A South Africa tertiary centre experience with redo mitral valve replacement

Background: Severe cardiac failure from mechanical mitral valve thrombosis due to poor warfarin control is a major cause of emergency redo mitral valve replacement (MVR) in South Africa. This study aimed to review the outcomes of redo MVR in patients presenting with mitral valve failure to a tertiary South African centre. Methods: Retrospective chart review of patients undergoing redo MVR over a 10-year period (2005-2014). Patient demographics, aetiology of valve dysfunction, preoperative clinical assessment and outcomes were analysed. Results: Sixty-four patients had 80 mitral valve procedures. The M:F ratio was 1:2.8 and the median age was 18 (IQR 14-28.5) and 25 (IQR 18-40) at initial surgery and at redo surgery, respectively. Median interval between original and redo MVRs was 47.5 (IQR 7.5-124) months. Rheumatic valve disease was the original pathology in 58 patients (90.6%). Fifty-two patients underwent a single redo MVR and 12 patients had multiple redo MVRs. Fifty-eight (72.5%) were emergency redo procedures. Prosthetic valve thrombosis was present in 73.8%. Ten patients (15.6%) developed postoperative complications. The median hospital stay and ICU stay were 19 (IQR 12-27.5) days and 4 (IQR 3-7) days, respectively. Two patients died in the postoperative period (3.1%). The mean patient follow-up was 42 months. Three patients died during follow-up. Conclusion: The majority of redo MVR procedures were undertaken as an emergency with valve thrombosis being the most common aetiology. The mortality rate was 3.1% and postoperative complication rate was 15.6%.