Indications for intervention in asymptomatic children with chronic mitral regurgitation

Area of Science:

• Pediatric Cardiology
• Cardiovascular Surgery
• Echocardiography

Background:

• Indications for mitral valve surgery in asymptomatic children with chronic mitral regurgitation (MR) are not well-defined.
• Adult guidelines for MR surgery do not directly translate to pediatric populations.
• Predicting postoperative left ventricular (LV) dysfunction in children requires specific pediatric data.

Purpose of the Study:

• To identify predictors of late left ventricular (LV) dysfunction after mitral valve surgery in asymptomatic children with chronic mitral regurgitation (MR).
• To establish echocardiographic criteria for surgical intervention in pediatric MR.
• To guide timing of surgery to optimize LV function preservation.

Main Methods:

• Retrospective review of a surgical database for children undergoing mitral valve surgery for chronic MR between 2000 and 2012.
• Exclusion of patients with preoperative symptoms, acute MR, cardiomyopathy, or other cardiac defects.
• Analysis of preoperative and follow-up clinical and echocardiographic data, defining LV dysfunction as ejection fraction (EF) ≤55% or shortening fraction (SF) ≤28%.

Main Results:

• Nine out of 25 eligible children (36%) developed late LV dysfunction.
• Lower preoperative shortening fraction (SF) (OR 0.6) and higher LV end-systolic Z score (LVESZ) (OR 1.7) were significantly associated with late LV dysfunction.
• A combination of LVESZ ≥ 5 and SF ≤ 33% predicted late LV dysfunction with 89% sensitivity and 88% specificity.

Conclusions:

• Asymptomatic children with chronic MR should be considered for surgery before LVESZ exceeds 5 and SF drops below 33% to prevent LV dysfunction.
• Preoperative SF > 33% was associated with a low incidence of late LV dysfunction, suggesting a potential threshold for monitoring.
• Serial echocardiographic monitoring may be appropriate for children with SF > 33%.