INFLUENCE OF THE SIZE OF AORTIC-VALVE PROSTHESES ON HEMODYNAMICS AND CHANGE IN LEFT-VENTRICULAR MASS - IMPLICATIONS FOR THE SURGICAL-MANAGEMENT OF AORTIC-STENOSIS

Discussion of aortic valve replacement has primarily concerned the cho ice between tissue and mechanical prostheses, Less emphasis has been p laced on prosthesis size, Despite technical advances increasing prosth esis orifice area, small valves implanted in the unenlarged aortic roo t may not be significantly less obstructive than the stenotic native v alves they replace, Methods: In this work we studied 52 patients (31 w omen, 21 men; mean age 59.2 years) in whom valve prostheses sized 19, 21, 23, or 25 mm (30 bioprostheses and 22 tilting disc valves) had bee n implanted to replace stenotic aortic valves, Most patients with 19 o r 21 mm prostheses were women, Doppler and conventional echocardiograp hic studies were performed in the 10 days preceding the operation and between 10 and 40 months (mean 18 months) after the operation, The pat ients receiving larger valve sizes had significantly larger body surfa ce areas than those receiving smaller valve sizes (mainly women), Resu lts: No significant differences were observed between preoperative and postoperative diameters or left ventricular systolic function paramet ers, but left ventricular mass and mass index decreased in all four gr oups (albeit nonsignificantly in the 19 mm group, and with less statis tical significance in the 21 mm group than in the 23 and 25 mm groups) , Postoperative peak and mean transvalvular pressure drops were signif icantly greater in the 19 mm group than in the other groups, and the 2 1 mm group had significantly greater transvalvular pressure drops than the 25 mm group, Postoperative effective valve area was significantly smaller in the 19 mm group than in the 21 mm group, and significantly smaller in the 21 mm group than in the 23 and 25 mm groups. Conclusio n: We conclude that despite undeniable recent improvements in the desi gn of artificial heart valves, 19 mm aortic prostheses continue to cre ate significant obstruction of the left ventricular outflow tract and, possibly as a consequence of this, fail to bring about significant re duction in left ventricular hypertrophy.