Clinical Research Directory

Federated Learning for Point-of-Care Cardiac Ultrasound

This prospective, multicenter study will evaluate a federated machine-learning system designed to analyze focused cardiac point-of-care ultrasound examinations. Federated learning allows participating clinical sites to contribute to model development while keeping raw ultrasound images and directly identifiable patient information within each site's controlled computing environment. Encrypted model updates, rather than patient images, will be transmitted for secure aggregation. The prospective validation cohort will include approximately 3,000 adults undergoing clinically indicated focused cardiac ultrasound. Model performance will be compared with an expert interpretation of a comprehensive transthoracic echocardiogram performed within 24 hours. The primary objective is to determine how accurately the model identifies reduced left ventricular systolic function, defined as a left ventricular ejection fraction below 40%. During the initial validation period, the investigational software will operate in silent mode. Its results will not be displayed to treating clinicians and will not be used to diagnose participants, select treatment, or replace standard clinical interpretation. The study will also evaluate image-quality classification, cardiac-view recognition, performance across clinical sites and ultrasound systems, model calibration, processing time, cybersecurity, privacy resilience, and performance across demographic and clinical subgroups. Long-term monitoring will assess whether model performance changes as clinical populations, ultrasound equipment, acquisition practices, and software environments evolve during the 2026-2037 study period.

Resistance Exercise With Blood Flow Restriction by Vascular Occlusion on Myocardial Function in Heart Failure With Reduced Ejection Fraction

Exercise is essential in cardiac rehabilitation for heart failure patients.Aerobic training and resistance training are both recommended. Resistance training improves muscle mass and strength and also improves the remodeling of cardiac function, thus reducing exercise intolerance in these patients. However, to obtain these adaptations, resistance training must be done at moderate to high intensities, which cannot always be sustained by the most fragile and deconditioned patients, such as those with reduced ejection fraction (Heart failure with reduced Ejection Fraction). Blood flow restriction (BFR) by vascular occlusion training is an interesting alternative to conventional resistance training for these deconditioned patients. Preclinical and clinical studies have shown that, for low-intensity regimens, resistance training and blood flow restriction by vascular occlusion improves muscle strength and left ventricular function, unlike resistance training alone. Tissue hypoxemia, initiated by vascular occlusion and exacerbated by maintenance of exercise, is a key element in the peripheral adaptations documented in blood flow restriction, triggering a cascade of signaling pathways involving neurohumoral factors in particular, with effects both locally (i.e. striated skeletal muscle) and remotely, on the myocardium among others. The feasibility and safety of blood flow restriction in heart failure patients has been well demonstrated. Left ventricle ejection fraction remains a very global functional index, with poor reproducibility influenced by cardiac load conditions, making it impossible to draw any conclusions as to possible improvements in myocardial function, linked to changes in intrinsic tissue decontractility/relaxation properties. New cardiac imaging techniques like Speckle Tracking Echography have made it possible to assess the effects of blood flow resistance on myocardial function but so far no studies have used these tools to compare the effects of BFR+resistance training and resistance training alone on myocardial function in heart failure patients. It is suggested that resistance training combined with blood flow resistance could further improve cardiac and muscular function compared with resistance training alone, by activating neurohumoral mediators, like certain micro ribonucleic acids.