Preservation of the subvalvular apparatus during mitral valve replacement of rheumatic valves does not affect long-term survival.

Objectives: The importance of preservation of the subvalvular apparatus (PSVA) during mitral valve replacement (MVR) in non-rheumatic mitral valves is well recognized. Our aim was to analyse the impact of PSVA in MVR for rheumatic valves on long-term survival.
Methods: From January 1992 to December 2012, 605 consecutive patients with rheumatic mitral valve disease were submitted to MVR. PSVA (limited to the posterior leaflet) was achieved in 224 (37.7%) patients. Follow-up was 4259 patient-years, and complete for 97% of the patients. Propensity score analysis was introduced to reduce selection bias.
Results: Patients with PSVA were slightly older (61.9 vs 59.8 years, P = 0.014), with lower incidence of calcification (54.9 vs 63.0%, P = 0.05), pure mitral stenosis (29.9 vs 38.9%, P = 0.014) and history of rheumatic fever (44.6 vs 53.9%, P = 0.028). Mechanical prostheses were more frequently implanted in the Non-PSVA group (75.1 vs 65.6%, P = 0.013). Thirty-day mortality was 1.1%. Late survival rates at 5, 10 and 18 years were 86.6 ± 2.0, 70.8 ± 3.2 and 48.0 ± 5.1%, respectively, with no difference between groups. Both groups had compromised late survival when compared with the general population (age and gender matched, P < 0.001). Only age, large left atrium, pulmonary hypertension and 'pure' MR appeared as independent predictors for late mortality. There was no difference regarding adverse valve-related events between groups.
Conclusions: Patients submitted to MVR for rheumatic mitral valve disease have a poor prognosis, independently of having the subvalvular apparatus preserved. PSVA did not improve late survival in this setting.
(© The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.)