Implications of valve prosthesis-patient mismatch in patients undergoing aortic valve replacement; who tolerates and who does not?

Abstract

Background: The problem of Valve Prosthesis – Patient Mismatch (VP-PM) and small aortic annulus is closely related. Claims of this problem being negligible with modern prosthesis in smaller sizes have not yet been substantiated. The choice of the best prosthesis in the small aortic root is still an issue of debate. Materials and methods: We sought to study 37 of the 42 patients of isolated aortic valve replacement, with mechanical prosthesis, with respect to improvement in the functional status, regression in the left ventricular hypertrophy and transprosthetic gradients. A total of 28 male and 9 female patients were followed up for 13.24±5.17 months. 36 of the patients had mild VP-PM as per the guidelines of Rahimtoola et al 1 . Results: All patients except 5 (13.51%) had a complete regression of their symptoms at 6 months following surgery. Five patients continue to have dyspnoea on exertion of variable grade. These patients had received size 19 valves. On comparing size19, 21 and 23 valves, we found that the regression in peak systolic gradients and left ventricular mass across the aortic valve, following surgery was comparable among all three valve sizes However, the residual gradients and left ventricular mass across the size 19 prostheses were significantly higher than expected. Conclusions: All patients in this study had VP-PM of varying severity. Among patients with mild VP-PM, patients with size19 prosthesis manifested with symptoms and signs of VP-PM. In spite of having Mild VPPM the performance of size 21 and 23 valves was found satisfactory. (Ind J Thorac Cardiovasc Surg, 2005; 21: 256–261)