The American Heart Association’s 2013
recommendation for expanded statin use has raised eyebrows over whether the
medications are now prescribed too much.
But researchers at Washington University
have found that analyzing genetics may help doctors determine who is most
likely to benefit from the cholesterol-lowering therapy.
For their study, published on March 4th, 2015
- in The Lancet, scientists used
statistical methods to examine heart attack risk among a total of 49,000 people
enrolled in five studies.
Researchers
adjusted for traditional heart disease factors like age, sex, cholesterol
levels, smoking history and diabetes diagnosis to designate the group of
individuals deemed at a high risk for having a heart attack based solely on
their genetics.
According to a news release, the high-risk group had a 70
percent greater chance of having a heart attack compared to those at the lowest
genetic risk. And statins— which help improve cholesterol and thus lower the
likelihood of having a heart attack— helped reduce that risk by 48 percent
among the high genetic-risk group, compared to a 29 percent reduced risk among
the intermediate group and a 13 percent reduced risk among the low genetic-risk
group.
There is ongoing debate over which individuals should be
allocated statin therapy to prevent a first heart attack. Genetics appears to
be one way to identify high-risk patients.
The latest findings are new because previous studies haven’t
differentiated statin success among genetically different individuals. Prior
research has indicated the same relative risk reduction, from 30 to 45 percent,
across all categories of patients.
We need more research to confirm these results. Regardless, we
can at least say that patients with a high genetic-risk score appear to benefit
more from statin therapy because they’re starting at a higher baseline risk,
even controlling for all the clinical measures we routinely examine.
Study authors analyzed 27 individual components of each
patient’s DNA code to calculate their genetic-risk score. Previous research
suggests these 27 immutable “letters” are linked to coronary heart disease, and
that locations hold different weight with respect to risk.
Researchers also calculated the number of patients that doctors
would need to treat with statins to prevent one heart attack over a 10-year
period, and they observed that the high genetic-risk group saw the biggest
benefit from statin use, according to the news release.
Among the low genetic-risk group, doctors would need to treat 57
to 66 patients for 10 years to prevent a heart attack, while only 20 to 25 high
genetic-risk patients would need to take a statin for 10 years to prevent one
individual’s heart attack.
In fact, further research
needs to be done to determine whether a genetic-risk analysis may be an
effective tool to determine whether statins are appropriate for a given
patient. But he added that because DNA don’t change, the test has the potential
to detect heart attack risk even before traditional measures such as blood
work.
According to the Centers for Disease Control and Prevention
(CDC), the percentage of adults aged 40 and older using cholesterol-lowering
medication rose from 20 percent to 28 percent between 2003 and 2012. Statin use
climbed from 19 to 26 percent during that period, and from 2011 to 2012, about
93 percent of adults using a medication to combat high cholesterol reported
using a statin.
The American Heart Association and the American College of
Cardiology said in 2013 that statins could be prescribed to an estimated 33
million Americans without heart disease who have at least a 7.5 percent
risk for heart attack or stroke within the next 10 years.
In 2002,
federal cholesterol guidelines recommended that people take a statin only if
their 10-year risk level surpassed 20 percent— a suggestion based only on heart
disease risk, not stroke.
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