Impact of prosthesis-patient mismatch on survival after mitral valve replacement: a systematic review.

OBJECTIVE: To determine whether the prosthesis-patient mismatch has a deleterious impact on survival after mitral valve replacement. DATA SOURCES: A comprehensive literature search of PubMed, Embase, and ScienceDirect was carried out. References and cited papers of relevant articles were also checked. STUDY SELECTION: All articles published after January 1980 was initially considered. Non-English and non-human studies, case reports, and reviews were excluded from the initial search. References and cited papers of relevant articles were also checked. RESULTS: A total of 8 retrospective cohort studies were identified for this review. The overall incidence of prosthesis-patient mismatch (<1.3 to <1.2 cm(2)/m(2)) after mitral valve replacement ranged from 3.7% to 85.9% (moderate prosthesis-patient mismatch (0.9 to 1.2 cm(2)/m(2)) in 37.4% to 69.5%, severe prosthesis-patient mismatch (<0.9 cm(2)/m(2)) in 8.7% to 16.4%). Four studies demonstrated an association of prosthesis-patient mismatch with reduced long-term survival, but the other four studies found no significant deleterious impact of prosthesis-patient mismatch after mitral valve replacement. No definite conclusion could be derived from these conflicting results. CONCLUSIONS: Current evidence is insufficient to derive a definite conclusion whether mitral prosthesis-patient mismatch affects long-term survival because of the biases and confounding factors that interfere with late clinical outcomes. Goodquality prospective studies are warranted to evaluate the impact of mitral prosthesis-patient mismatch after mitral valve replacement in the future.