Tailoring treatment to risk factors
for MI better than targeting cholesterol levels
A new study by the University of Michigan Medical School
and VA Ann Arbor Health System challenges the medical thinking that the lower
the cholesterol, the better.
Tailoring treatment to a patient's overall risk for cardiovascular
disease by considering all their risk factors, such as age, family history, and
smoking status, was more effective, and used fewer high-dose statins, than current
strategies to drive down cholesterol to a certain target, according to the study.
While study authors support the use of cholesterol-lowering
statins, they conclude that patients and their doctors should consider all the
factors that put them at risk for myocardial infarction and strokes.
The findings will be released online Monday ahead of
print in the Annals of Internal Medicine.
"We've been worrying too much about people's cholesterol
level and not enough about their overall risk of heart disease," says Rodney
A. Hayward, M.D., director of the Veterans Affairs Center for Health Services
Research and Development and a professor of internal medicine at the University
of Michigan Medical School.
The National Cholesterol Education Program recommends
harmful LDL cholesterol levels should be less than 130 for most people. High-risk
patients should be pushed even lower -- to less than 70.
The U-M study took a different approach, called tailored
treatment, which uses a person's risk factors and mathematical models to calculate
the expected benefit of treatment, by considering:
-- A person's risk of a heart attack or stroke without
treatment; -- How much a statin decreases the risk; and -- Potential harms from
the treatment
"These are the three factors that determine the net benefit of a treatment.
Our fixation on just one factor, LDL cholesterol, is leading us to often treat
the wrong people," Hayward says.
In the recent study, U-M physicians who worked with Yale
University School of Medicine used data from statin trials that included Americans
ages 30-75 with no history of myocardial infarction.
Study authors evaluated the benefit of five years of
treatment that was tailored, on coronary artery disease risk factors such as age,
family history, diabetes, high blood pressure, smoking status, and recently CRP,
C-reactive protein.
The tailored approach was more efficient and prevented
substantially more heart attacks, strokes and cardiovascular deaths than the currently
recommended treat-to-target approaches.
The tailored strategy treated fewer individuals with
high-dose statins and saved 500,000 more quality-adjusted life years.
"The bottom line message -- knowing your overall
heart attack risk is more important than knowing your cholesterol level,"
Hayward says. "If your overall risk is elevated, you should probably be on
a statin regardless of what your cholesterol is and if your risk is very high,
should probably be on a high dose of statin," the U-M physician says.
"However, if your LDL cholesterol is high, but your
overall cardiac risk is low, taking a statin does not make sense for you,"
Hayward says. "If your cholesterol is your only risk factor and you're younger,
you should work on diet and exercise."
Research has increasingly emerged questioning the value of cholesterol targets
and which of statins mechanisms is most important to preventing cardiac events.
"Statins also affect inflammation on the inside
of our blood vessels which is often what causes heart attacks and strokes -- it's
not just a matter of cholesterol alone," Hayward says.
Additional authors are Harlan M. Krumholz, M.D., Yale
University School of Medicine, and Donna M. Zulman, M.D., Justin W. Timbie, Ph.D.,
and Sandeep Vijan, M.D., all of the VA Center for Health Services Research and
Development, VA Ann Arbor Health Care System.
This study was funded by the VA Health Services Research
and Development Service's Quality Enhancement Research Initiative and the Measurement
Core of the Michigan Diabetes Research & Training Center of the National Institutes
of Health.
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