Patient-prosthesis mismatch and reduction in left ventricular mass after aortic valve replacement.

BACKGROUND: The presence of patient-prosthesis mismatch (PPM) after aortic valve replacement may influence patient survival. We examined the relationship between PPM and changes in left ventricular mass index at 3 months follow-up and also overall survival.

METHODS: From patients included in the Mosaic trial, we studied data from 266 patients who underwent aortic valve replacement with the Medtronic Mosaic porcine bioprosthesis and had an echocardiography performed 3 months postoperatively. Complete echocardiographic data, to calculate left ventricular mass index, was available in 78% of the patients. The primary outcome for this substudy was prevalence and severity of PPM. Secondary outcomes were reduction in left ventricular mass index at 3 months follow-up and medium-term survival. Patients without PPM were defined as having an indexed effective orifice area greater than 0.85 cm(2)/m(2), and those with moderate and severe PPM as having an indexed effective orifice area between 0.65 cm(2)/m(2) and 0.85 cm(2)/m(2) or below 0.65 cm(2)/m(2), respectively.

RESULTS: PPM was found in 217 (82%) patients. No difference in overall survival was found between patients with PPM and those without PPM. The change in left ventricular mass index was significantly different between groups (no PPM -31.4 ± 28.0 g/m(2), moderate PPM 1.1 ± 34.4 g/m(2), and severe PPM -5.9 ± 29.7 g/m(2), respectively (p = 0.01).

CONCLUSIONS: The presence of PPM did not influence medium-term survival. However, patients without PPM showed a marked reduction in left ventricular mass index as soon as 3 months postoperatively.