Outcomes after rheumatic mitral valve repair in children

Background: It has been shown that mitral valve repair is superior to mechanical replacement in children with rheumatic heart disease; however there are limited data on the factors affecting the long-term durability of repaired mitral valves. This study describes outcomes after rheumatic mitral valve repair, with adaptation of a risk score to clarify some novel predictors of repair instability. 

Methods: A total of 79 children (median age, 11.4 years) with rheumatic heart disease underwent their first mitral valve surgery between 1997 and 2015. Patients with concomitant aortic and tricuspid repair were included. Mean follow-up time was 7.72 years. Mitral valve deterioration (defined as cardiac death, reoperation, or recurrent moderate to severe valvular disease) was used as a key end point. Preoperative echocardiographs were analyzed and graded with respect to valvular mobility, subvalvular apparatus alteration, and function. 

Results: All patients underwent successful mitral valve repair. Seven patients died during follow-up. Kaplan-Meier analysis demonstrated survival at 15 years to be 83%. A total of 38 patients were deemed to have deterioration in mitral valve function, with a rate of freedom from deterioration at 15 years of 28%. The presence of an immobile anterior mitral leaflet preoperatively and the technique of posterior patch extension were shown to be significant determinants of mitral valve deterioration. 

Conclusions: The outcomes after mitral repair for rheumatic heart disease in the young were in keeping with those reported in previous studies. Although the survival was high, long-term valve stability was poor. These findings suggest that the preoperative finding of a restricted anterior mitral leaflet is a negative predictor of repair durability.