Alberto Fernández-Villar’s research while affiliated with Centro de Investigación Biomédica en Red de Enfermedades Respiratorias and other places

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Publications (281)


Prevalence of Sleep Apnea in Patients with Syncope of Unclear Cause: SINCOSAS Study
  • Article
  • Full-text available

May 2025

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14 Reads

María-José Muñoz-Martínez

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Alberto Fernández-Villar

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[...]

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Bernardo Sopeña

Background and Objectives: The association between syncope and sleep apnea (SA) has been scarcely investigated. Dysfunction of the autonomic nervous system (ANS) may represent a shared pathophysiological mechanism. This study aimed to determine the prevalence of SA in patients with syncope of unclear cause (SUC), identify potential associated factors, and evaluate nocturnal heart rate variability (HRV) as a marker of ANS function. Materials and Methods: A prospective cohort study was conducted in adult patients diagnosed with SUC. Nocturnal cardiorespiratory polygraphy was performed to detect the presence of SA. A range of variables potentially associated with SA was collected. Both SA diagnosis and HRV parameters were assessed using the Embletta® MPR polygraph system. Results: A total of 156 patients were enrolled (57% male), with a mean age of 64 years and a mean body mass index of 27.5 kg/m² (range: 24.8–32.2). Hypertension was present in 46% of the cohort. The overall prevalence of SA was 78.2% (95% CI: 71.7–84.4%), with 28.7% classified as severe. Age (OR = 1.04; 95% CI: 1.01–1.07) and BMI (OR = 1.17; 95% CI: 1.06–1.28) were independent predictors of SA. Mean RR interval was significantly lower in patients with SA compared to those without (942 ms vs. 995 ms; p = 0.04). No significant differences in HRV parameters were observed between the two groups. Conclusions: This study found a high prevalence (nearly 78%) of SA among adult patients with SUC, particularly in individuals over 50 years of age and those who were overweight. However, this association could not be predicted based on clinical variables alone. No significant differences in nocturnal HRV were detected between patients with SUC with and without SA.

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Flow diagram of the intelligent decision support system: The system is organized in three stages. Stage 1: Collection of patient data. Stage 2: Data processing, divided into two sublevels. In Stage 2.1, variable selection is performed in two steps: filter-type methods and recursive feature selection. In Stage 2.2, three ML models predict the risk of readmission, and an expert system based on fuzzy logic combines the predictions into a final output. Stage 3: Alert generation and support for clinical decision-making.
Screenshot of the main system interface.
Selected variables ranked by importance after the variable selection process using RFE.
ROC curve on the test set. A red point is highlighted, related to the point that maximizes the value of the Matthews correlation coefficient.
Determination of the optimal cutoff point based on the Matthews correlation coefficient.

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Predicting COPD Readmission: An Intelligent Clinical Decision Support System

January 2025

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35 Reads

Background: COPD is a chronic disease characterized by frequent exacerbations that require hospitalization, significantly increasing the care burden. In recent years, the use of artificial intelligence-based tools to improve the management of patients with COPD has progressed, but the prediction of readmission has been less explored. In fact, in the state of the art, no models specifically designed to make medium-term readmission predictions (2–3 months after admission) have been found. This work presents a new intelligent clinical decision support system to predict the risk of hospital readmission in 90 days in patients with COPD after an episode of acute exacerbation. Methods: The system is structured in two levels: the first one consists of three machine learning algorithms —Random Forest, Naïve Bayes, and Multilayer Perceptron—that operate concurrently to predict the risk of readmission; the second level, an expert system based on a fuzzy inference engine that combines the generated risks, determining the final prediction. The employed database includes more than five hundred patients with demographic, clinical, and social variables. Prior to building the model, the initial dataset was divided into training and test subsets. In order to reduce the high dimensionality of the problem, filter-based feature selection techniques were employed, followed by recursive feature selection supported by the use of the Random Forest algorithm, guaranteeing the usability of the system and its potential integration into the clinical environment. After training the models in the first level, the knowledge base of the expert system was determined on the training data subset using the Wang–Mendel automatic rule generation algorithm. Results: Preliminary results obtained on the test set are promising, with an AUC of approximately 0.8. At the selected cutoff point, a sensitivity of 0.67 and a specificity of 0.75 were achieved. Conclusions: This highlights the system’s future potential for the early identification of patients at risk of readmission. For future implementation in clinical practice, an extensive clinical validation process will be required, along with the expansion of the database, which will likely contribute to improving the system’s robustness and generalization capacity.



