Severe symptomatic aortic stenosis is a common and clinically relevant condition in elderly and high-risk patients. Transcatheter aortic valve implantation (TAVI) is an established treatment option for patients with an appropriate indication after multidisciplinary Heart Team evaluation. As the number of patients eligible for TAVI continues to increase, access to timely treatment may be limited by the availability and capacity of hospitals with on-site cardiac surgery. Historically, TAVI has generally been performed in centers with on-site cardiac surgery because of the potential need for emergency surgical management of rare but severe procedural complications. However, advances in patient selection, pre-procedural imaging, device technology, procedural planning, and operator experience have reduced the frequency of complications requiring emergent cardiac surgery. These developments have raised the question of whether selected patients can safely undergo TAVI in appropriately organized centers without on-site cardiac surgery, provided that strict procedural safeguards are in place. The TRACS study was previously conducted as a pilot randomized clinical project to evaluate this strategy. That study supported the feasibility and safety of performing TAVI in selected centers without on-site cardiac surgery under a structured protocol, experienced operators, multidisciplinary patient selection, and predefined safety procedures. TRACS-PRIME is designed to extend this experience in a larger and more generalizable randomized trial. TRACS-PRIME is a prospective, randomized, multicenter, open-label trial with blinded adjudication of clinical outcomes. Patients with severe aortic stenosis and an indication for TAVI confirmed by a multidisciplinary Heart Team will be considered for enrollment. Before randomization, patients will undergo standard clinical, echocardiographic, laboratory, coronary, and computed tomography evaluation to confirm eligibility, assess procedural feasibility, and identify factors that may increase procedural risk. Eligible patients who provide written informed consent will be randomized to one of two treatment strategies. In the experimental strategy, TAVI will be performed in a participating center without on-site cardiac surgery. These centers must have experienced TAVI operators, advanced cardiac imaging, established collaboration with a referral cardiac surgery department, and predefined procedures for rapid transfer in case of complications. In the control strategy, TAVI will be performed in a center with on-site cardiac surgery. In both groups, the procedure will be performed according to current guidelines, local standards of care, and the judgment of experienced TAVI operators. The study is intended to evaluate whether TAVI performed in centers without on-site cardiac surgery is not inferior to TAVI performed in centers with on-site cardiac surgery in terms of clinical efficacy and safety at 1 year. Clinical events will be collected prospectively and adjudicated by an independent Clinical Events Committee blinded to treatment allocation. Patient safety and trial conduct will be monitored by an independent Data Safety Monitoring Board. After hospital discharge, participants will undergo structured clinical follow-up to assess clinical status, adverse events, hospitalizations, and other relevant outcomes. The overall aim of TRACS-PRIME is to determine whether a carefully controlled strategy of TAVI in selected centers without on-site cardiac surgery can preserve patient safety while potentially improving access to timely treatment for patients with severe aortic stenosis.
