Pushing the limits for interventional treatment of aortic valve stenosis.

As we approach 20 years of clinical experience with transcatheter aortic valve replacement (TAVR), a vast portfolio of high-quality clinical data has accumulated, confirming the safety and efficacy of TAVR across the entire spectrum of surgical risk. Although many aspects of this innovative therapy have been thoroughly studied, several challenges remain. As TAVR is expanding to include younger low-risk patients, with longer life expectancy, one major unsolved issue is represented by transcatheter heart valve (THV) durability, since robust THV durability data are currently limited to approximately 5-6 years. Additionally, steric interactions between THV components and coronary ostia may render coronary access particularly difficult, and thus personalized decisions regarding THV type and implanting techniques are of paramount importance to secure future coronary access. Since bicuspid aortic valve (BAV) stenosis may be associated with unfavorable anatomic factors, it has represented an exclusion criterion in major randomized TAVR trials. Albeit promising data are available from multicenter registries, results of specifically designed randomized trials are eagerly needed to inform use of TAVR for BAV stenosis. Although valve-in-valve (ViV) TAVR has emerged as an effective treatment option for degenerated aortic bioprostheses, ViV procedures are associated with specific risks, which mandated the development of specific techniques aimed at reducing the occurrence of periprocedural adverse events. Despite the transfemoral approach represents the access of choice for TAVR, a significant proportion of patients have significant peripheral artery disease and alternative vascular access routes have been increasingly evaluated with encouraging data regarding their safety and feasibility.