Background: Patient prosthesis mismatch (PPM) has been recognized as clinical problem post prosthetic valve replacement since the first publication by Rahimtoola in 1978 and the only parameter that has been validated to identify PPM is the indexed EOA. This study was done to determine if targeting a minimum indexed effective aortic orifice area preoperatively can prevent PPM.
Method: A total of 48 patients were recruited in this study during the period of July 1, 2013 January 31, 2015. All patient underwent elective aortic valve replacement. The type and size of prosthetic valve were surgeon's choice. They are classified as adherent to indexed EOA calculation if the value used has EOA is equal or more than the computed EOA (computed EOA=IEOA (0.86) x BSA), and not adherent if it is less than the computed EOA. All patient were evaluated for PPM 2-4 weeks post operatively by 2D echocardiography with doppler. PPM is diagnosed based on the algorithm on American Society of Echocardiography.
Results: Patient's characteristics such as age, sex, BSA, etiology and aortic lesion, and type and size of prosthetic valve used were not significant in both groups thus unlikely to have effects on result. Out of 48 patients, 42 (87.5%) belongs to adherent group and 6 (12.5%) in non adherent group. Among the subjects, four patient had patient prosthesis mismatch, with an incidence rate of 8.33% (95% CI: 2.32%-19.98%). The proportion of subject in adherent group without PPM is 93.2% which is higher than of that subject without PPM is 93.2% which is higher that of the subject without with PPM at 25%. This translates to odds ratio of 41, which means the odds of PPM s 41 times among non adherent group (p value = 0.008)
Conclusion: There is correlation between PPM and the adherence to indexed EOA calculation in choosing aortic valve size in patient undergoing valve replacement thus targeting a minimum indexed effective aortic office area preoperatively can prevent PPM.