Biomarkers expression.
Demographic and clinical characteristics of patient included in the analysis.
Clinical and demographic differences in patients with and without EGFR presence.
Clinical, demographical and treatment characteristics in patients with or without MPE.
Clinical and Molecular Features of Malignant Pleural Effusion in Non-Small Cell Lung Cancer (NSCLC) of a Caucasian Population

November 2024

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14 Reads

Background and Objectives: The diversity of patients with malignant pleural effusion (MPE) due to non-small cell lung cancer (NSCLC) as well as the variability in mutations makes it essential to improve molecular characterization. Objective: Describe clinical, pathological, and molecular characteristics MPE in a Caucasian population. Materials and Methods: Retrospective study of patients with NSCLC diagnosis who had undergone a molecular study from 1 January 2018–31 December 2022. Univariate analysis was performed to compare patient characteristics between the group with and without MPE and molecular biomarkers. Results: A total of 400 patients were included; 53% presented any biomarker and 29% had MPE.PDL1, which was the most frequent. EGFR mutation was associated with women (OR:3.873) and lack of smoking (OR:5.105), but not with MPE. Patients with pleural effusion were older and had lower ECOG. There was no significant difference in the presence of any biomarker. We also did not find an association between the presence of specific mutations and MPE (22.4% vs. 18%, p = 0.2), or PDL1 expression (31.9% vs. 35.9%, p = 0.3). Being younger constituted a protective factor for the presence of MPE (OR:0.962; 95% CI 0.939–0.985, p = 0.002), as well as ECOG ≤ 1 (OR:0.539; 95% CI 0.322–0.902, p = 0.01). Conclusions: This is the first study that describes the clinical, pathological, and molecular characteristics of MPE patients due to NSCLC in a Caucasian population. Although overall we did not find significant differences in the molecular profile between patients with MPE and without effusion, EGFR mutation was associated with a tendency towards pleural progression.


Clinical and Social Characterization of Patients Hospitalized for COPD Exacerbation Using Machine Learning Tools

November 2024

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24 Reads

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4 Citations

Archivos de Bronconeumología

Objective: This study aims to employ machine learning (ML) tools to cluster patients hospitalized for acute exacerbations of chronic obstructive pulmonary disease (COPD) based on their diverse social and clinical characteristics. This clustering is intended to facilitate the subsequent analysis of differences in clinical outcomes. Methods: We analysed a cohort of patients with severe COPD from two Pulmonary Departments in north-western Spain using the k-prototypes algorithm, incorporating demographic, clinical, and social data. The resulting clusters were correlated with metrics such as readmissions, mortality, and place of death. Additionally, we developed an intelligent clinical decision support system (ICDSS) using a supervised ML model (Random Forest) to assign new patients to these clusters based on a reduced set of variables. Results: The cohort consisted of 524 patients, with an average age of 70.30±9.35 years, 77.67% male, and an average FEV1 of 44.43±15.4. Four distinct clusters (A-D) were identified with varying clinical-demographic and social profiles. Cluster D showed the highest levels of dependency, social isolation, and increased rates of readmissions and mortality. Cluster B was characterized by prevalent cardiovascular comorbidities. Cluster C included a younger demographic, with a higher proportion of women and significant psychosocial challenges. The ICDSS, using five key variables, achieved areas under the ROC curve of at least 0.91. Conclusions: ML tools effectively facilitate the social and clinical clustering of patients with severe COPD, closely related to resource utilization and prognostic profiles. The ICDSS enhances the ability to characterize new patients in clinical settings.




