The aortic valve is the one-way gate between the heart's main pumping chamber and the rest of the body. In aortic stenosis, this valve becomes narrowed and causes the heart to work harder. The only treatment for severe aortic stenosis is surgical replacement of the valve.
A new understanding of the aortic stenosis disease process led to the statin study. "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," says Maurice Sarano, M.D., the Mayo Clinic cardiologist who led the study. "Since the disease process is similar to what happens when plaques cause blockages in arteries, reducing the risk factors that lead to heart attack may also help keep the valve from narrowing."
Dr. Sarano and his colleagues screened all adults with aortic stenosis in Olmsted County, Minn. They measured the extent of aortic stenosis using ultrasound and then followed 156 patients for an average of 3.7 years. Because of the close association between high cholesterol and atherosclerosis, the researchers first looked for a link between cholesterol levels and worsening of aortic stenosis. "We were initially somewhat disappointed, because we saw absolutely no association," says Dr. Sarano.
However, when they compared changes in aortic stenosis measurements between the 38 patients who were taking cholesterol-lowering statin drugs and the 118 patients who were not on statin therapy, the statin-therapy patients had about half the rate of progression of the patients not treated with statins.
Dr. Sarano noted other studies have found statin therapy appears to improve the body's handling of calcium, increasing deposition of calcium in the bones, while decreasing potentially harmful calcium deposits in places such as heart valves. Therefore, he concluded, it is possible statins offer a triple benefit with regard to aortic stenosis by reducing cholesterol, inflammation and calcium deposition.
Dr. Sarano says the study's findings need to be confirmed in clinical trials. "While we are quite excited by the possibilities, I don't think we should immediately begin prescribing statins for these patients yet," he said. "We ought to formally test those medications in a clinical trial, so we can be more certain that statins do decrease the progression of aortic stenosis. If these findings are confirmed, we may be able to eliminate the need for valve replacement surgery in many patients."
Lee Aase
507-284-5005 (days)
507-284-2511 (evenings)
e-mail: newsbureau@mayo.edu
Journal
Journal of the American College of Cardiology