MITRAL-VALVE REPLACEMENT IN REUNION ISLAN D, EARLY AND INTERMEDIATE-TERM RESULTS

Mitral Valve surgery represents 34.6 % of all open heart surgery in ou r unit. The aim of this study is to assess the early and intermediate term results in a consecutive series of 81 mitral valve replacements ( mechanical: 67, bioprosthesis: 14) performed between September 1991 an d December 1993. The mean age was 45.7 +/- 15 years (male 26, female 5 5). Twenty five patients (30.9 %) were classified as functional class Il of the New York Heart Association classification (NYHA) and 56 (69. 1 %) as class III or IV. Eight were operated in an emergency. Acute rh eumatic fever (49.3 %) and bioprosthetic dysfunction were the two main etiologies. Thirty patients (37 %) had a history of previous cardiac surgery. Hospital mortality was 13.6 % (11 patients). Risk factors ass ociated with high operative mortality were: age, emergency, previous c ardiac surgery, atrial fibrillation and tricuspid annuloplasty. All su rvivors were contacted. Mean follow-up was 30.8 +/- 9 months (range: 3 .1-46.4). Five patients had died by the last date of follow-up. Acturi al survival at 1 and 4 years was 86 % and 77 %, respectively. Late eve nts were mainly 9 episodes of thrombosis, 3 cases of thromboembolism a nd 1 peri-prosthetic leak; five patients were reoperated. The lineariz ed incidence of these events was respectively: 5.1 %, 1.7 %, 0.5 % and 3.4 % per patient/year, respectively. There were no complications in case of bioprostheses. Functional improvement was satisfactory and 93 % of patients were in NYHA class I or II at the most recent followup. Functional results after mitral valve replacement were satisfactory, r egardless the type of prosthesis; however valve-related complications are very serious. Conservative mitral surgery is currently our first c hoice whenever possible.