HealthDay
Reporter
MONDAY, Nov. 18, 2013 (HealthDay News) -- A new online cholesterol
risk calculator produced by two leading U.S. heart organizations is flawed and
overstates a person's risk of heart disease, a pair
of Harvard Medical School professors say.
The professors contend that this flaw could lead the calculator to
mistakenly suggest that millions of people should be taking cholesterol-lowering
statin drugs, The New York Times reported Monday.
Key officials with the American Heart Association (AHA) and the
American College of Cardiology (ACC) stood by the calculator during a hastily
gathered news conference Monday morning at the heart association's annual
meeting in Dallas.
Harvard professors Dr. Paul Ridker and Dr. Nancy Cook reportedly
pointed out problems with the calculator a year ago, saying that it did not seem
to work accurately when they tested it using patient data, the Times
reported.
When the online calculator went live last week, Ridker and Cook
again tested it and reported serious flaws that could overestimate a person's
risk of heart disease by 75 percent to 150 percent, the newspaper reported.
Their findings are to be published Tuesday in the medical journal The
Lancet, according to the Times' report.
AHA and ACC officials said Monday that the Harvard professors'
analysis of the calculator relied on patient data from three heart studies
involving people both younger and healthier than the average American.
"These people exist in the U.S. population, but it's a very
healthy, skewed group," said Dr. Donald Lloyd-Jones, chair of the department of
preventive medicine at Northwestern University's Feinberg School of
Medicine.
Lloyd-Jones said he and others met with Ridker on Saturday, as the
AHA meeting got under way, and reviewed a limited amount of the Harvard doctors'
data. He said he's still waiting to see the full report.
"I think all of us would like to see Dr. Ridker's data, and see
that play out in scientific discussion rather than in the media," Lloyd-Jones
said.
The two heart health groups said they
created the calculator -- as well as a set of aggressive new
cholesterol-lowering guidelines -- using a broad range of patient data that
allowed them to incorporate factors that hadn't been included in previous risk
assessments. For example, prior attempts did not include calculations for
African-American populations, and did not attempt to include stroke risk.
"The truth is, the risk equations work exactly the way we asked
them to," Lloyd-Jones said.
Officials from both heart groups added that just because the
calculator suggests some people would benefit from statins doesn't mean they
absolutely have to take them.
Instead, the calculator should prompt a conversation with their
doctor about whether they need to take statins or undertake other lifestyle
changes to lower their cholesterol.
"We're acknowledging the unique judgment of a physician when he
looks at the patient's specific condition," said Dr. Neil Stone, chair of the
AHA's cholesterol guideline committee and a professor of preventive cardiology
at Northwestern's Feinberg School of Medicine.
Cardiologists are
concerned that the confusion surrounding the calculator and new cholesterol
treatment guidelines could cause patients to refuse to take statins.
"I fear that the confusion is going to shake the public's
confidence in these lifesaving drugs," said Dr. Kevin Marzo, chief of cardiology
at Winthrop-University Hospital in Mineola, N.Y. "It is my hope that the
guideline writers will revise the online calculator so that any deficiencies
created will be quickly corrected."
The two heart groups unveiled the calculator last week in
connection with aggressive new guidelines for combating high
cholesterol. Those guidelines call for the use of statins to treat more
people.
Previously, doctors adhered to rigid clinical guidelines to
prescribe a statin when cholesterol
levels reached a certain threshold.
Under the new guidelines, people will be advised to take statins
based on a number of different health risk factors. These risk factors include
if they already have heart disease, if their bad (LDL) cholesterol is extremely
high (190 milligrams per deciliter of blood or more) or if they're middle-aged
with type 2 diabetes.
In addition, people between 40 and 75 years of age with an
estimated 10-year risk of heart disease of 7.5 percent or more are advised to
take a statin. Experts say this new rule could greatly alter the number of
patients who will now be advised to take such a drug.
"We've come up with an approach that calls for treating about a
third of adults between 40 and 75 years of age with statins for primary
prevention," said Dr. David Goff, co-chair of the risk assessment working group
for the guidelines and dean of the Colorado School of Public Health at the
University of Colorado-Denver.
"I think it sounds about right," given that one out of three
adults in America die from heart disease and stroke, Goff said.
The alleged problems with the calculator prompted at least one
prominent cardiologist to tell the Times that implementation of the new
cholesterol treatment guidelines should be delayed.
"It's stunning," Dr. Steven Nissen, chief of cardiovascular
medicine at the Cleveland Clinic, told the newspaper. "We need a pause to
further evaluate this approach before it is implemented on a widespread
basis."
Dr. Sidney Smith, a cardiologist at the University of North
Carolina at Chapel Hill and a past AHA president, said that would not
happen.
"We intend to move forward with these guidelines and develop
effective strategies to implement them," Smith said.
By Dennis Thompson
HealthDay
Reporter
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