PREOPERATIVE ECHOCARDIOGRAPHIC PREDICTION OF SMALL PROSTHESIS SIZE FOR AORTIC-VALVE REPLACEMENT

Background and aims of the study: Prosthesis size is known to have an effect on long term outcome after heart valve replacement. We evaluate d 115 patients subjected to aortic valve replacement to assess the abi lity by preoperative echocardiography to identify patients having smal l aortic roots and thereby likely to receive a small prosthesis (size 19 or 21), previously shown to be associated with a worse prognosis. M ethods: From an initial part of the study (Group A), comprising 67 pat ients, we evaluated the influence of image quality on the accuracy for prediction of patients receiving a small prosthesis. In a second seri es of 48 patients (Group B), we tested the predictive value of various limits of aortic annulus diameter to define patients at risk of a sma ll receiving cr prosthesis. Results: The measurement of aortic annulus diameter in Group A,gave a reasonable correlation to subsequent prost hetic dimension (r = 0.73, n = 59). However, there was a considerable variation of echocardiographic aortic annulus diameter among patients receiving prostheses of the same size. In Group B, an aortic annulus d iameter of 122 mm correctly identified 10 of 13 patients receiving a s mall prosthesis (sensitivity 77%). Twenty-two of 25 patients (88%) wit h an aortic annulus diameter > 22 mm received a large prosthesis. Conc lusions: We conclude that the echocardiographic measurement of the aor tic annulus diameter is a fairly sensitive method to identify patients receiving a small prosthesis. However, the predictive accuracy is dep endent upon training as well as image quality. Furthermore, the value of planning in advance the type of prosthesis, annuloplasty or homogra ft for aortic valve replacement remains to be shown.