECT score (AUC:0.68) and the 3C-HF score (AUC: 0.68) showed better performance than the ACUTE-HF score (AUC: 0.54). At 6-month and 1-year follow-up, the EFFECT score (ROC: 0.69 and 0.69) outperformed the ADHERE score (AUC: 0.53 and 0.56), and EFFECT (AUC: 0.69 and 0.69), GWRG-HF (AUC = 0.68 and 0.66), and 3C-HF (AUC:0.67 and 0.67) scores outperformed the ACUTE-HF score (AUC:0.53 and 0.56). The best results with NN algorithms were obtained with a two-hidden layer multilayer perceptron. A 24-9-7-2-layer architecture NN was used with the following results: AUC: 0.82, negative predictive value (NPV) 93.2% and positive predictive value (PPV) 66.7% for 30-day mortality; AUC: 0.87, NPV: 89.1% and PPV: 78,6% for 6-month mortality; and AUC: 0.85, NPV: 85.6% and PPV: 78.9% for 1-year mortality. In terms of discrimination, NN algorithms outperformed all the traditional scores (p <0.001). For this algorithm, the most influential factors in descending order that scored ≥50% normalized importance to predict 30-day mortality were serum creatinine, hemoglobin, respiratory rate, blood urea nitrogen, serum sodium, age and systolic blood pressure. Also, NYHA functional class III-IV and dementia added prognostic capacity to 6-month mortality, and heart rate and chronic kidney disease to 1-year mortality. Conclusions: The models with NN algorithms were significantly superior to traditional risk scores in our population of patients with HF. These findings constitute a working hypothesis to be validated with a larger and multicenter sample of cases.

Training in statistical analysis reduces the framing effect among medical students and residents in Argentina.

PURPOSE: The framing effect refers to a phenomenon wherein, when the same problem is presented using different representations of information, people make significant changes in their decisions. This study aimed to explore whether the framing effect could be reduced in medical students and residents by teaching them the statistical concepts of effect size, probability, and sampling for use in the medical decision-making process. Methods: Ninety-five second-year medical students and 100 second-year medical residents of Austral University and Buenos Aires University, Argentina were invited to participate in the study between March and June 2017. A questionnaire was developed to assess the different types of framing effects in medical situations. After an initial administration of the survey, students and residents were taught statistical concepts including effect size, probability, and sampling during 2 individual independent official biostatistics courses. After these interventions, the same questionnaire was randomly administered again, and pre- and post-intervention outcomes were compared among students and residents. RESULTS: Almost every type of framing effect was reproduced either in the students or in the residents. After teaching medical students and residents the analytical process behind statistical concepts, a significant reduction in sample-size, risky-choice, pseudo-certainty, number-size, attribute, goal, and probabilistic formulation framing effects was observed. Conclusion: The decision-making of medical students and residents in simulated medical situations may be affected by different frame descriptions, and these framing effects can be partially reduced by training individuals in probability analysis and statistical sampling methods.

Correlation between moral courage score and social desirability score of the medical residents and fellows in Argentina.

Purpose: Moral courage is the conviction to take action on one's ethical beliefs despite the risk of adverse consequences.. It aimed to evaluate the correlation between social desirability score and moral courage scores of medical residents and fellows, and to explore gender and specialty-based differences of moral courage scores. Methods: In April 2018, the Moral Courage Scale for Physicians (MCSP), the Professional Moral Courage (PMC) scale and the Marlowe-Crowne scale to measure social desirability were administered to 87 medical residents from Hospital Alemán of Buenos Aires, Argentina. Results: Cronbach's alpha coefficients were 0.78, 0.74 and 0.81 for the Marlowe-Crowne, MCSP and PMC scales, respectively. Correlation analysis showed that moral courage scores were poorly correlated with social desirability scores, while both moral courage scales were highly correlated with each other. Physicians who were training in a surgical specialty showed lower moral courage scores than nonsurgical specialty trainees, and male from any specialty tended to have lower moral courage scores than females. Particularly, individuals performing a surgical specialty ranked lower when assessing "multiple values", "endurance of threats", and "going beyond compliance" dimensions from PMC scale. Male individuals tended to rank lower than females on "multiple values", "moral goals" and "endurance of threats" dimensions. Conclusion: There was a poor correlation between two validated moral courage scores and social desirability score of the medical residents and fellows in Argentina. Conversely, both moral courage tools showed a good correlation and concordance between them, making these scales reasonably interchangeable.

Mortality in low- and very low-risk patients undergoing cardiac surgery: evaluation according to the EuroSCORE II as a new standard.

