PLANIMETRY OF AORTIC-VALVE AREA USING MULTIPLANE TRANSESOPHAGEAL ECHOCARDIOGRAPHY IS NOT A RELIABLE METHOD FOR ASSESSING SEVERITY OF AORTIC-STENOSIS

Objective-To assess the reliability of aortic valve area planimetry by multiplane transoesophageal echocardiography (TOE) in aortic stenosis . Design-Study of the diagnostic value of aortic valve area planimetry using multiplane TOE, compared with catheterisation and the continuit y equation, both being considered as criterion standards. Setting-Univ ersity hospital. Patients-49 consecutive patients (29 male, 20 female, aged 44 to 82 years, average 66.6 (SD 8.5)), referred for haemodynami c evaluation of an aortic stenosis, were enrolled in a prospective stu dy. From this sample, 37 patients were eligible for the final analysis . Methods-Transthoracic and multiplane transoesophageal echocardiogram s were performed within 24 hours before catheterisation. At transthora cic echo, aortic valve area was calculated by the continuity equation. At TOE, the image of the aortic valve opening was obtained with a 30- 65 degrees rotation of the transducer. Numerical dynamic images were s tored on optical discs for off-line analysis and were reviewed by two blinded observers. Catheterisation was performed in all cases and aort ic valve area was calculated by the Gorlin formula. Results-Feasibilit y of the method was 92% (48/52). The agreement between aortic valve ar ea measured at TOE (mean 0.88 (SD 0.35) cm(2)) and at catheterisation (0.79 (0.24) cm(2)) was very poor. The same discrepancies were found b etween TOE and the continuity equation (0.72 (0.26) cm(2)). TOE planim etry overestimated aortic valve area determined by the two other metho ds. Predictive positive and negative values of planimetry to detect ao rtic valve area < 0.75 cm(2) were 62% (10/16) and 43% (9/21) respectiv ely. Conclusions-Planimetry of aortic valve area by TOE is difficult a nd less accurate that the continuity equation for assessing the severi ty of aortic stenosis.