Comparative Outcomes of Transcatheter Aortic Valve Replacement and Conservative Management in Patients with Low-Flow, Low-Gradient Aortic Stenosis.

Transcatheter aortic valve replacement (TAVR) is a standard treatment for severe aortic stenosis (AS), but outcomes vary based on flow state. Low-flow, low-gradient aortic stenosis (LFLG AS) is a heterogenous condition and growing evidence suggests that response to TAVR differs by subtype. However, the generalizability of these studies to U.S. populations remains uncertain. This single-center, US-based retrospective study compared mortality outcomes from TAVR versus conservative management strategies in patients with classical (cLFLG) and paradoxical (pLFLG) LFLG AS. Adults with severe LFLG AS (valve area ≤1.0 cm2, stroke volume index ≤35 mL/m2, and mean pressure gradient <40 mmHg) evaluated for TAVR between 2019 and 2021 were included. Patients were stratified by subtype (cLFLG: left ventricular ejection fraction [LVEF] <50%; pLFLG: LVEF ≥50%) and treatment strategy (TAVR or conservative management). Of 490 patients included (207 cLFLG, 283 pLFLG), 67% underwent TAVR. Median follow-up was 19 months. TAVR was associated with lower mortality than conservative management (adjusted hazard ratio [HR] 0.47; 95% CI 0.33 to 0.69; p <0.001). In cLFLG AS, TAVR significantly reduced mortality (adjusted HR 0.37; 95% CI 0.23 to 0.60; p <0.001). In pLFLG AS, a nonsignificant trend towards benefit was observed (adjusted HR 0.62; 95% CI 0.33 to 1.15; p = 0.127). Among patients managed conservatively, those with pLFLG AS had lower mortality than cLFLG AS (adjusted HR 0.50; 95% CI 0.25 to 0.99; p = 0.046). In conclusion, TAVR is associated with improved survival in LFLG AS, particularly in patients with cLFLG AS. Comparable outcomes in conservatively managed pLFLG AS patients support a more individualized, phenotype-driven treatment approach.