From Last Resort to Standard of Care: The Evolution and Future of Transcatheter Aortic Valve Implantation.

Transcatheter aortic valve implantation (TAVI) has evolved from an experimental, last-resort procedure in 2002 to a first-line therapy for aortic stenosis; moreover, the 2025 ESC/EACTS (European Society of Cardiology/European Association for Cardiothoracic Surgeons) guidelines marked a paradigm shift beyond traditional risk stratification toward earlier intervention and broader patient selection. Current evidence demonstrates the non-inferiority or superiority of TAVI to surgical aortic valve replacement across all risk categories, with the guidelines now recommending TAVI for patients aged ≥70 years and formally endorsing early intervention in asymptomatic severe stenosis when procedural risk is low. Meanwhile, critical challenges persist despite large-scale systematic reviews demonstrating significant mortality reduction following TAVI, including paravalvular leak rates of 10-25% compared to near-zero rates with surgery, and subclinical leaflet thrombosis affecting up to 30% of patients with unclear optimal management strategies. Moreover, the expansion toward younger populations exposes critical knowledge gaps, including unknown long-term durability beyond 10 years, structural valve degeneration rates of 4.8-13.3% at 5-7 years, and complex reintervention scenarios with reported mortality rates of 17.1% for surgical TAVI explantation. Thus, this review synthesizes contemporary evidence within the framework of the 2025 guidelines while examining unique aspects, including the pathophysiology of subclinical leaflet thrombosis, polymeric heart valve technologies as next-generation solutions, and the critical durability questions that will determine the role of TAVI in younger patients. Next-generation polymeric valves utilizing materials such as polyhedral oligomeric silsesquioxanes-polycarbonate urethane (POSS-PCU), poly(styrene-b-isobutylene-b-styrene) (SIBS), and siloxane polyurethane-urea have shown promising preclinical results in terms of enhanced durability and reduced thrombogenicity, although comprehensive clinical validation remains necessary. As TAVI practice evolves under new guideline recommendations emphasizing early intervention and simplified antithrombotic management, this thorough analysis can provide essential context for understanding both current capabilities and future directions in transcatheter valve therapy.