[Prosthesis-patient mismatch in the mitral valve position: the initial result of a single-institutional observational...

To analysis the causes of valve prosthesis-patient mismatch (PPM) after mitral valve replacement in Chinese patients.

Consecutive 100 patients for elective mitral valve replacement from January 2009 to June 2009 were enrolled and followed for this study. There were 37 males and 63 females. The mean age at operation was (52 ± 9) years (ranging 32 to 76 years). The predominant mitral valve lesion was stenosis in 60 patients, regurgitation in 14 patients and mixed in 26 patients. Among them, 63 patients were combined tricuspid valve regurgitation. Mitral valve effective orifice area was measured by Doppler echocardiography in 100 patients who received mitral valve replacement and indexed for body surface area (EOAI). PPM was defined as not clinically significant if the EOAI was above 1.2 cm(2)/m(2), as moderate if it was >0.9 and ≤ 1.2 cm(2)/m(2), and as severe if it was ≤ 0.9 cm(2)/m(2). By using the criteria, all 100 patients were classified to two groups: PPM group and no PPM group. The clinical characteristic of the patients between the two groups was compared to determine the causes of PPM and the predictors of outcomes after mitral valve replacement, such as the gender, age, valve prosthesis type, size, body surface area, and mitral valve lesion, et al.

Of the 100 patients after MVR, 52 (52.0%) had significant PPM, 51 (51.0%) had moderate PPM, and 1 (1.0%) had severe PPM. In comparison to patients in no PPM group, patients in PPM group had a significantly larger body surface area [(1.76 ± 0.17) m(2) vs. (1.59 ± 0.13) m(2), P < 0.01] and higher prevalence of male gender (55.8% vs. 16.6%, P < 0.01). The other preoperative and operative data were similar in both groups, such as the valve prosthesis type, size, and mitral valve lesion, et al. There were no significant differences in postoperative Doppler-echocardiographic data of cardiac structure and heart function between the two groups (P > 0.05).

The higher incidence of PPM in mitral valve position was in male or large body surface area patients. At the time of operation, surgeons should consider the related factors, such as the patient's gender and body surface area, et al. A larger prosthesis size might be implanted to avoid PPM in mitral valve position.