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 mitre] 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. Good-quality prospective studies are warranted to evaluate the impact of mitral prosthesis-patient mismatch after mitral valve replacement in the future.