Impact of valve type on outcomes after redo mitral valve replacement in patients aged 50 to 69 years

OBJECTIVES: Little data are available with regard to valve selections in redo valvular surgery. We investigated the impact of valve types on late outcomes after redo mitral valve replacement (MVR). METHODS: We retrospectively reviewed 66 patients aged 50-69 (mean age 62.2 ± 5.1) years who underwent redo MVR over the past 25 years. In redo MVR, 46 (69.7%) redo procedures were the 1st redo valvular surgeries, 16 (24.2%) were 2nd redos, 3 (4.5%) were 3rd redos and 1 was a 4th (1.5%) redo. We classified 66 patients into 2 groups: mechanical MVR group (M-MVR, n = 44) and biological MVR group (B-MVR, n = 22). The mean follow-up period was 8.2 ± 6.3 years. RESULTS: Hospital mortality rates were 3.3% in M-MVR and 9.7% in B-MVR (P = 0.3328). Survival rates in M-MVR and B-MVR at 5 and 10 years were 93.0 ± 4.8% vs 76.0 ± 10.5% and 77.6 ± 9.1% vs 51.3 ± 13.7%, respectively (log-rank test, P = 0.0072). Late death occurred in 7 patients in M-MVR and 9 in B-MVR. Freedom rates from valve-related events in M-MVR and B-MVR at 5 and 10 years were 100.0 ± 0.0% vs 76.5 ± 10.3% and 93.3 ± 6.4% vs 52.4 ± 13.6%, respectively (log-rank test, P < 0.0001). No bleeding and thromboembolic events were observed in M-MVR, whereas gastrointestinal bleeding (n = 1), subarachnoid haemorrhage (n = 1) and cerebral infarction (n = 2) were observed in B-MVR. A predictor of late death was a biological valve in redo MVR (P = 0.0206, hazard ratio = 3.402, 95% confidence interval 1.207-9.591). CONCLUSIONS: It would seem that redo MVR using a mechanical valve was associated with better early and late outcomes in this age group.