Clinical outcomes up to one year after transcatheter aortic valve implantation (TAVI) in low-risk patients with symptomatic, severe bicuspid aortic stenosis are consistent with those witnessed during early analysis, which supported the safety of TAVI in this patient group.
The findings were presented by Toby Rogers (MedStar Heart & Vascular Institute, Washington, USA) during a late-breaking trial session at the 2021 Cardiovascular Research Technologies meeting (CRT 21 Virtual, 13 February–24 April) on behalf of the LRT (Low-risk TAVI) study team.
The LRT trial is the first US Food and Drug Administration (FDA) approved investigational device exemption (IDE) to study low-risk bicuspid patients with AS undergoing TAVI.
Interim, 30-day findings from the LRT trial were presented at CRT 2020 by Ron Waksman (Georgetown University and MedStar Heart & Vascular Institute, Washington DC, USA).
Presenting the one-year findings last Saturday, Rogers said that the clinical outcomes and TAVI valve haemodynamics “remained excellent” at one-year, and repeated the initial finding that subclinical leaflet thrombosis rate was similar to patients with tricuspid aortic stenosis.
The results also showed that bicuspid patients are younger than patients with tricuspid aortic sentosis.
LRT is a prospective, multicentre registry, with a primary outcome of all-cause mortality at 30 days (VARC-II defined). Secondary outcomes include safety and efficacy (New York Heart Association, NYHA), clinical outcomes (VARC II), valve haemodynamics by echocardiography, and subclinical leaflet thrombosis evaluation by computed tomography (CT) at 30 days. Patients were enrolled between 2016–2020.
The objective of the bicuspid cohort within LRT was to assess the feasibility of TAVI with commercially available valves in low-risk patients with symptomatic severe aortic stenosis, Rogers said.
Researchers enrolled a total of 72 patients, all of whom were confirmed as low-risk for surgery, with an STS Score <3, and who were eligible for transfemoral TAVI. The patient cohort had a mean age of 68.1 ±7.7 years, were majority women (54.2%), and 15 (20.8%) had NYHA classification III or IV. These were we compared to a contemporary cohort of patients undergoing surgical aortic valve replacement (SAVR) from the same institutions, although one-year outcomes were not available for these patients.
Rogers reported that at one-year follow-up, death occurred in one patient out of the 67 for whom complete data was available, while non-disabling stroke was seen in two patients.
The permanent pacemaker rate at one year was 13.6%, which Rogers commented is “almost double that of the tricuspid cohort, which was 7.3%. That is clearly something we have to think about when we are considering TAVI versus surgery in a younger patient.”
Improvements in NYHA class were borne out to one-year as expected, Rogers said, while valve haemodynamics were also consistent with previous TAVI studies.