Nomograms for severity of aortic valve stenosis using peak aortic valve pressure gradient and left ventricular ejection fraction

Continuity equation to evaluate aortic valve area (AVA _CE ) is critically dependent on accurate measurement of left ventricular outflow tract diameter and velocity. To circumvent these limitations, the present study aimed to generate nomograms for a facilitated estimation of aortic valve area using peak aortic valve pressure gradient (ΔpAv) and left ventricular ejection fraction (LVEF).

Two hundred and fifty-five subjects with non-invasively and invasively defined aortic valve stenosis (AS) formed the basis of this study. Basis of the nomograms was the correlation analysis between ΔpAv and AVA as estimated by AVA _CE within different LVEF groups. LVEF differed from 65.6 ± 1.8% (Group I, LVEF > 60%) to 34.5 ± 4.3% (Group IV, LVEF ≥ 30%). ΔpAv and AVA varied from 85.6 ± 19.5 mmHg and 0.69 ± 0.16 cm ² in Group I to 58.5 ± 15.9 mmHg and 0.73 ± 0.23 cm ² in Group IV (ΔpAv: P < 0.001). Mean AVA _CE showed no significant difference between the groups. Correlation between ΔpAv and AVA _CE was statistically significant with P < 0.001 in all subgroups ( R² between 0.72 and 0.76). Furthermore, a prospective estimation of AVA using the developed nomograms correlated very well with invasively determined AS using the Gorlin formula ( R² = 0.76, SEE = 0.21 cm ² , bias 0.04 cm ² ).

The present study has established and confirmed a solid, easy to use nomogram-based method to accurately quantify severe AS.