ESTRATEGIAS PARA OPTIMIZAR LOS CUIDADOS AL FINAL DE LA VIDA EN PACIENTES CON EPOC: DESARROLLO DE UN SISTEMA INTELIGENTE PARA PREDECIR LA MORTALIDAD A UN AÑO TRAS LA EXACERBACIÓN GRAVE

Objetivo Diseñar un sistema inteligente de soporte a la decisión clínica (SISDC) para predecir la mortalidad a un año tras una exacerbación aguda de EPOC. Material y métodos Se utilizó una base de datos con 524 pacientes, recopilada entre 2018 y 2022 en los hospitales Álvaro Cunqueiro y Lucus Augusti, que incluye variables clínicas, demográficas y sociales. Para el desarrollo del SISDC, primero se abordó un proceso de selección de características mediante Regresión Lasso (RL), para identificar las variables con mayor poder predictivo. Posteriormente, se desarrolló un contenedor estructurado pseudo-simbólico que encapsula la información de cada paciente. Su construcción contempla dos pasos: (1) se definió una estrategia para crear un lenguaje común sonoro basado en las características del paciente, y (2) se calculó el espectrograma asociado al sonido, generando una imagen por paciente. Estas imágenes, que actúan como pseudo-símbolos al integrar datos y conocimiento, fueron analizadas mediante una Red Neuronal Convolucional, SqueezeNet, entrenada para calcular el Riesgo de Mortalidad. El análisis y procesamiento de los datos se realizaron en Python© y MATLAB©, reservando un 10% para pruebas. Resultados La RL permitió seleccionar las variables más relevantes, ordenadas según importancia: oxigenoterapia domiciliaria, número de actividades elaboradas para las que necesita ayuda, edad, IMC, disnea mMRC, número de actividades básicas para las que necesita ayuda, número de hospitalizaciones año previo, FEV1 porcentual, vivienda propia y tabaquismo activo. Posteriormente, se implementó una aplicación. En el conjunto de prueba, se alcanzó un área bajo la curva ROC próxima a 0.85. Conclusiones La propuesta es eficaz para predecir la mortalidad a un año, integrando variables de distintas esferas. Tiene el potencial para mejorar la planificación de los cuidados al final de la vida. No obstante, en el futuro será necesario realizar nuevos estudios para validar el SISDC.


CLUSTERIZACIÓN CLÍNICO-SOCIAL DE PACIENTES CON AGUDIZACIÓN GRAVE DE EPOC MEDIANTE TÉCNICAS DE MACHINE LEARNING Y SU RELACIÓN CON REINGRESOS Y MORTALIDAD

Objetivo Identificar perfiles clínico-sociales en pacientes hospitalizados por agudización de EPOC mediante Machine Learning (ML) no supervisado, evaluar su impacto en el consumo de recursos y pronóstico, y desarrollar un Sistema Inteligente de Soporte a la Decisión Clínica (SISDC) que permita asignar nuevos pacientes a los grupos con un conjunto reducido de variables. Material y métodos Se analizó una cohorte de 524 pacientes hospitalizados por AEPOC entre 2018 y 2022 en dos hospitales (Álvaro Cunqueiro y Lucus Augusti), con datos demográficos, clínicos y sociales. Se utilizaron k-prototypes y el método del codo para identificar cuatro clústeres, evaluando sus diferencias con pruebas estadísticas. Posteriormente, se desarrolló el SISDC basado en Random Forest y Recursive Feature Elimination, el cual se implementó en una aplicación web. Resultados Se identificaron cuatro clústeres. El clúster A, el más frecuente, incluye a varones con una enfermedad menos grave, que residen en zonas rurales, con buenas relaciones sociales y baja dependencia, mostrando un consumo moderado de recursos y un pronóstico favorable. El clúster B, formado por pacientes mayores, principalmente varones, con comorbilidades cardiovasculares y un alto uso de oxigenoterapia, residentes en áreas urbanas, presentó un riesgo intermedio de reingreso y mortalidad, respaldado por una mejor situación económica y social. El clúster C, el más joven, con una mayor proporción de mujeres, bajo IMC, tabaquismo y ansiedad, mostró un índice considerable de reingresos, aunque sin un pronóstico marcadamente desfavorable. Finalmente, el clúster D, compuesto por pacientes más dependientes y con relaciones limitadas al núcleo familiar, mostró el peor pronóstico y mayor consumo de recursos. El SISDC demostró una alta capacidad predictiva, asignando nuevos pacientes con solo 5 variables y alcanzando AUC superiores a 0.9. Conclusiones El uso de técnicas de ML permitió identificar perfiles heterogéneos de pacientes, subrayando la importancia de los factores sociales.


