August 24, 2004
DALLAS, TX (AHA)
– Early cholesterol-lowering drug therapy after
hospitalization for acute coronary syndrome appears to reduce
artery-clogging plaque, according to a study reported in
Circulation: Journal of the American Heart Association.
This was true even among patients who did not have very
high low-density lipoprotein (LDL or “bad”) cholesterol
levels. Acute coronary syndrome includes unstable angina
(chest pain), ST-elevation or non-ST elevation heart attack.
“This is the first evidence that plaque can regress with early
statin treatment in heart attack patients,” said Shinya
Okazaki, M.D., the study’s lead author and an instructor in
the department of cardiology at Juntendo University School of
Medicine in Tokyo. “This evidence provides further support for
the use of statins after a heart attack.”
Researchers studied 70 patients who had emergency procedures
to re-open narrowed arteries after having heart attacks or
unstable angina. Half of the patients received daily 20 mg
doses of the cholesterol-lowering drug atorvastatin. The other
half (control group) received a cholesterol-lowering diet. If
their LDL cholesterol level was still very high (150 mg/dL or
higher) a month later even with the diet, doctors prescribed a
cholesterol absorption inhibitor.
“We hypothesized that the early statin treatment would reduce
artery plaque volume after a heart attack and, therefore,
would decrease one’s chance of having another heart attack,”
Okazaki and colleagues measured each patient’s plaque volume
using intracoronary ultrasound technology at the start of the
study and after six months of therapy.
They found, at six months, that the LDL-C level was decreased
by 41.7 percent in the atorvastatin group compared with a 0.7
percent increase in the control group.
The plaque in the vessel was reduced by an average of 13.1
percent in the atorvastatin group, but it increased — by an
average of 8.7 percent — in the control group.
“The positive effect of atorvastatin was evident whether
people went into the study with an LDL-C above 125 mg/dL or
not, indicating that this lipid-lowering therapy would be
beneficial whether people who have heart attacks have very
high cholesterol or not,” Okazaki said. “It could be that,
when it’s given for six months immediately after heart attack,
the therapy targets the ‘vulnerable,’ lipid-rich plaque in the
Okazaki said early cholesterol-lowering may not only cause
vulnerable plaque to regress, but might also stabilize it,
although this was not assessed in this study. This could be an
important way to reduce the chance of a recurrent heart attack
— regardless of a patient’s LDL-C level. In this small,
short-term study, there were no differences in cardiac events
(heart attack, cardiac death, angina, repeat angioplasty or
repeat bypass surgery.)
Future studies should examine how statin therapy stabilizes
plaque early after a heart attack, as well as the effects of
other new LDL cholesterol-lowering drugs, he said.
Co-authors are: Takayuki Yokoyama, M.D.; Katsumi Miyauchi,
M.D.; Kazunori Shimada, M.D.; Takeshi Kurata, M.D.; Hitoshi
Sato, M.D.; and Hiroyuki Daida, M.D.