If observational findings of a correlation between statin therapy and slowed progression of aortic stenosis are confirmed, many patients could be spared valve-replacement surgery, according to an article in the November 20th issue of the Journal of the American College of Cardiology.

"It gives the hope that statins may have a therapeutic effect and reduce the speed of progression of aortic stenosis, and possibly in some patients may avoid the need for surgery," said the study's lead author, Dr. Maurice Sarano, M.D.

"In the past few years there has been a total change in our way of thinking because we realized that what was happening on the aortic valve was a phenomenon similar to atherosclerosis."

The comparison with plaques suggested that perhaps similar risk factors might play a role in the development of aortic stenosis, and that ultimately similar treatments might be beneficial. Dr. Sarano and his colleagues screened all adults with aortic stenosis in the county surrounding the Mayo Clinic. They measured the extent of valvular stenosis with ultrasound and followed 156 patients for an average of 3.7 years.

The researchers first looked for a link with cholesterol levels based on the close association between high cholesterol and atherosclerosis. "When we looked at that, we were initially somewhat disappointed, because we saw absolutely no association between the cholesterol level and the progression of aortic valve stenosis."

However, when the researchers compared changes in the measurement of aortic stenosis between the 38 patients who were taking a statin drug and the 118 patients who were not on statin therapy, the statin group had approximately one half the rate of progression of the patients not treated with statins.

"We were quite surprised and quite excited by that," said Dr. Sarano.

The result raised the question of why cholesterol-lowering treatment might have an effect when cholesterol levels themselves did not seem to be a factor in the progression of the disease. It appeared that other beneficial effects of statins, which have also been noted in other heart disease studies, may play a role in progression of stenosis.

In an accompanying editorial, Alan S. Pearlman, M.D., called the results tantalizing. "Their study and those of some others raise the intriguing possibility that the effects that lipid-lowering treatment may have on aortic stenosis progression rates may be separate from their effects on lipid lowering, and may be related to anti-inflammatory effects in particular."

Dr. Sarano noted that other studies have found that statin therapy appears to improve the body's handling of calcium, increasing deposition of calcium in the bones and decreasing calcium deposition in sites such as heart valves. Therefore, he concluded, it is possible that statins offer a triple benefit with regard to aortic stenosis by reducing cholesterol, inflammation, and calcium deposition.

Dr. Sarano said the study's findings need to be confirmed in clinical trials. "I don't think that we should treat patients now," he said. "We should formally test those medications in a clinical trial, so that we can know really that statins do decrease the progression of aortic stenosis."

Dr. Pearlman noted that the potential to delay or prevent heart valve replacement therapy in these patients is a goal worth pursuing. The findings of the Mayo Clinic team, he said, "appear to offer the promise that a safe and effective medical therapy for aortic stenosis is not just wishful thinking."