At what flow rate does the aortic valve gradient become severely elevated? Implications for guideline recommendations on aortic valve area cutoffs

Abstract

Introduction Aortic stenosis (AS) is considered severe when the aortic valve area (AVA) is 40 mm Hg, we sought to determine the AVA at which mAVG tends to exceed 40 mm Hg in a sample of subjects with varied transvalvular flow rates. Material and methods Our echocardiography database was queried for subjects with native valve AS. We selected 200 subjects with an AVA 40 mm Hg at a wide range of MSF. In contrast, those with severe AVA typically (75%) had mAVG > 40 mm Hg when MSF was normal (> 200 ml/s). Those with critical AVA frequently (44%) had mAVG > 40 mm Hg, even when MSF was reduced. Conclusions Subjects with AVA of 0.8 and 0.9 cm 2 rarely had mAVG > 40 mm Hg, even when the transvalvular flow rate was normal. Using current guidelines, it is not clear if such cases should be classified as severe.

Keywords

• low-flow
• low-gradient aortic stenosis
• mean systolic flow
• ejection time