Long-term survival after TAVI in low-flow, low-gradient aortic valve stenosis.

Background: In patients undergoing transcatheter aortic valve implantation (TAVI), the presence of a low-flow, low-gradient (LFLG) status has been associated with higher mortality at short-term follow-up.

Aims: We aimed to evaluate long-term survival after TAVI in patients with classical (cLFLG) and paradoxical LFLG (pLFLG) aortic stenosis (AS) compared to high-gradient (HG)-AS.

Methods: Patients undergoing TAVI at our centre with a hypothetical minimum 5-year follow-up were divided into 3 groups: (1) HG-AS (mean gradient [MG] >40 mmHg), (2) cLFLG-AS (MG <40 mmHg, ejection fraction [EF] <50%), and (3) pLFLG-AS (MG <40 mmHg, EF ≥50%). The primary endpoint of the study was all-cause mortality. Propensity score-weighted survival analysis was performed to adjust for possible baseline confounders.

Results: A total of 574 subjects were included (73% HG-AS, 15% pLFLG-AS, 11% cLFLG-AS). The median survival time was 4.8 years, with a maximum of 12.3 years. Patients with cLFLG-AS presented the highest baseline cardiovascular risk. At unadjusted survival analysis, patients with cLFLG-AS showed the worst long-term prognosis, with a rapid decrease in survival within the first year, while pLFLG- and HG-AS patients presented similar survival rates (p=0.023). At weighted long-term analysis, cLFLG- and HG-AS had similar survival rates. Baseline EF was not related to long-term mortality, while patients with a post-TAVI left ventricular ejection fraction (LVEF) improvement >10% lived significantly longer (p=0.02).

Conclusions: Classical LFLG-AS patients had lower long-term survival rates as compared to pLFLG-AS and HG-AS patients. However, after adjustment for possible baseline confounders, a low-flow status per se did not have an impact on long-term mortality after TAVI. Post-TAVI LVEF recovery was associated with improved long-term outcome.