Reliability of two-dimensional echocardiography in assessing the severity of valvular aortic stenosis

Two-dimensional echocardiographic studies have shown that maximum long-axis systolic aortic cusp separation (MACS) represents a useful, noninvasive method for estimating severity of valvular aortic stenosis in adults. Although mean values for patients with mild, moderate, and severe aortic stenosis have been clearly separated by this method, overlap occurs among individual patients. In this study, 81 adults with aortic stenosis were studied by two-dimensional echocardiography in the long-axis view. Long-axis assessment of aortic stenosis was obtainable in 93 percent of the patients. Less than 8-mm separation was 97 percent predictive of severe stenosis and 100 percent predictive of moderate or severe stenosis. Eight- to 12-mm had a low predictive value for the severity of stenosis. Greater than 12-mm separation was 96 percent predictive of mild aortic stenosis. Short-axis scans were attempted in 61 of the 81 subjects. Short axis assessment of aortic stenosis based on patterns of leaflet motion was obtainable in 46 of the 61 patients (73 percent) and provided a valuable index of severity. When short-axis scans were included in the assessment of severity in the subgroup of patients with 8- to 12-mm MACS, the predictive value improved greatly (86 percent vs 46 percent). Direct recording of aortic valve area in short-axis was successful in only 13 percent of the subjects. The echo aortic valve area compared with the hemodynamic calculated aortic valve area yielded an r=0.87.