PROPUESTA Y DEFINICIÓN DE UN SISTEMA INTELIGENTE DE SOPORTE A LA DECISIÓN APLICADO EN EL MANEJO DE PACIENTES QUE ACUDEN A URGENCIAS CON UN POSIBLE CUADRO DE COVID-19 BASADO EN TÉCNICAS DE DEEP LEARNING

Introducción y objetivo La pandemia de COVID-19 ha transformado drásticamente la visión sobre la integración de la tecnología en la medicina, poniendo a prueba la capacidad de los sistemas de salud para tomar decisiones rápidas y efectivas, especialmente en servicios de urgencias desbordados. Presentamos un Sistema Inteligente de Soporte a la Decisión aplicado en el manejo de pacientes sospechosos de padecer neumonía COVID-19 a su llegada al servicio de urgencias. Material y método Se despliegan dos módulos que discurren de forma secuencial, basados en Redes Neuronales Convolucionales: (fig.1) El primero: DIAGNÓSTICO: escala 0-100, emplea DenseNet-121, para identificar si se existe neumonía en la Radiografías de Tórax (RT) El segundo: SEVERIDAD, utiliza COVID-Net CXR-S, busca cuantificar la severidad de la opacidad del espacio aéreo en la RT (ASOS): escala 0-24. Esta arquitectura plantea la Generación de Alertas y Toma de Decisiones: • Presenta neumonía y 0 ≤ ASOS < 5: seguimiento • Presenta neumonía y 5 ≤ ASOS < 15: hospitalización. • Presenta neumonía y 15 ≤ ASOS ≤ 24: ingreso en UCI. Base de RT Povisa: 2438 RT:1450 neumonía (59.5%) /988 no neumonía (40.5%).533 RT para pruebas test en el primer módulo y 200 para el segundo. Resultados Los resultados obtenidos en el conjunto de prueba: (fig. 2) AUC > 0.9 para módulo DIAGNÓSTICO. Root Mean Squared Error próximos a 6 para módulo SEVERIDAD. Conclusiones Estos hallazgos subrayan la capacidad del sistema para actuar como aliado fiable en la lucha contra el COVID-19, mejorando significativamente la gestión de pacientes en entornos de urgencia. En el futuro, se plantea la necesidad de expandir y profundizar en la validación de este sistema en otras patologías, además de desarrollar técnicas de explicabilidad


Citations (59)


... To determine one label or another (readmission vs. no readmission) it is necessary to determine a threshold value to interpret the Risk of Readmission at 90 days (the output of the expert system). In this case, the use of a graphical optimization process on the test set based on the Matthews correlation coefficient (Mcc) [65][66][67] is chosen, similar to that used by Casal-Guisande et al. in other works [30,31,34,64]. This is a coefficient that behaves especially well in situations where there is imbalance in the data. ...

Reference:

Predicting COPD Readmission: An Intelligent Clinical Decision Support System
Proposal and Definition of an Intelligent Decision- Support System Based on Deep Learning Techniques for the Management of Possible COVID-19 Cases in Patients Attending Emergency Departments

IEEE Access

... The evolution of these comorbidities could therefore not be ruled out as a possible explanation for the increase in post-COVID-19 deaths in the long term. Additionally, it should also be associated with long-term persistence of functional impairment in survivors of severe COVID-19 (SARS), as cited in various studies (46)(47)(48)(49). In the long term period, liver disease was also a comorbidity associated with high mortality risk, which could be explained by the liver involvement developed due to COVID-19 disease in hospitalized patients or previous liver disease as reported in a study of systematic review and meta-analysis (50). ...

Medium-Term Disability and Long-Term Functional Impairment Persistence in Survivors of Severe COVID-19 ARDS: Clinical and Physiological Insights
  • Citing Article
  • May 2024

Archivos de Bronconeumología

... To determine one label or another (readmission vs. no readmission) it is necessary to determine a threshold value to interpret the Risk of Readmission at 90 days (the output of the expert system). In this case, the use of a graphical optimization process on the test set based on the Matthews correlation coefficient (Mcc) [65][66][67] is chosen, similar to that used by Casal-Guisande et al. in other works [30,31,34,64]. This is a coefficient that behaves especially well in situations where there is imbalance in the data. ...

