Doppler echocardiography in aortic stenosis: feasibility and clinical impact

Abstract

The clinical utility of Doppler echocardiography for the assessment of aortic stenosis was prospectively studied in 425 consecutive patients referred to the echocardiography laboratory over 1 year with the clinical diagnosis of aortic stenosis. Optimal peak Doppler velocities were obtained in 405 (95%) patients of all ages. In 108 patients, the severity of aortic stenosis as determined by subsequent cardiac catheterization was compared with that found by Doppler assessment. Categorization of severity was concordant in 8 (89%) of 9 cases of mild aortic stenosis and in 28 (78%) of 36 cases of severe aortic stenosis, but there was considerable diagnostic overlap in cases of moderate stenosis. Forty-nine patients with mild aortic stenosis as determined clinically had moderate or severe stenosis as assessed by Doppler; 7 (14%) of these patients underwent subsequent replacement of the aortic valve. Increased aortic velocity, as determined by Doppler, was associated with a significant incidence of subsequent (mean follow-up period, 22 months) cardiac events (cardiac death, aortic valvar replacement, New York Heart Association functional class III or IV). Patients with mild aortic stenosis as assessed by Doppler (peak aortic velocity < 2.5 m/sec) had > 95% event-free survival at 1 year and rarely required cardiac catheterization. Conversely, only 45% of patients with severe aortic stenosis as determined by Doppler were free of a cardiovascular event at 1 year. Although the noninvasive assessment of aortic stenosis should ideally include determination of the area of the aortic valve and the mean aortic gradient by Doppler echocardiography, this is not always possible. Prognostic information derived from peak aortic velocity alone is clinically useful. It has the additional advantage that it is much less laborious and time-consuming to obtain and is obtainable in almost all (99%) patients.