Heart specialists at the
Johns Hopkins Heart Institute have been awarded more
than $1.5 million from the France-based Leducq Foundation
Trans-Atlantic Network of Excellence to study the genetic
origins of sudden cardiac death. An estimated 1 million
Americans or more die each year from sudden heart attacks,
a third of them due to disturbingly fast and abnormal
heartbeats that wreck the heart's normal electrical
rhythms.
The five-year Leducq funding is part of an
international effort across four countries — the
United States, France, Germany and the Netherlands —
to identify genes involved in the process. The Johns
Hopkins researchers hope the study will eventually lead to
a screening test for those at risk. Fewer than 10 percent
survive sudden heart attacks.
"This latest effort combines for the first time
international resources that comprise unique collections of
DNA and electrocardiographic information on hundreds of
patients who experience sudden cardiac death events," said
cardiology investigator Peter Spooner, an associate
professor at the Johns Hopkins School of Medicine and its
Heart Institute, who will serve as a lead investigator.
"One of our priorities at Hopkins is to expand existing
research on related matters being studied in our Reynolds
Cardiovascular Clinical Research Center." Spooner is
executive director of Hopkins' Reynolds Center.
Nearly a dozen Johns Hopkins faculty and staff,
including cardiologists, geneticists, physiology
technicians and research nurses, will be involved in the
Leducq initiative, which will also involve research centers
in Nashville and Miami.
Research at Hopkins and elsewhere has uncovered
substantial evidence that the risk of fatal arrhythmias is
linked to mutations in the genes that control the heart's
electrical signaling machinery. "These mutations could well
serve as markers for heightened risk and buy time for
medical and surgical interventions to reduce the risk,"
Spooner said.
Preventive therapies include implantation of a cardiac
defibrillator to reset normal rhythms and drugs that
stabilize rhythms.
An understanding of the genetics could also lead to
further targets for treatment, said Eduardo Marban,
professor and chief of
cardiology at the Johns Hopkins School of Medicine and
its
Heart Institute.
Marban said that even a minor improvement, from 10
percent to 20 percent, in determining who is more at risk
of sudden cardiac death could lead to saving more than
100,000 Americans each year. Marban, who also is the
Michel Mirowski, M.D., Professor of Medicine at Hopkins and
director of its Reynolds Center and Institute of Molecular
Cardiobiology, will serve as site co-principal investigator
with Spooner. Aravinda Chakravarti, a professor at Hopkins'
McKusick-Nathans Institute of Genetic Medicine and an
authority on diseases with multiple genetic roots, will
serve as collaborating investigator. Study results are not
expected until 2010.