Comparison of Doppler-derived pressure gradient to that determined at cardiac catheterization in adults with aortic valve stenosis: implications for management

Abstract

Over a 1-year period cardiac catheterization was performed in 58 patients, mean age 66 years, who had elevated aortic blood flow velocity (more than 1.7 m/s) by continuous-wave Doppler echocardiography. Doppler echo signals were initially judged acceptable for quantitative analysis in 95% of patients, usually from the apical transducer position. Cardiac catheterization was performed within a mean of 8 days (60% within 1 day) of the Doppler echo study. The aortic valve mean pressure gradients at catheterization ranged from 0 to 93 mm Hg. The linear correlation coefficient (r value) between the mean pressure gradient determined by Doppler echocardiography and catheterization was 0.87. The correlation was maintained in 15 patients with aortic regurgitation (r = 0.91) and in 16 patients with significant coronary artery disease (r = 0.93). In the 16 patients with reduced cardiac output (mean 3.2 liters/min, range 2.2 to 3.9) the correlation was 0.81. A strategy for using the Doppler echo-calculated pressure gradient to manage patients with valvular aortic stenosis (AS) was derived by investigating the relation of the Doppler echo gradient to the aortic valve area in 35 patients with no aortic regurgitation detected at catheterization. All 12 patients with a Doppler echo mean gradient of less than 30 mm Hg had an aortic valve area of more than 0.75 cm2 and all 11 patients with a Doppler echo mean gradient of more than 50 mm Hg had an aortic valve area of less than 0.75 cm2.(ABSTRACT TRUNCATED AT 250 WORDS)