Objectives: Balancing anticoagulation and reoperation risks determines prostheses
choice (mechanical/biological) for mitral valve replacement. We aimed to re-evaluate
the outcomes after biological versus mechanical mitral valve replacement. Methods:
We compared long-term benefits and risks of mechanical and biological prostheses in
2056 patients (52% men, 48% women; 65.4 +/- 12.1 years) who underwent mitral valve
replacements between 1993-2017, in a retrospective single-centre study. Data sources
included prospective institutional database, social registry, general practitioner
data and follow-up questionnaire. Patients were stratified by age: < = 39 y (n = 82),
40-49 y (n = 164), 50-59 y (n = 335), 60-69 y (n = 593), 70-79 y (n = 743) and > =
80 y (n = 139). Long-term outcomes (mortality, reoperations, bleeding) were analysed.
Results: Altogether, 1308 mechanical (53% men, 47% women; 61.5 +/- 11.7 years) and
748 biological (50% men, 50% women; 72.3 +/- 9.6 years) valves were implanted. The
reason for valve replacement was stenosis in 162, insufficiency in 823 and combined
in 323 cases for mechanical, while it was 46, 567 and 135 for biological valves, respectively.
Overall cumulative survival was higher with mechanical prosthesis (mean: 139 +/- 4
vs. 102 +/- 5 months, 10 y: 55% vs. 33%, p < 0.0001). Subgroup analysis revealed higher
survival among patients receiving mechanical prosthesis up to 60 years (< = 39 y p
= 0.047, 40-49 y p < 0.0001, 50-59 y p = 0.001). In patients 60-69 years, overall
survival did not differ; however, in survivors beyond 8 years, mechanical prosthesis
showed improved survival (p = 0.014). While between 70-79 years survival was nearly
identical, for above 80 years, patients had a higher survival with biological prosthesis
(p = 0.014). Conclusion: The present data demonstrated a higher survival of mechanical
prosthesis in a wide range of patients after mitral valve replacement.
