MRI Scan Reveals How Cholesterol Drugs Work
Imaging Shows Cholesterol-Lowering Statins Shrink Plaque
July 5, 2005 -- High-tech scans may show how cholesterol-lowering statin
drugs work to prevent heart disease.
In a new study, high resolution MRI (magnetic resonance imaging) scans
showed that treatment with statins shrank artery-clogging plaques in people
with high cholesterol.
Researchers say those plaque-fighting benefits were in addition to statins'
already proven effects of lowering LDL "bad" cholesterol levels in
Atherosclerotic plaque can rupture. A "vulnerable" plaque which
ruptures leads to clots that cause heart attacks and strokes. Reducing LDL
cholesterol in blood helps reduce the risk of heart disease.
"In the mostly average patients, if you are able to achieve an LDL lower
than 100 milligrams per deciliter, you will be able to significantly avoid
plaque progression and you may even induce plaque regression," says Juan J.
Badimon, PhD, of the Mount Sinai School of Medicine in New York City, in a news
Statins May Shrink Plaques
In the study, which appears in the Journal of the American College of
Cardiology, researchers followed 51 people recently diagnosed with high
cholesterol. On scanned images, all the participants had plaque lesions of the
major vessel. They received either 20 milligrams or 80 milligrams of Zocor
After a year and a half of treatment, MRI scans showed that both groups
ended up with similar reductions in plaque size, regardless of the strength of
their statin dose.
Although this study used MRI to measure the effect of statin treatment on
reducing plaque size, researchers say not every person using statins needs to
have their arteries scanned.
Reduction in the size of blood vessel wall plaque was greater in people
whose LDL cholesterol dropped below 100 mg/dl. Therefore, monitoring LDL
cholesterol can also be used to gauge the effectiveness of statin therapy.
In addition, the group that received the higher statin dose experienced a
46% reduction in LDL levels compared with a 36% reduction in LDL among those
with the lower dose.
The researchers note that the group assigned to receive the higher dose also
had higher LDL levels at the start of the study. However they reached similar
absolute reductions in cholesterol.
"The change in blood vessel wall [plaque size] is more related to LDL
reduction rather than to the dose of statin," they conclude.
Merck, which makes Zocor, partially funded the study, but researchers
conducted the study without any input from those supplying the funds. Merck is
a WebMD sponsor.