Early safety and mid-term clinical outcomes of technology transfer of transcatheter aortic valve implantation in patients with severe aortic valve stenosis in Vietnam: a single-center experience of 90 patients.

Background: This study investigated the early safety and mid-term outcomes of stepwise implementation of transcatheter aortic valve implantation (TAVI) in Vietnamese patients with severe aortic stenosis (AS) at a single center, following the process of technical transfer. Methods: From 2017 to 2022, 90 patients with symptomatic severe AS underwent TAVI at a tertiary hospital in Vietnam. The first 30 cases received support for technology transfer from international proctors. One-year outcomes were evaluated using the Valve Academic Research Consortium-2 (VARC-2) criteria. Findings: Forty patients (45.5%) had bicuspid aortic valve (BAV). The Medtronic Evolut R/Pro self-expanding valve system was used in 98.9% of all cases, with a 29-mm valve being the most common. Device success was achieved in 95.6% of cases, whereas one procedural death occurred. At one year, four deaths (5.3%) occurred and all were in the BAV group. Other complications included stroke (2.8%), hospital readmission due to the valve or worsening heart failure (2.8%), permanent pacemaker implantation (9.9%), and moderate paravalvular leak (3.0%). The left ventricular ejection fraction and mean transvalvular gradient significantly improved after TAVI. There were no significant differences in procedural success and mortality when the proctor support period and the subsequent solo operator period were compared. Interpretation: TAVI procedure is safe for treating severe AS in Vietnamese patients, despite the high prevalence of BAV. The procedural complication rate was low, with promising outcomes at one year. These results also highlight the effectiveness of the TAVI technical transfer model in Vietnam. Funding: No funding was provided for this study.