Abstract Body (Do not enter title and authors here): Background: Patients with a small aortic annulus are at risk for worse hemodynamic performance after transcatheter aortic valve replacement (TAVR). There is a debate on whether they have worse clinical outcomes compared to patients with a non-small annulus.

Hypothesis: Patients with a small annulus have worse hemodynamic and clinical outcomes post-TAVR than those with a non-small annulus.

Aims: To explore the hemodynamic and clinical outcomes following TAVR in patients with a small annulus compared to those with a non-small annulus.

Methods: This is a retrospective cohort of patients >18 years of age who underwent TAVR at Cleveland Clinic between 2016 and 2020. Patients were classified into 2 groups according to the annular size assessed by contrast-enhanced computed tomography or cardiac magnetic resonance: small (area ≤430 mm²), and non-small annulus (>430 mm²). Patients who underwent TAVR with a self-expanding valve and those with annular sizing using transesophageal echocardiography were excluded. Clinical outcomes included overall mortality, and heart failure rehospitalization at 3 years using Cox regression, in addition to ischemic stroke, and permanent pacemaker (PPM) implantation. Echocardiographic outcomes included moderate to severe paravalvular leak (PVL), aortic valve (AV) mean gradient, and dimensionless valve index (DVI), with up to 3 years of follow-up.

Results: A total of 2630 patients underwent TAVR between 2016 and 2020. The study included 2122 patients, of which, 782 (37%) had a small annulus. Patients with a small annulus had significantly higher AV mean gradients and lower DVI at all follow-up intervals. However, there was no difference in clinical outcomes between the 2 groups. The hazard ratio [HR] for mortality was 0.89 (p-value= 0.328), and for heart failure rehospitalization was 1.06 (p-value= 0.712) (reference is non-small annulus). The incidence of moderate to severe PVL was not significantly different between the 2 groups at any of the follow-up intervals (Figure 1).

Conclusions: Patients with a small annulus had higher AV mean gradients post-TAVR than those with a non-small annulus. However, there was no significant difference in clinical outcomes or PVL between the 2 populations.