Outcomes after repair of the anterior mitral leaflet for degenerative disease.

BACKGROUND: Repair of anterior mitral disease is challenging. Objectives of this study were to (1) compare patients with anterior versus posterior disease, (2) identify factors predisposing to replacement rather than repair in anterior disease, (3) determine durability of, and survival after, repair, and (4) compare outcomes with those after posterior repair.
METHODS: From January 1985 to January 2006, 3,544 patients underwent primary isolated mitral valve surgery for degenerative disease, including 307 isolated anterior (252 repairs, 82%) and 2,754 isolated posterior (2,650 repairs, 96%) leaflet procedures. Logistic regression analysis was used to identify predictors of valve replacement and to generate propensity scores for risk-adjusted comparisons. Durability was assessed by reoperation and return of mitral regurgitation.
RESULTS: Patients with anterior disease were older and more symptomatic, with more chordal elongation and greater changes in cardiac morphology and function; advanced age was associated with replacement (p < 0.0001). Unadjusted freedom from reoperation was 89% at 10 years, worse than after posterior repair (p < 0.0001). Return of 3+ to 4+ mitral regurgitation was more common in those with anterior than posterior repair (11% versus 4% at 1 year; p = 0.03). Unadjusted survival was 83% versus 88% 10 years after posterior repair, but propensity-adjusted survival was similar (p >or= 0.5).
CONCLUSIONS: Patients with anterior disease have more symptoms and greater changes in cardiac structure and function than do patients with posterior disease. Anterior repair is less durable than posterior, but is associated with comparable, excellent long-term survival. More durable repair techniques, applicable to the broader spectrum of anterior disease, are needed.