Introduction:
Congenital aortic stenosis (AS) has been reported to manifest a slow rate of progression in mild disease with a greater likelihood of progression in patients with moderate-severe disease. The natural history of the Doppler estimated peak gradient (DEPG) in patients after balloon aortic valvuloplasty (BAV) has not previously been studied on a large scale.
Methods:
A retrospective review was performed of 360 patients from 1984-2012 with AS providing a total of 2051 echocardiograms before and after BAV. Patients were excluded if they had an intervention within the first 30 days of life. The relationships between the AS DEPG and several predictors (age at time of initial echocardiogram, valve morphology, and history of intervention) were explored using linear mixed effect models. The DEPG slope was then calculated in patients who had at least 2 echocardiograms before and after balloon dilation using linear regression modeling.
Results:
The rate of increase in the DEPG for all patients with AS was 5.6 mmHg per 10 years of age (p<0.001). The DEPG increased over time regardless of age at presentation with the greatest mean increase in patients presenting from 10-14.9 years (n=59; 11.9 mmHg per 10 years; p<0.001). Patients who went on to have a BAV or surgical intervention on the aortic valve had a significantly higher rate of AS progression than the overall patient cohort (n=59; 18.0 mmHg/10 years and n=36; 13.1 mmHg/10 years). Patients with a unicommissural (n=39) aortic valve had a significantly higher rate of progression compared to those with a bicommissural (n=270) aortic valve (8.1 mmHg/10 years and 4.5 mm Hg/10 years; p<0.001). The median rate of progression in the post-BAV group was significantly lower than the median pre-BAV rate of progression (n=34; pre-BAV 3.97 (1.69-8.7) mmHg/year; post-BAV 0.40 (-1.80-3.88) mmHg/year; p<0.01).
Conclusions:
The DEPG of native valve congenital aortic stenosis shows a slow, linear rate of progression prior to intervention. The rate of progression is significantly higher in patients with a unicommissural aortic valve as well as those patients that go on to have a BAV and/or surgical intervention. The rate of the DEPG progression is significantly lower after BAV.
The natural history of congenital aortic stenosis.
