Across 313 cardiology Phase II–III trials authorized in 2024–2026, the most active named site network was Assistance Publique–Hôpitaux de Paris, with 29 trial-site listings. Activity was concentrated in large academic hospital networks: the top 10 recurrent site networks accounted for 120 listings, with France alone representing 61 of those 120 listings.
The top 10 recurrent site networks generated 120 site listings. Assistance Publique–Hôpitaux de Paris led with 29 of 120 top-10 listings (24.2%), followed by CHU Toulouse with 14 (11.7%), Charité Berlin with 12 (10.0%), Hospital Universitario La Paz with 11 (9.2%), and Všeobecná Fakultní Nemocnice v Praze with 10 (8.3%).
The leading sites are mostly large academic hospital systems rather than single-specialty practices. This suggests that repeat cardiology trial activity is concentrated where multiple cardiovascular subspecialties, imaging, emergency care, intensive care, and trial operations can be coordinated inside the same institution or network.
Phase III represented 207 of 313 included cardiology trials (66.1%), while Phase II represented 106 of 313 trials (33.9%). The Phase III share was stable across the period: 66.7% in 2024, 64.4% in 2025, and 68.0% in 2026.
The site-ranking signal is primarily a late-stage execution signal. Phase III trials usually require broader multicenter footprints, which increases recurrence for hospital networks already capable of managing large cardiovascular programs.
Among the top 10 recurrent site networks, France contributed 61 of 120 site listings (50.8%). Germany and Spain each contributed 20 of 120 listings (16.7% each), while Czechia contributed 10 (8.3%) and Belgium contributed 9 (7.5%).
France is the clearest country-level signal in the top-site ranking, driven by AP-HP and multiple CHU networks. Germany and Spain also show repeated activity, but it is distributed across fewer top-listed networks.
Eight of the top 10 recurrent site networks were large public university hospitals, CHU systems, or academic hospital networks. This represents 80.0% of the top-10 institutions and indicates that repeat cardiology trial participation is structurally concentrated in broad tertiary-care systems.
This pattern fits the operational reality of cardiology development: recurrent sites need access to multiple disease streams, imaging, interventional services, emergency care, intensive care, and specialized investigators. The ranking therefore reflects institutional breadth as much as single-department cardiology volume.
Site recurrence means the number of times a named site or site network appears in trial geography records. It is not the same as enrolled patients. Phase II refers to mid-stage clinical evaluation; Phase III refers to larger confirmatory clinical trials.