Determination of severity of valvular aortic stenosis by Doppler echocardiography and relation of findings to clinical outcome and agreement with hemodynamic measurements determined at cardiac catheterization

To determine the relation of Doppler findings to clinical outcome and the agreement between Doppler and cardiac catheterization in the assessment of aortic stenosis (AS) severity, 510 consecutive patients with suspected AS studied in our laboratory were analyzed. Adequate echocardiographic and Doppler examinations were obtained in 498 patients or 98% of the population. Clinical data were available for analysis in 497 patients. In 160 patients, Doppler demonstrated an aortic valve area ≤0.75 cm² or a peak jet velocity ≥4.5 m/s consistent with critical AS. In the subgroup with cardiac catheterization (n = 105), Doppler was 97% accurate. Aortic valve replacement or balloon valvuloplasty was performed in 109 patients, 106 of whom were symptomatic. Noncritical AS was detected by Doppler in 327 patients, with 95% accuracy in the subgroup with cardiac catheterization (n = 133). Aortic valve replacement was performed in 15 patients with symptoms of AS and with valve areas assessed by Doppler to be between 0.76 and 0.80 cm² or with peak jet velocities >3.5 m/ s. In 20 patients, aortic valve replacement was performed because of moderate to severe aortic regurgitation, and in 11 elderly (>70 years old) patients with valve areas between 0.80 and 1.0 cm², valve replacement was performed at the time of coronary artery bypass surgery in an attempt to prevent the need for a repeat surgical procedure in the future. These observations allow the following conclusions. In the symptomatic patient with critical or near critical AS by Doppler, cardiac catheterization does not provide additional information beyond that provided by Doppler. In these patients, the procedure could be limited to coronary arteriography when indicated. Likewise, the asymptomatic patient with noncritical AS by Doppler can be followed noninvasively without catheterization to monitor the progression of AS. In a subgroup of patients with noncritical AS by Doppler in whom symptoms and physical findings suggest significant AS, cardiac catheterization may still be indicated to confirm or exclude the presence of significant stenosis. Overall, Doppler echocardiography is highly accurate in the assessment of AS severity and its use should allow for a more conservative application of cardiac catheterization in these patients.