New insights into the progression of aortic stenosis - Implications for secondary prevention

Background-The risk factors affecting aortic stenosis (AS) progression are not clearly defined. Insights into this may allow for its secondary prevention. Methods and Results-We investigated predictors of AS progression in 170 consecutive patients with AS who had paired echocardiograms greater than or equal to 3 months (23+/-11) apart. Various clinical, echocardiographic, and biochemical variables were related to the change in aortic valve area (AVA). The annual rate of reduction in AVA was 0.10+/-0.27 cm(2) or 7+/-18% per year. The reduction in AVA per year was significantly related to initial AVA (r=0.46, P<0.0001), the mean aortic valve gradient (r=0.27, P=0.04), left ventricular (LV) outflow tract velocity (r=0.26, P=0.001), and LV end-diastolic diameter (r=0.20, P=0.04) and marginally to serum creatinine level (r=0.15, P=0.08). Patients with a rate of reduction in AVA faster than the mean had higher serum creatinine (P=0.04) and calcium (P=0.08) levels. Those with a serum cholesterol level >200 mg/dL had a rate of AVA reduction roughly twice that of those with a lower cholesterol level (P=0.04). Stepwise multiple regression analysis identified initial AVA, current smoking, and serum calcium level as the independent predictors of amount of AVA reduction per year. Conclusions-Absolute and percentage reduction in AVA per year in those with AS is greater in those with milder degrees of stenosis and is accelerated in the presence of smoking, hypercholesterolemia, and elevated serum creatinine and calcium levels, These findings may have important implications in gaining further insights into the mechanism of AS progression and in formulating strategies to retard this process.