Relationship between Cutoff Values of Peak Aortic Valve Velocity and Those of Other D oppler Echocardiographic Parameters of Severity in Patients with Aortic Stenosis and Normal Flow

Background: Previous studies have reported inconsistencies between echocardiographic parameters of severity in aortic valve stenosis ( AS ). Peak aortic valve velocity ( V max ) strongly predicts outcome in AS patients. This study was therefore designed to identify the cutoff values of echocardiographic parameters of severity corresponding to a V max  ≥ 3 m/sec, ≥4 m/sec, 5 m/sec, or 5.50 m/sec in a large cohort of patients with normal flow (NF) AS . Methods and Results: We retrospectively reviewed the echocardiograms of 528 consecutive patients with normal flow (NF) AS , left ventricular ( LV ) ejection fraction ≥0.50, and NF (stroke volume index > 35 mL/m²). The values of mean pressure gradient ( MPG ), aortic valve area ( AVA ), and indexed aortic valve area ( IAVA ) corresponding to V max  ≥ 3 m/sec obtained from receiver operating characteristic ( ROC ) curves analysis were 22 mmHg, 1.15 cm 2 , and 0.60 cm 2 /m 2 , respectively. While a cutoff of V max  ≥ 4 m/sec to define severe AS was consistent with a value of 39 mmHg for MPG , corresponding values for AVA and IAVA of 0.90 cm² and 0.48 cm²/m², respectively, were substantially different from those recommended in current guidelines. MPG  ≥60 and 65 mmHg, AVA  ≤0.76 and ≤0.68 cm², and IAVA  ≤0.41 and ≤0.35 cm 2 /m 2 were related to a V max  ≥5 and ≥5.5 m/sec (very severe AS ), respectively. Conclusions: Guidelines recommended cutoff values for AVA and IAVA are not consistent with those of V max and MPG . The results of this study may serve as safeguard in case of apparent inconsistencies between echocardiographic parameters of severity in NF AS .