Measuring the Power of Statins
Scan assesses how well the drugs lower calcium buildup in arteries
MONDAY, Aug. 5, 2002 (HealthDayNews) -- Peering into the arteries of people who take statins, German cardiologists say they can see how well the cholesterol-lowering drugs are working.
They used a widely available technique called electron beam tomography (EBCT) and focused on calcium, a major player in the process of atherosclerosis, which can transform a fatty, flexible plaque into rigid, fragile deposits that can break off and form an artery-blocking clot, says a report in tomorrow's issue of Circulation.
"Calcium is a good surrogate marker for the amount of atherosclerosis in coronary arteries," explains study author Dr. Stephan Achenbach, a staff cardiologist at the University of Erlangen- Nurnberg. "From outside, it is difficult to tell if atherosclerosis is progressing. Looking at calcium by EBCT is an easy, noninvasive test that tells you how much atherosclerosis is present."
The ideal would be to use ECBT as a routine test to check on the state of arteries so statin treatment could be regulated appropriately, Achenbach says. "But we do not know yet whether the test is accurate enough so that we could look at one patient, and change the way we treat," he adds.
The two-year study, which is the first to examine how reducing cholesterol levels affects calcium buildup, included 66 patients, all of whom had blood cholesterol readings higher than the 130 danger level.
Each had an EBCT scan at the start of the study. For a year, they did not take a statin. A second EBCT scan showed an average increase of coronary calcium of 25 percent. Statin treatment was started and, after one year, the calcium buildup was reduced to 8.8 percent, on average.
"Average" is the key word, Achenbach says, because the results varied widely from patient to patient. "There is variability to the test," he says. "We need further research to find methods that permit us to assess the efficacy of treatment in one single patient."
Dr. Philip Greenland is chairman of the department of preventive medicine at Northwestern University and a spokesman for the American Heart Association. He says, "I agree with the authors of the paper. The average finding was that intensively treated patients seemed to get a reduction in calcium buildup, but there is a fair amount of variability here."
The German results "would suggest that the drug had an effect on slowing calcium buildup," Greenland says. "I would buy that, because we have other studies that suggest that is going on. So, this is a new way of demonstrating something we already know.
"What is really new is whether this fairly readily available test now can be used to monitor patients. My answer is not yet, because of the variability of the results. Some patients had a lowering, others had a buildup, and we don't have any alternative assessment of what is going on in the arteries," he says.
The good news, Greenland says, is the German study adds to the growing body of evidence about the beneficial effects of statins.
"It is confirmation of what we know, that cholesterol lowering is a good thing," he says. "As to the role of this test in monitoring patients, that is up in the air."
What To Do