163: Relationship between cut-off values of peak aortic valve velocity and those of other Doppler echocardiographic parameters of severity in patients with aortic stenosis and normal flow

BackgroundPrevious studies have reported inconsistencies between echocardiographic parameters of severity in aortic valve stenosis (AS). Peak aortic valve velocity (Vmax) strongly predicts outcome in AS patients. The present study was therefore designed to identify the cut-off values of echocardiographic parameters of severity in normal flow (NF) AS corresponding to a Vmax ≥3m/s, ≥4m/s, 5m/s or 5.50m/s. This study was therefore designed to identify the cut-off values of echocardiographic parameters of severity that correspond to Vmax≥3, 4, 5 and 5.5m/s.Methods and resultsWe retrospectively reviewed the echocardiograms of 528 consecutive patients with AS, left ventricular (LV) ejection fraction> 0.50 and NF (stroke volume index>35mL/m2. The accuracy of mean pressure gradient (MPG), aortic valve area (AVA), and indexed AVA for BSA (IAVA) to predict Vmax≥3, 4, 5 and 5.5m/s ranged from 0.89 to 0.99, and the best predictor was MPG for various levels of Vmax. The best values of MPG, AVA, and IAVA to predict Vmax≥3 m/s were 22mmHg, 1.15cm2, 0.60cm2/m2, respectively. While a cut-off of Vmax≥4m/s to define severe AS was consistent with a value of 39 mmHg for MPG, corresponding values for AVA and IAVA of 0.90cm2 and 0.48cm2/m2 respectively were substantially different from those recommended in current guidelines. MPG≥60 and 65mmHg, AVA≤0.76 and ≤0.68cm2, and IAVA≤0.41 and ≤0.35cm2/m2 were identified as predictors of Vmax≥5m/s and ≥5.5m/s (very severe AS), respectively.ConclusionsGuidelines recommended cut-off values for AVA and IAVA are not consistent with those of Vmax and MPG. The results of the present study may serve as safeguards in case of apparent inconsistencies between echocardiographic parameters of severity in NF AS