Abstract Body (Do not enter title and authors here): Background: Patients with low-flow low-gradient (LFLG) aortic stenosis (AS) are at risk of worse outcomes following transcatheter aortic valve replacement (TAVR). Flow is known to improve after TAVR, however the clinical and echocardiographic characteristics correlating with flow improvement in patients with LFLG AS are still unclear.

Hypothesis: Some baseline and discharge clinical and echocardiographic characteristics correlate with flow improvement in patients with LFLG AS post-TAVR.

Aims: The present study sought to explore the clinical and echocardiographic characteristics correlating with flow improvement in patients with LFLG AS post-TAVR.

Methods: This is a retrospective cohort of patients >18 years of age who underwent TAVR at Cleveland Clinic between 2016 and 2020. Only patients with aortic valve (AV) area <1 cm², AV mean gradient <40 mmHg, and stroke volume index (SVI) <35 mL/m² were included. Patients were classified into 2 groups according to whether SVI improved by 20% or more at the 30-day follow-up. Patients who underwent valve-in-valve TAVR were excluded. Binary logistic regression was used to evaluate the predictors of flow improvement.

Results: A total of 2630 patients underwent TAVR between 2016 and 2020. The study included 633 patients. 228 patients (36%) had SVI improvement by 20% or more. Male sex (odds ratio (OR)=1.89, p=0.01), left ventricular ejection fraction (LVEF) improvement by 10% or more 1 month post-TAVR (OR=6.93, p<0.001), and lower baseline SVI (OR=0.81, p<0.001), were statistically significant predictors of flow improvement, whereas moderate to severe tricuspid regurgitation (TR) at discharge was a statistically significant predictor of no improvement in flow.

Conclusions: The present study demonstrates that male sex, LVEF improvement post-TAVR, and lower baseline SVI are associated with flow improvement, whereas moderate to severe TR at discharge is associated with no flow improvement post-TAVR in patients with LFLG AS.