In a study of patients on cholesterol-lowering "statin" treatment, those who
had a heart attack during 3 years of follow up had significantly more buildup of
coronary artery calcium than those who did not have a heart attack, despite
similar LDL ("bad") cholesterol levels.
"Continued expansion of coronary artery calcium may indicate failure of some
patients to benefit from statin therapy and an increased risk of having
cardiovascular events," researchers suggest in the July issue of
Arteriosclerosis, Thrombosis, and Vascular Biology.
In comments to Reuters Health, Dr. Paolo Raggi from Tulane University in New
Orleans, Louisiana, who led the study, said statins are "greatly effective at
reducing the rate of heart attacks, but the event rate is reduced at best by 35
percent. Why are so many people--65 percent of those treated--still having
events?"
In the current study, Raggi and his colleagues monitored calcium buildup in
patients taking statins.
Of 495 participants with similar LDL levels and no symptoms, 41 had a heart
attack during follow up. On average, these patients showed a "greater and
faster" accumulation of coronary artery calcium than those who did not, Raggi
said.
In particular, he noted, the risk of a heart attack "was about 17-fold
greater" when calcium progression was substantial -- more than 15 percent per
year -- than when calcium buildup was absent.
However, the best predictor of a heart attack "was a combination of LDL level
and calcium change," Raggi explained.
This suggests, he concluded, that in addition to monitoring LDL cholesterol,
doctors should also "include some measurement of vascular health in our
assessment of the individual patient to have a clearer idea of his or her health
status."
SOURCE: Arteriosclerosis, Thrombosis, and Vascular Biology, July 2004.
