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(HealthNewsDigest.com) – DALLAS, July 26, 2011 (GLOBE NEWSWIRE) — People are significantly more likely to inherit a predisposition to heart attack than to stroke,
according to research reported in Circulation: Cardiovascular Genetics, an American Heart Association journal.
The study results have implications for better understanding the
genetics of stroke and suggest the need for separate risk assessment
models for the two conditions.
“We found that the association between one of your parents having a
heart attack and you having a heart attack was a lot stronger than the
association between your parent having a stroke and you having a
stroke,” said senior author Peter M. Rothwell, M.D., Ph.D., professor
of clinical neurology at Oxford University in England. “That suggests
the susceptibility to stroke is less strongly inherited than the
susceptibility to heart attack.”
A second analysis, which included patients’ siblings as well as
parents, yielded the same result: Family history proved a stronger risk
predictor for heart attack than for stroke.
Rothwell and his colleagues conducted the study to clarify and confirm
evidence suggesting a great difference in genetic predisposition
between heart attacks and strokes. “We had found previously that much
of the heritability of stroke is related to the genetics of high blood
pressure, which doesn’t seem to be the case for heart attack,” Rothwell
said. Hypertension appears to be closely related with stroke rather
than heart attack, which is why a family history of hypertension is
related to a higher risk of stroke.
In the report published today, all patients were enrolled in the
ongoing Oxford Vascular Study. OXVASC, as the study is known, that
began in 2002 to study strokes, heart attacks and other acute vascular
events in a part of Oxfordshire County where more than 91,000 people
are served by one hospital. Previous analyses in the same population
conducted by lead author, Amitava Banerjee MPH PhD, have shown the
particular importance of family history in mother-daughter transmission
in both heart attacks and stroke. “Family history of heart attacks and
family history of strokes have rarely been studied in the same
population,” Banerjee said.
The researchers used data from 906 patients (604 men) with acute heart
ailments and 1,015 patients (484 men) who suffered acute cerebral
events. Among the study’s findings:
— In the heart patients, 30 percent had one parent who’d had a heart
attack, 21 percent had at least one sibling who had suffered a heart
attack. Seven percent had two or more siblings who had heart attacks and
5 percent had two parents with heart attack.
— Among the patients with a stroke or transient ischemic attacks (TIAs,
often called a mini-strokes or warning strokes), 21 percent had one
parent who had a stroke, and 2 percent had two parents with stroke.
Eight percent had at least one sibling with a stroke and 1.4 percent had
at least two siblings with stroke.
— The risk of a sibling developing acute heart problems was similar for
those with heart attack or stroke.
— The risk for an acute cardiac event was six times greater if both
parents had suffered a heart attack and one-and-a-half times greater if
one parent had a heart attack. In contrast, the likelihood of stroke
did not change significantly with parents’ stroke history.
The findings, if confirmed by additional studies, hold two significant
implications, Rothwell said.
“First, the way physicians predict the odds of a healthy person
suffering a heart attack or stroke needs refining,” he said.
“Currently, most risk models lump a patient’s family history of stroke
and heart attack together. We probably should model family history of
stroke and heart attack separately in the future.”
The new data also indicated that using the same criteria to predict
both medical events overestimate the risk of stroke, he added. “The
knowledge of genetic factors in stroke lags behind that in coronary
artery disease,” Rothwell said. The discovery that genes play a
significantly smaller role in stroke could mean that genetic studies of
stroke may not be critical to the field, he added.
Co-authors are Amitava Banerjee, MPH Ph.D.; Louise E. Silver, R.G.N.,
Ph.D.; Carl Heneghan, Ph.D.; Sarah J. V. Welch, R.G.N. MA; Ziyah Mehta,
Ph.D.; and Adrian P. Banning, M.D.
Author disclosures and funding are on the manuscript.
Statements and conclusions of study authors published in American Heart
Association scientific journals are solely those of the study authors
and do not necessarily reflect the association’s policy or position.
The association makes no representation or guarantee as to their
accuracy or reliability. The association receives funding primarily
from individuals; foundations and corporations (including
pharmaceutical, device manufacturers and other companies) also make
donations and fund specific association programs and events. The
association has strict policies to prevent these relationships from
influencing the science content. Revenues from pharmaceutical and
device corporations are available at
www.americanheart.org/corporatefunding.
NR11 — 1107 (CircGEN/Rothwell)
Additional resources :
— More information about heart attacks can be found at
www.heart.org/heartattack
- Downloadable stock footage, animation
and our image gallery are located at www.heart.org/news under
Multimedia.###
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