{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,4]],"date-time":"2026-06-04T19:45:21Z","timestamp":1780602321998,"version":"3.54.1"},"reference-count":57,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T00:00:00Z","timestamp":1774915200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Union\u2019s Horizon 2020 research and innovation programme","award":["965343"],"award-info":[{"award-number":["965343"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Computers"],"abstract":"<jats:p>Heart failure management increasingly relies on heterogeneous clinical and real-world data generated through remote monitoring technologies. However, transforming these multimodal data streams into actionable insights requires robust interoperability infrastructures. This study presents the RETENTION interoperability framework, a federated HL7 Fast Healthcare Interoperability Resources (FHIR)-based architecture designed to support multi-site heart failure monitoring across five independent clinical environments. A semantic reference model comprising 444 clinical and contextual variables was developed and aligned with FHIR R4 resources and internationally recognised terminology systems. The platform adopts a selective profiling strategy, extending only the Patient resource while standardising the remaining variables through example-driven Implementation Guide documentation. Identifiable data are retained locally within Clinical Site Backends, whereas anonymised datasets are periodically aggregated into a Global Insights Cloud to enable centralised analytics and controlled third-party interactions. The framework was deployed across six hospitals (with two Spanish hospitals sharing the same deployment), supporting 390 patients and over 130,000 patient-days of monitoring, with more than 3.6 million remote device data points harmonised without schema conflicts. The results demonstrate that large-scale semantic harmonisation and privacy-preserving aggregation can be achieved using a lightweight profiling approach, providing a scalable and reproducible interoperability model for multi-centre digital health research infrastructures.<\/jats:p>","DOI":"10.3390\/computers15040212","type":"journal-article","created":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T13:23:17Z","timestamp":1774963397000},"page":"212","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["A Federated FHIR-Based Interoperability Framework for Multi-Site Heart Failure Monitoring: The RETENTION Project"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-5486-6508","authenticated-orcid":false,"given":"Nikolaos","family":"Vasileiou","sequence":"first","affiliation":[{"name":"Biomedical Engineering Laboratory, Institute of Communication and Computer Systems of the National Technical University of Athens, 15773 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4473-2070","authenticated-orcid":false,"given":"Olympia","family":"Giannakopoulou","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Laboratory, Institute of Communication and Computer Systems of the National Technical University of Athens, 15773 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2071-1144","authenticated-orcid":false,"given":"Ourania","family":"Manta","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Laboratory, Institute of Communication and Computer Systems of the National Technical University of Athens, 15773 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6176-2282","authenticated-orcid":false,"given":"Konstantinos","family":"Bromis","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Laboratory, Institute of Communication and Computer Systems of the National Technical University of Athens, 15773 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Theodoros P.","family":"Vagenas","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Laboratory, Institute of Communication and Computer Systems of the National Technical University of Athens, 15773 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ioannis","family":"Kouris","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Laboratory, Institute of Communication and Computer Systems of the National Technical University of Athens, 15773 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maria","family":"Roumpi","sequence":"additional","affiliation":[{"name":"Biomedical Research Institute, Foundation for Research and Technology-Hellas (FORTH), University of Ioannina, 45110 Ioannina, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lefteris","family":"Koumakis","sequence":"additional","affiliation":[{"name":"Department of Electrical and Computer Engineering, Hellenic Mediterranean University, 71004 Heraklion, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6227-0810","authenticated-orcid":false,"given":"Yorgos","family":"Goletsis","sequence":"additional","affiliation":[{"name":"Laboratory of Business Economics and Decisions (LABED@UoI), Department of Economics, University of Ioannina, 45110 Ioannina, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1136-8209","authenticated-orcid":false,"given":"Maria","family":"Haritou","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Laboratory, Institute of Communication and Computer Systems of the National Technical University of Athens, 15773 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2600-9914","authenticated-orcid":false,"given":"George K.","family":"Matsopoulos","sequence":"additional","affiliation":[{"name":"Biomedical Engineering Laboratory, Institute of Communication and Computer Systems of the National Technical University of Athens, 15773 Athens, Greece"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7362-5082","authenticated-orcid":false,"given":"Dimitris","family":"Fotiadis","sequence":"additional","affiliation":[{"name":"Biomedical Research 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