Flow State After Transcatheter Aortic Valve Replacement in Low-Flow Severe Aortic Stenosis: Predictors and Outcomes Across Valve Types.

Low-flow severe aortic stenosis (LFSAS) is a high-risk phenotype associated with increased mortality after transcatheter aortic valve replacement (TAVR). The prognostic value of postprocedural normalization of stroke volume index (SVi), and its variation across valve types, remain uncertain. To evaluate the association between post-TAVR flow state and 1-year clinical outcomes among patients with LFSAS, and to determine whether this association differs between balloon-expandable valves (BEV) and self-expanding valves (SEV). We retrospectively analyzed consecutive patients with LFSAS (SVi ≤ 35 ml/m²) who underwent TAVR at a single quaternary center from 2019 to 2022 The primary endpoint was a composite of all-cause mortality or heart failure hospitalization at 1-year follow-up. Predictors of flow change post-TAVR were also assessed. Of 567 patients included, 54.9% received BEV and 45.1% SEV; 42.2% achieved flow normalization post-TAVR. The primary endpoint occurred in 13.8% of the normalized flow group and 17.4% of the maintained flow group (adjusted HR 0.82, 95% CI 0.51 to 1.30; p = 0.40). There was no statistically significant interaction between valve type (BEV vs SEV) and flow normalization status in the primary endpoint (pint = 0.31). In multivariable analysis, post-TAVR flow normalization was not independently associated with improved 1-year outcome in patients with LFSAS. The findings suggest that underlying myocardial and systemic factors may drive prognosis more strongly than procedural flow changes.