[The development of a Hub & Spoke network for transcatheter aortic valve replacement procedures: the operational model of the Interventional Cardiology Unit at the IRCCS San Raffaele Hospital (OSR Hub-Spoke)].

Recently, an increase in the number of patients with severe aortic stenosis eligible for transcatheter aortic valve implantation (TAVI) has been observed worldwide. In order to reduce waiting lists, provide to all patients referred to us equal access to care and to further improve the collaboration with spoke centers, we developed a specific Hub & Spoke specific protocol for TAVI. According to our protocol, a clinical selection (with echo and computed tomography scan) is done by Spoke centers, the case is discussed with a multidisciplinary team online and the procedure is planned (access, valve type size). At day 0, the patient is admitted in Spoke centers where blood samples are taken; at day 1, the patient is transferred to a Hub center for the TAVI procedure and after 2 h of observation, if no adverse events are registered, the patient is transferred back to the Spoke center. Since 2019, an agreement among our center and two hospitals has been signed. According to this Hub & Spoke model, a total of 72 patients with aortic stenosis were treated with TAVI (mean age 83 years, 48.6% female, median Society of Thoracic Surgeons risk 2.4 ± 1.1%, left ventricular ejection fraction 58.0 ± 7.75%). More frequently CoreValve Evolut R (47.2%) was used. Only 2 patients had a prolonged admission at Hub and were not transferred at day 1 (1 vascular complication and 1 intra-procedural resuscitated cardiac arrest). This Hub & Spoke model guaranteed shortening of waiting lists, more effective turnover of bed, equal access to care to patients referred to our center. In addition, it helped also to increase Awareness and education as well as appropriate training of the teams from spoke facilities.