Impact of Patient-Prosthesis Mismatch in the Aortic Position: Twenty-Year Experience with Korean Patients

Background and aim of the study: The impact of patient-prosthesis mismatch (PPM) on clinical outcomes following aortic valve replacement (AVR) remains controversial. The study aim was to evaluate the impact of PPM on long-term clinical outcomes following AVR. Methods: Between January 1987 and September 2007, a total of 198 consecutive patients (mean age 59.6 +/- 10.5 years; range: 31-85 years) underwent isolated AVR for pure aortic stenosis at the authors' institutions. PPM was defined as an indexed effective orifice area (EOAI) <0.85cm(2)/m(2), and was present in 45 patients (22.7%). The mean follow up duration was 102.6 +/- 71.6 months (maximum 270 months). Results: The early mortality was 1.5% (n = 3). The late mortality was similar in both the PPM and non-PPM groups (4.4% versus 4.7%; p = 0.950). The left ventricular mass index during follow up was higher in the PPM group (128.5 +/- 36.1 versus 114.5 +/- 39.1 g/m(2), p = 0.037). Freedom from cardiac-related mortality at 15 years was 86.5 +/- 4.3% in the non-PPM group, and 92.9 +/- 4.9% in the PPM group (p = 0.282). Freedom from heart failure events at 15 years was 74.6 +/- 6.6% in the non-PPM group and 61.6 +/- 8.5% in the PPM group (p = 0.028). Predictors of heart failure events were female gender (p = 0.041, hazards ratio (HR) = 2.5, 95% confidence interval (CI) = 1.1-5.9) and PPM (p = 0.001, HR = 5.1, 95% CI = 1.9-13.7). Conclusion: In AVR patients with pure aortic stenosis, PPM, when defined by the threshold value of EOAI <0.85 cm(2)/m(2), was not associated with differences in cardiac-related mortality. However, PPM was related to an increased incidence of postoperative heart failure events.