Loma Linda, CA - Aortic stenosis (AS) progresses more rapidly in patients who have milder degrees of stenosis initially, and who also smoke, have hypercholesterolemia, and have elevated serum creatinine and calcium levels. These findings may lead to further insights into the mechanism of AS progression and eventual strategies to retard this common disease, investigators write in the May 30, 2000 issue of Circulation.1

To determine predictors of AS progression, Dr Sanjeev Palta and colleagues (Loma Linda VA Medical Center University and Loma Linda University) retrospectively studied 170 consecutive subjects who had any degree of AS and who had paired echocardiograms 3 or more months apart. The majority of the study cohort (78%) was men and subjects' ages ranged from 62 to 80. Aortic stenosis progression was assessed according to the yearly rate of reduction in aortic valve area (AVA). Clinical and biochemical data, including history of current smoking, serum calcium, creatinine, and cholesterol levels, were also obtained.

High cholesterol doubled rate of AVA reduction
The rate of AS progression varied widely from patient to patient, with a mean annual rate of AVA reduction of 0.10 0.27 cm2 or 7% 18%. Smoking and male sex were two of the clinical characteristics that were associated with faster AS progression, but hypertension, diabetes, and age were not. Larger initial AVA, high serum cholesterol, and high levels of serum creatinine and calcium were also associated with more rapid progression of AS. Individuals whose cholesterol levels were higher than 200 mg/dL had a rate of AVA reduction that was roughly twice that of those with a lower cholesterol level, Palta and colleagues wrote.

As has been found previously, progression of AS was slower in severe stenosis. The investigators speculate that the "stretching effect of a larger gradient in patients with more severe AS retards progression." Higher left ventricular (LV) outflow tract velocity also accelerated the advance of AS, leading the investigators to comment on the potential importance of mechanical factors in disease progression. "Clearly, the effect of LV size, function, and mechanical influences on the aortic valve need further evaluation."

The effect of hypercholesterolemia is "new"
Palta et al. note that their finding that high cholesterol levels were linked to more rapid disease progression is "new", although its association with AS progression in the bicuspid valve has been documented in cases of familial hypercholesterolemia.

The investigators caution that theirs is a retrospective study and that the population is too small to exclude the contribution of other risk factors to AS progression. Although several new risk factors, including elevated serum creatinine and calcium, have emerged, the mechanisms by which they operate are not clear and require further elucidation.

They conclude that the rate of AS progression is unpredictable in a given patient and that modifying known cardiovascular risk factors, such as smoking and cholesterol, and managing other biochemical factors may be important for secondary prevention in these patients.

Obtained from theheart.org...
10/2/2013 08:51:20 am

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