5. Mitral valve replacement for mitral stenosis: 15 years single center experience

Abstract

Mitral valve replacement (MVR) with either a bioprosthetic or a mechanical valve is the treatment of choice for severe mitral stenosis. This study aimed to evaluate and compare the early and late outcome of mitral valve replacement (mechanical versus bioprosthetic) for severe mitral stenosis. A retrospective cohort study was performed on prospectively collected data involving mitral stenosis patients who have undergone MVR with either bioprosthetic (BMV) ( n =50) or mechanical (MMV) ( n =145) valves in our institute from 1999 to 2012. Data were analyzed for early and late mortality, NYHA functional classes, stroke, early and late valve-related complications, and survival. Chi Square test, logistic regression, Kaplan Meier curve, and dependent proportions tests were performed. A total of 195 patients were included in the study with a follow-up of 190 patients (97.5%). One patient died early post-operatively; twelve patients died late in the post-operative period, BMV group (6) and the MMV (6). The Late mortality had significantly associated with post-op stroke ( p p =0.002). Post-op NYHA class was significantly associated with age ( p =0.003), pulmonary disease ( p =0.02), mitral valve implant type ( p =0.01), and post-op stroke ( p =0.02); 14 patients had strokes in the MMV (9) and in the BMV (5) groups. NYHA classes were significantly better after the replacement surgeries ( p p =0.03), worse NYHA post-op ( p =0.01), and more re-operations ( p =0.006). Survival was significantly better with mechanical valves ( p =0.03). When the two groups were matched for age and mitral regurgitation, the analysis revealed that bioprosthetic valves were significantly associated with re-operations ( p =0.02) but not significantly associated with worse survival ( p =0.4) or worse NYHA ( p =0.4). Mechanical mitral valve replacement in mitral stenosis patients is associated with lower re-operation rate, but no difference in survival as compared to bioprosthetic mitral valve replacement. Furthermore, post-operative stroke occurrence (14%) is associated with late mortality and worse NYHA classes.