Title : Predictors of patient prosthesis mismatch in patients with mechanical prosthesis in the aortic position
Abstract:
Background: Several studies have reported that the prevalence of Prosthesis-patient mismatch (PPM) after surgical aortic valve replacement (SAVR) ranged from 20-70%. Meta-analysis has reported that older age female sex, BSA, valve size are predictors of moderate and severe PPM which was associated with higher overall mortality. Most of studies are done on bioprosthetic valve or included both mechanical or bioprosthetic valve in patients from western world and are less well studied in Asian region. This study aimed to evaluate various predictors of PPM with mechanical prostheses in aortic valve position and correlation between its severity with various valve size, types and their Performance Index (PI) in developing Asian countries like India.
Methods: This is a prospective observational single center study including all patients that underwent AVR or DVR attending cardiology or CVTS OPD from 2022-2024. 55 patients were enrolled and various clinical demographic and various 2D-ECHO parameters were evaluated. PPM was defined if indexed EOA was < 0.85 cm2/m2, moderate PPM as ≥0.65 cm2/m2 and ≤0.85 cm2/m2, and severe PPM as <0.65 cm2/m². Qualitative data were analysed using descriptive statistics followed by Pearson Chi Square Test quantitative data were analysed using Kruskal Wallis one way ANOVA test, t-test and regression analysis.
Results: Out of 55 patients over a median follow up of 5 years, 39 patients (70.9%) were between age 41-70 years, mean age of patients with severe PPM and moderate PPM were 53.45 years and 50.44 years respectively. Females were 25.5%. Patient with no PPM were 47.3%, (26.9% females), with moderate PPM 16.4% (22.2% were females) and 36.4% have severe PPM (25% were females). SJM valve was used in maximum patients (30.9%). PI of TTK valve was found to be maximum (mean PI=0.52) and minimum of Medtronic Hall (mean PI 0.29; SD 0.20). Valve size of 24 mm has maximum mean PI of 0.49. PPM was found to have significant correlation with PI (Severe PPM mean PI=0.19; SD=0.20, Moderate PPM mean PI=0.33; SD=0.06 and with No PPM mean PI=0.45; SD=0.13, P value=0.00). Linear regression model showed significant correlation between PPM BSA and valve size (R Square=0.304; Adjusted R Square=0.277; P value= 0.002.
Conclusion: Patients undergoing AVR with Mechanical Aortic Valve Prosthesis severity of PPM have significant correlation with PI and PPM can be fairly predicted by BSA and valve size, so can be largely avoided with the use of a prospective strategy at the time of operation.
Keywords: PPM, EOA, Performance Index, BSA.
