Effects of mitral valve disease etiology on the outcomes of mechanical and biological valve replacement: retrospective cohort study.

INTRODUCTION: The choice of an artificial mitral valve (MV) is a crucial clinical decision that affects the long-term survival and quality of life of patients. However, current guidelines recommend selecting MV based on patient age and life expectancy at the time of MV replacement (MVR), without considering the etiology of MV disease. This study aimed to investigate whether MV disease etiology should be considered when choosing a valve for MVR and to evaluate the impact of MV disease etiology on long-term patient survival.

METHODS: Using data (2002 to 2018) from Taiwan's National Health Insurance Research Database, we conducted a nationwide retrospective cohort study to compare the biological and mechanical valves in terms of all-cause mortality as the primary outcome. The inverse probability of the treatment weighting method was used to reduce the effects of the confounding factors. The following etiologies were assessed: infective endocarditis (IE), rheumatic heart disease (RHD), ischemic mitral regurgitation (IMR), and degenerative mitral regurgitation (DMR).

RESULTS: In patients aged <70 years, it was observed that mechanical valves demonstrated an association with benefits compared to biological valves in the context of survival. In patients with IE aged <72 years, mechanical valves were associated with survival benefits, but not in those with stroke during hospitalization. These valves were also found to be linked with survival advantages for patients with RHD aged <60 years and for those with DMR aged < 72 years. However, no age-dependent effects of valve type on all-cause mortality were observed in patients with IMR.

CONCLUSION: The etiology of MV disease appears to be important in the selection of a suitable MV and determination of a cutoff age for mechanical and biological MVR.