Impact of early ventricular unloading on exercise performance in preadolescents with single ventricle fontan physiology

OBJECTIVES We sought to determine if early ventricular volume unloading imp roves aerobic capacity in patients With single ventricle Fontan physiology. BACKGROUND Surgical strategies for patients with single ventricle include i ntermediate staging or early Fontan completion to reduce the adverse affect s of prolonged ventricular Volume load. The impact of this strategy on exer cise performance has not been evaluated. METHODS Retrospectively, we reviewed the exercise stress test results of al l preadolescents with single ventricle Fontan physiology. "Volume unloading " was considered to have occurred at the time of bidirectional cavopulmonar y anastomosis or at the time of Fontan surgery in those patients who did no t undergo intermediate staging. Potential predictors of aerobic capacity we re analyzed using multivariate regression. RESULTS The patients (n = 46) achieved a mean percentage predicted of maxim al oxygen consumption ((V) over dotO(2)max) of 76.1% +/- 21.1%. The mean ag e at the time of volume unloading was 2.7 +/- 2.4 years, and the mean age a t testing was 8.7 +/- 2 years. Intermediate staging was performed in 16 of 46 patients (35%). In multivariate analysis, younger age at volume unloadin g was associated with increased aerobic capacity (p = 0.003). Other variabl es were not predictive. The subgroup of patients who underwent Volume unloa ding before two years of age achieved a mean percentage predicted (V) over dotO(2)max of 88.6% +/- 24.1%. CONCLUSIONS Preadolescents with single ventricle who undergo volume unloadi ng surgery at an early age demonstrate superior aerobic capacity compared w ith those whose surgery is delayed until a later age. (C) 1999 by the Ameri can College of Cardiology.