Patients with low-flow, low-gradient (LFLG) aortic stenosis (AS) have precarious hemodynamics and are a fragile population for intervention. Quantification of aortic valve calcification (AVC) severity is a critical component of the evaluation for transcatheter aortic valve replacement (TAVR); this study aims to further clarify its utility for risk stratification in LFLG AS.

This retrospective study evaluated 467 patients with LFLG AS undergoing TAVR at a large quaternary-care hospital from January 2019 to December 2021. AVC was quantified with Agatston scores using pre-operative computed tomography angiograms. Primary endpoint was a composite of all-cause mortality and heart failure rehospitalization rates.

51 patients (10.9 %) had mild calcification, 137 (29.3 %) had moderate, and 279 (59.7 %) had severe. Increased AVC severity correlated with increased AS severity by aortic valve area (0.69cm² for mild AVC vs. 0.63cm² for severe; p ≤0.001), peak velocity (3.1 m/s vs. 3.9 m/s; p ≤0.001), and mean gradient (21 mmHg vs. 36 mmHg; p ≤0.001). Kaplan-Meier analysis showed increased reductions in the primary composite endpoint (p = 0.023) and heart failure rehospitalization rates (p = 0.005) for patients with greater AVC severity undergoing TAVR. Multivariate adjustments confirmed a significant reduction in heart failure rehospitalizations when comparing TAVR outcomes between mild and severe AVC (HR 0.40, 95 % CI 0.18–0.91; p = 0.028). Between the 3 groups, there were no significant differences in adjusted rates of paravalvular leak or other periprocedural complications.