BACKGROUND: Only a few reports have analyzed low-risk patient outcomes and in every case, the risk was based on a logistic EuroSCORE ≤ 2. Since this original EuroSCORE overestimates surgical risk, we developed this study to prospectively evaluate the immediate results of cardiac surgery in patients with an expected mortality risk ≤ 2% according to the EuroSCORE II as a new gold standard. We also examined the cause of death and whether it could be considered preventable. METHODS: A prospective risk stratification of all cardiac surgical patients treated at the Bue-nos Aires University Hospital of Argentina was performed between 2012 and 2014 using the EuroSCORE II. Causes of death were classified as preventable or not preventable. RESULTS: From a total of 990 patients, 63.2% had EuroSCORE II ≤ 2 (low-risk group) and 32.5% EuroSCORE II < 1 (very low-risk group). In the low-risk group, in-hospital mortal-ity was 1.8%, whereas predicted mortality was 1.04% (AUC 0.765). The observed/expected ratio was 1.73 (95% CI 0.68-4.43) and the observed-expected difference was 0.76 (95% CI -0.68-2.10). Fifty-four percent of deaths were considered preventable. CONCLUSIONS: We propose to use and further validate the EuroSCORE II as a new standard for assessing low-risk patients. This model proved to be useful in evaluating the quality standards of local cardiac surgery. The review of cause of death in low-risk patients provided valuable information, which revealed potentially correctable issues. Adoption of a more demanding standard, as the EuroSCORE II to identify low-risk patients, avoids the sense of safety offered by previous versions of the score.

Measurement of empathy among Argentine cardiologists: Psychometrics and differences by age, gender, and subspecialty.

BACKGROUND: Cardiologists are involved in the management of patients with multiple cardiovascular risk factors and chronic heart diseases, so empathy is a necessary feature to deal with them. The aim of the study was to evaluate the validity and reliability of the Spanish version of the Jefferson Scale of Physician Empathy (JSPE) among Argentine cardiologists and to explore the potential differences by age, gender, and subspecialty. METHODS: Between August and September 2012, we performed a survey in a non-randomized sample of 566 Spanish-speaking cardiologists of Argentina. A Principle Component Analysis (PCA) was used to explore the link between observed variables and latent variables in order to identify the factor structure. The PCA criteria for identifying the factor structure were examined with the Kaiser-Meyer-Olkin (KMO) analysis. RESULTS: The KMO measure of sampling adequacy was 0.86 and Bartlett's test of sphericity was highly significant (p = 0.000), determining the suitability of the data set for factor analysis. The PCA of 20 items yielded a three factor model that accounted for 40.6% of the variance. The JSPE mean rank score for women was 307.9 vs. 275.0 for men (p = 0.017). The comparison of mean rank score according to age (quartiles) showed a significant relation between older age and empathy. No difference was found when the mean rank scores were compared by respondent subspecialty. CONCLUSIONS: JSPE provides a valid and reliable scale to measure Argentine cardiologists' attitudes towards empathy. Female cardiologists seem to be more empathic than their male colleagues, and a positive relationship between age and empathy was found.

Perception of consultation length in cardiology and its ethical implications.

OBJECTIVES: This study considered whether the time employers allotted to medical consultations in many working environments in Argentina might be inadequate to carry out an interview. The objective was to conduct a survey to gather information on the length of cardiologic medical consultations in Argentina. METHODS: During 2007, a survey was carried out that included 816 cardiologists. RESULTS: Seventy-six percent of participants said they needed 20 to 30 minutes, and 14% considered that 15 minutes was sufficient, for an adequate consultation. On the other hand, 64% reported that their employer required that consultations be done in 10 to 15 minutes, and 86% cited limits of less than 20 minutes (P < 0.0001). This time was inadequate for 60% of physicians. With regard to ethics, 89% answered affirmatively that requiring that patients be attended in such a short time could be considered an ethical flaw of the employer; 75% acknowledged their own ethical flaw when agreeing to conduct the consultation in an inadequate amount of time. When opinions were grouped, 22% considered that an adequate consultation length was fundamental for a correct patient-physician relationship, 27% reported that this time depended on "pressures" of the system, 19% indicated that inadequate consultation length affected the quality of attention patients received, 17% thought that low fees forced employers to reduce this time with a resulting detriment in quality of care, and 15% said that consultation length was variable and depended on the patient. CONCLUSIONS: This study showed that 60% of physicians perceived as insufficient the time their employers allotted for conducting an adequate consultation. Most believed that allotting such a short time for examining patients could be considered an ethical flaw.

