Hemolysis after mitral valve repair: mechanisms and treatment

The objectives of this study were to determine the mechanisms of hemolysis after mitral valve repair and to determine outcomes after surgical treatment (mitral replacement or re-repair).

Between 1981 and 2002, 32 patients (mean age, 58 years) presented with hemolytic anemia after mitral valve repair for degenerative, rheumatic, or ischemic mitral regurgitation (MR). Three types of annuloplasty were used at the initial mitral valve repair: Cosgrove-Edwards, Carpentier-Edwards, and bovine pericardial (Perigard). The diagnosis and the mechanisms of hemolysis were investigated with laboratory testing and echocardiography.

Median interval from initial mitral valve surgery to diagnosis of hemolysis was 3 months (range, 1 week to 4 years). At presentation, mean hematocrit was 27.5% +/- 4.9% and 22 patients (69%) required transfusion. Echocardiographic findings varied. Twenty-four patients (77%) had grade 3 or 4 MR. Mitral regurgitant jet types included fragmentation (11 patients, 34%), acceleration (10, 31%), slow deceleration (5, 16%), collision (4, 13%), and free jet (2, 6%). Mitral valve replacement was performed in 28 patients, mitral valve re-repair in 3, and 1 patient did not undergo reoperation. At reoperation the mitral valve repair was physically intact in 25 of 31 patients (81%). There were 2 hospital deaths in patients having reoperation (6%). Actuarial survival was 95% at 1 year and 85% at 5 years. In 1 patient recurrent mechanical hemolysis developed caused by a perivalvular leak after mitral valve replacement.

Hemolysis is a mode of failure of mitral valve repair. Patients with hemolysis generally present within 3 months of mitral valve repair. Although echocardiographic features varied, most patients had high-grade MR and regurgitant jets that fragmented or accelerated. Mitral valve replacement yields favorable outcomes for patients with hemolysis after mitral valve repair.