Outcome and growth potential of left heart structures after neonatal intervention for aortic valve stenosis.

Objectives: The purpose of this study was to determine trends of growth of left heart structures after intervention for neonatal aortic valve stenosis.

Background: The growth potential of left heart structures in neonatal aortic valve stenosis after relief of obstruction might influence risk for subsequent outcomes.

Methods: From 1994 to 2004, 53 patients underwent neonatal (< or =30 days old) balloon aortic valve dilation. Factors associated with time-related outcomes (death, reintervention, aortic valve replacement) and longitudinal changes in normalized left heart dimensions were sought.

Results: The median age at intervention was 3.5 days (range 1 to 30 days). During a median follow-up of 3.2 years ranging up to 10.9 years, there were 31 reinterventions on the aortic valve in 21 (40%) patients and 7 deaths (13%). The presence of moderate or severe left ventricular (LV) endocardial fibroelastosis was the only independent predictor for time-related mortality (hazard ratio 22.1; p = 0.004), and a smaller initial aortic valve annulus z-score was a significant independent predictor for aortic valve replacement (hazard ratio 0.63 per 1-U change; p = 0.007). Aortic valve annulus, aortic sinus, and LV dimension z-scores significantly increased over time, whereas mitral valve z-scores remained below normal. The structure's initial z-score and concomitant size of other left heart structures were significant independent factors associated with subsequent z-scores.

Conclusions: There is potential catch-up growth of the aortic valve and LV over time for neonates after intervention for aortic valve stenosis. However, the continued hypoplasia of the mitral valve warrants further consideration in the long-term management of these patients.