Frequency and degree of change of peak transvalvular pressure gradient determined by two Doppler echocardiographic examinations in newborns and children with valvular congenital aortic stenosis.

The natural history of congenital aortic stenosis (AS) has been described predominantly using data derived from catheterization studies. Because of the inherent selection bias of many of these studies, this study was conducted to determine the course of valvular AS using data from serial echocardiograms, for which this bias is less pervasive. The medical records of 103 patients (mean age 3.3+/-3.8 years at time of diagnosis) with congenital AS were examined, and data from the initial and most recent echocardiograms before any intervention on the aortic valve were recorded. The average change in gradient for the entire study population was +1 mm Hg/patient-year. Forty percent (8 of 20) of patients diagnosed in the newborn period (<2 months) required intervention before 6 months of age, compared with 11% (9 of 83) of those diagnosed after the newborn period who required intervention at any time during the study period (p<0.01). Patients diagnosed at >or=1 year of age were less likely to have acute increases in gradient or need intervention; those older patients whose gradients progressed more rapidly were more likely to have significant (more than mild) aortic insufficiency than those whose gradients did not progress (55% vs 28%, p<0.05). In conclusion, congenital AS is usually a slowly progressive disease. Risk factors for more rapid gradient progression include diagnosis as a neonate and the development of significant aortic insufficiency.