Top cardiologists who devised new US
guidelines for reducing risk of heart disease strenuously defended their
risk-calculation tool from criticism that it greatly overestimates health risks
and the need to be treated with statins.
Two Harvard professors, Dr Paul Ridker and
Dr Nancy Cook, sparked the controversy by saying the guidelines overestimate
risk of developing heart disease up to 150% for some populations, according to
a report in New York Times. The report said their criticisms would appear in
the British medical journal The Lancet.
Their concerns spurred prominent
cardiologist Steven Nissen of the Cleveland Clinic to call for a delay in
putting the new guidelines into practice, the report said.
Nissen could not immediately be reached by Reuters.
A half dozen cardiologists who helped formulate the guidelines over a four-year
period criticized Ridker's own methodology at a hastily called news conference
during the annual scientific sessions of the American Heart Association (AHA)
the risk formula
"We intend to move forward with the
implementation of these guidelines," said Dr Sidney Smith of the
University of North Carolina, a past president of the AHA who was executive
chairman of the guidelines committee."If we think there is something that
will make them better, you can count on that we'll do it," Smith said.
The guidelines were created by panels of
experts from the AHA and the American College of Cardiology and include a
formula for calculating the risk of developing heart disease over 10 years.
The guidelines no longer focus mainly on
reducing the level of "bad" LDL cholesterol to specific targets, but
instead assess each patient's personal risk factors of developing heart
People 40 to 75 years old found to have a
7.5% or higher risk of heart disease within the next 10 years, as assessed by
factors plugged into the calculator such as being obese or having diabetes, are
encouraged to be treated with cholesterol-lowering statin drugs, such as Pfizer
Inc's Lipitor (atorvastatin).
"These guidelines have been vetted by
multiple experts many, many times," AHA President Dr Mariell Jessup said.
Authors of the new guidelines on Monday
said Ridker based his conclusions of overstated risk on three large population
studies that involved subjects who are far healthier than the general
risk assessment instrument
The new guidelines were based on more
representative populations and consider for the first time the risk of stroke
and factor in African Americans, a group with a disproportionately high risk of
heart attacks and stroke."We think we came up with a good risk assessment
instrument," Smith said.
The guideline authors said Ridker notified
them on Friday of his criticisms for the first time, and that they would appear
in the Lancet.
Moreover, several members of the guidelines
committee, in interviews, said Ridker reviewed the proposed guidelines in 2012
and did not cite any such concerns."We got his review and he did not say
anything about these three population studies at that time," said David
Goff, dean of the Colorado School of Public Health and co-chair of the
Dr Donald Lloyd-Jones, professor of
preventive medicine at North-western University, said Ridker had not yet
provided the guidelines committee with specific data that underscore his
concerns."We used what we thought were the best available data,"
Lloyd-Jones said. "We'd all like to see Dr Ridker's data instead of seeing
this played out in the media."Neither Ridker nor Cook could immediately be
reached for a comment.