Clinical features and prognosis of patients with isolated severe aortic stenosis and valve area less than 1.0 cm.

Objective: Current guidelines define severe aortic stenosis (AS) as an aortic valve area (AVA)≤1.0 cm, but some authors have suggested that the AVA cut-off be decreased to 0.8 cm. The aim of this study was, therefore, to better describe the clinical features and prognosis of patients with an AVA of 0.8-0.99 cm.

Methods: Patients with isolated, severe AS and ejection fraction ≥55% with an AVA of 0.8-0.99 cm (n=105) were compared with those with an AVA<0.8 cm (n=155) and 1.0-1.3 cm (n=81). The endpoint of this study was a combination of death from any cause or aortic valve replacement at or before 3 years.

Results: Patients with an AVA of 0.8-0.99 cm group comprised predominantly normal-flow, low-gradient (NFLG) AS, while high gradients and low flow were more often observed with an AVA<0.8 cm. The frequency of symptoms was not significantly different between an AVA of 0.8-0.99 cm and 1.0-1.3 cm. The combined endpoint was achieved in 71%, 52% and 21% of patients with an AVA of 0.8 cm, 0.8-0.99 cmand 1.0-1.3 cm, respectively (p<0.001). Among patients with an AVA of 0.8-0.99 cm, NFLG AS was associated with a lower hazard (HR=0.40, 95% CI 0.23 to 0.68, p=0.001) of achieving the combined endpoint with outcomes similar to moderate AS in the first 1.5 years of follow-up. Patients with high-gradient or low-flow AS with an AVA of 0.8-0.99 cm had outcomes similar to those with an AVA<0.8 cm. The sensitivity for the combined endpoint was 61% for an AVA cut-off of 0.8 cm and 91% for a cut-off of 1.0 cm.

Conclusions: The outcomes of patients with AS with an AVA of 0.8-0.99 cm are variable and are more precisely defined by flow-gradient status. Our findings support the current AVA cut-off of 1.0 cm.