Doppler echocardiographic estimation of the pressure gradient in aortic stenosis. An updated assessment of the technique used in clinical practice in 249 patients.
This study included 249 consecutive patients with suspected significant aortic valve stenosis. Using contemporary ultrasound equipment we reassessed the value of out-patient Doppler-derived maximum pressure gradients for the prediction of peak-to-peak pressure gradients measured later at heart catheterization. It was possible to record the pressure gradient in 97% of the patients by Doppler examination and in 86% at heart catheterization. There was a fair, statistically significant correlation between Doppler and invasive gradients (n = 201, r = 0.80, p < 0.05, SEE = 21 mm Hg), independent of coexistent aortic regurgitation, atrial fibrillation, left ventricular function, number of days between the examinations and other variables analysed. A Doppler gradient > 80 mm Hg was 98% (90-100%) predictive of critical aortic stenosis (gradient > 50 mm Hg as determined by heart catheterization). Similarly, a Doppler gradient of < or = 30 mm Hg was 98% (87-100%) predictive of non-critical stenosis. In the remaining patients (53% of the population) the Doppler gradient did not contribute decisively to clinical management.