BACKGROUND: Substantial controversy exists regarding the clinical benefit of patients with severe paradoxical low-flow, low-gradient aortic stenosis (PLF-LG AS) from TAVI. Therefore, we compared post-TAVI benefit by long-term mortality (all-cause, CV and SCD), clinical improvement of heart failure symptoms, and cardiac reverse remodelling in guideline-defined AS subtypes. METHODS: We prospectively included 250 consecutive TAVI patients. TTE, 6mwt, MLHFQ, NYHA status and NT-proBNP were recorded at baseline and 6 months. Long-term mortality and causes of death were assessed. RESULTS: 107 individuals suffered from normal EF, high gradient AS (NEF-HG AS), 36 from low EF, high gradient AS (LEF-HG), 52 from "classic" low-flow, low-gradient AS (LEF-LG AS), and 38 from paradoxical low-flow, low-gradient AS (PLF-LG AS). TAVI lead to a significant decrease in MLHFQ score and NT-proBNP levels in all subtypes except for PLF-LG. Regarding reverse remodelling, a significant increase in EF and decrease in LVEDV was present only in subtypes with reduced baseline EF, whereas a significant decrease in LVMI and LAVI could be observed in all subtypes except for PLF-LG. During a follow-up of 3-5 years, PLF-LG patients exhibited the poorest survival among all subtypes (HR 4.2, P = 0.0002 for CV mortality; HR 7.3, P = 0.004 for SCD, in comparison with NEF-HG). Importantly, PLF-LG was independently predictive for CV mortality (HR 2.9 [1.3-6.9], P = 0.009). CONCLUSIONS: PLF-LG patients exhibit the highest mortality (particularly CV and SCD), the poorest symptomatic benefit and the least reverse cardiac remodelling after TAVI among all subtypes. Thus, this cohort seems to gain the least benefit.