Determinants of hospital mortality after repeat mitral valve surgery for rheumatic mitral valve disease.

Objective: The aim of this study is to detect the risk factors for hospital mortality in patients who underwent reoperative mitral valve replacement.

Methods: Rheumatic mitral valve patients who underwent primary mitral valve replacement (386 cases) and repeat mitral valve replacement (94 cases) were analysed retrospectively. The incremental effects of the reoperative procedure on hospital mortality were studied by comparing primary and reoperative procedures and analyzing a series of possible predisposing factors.

Results: Operative mortality for repeat procedures was found significantly higher than the first operations (respectively 12.8% versus 4.3%, p=0.022). Risc factors affecting the hospital mortality in reoperation group were determined as advanced age, diameter of left atrium, prolonged bypass time and development of postoperative low output state. The indication for surgery also had a significant role in patients' outcome. Mortality found significantly higher in cases operated due to endocarditis or mitral mechanical valve thrombosis compared to other reoperation groups.

Conclusion: Patients over age of 70 years, with a left atrial diameter over 60 mm, reoperated due to endocarditis and mechanical valve thrombosis, should be reevaluated for risk assessment while giving the decision of optimal operation timing. Especially patients with left ventricular hypertrophy and decreased myocardial reservoirs, efficient myocardial protection during the operation had an important role.