Abstract Body (Do not enter title and authors here): Background: Left ventricular (LV) global longitudinal strain (GLS) has been reported to decline before LV ejection fraction (EF) in patients with aortic stenosis (AS). The decrease in LVEF has been reported to result in poor prognosis after transcatheter aortic valve implantation (TAVI). However, the relationship between the degree of LV dysfunction caused by AS and the post-procedural outcomes has not been fully elucidated. Research questions: Is there a difference in the clinical outcome after TAVI according to the degree of LV dysfunction? Aim: The purpose of this study is to determine the relationship between the degree of LV dysfunction and outcomes after TAVI. Methods: This was a single-center, retrospective cohort study, in which 150 of 347 consecutive patients undergoing TAVI were included, excluding atrial fibrillation, inadequate echo image for analysis, and loss to follow-up echocardiography. The degree of LV dysfunction was classified into Grade I (EF ≥50%, GLS ≤-15%), Grade II (EF ≥ 50%, GLS > -15%), and Grade III (EF < 50%), and baseline echocardiographic parameters and changes from baseline to intermediate follow-up (6 months to 1 year) were compared between groups. Results: Baseline characteristics showed significant differences in the incidence of symptomatic heart failure. Baseline echocardiographic parameters were significantly impaired according to grade progression (Table). Although patients with Grade III showed improvement in cardiac function, significant differences remained in LV diastolic diameter, LV mass index, LVEF, and LV-GLS compared with those with Grade I. On the other hand, patients with Grade II showed improvement in LV diastolic diameter, LV mass index, and LVEF, resulting in values comparable to Grade I. However, regarding LV-GLS, although patients with Grade II showed improvement as well as Grade III, it did not improve to the same level as Grade I (Figure). Conclusions: The present study suggests that patients with impaired LV-GLS without reduced LVEF have a better improvement in cardiac function after TAVI compared to patients with reduced LVEF. The optimal timing of TAVI may be in the earlier stages of the deterioration of LV-GLS.