Proposal and Definition of an Intelligent Clinical Decision Support System Applied to the Prediction of Dyspnea after 12 Months of an Acute Episode of COVID-19

... Larger studies with more homogeneous selection criteria and methodology are needed to assess the true usefulness of elastography in the diagnosis and follow-up of interstitial diseases. [14][15][16][17] According to the findings discussed, TU is a useful and complementary tool in the management of the pulmonary fibrosis. Although it does not replace HRCT in terms of diagnostic accuracy, its practical advantages make it a valuable resource. ...

Current evidence for lung ultrasound elastography in the field of pneumology: a systematic review

ERJ Open Research

... The disease's progression is typically marked by exacerbations, which are acute episodes of worsening respiratory symptoms, often triggered by infections or environmental factors. These exacerbations further contribute to impaired lung function and a decline in overall health status [3]. Comprehensive management strategies, including smoking cessation, pharmacotherapy, and pulmonary rehabilitation, are crucial in mitigating the impact of COPD on patients' lives. ...

Chronic Obstructive Lung Disease: Treatment Guidelines and Recommendations for Referral and Multidisciplinary Continuity of Care

... From case reports and case series to prospective studies, clinical trials, and even a systematic review, all generally conclude that CryoEBUS was especially useful in cases of lymphomas or non-lung carcinomas and benign cases, with no significant differences found in specific cases of lung cancer. [12][13][14][15][16][17][18][19][20][21][22] Endobronchial ultrasound-guided mediastinal cryobiopsy (CryoEBUS) emerges as a promising alternative, yielding larger and higher-quality samples. This study, the first in Mexico and the first worldwide in HIV patients, evaluates its diagnostic efficacy, its usefulness and performance in patients with HIV infection, highlighting its potential to improve disease management in immunocompromised populations. ...

Is the diagnostic yield of mediastinal lymph node cryobiopsy (cryoEBUS) better for diagnosing mediastinal node involvement compared to endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA)? A systematic review
  • Citing Article
  • August 2023

Respiratory Medicine

... In recent years, there has been an increased development of intelligent decision support systems applied to the healthcare field, [27][28][29][30][31][32][33][34][35][36][37] and particularly to the diagnosis of OSA. [38][39][40][41][42][43][44][45] However, none of those posed systems have explored solutions that involved the processing of existing databases without prior pretreatment and filtering. Traditionally, the approaches that use simpler neural network architectures also require data pretreatment to make possible improving network processing. ...

Design of an Intelligent Decision Support System Applied to the Diagnosis of Obstructive Sleep Apnea

... Nevertheless, SCLC, which represents approximately 10-15% of all lung cancers [4], is associated with a more aggressive course, a high growth rate, earlier metastasis and low survival rates. SCLC is a cancer that correlates strongly with tobacco exposure [4], and to a lesser extent, radon exposure [5]. Patients with SCLC most commonly present with symptoms originating from the respiratory system such as cough, dyspnoea and haemoptysis, which may or may not be accompanied by systemic symptoms (e.g. ...

Occupation as a risk factor of small cell lung cancer

... To determine one label or another (readmission vs. no readmission) it is necessary to determine a threshold value to interpret the Risk of Readmission at 90 days (the output of the expert system). In this case, the use of a graphical optimization process on the test set based on the Matthews correlation coefficient (Mcc) [65][66][67] is chosen, similar to that used by Casal-Guisande et al. in other works [30,31,34,64]. This is a coefficient that behaves especially well in situations where there is imbalance in the data. ...

Design and Conceptual Proposal of an Intelligent Clinical Decision Support System for the Diagnosis of Suspicious Obstructive Sleep Apnea Patients from Health Profile

... 6 Núñez-Fernández and colleagues found that the average oxygen saturation at hospital admission was 92% (89-97%). The average length of stay for all analyzed patients was 7 (4-13.2) days; 26 patients (13.4%) required invasive mechanical ventilation [22]. COVID-19 ...

Evolution and long‑term respiratory sequelae after severe COVID-19 pneumonia: nitric oxide diffusion measurement value

Respiratory Research