Perception of consultation length in cardiology and its ethical implications / Percepción sobre la duración de las consultas de cardiología y sus implicaciones éticas

OBJECTIVES: This study considered whether the time employers allotted to medical consultations in many working environments in Argentina might be inadequate to carry out an interview. The objective was to conduct a survey to gather information on the length of cardiologic medical consultations in Argentina. METHODS: During 2007, a survey was carried out that included 816 cardiologists. RESULTS: Seventy-six percent of participants said they needed 20 to 30 minutes, and 14 percent considered that 15 minutes was sufficient, for an adequate consultation. On the other hand, 64 percent reported that their employer required that consultations be done in 10 to 15 minutes, and 86 percent cited limits of less than 20 minutes (P < 0.0001). This time was inadequate for 60 percent of physicians. With regard to ethics, 89 percent answered affirmatively that requiring that patients be attended in such a short time could be considered an ethical flaw of the employer; 75 percent acknowledged their own ethical flaw when agreeing to conduct the consultation in an inadequate amount of time. When opinions were grouped, 22 percent considered that an adequate consultation length was fundamental for a correct patient-physician relationship, 27 percent reported that this time depended on "pressures" of the system, 19 percent indicated that inadequate consultation length affected the quality of attention patients received, 17 percent thought that low fees forced employers to reduce this time with a resulting detriment in quality of care, and 15 percent said that consultation length was variable and depended on the patient. CONCLUSIONS: This study showed that 60 percent of physicians perceived as insufficient the time their employers allotted for conducting an adequate consultation. Most believed that allotting such a short time for examining patients could be considered an ethical flaw.

OBJETIVOS: Se analizó si el tiempo asignado por los empleadores para las consultas médicas en centros de trabajo en Argentina es insuficiente. El objetivo fue recopilar información mediante una encuesta sobre la duración de las consultas de cardiología en Argentina. MÉTODOS: Se aplicó una encuesta a 816 cardiólogos en 2007. RESULTADOS: De los participantes, 76 por ciento dijo necesitar de 20 a 30 minutos para una consulta adecuada, mientras 14 por ciento consideró que 15 minutos era suficiente. Por otra parte, 64 por ciento informó que sus empleadores exigían que las consultas se realizaran en 10-15 minutos y 86 por ciento citó límites menores de 20 minutos (P < 0,0001); 60 por ciento de los médicos consideraron inadecuado ese tiempo. De los entrevistados, 89 por ciento respondió que exigir que se atienda a los pacientes en ese corto tiempo podría considerarse una falla ética de los empleadores; 75 por ciento reconoció su propia falla ética al aceptar realizar la consulta en un tiempo inadecuado. Cuando se agruparon las opiniones, 27 por ciento manifestó que ese tiempo dependía de "presiones" del sistema, 22 por ciento consideró que realizar la consulta en un tiempo suficiente era fundamental para una correcta relación médico-paciente, 19 por ciento indicó que un tiempo insuficiente de consulta afectaba a la calidad de la atención que recibía el paciente, 17 por ciento pensaba que los bajos honorarios forzaban a los empleadores a reducir ese tiempo con el consiguiente detrimento en la calidad de la atención y 15 por ciento dijo que la duración de la consulta era variable y dependía del paciente. CONCLUSIONES: Estos resultados muestran que 60 por ciento de los médicos percibían como insuficiente el tiempo que sus empleadores les asignaron para llevar a cabo las consultas. La mayoría consideró que asignar un tiempo tan corto para examinar a los pacientes puede considerarse una falla ética.

Perspectivas del xenotrasplante cardíaco / The future of heart xenotransplants

El desarrollo actual de la biología molecular y de la ingeniería genética permiten vislumbrar la posibilidad de fabricar xenoinjertos compatibles con características moleculares semejantes a las humanas. Un enfoque para la construcción de un xenoinjerto cardíaco a partir de una especie filogenéticamente distanciada (cerdo) consiste en reducir la densidad del epítope alfa-galactosil de la superficie celular por medio de la transferencia y sobre expresión en el cerdo del gen de la fucosiltransferasa humana, lo que permitiría al animal producir un epítope semejante al antígeno H humano. El volumen de conocimientos acumulado hasta el momento permite plantear bases teóricas claras para la fabricación de xenoinjertos compatibles

Perspectivas del xenotrasplante cardíaco / The future of heart xenotransplants

El desarrollo actual de la biología molecular y de la ingeniería genética permiten vislumbrar la posibilidad de fabricar xenoinjertos compatibles con características moleculares semejantes a las humanas. Un enfoque para la construcción de un xenoinjerto cardíaco a partir de una especie filogenéticamente distanciada (cerdo) consiste en reducir la densidad del epítope alfa-galactosil de la superficie celular por medio de la transferencia y sobre expresión en el cerdo del gen de la fucosiltransferasa humana, lo que permitiría al animal producir un epítope semejante al antígeno H humano. El volumen de conocimientos acumulado hasta el momento permite plantear bases teóricas claras para la fabricación de xenoinjertos compatibles (AU)