By Matt Jones
NEW YORK (GenomeWeb News) – Researchers at the Cedars-Sinai Heart Institute will use a $1.7 million grant from the National Heart, Lung, and Blood Institute to use electrophysiology, genomics, and data from a large heart study to develop a system to predict which individuals may experience sudden cardiac arrest.
The four-year grant will support research at the Los Angeles research hospital aimed at increasing the potential treatment options for people who are struck by sudden cardiac arrest, a heart rhythm disruption that is far deadlier than heart attacks, which are often caused by coronary artery problems.
"Cardiac arrest is probably the most difficult human condition to take care of, because it is the only human disease where there is a 95 percent chance of dying instantaneously," the principal investigator and Associate Director of the Cedars-Sinai Heart Institute, Sumeet Chugh, told GenomeWeb Daily News today.
"The reason it is so difficult is that by the time it happens, it's too late… there's no cancer like that, really no other human disease like that," he added.
Because these sudden events happen outside of the hospital, where treatments are not available, "prevention acquires a very important significance for this particular condition," Chugh said.
There are some treatment options for sudden cardiac arrest, most notably implantable defibrillators, but because there is no easy way to know who needs them, these tools are not as useful as they can be, and they can be expensive and wasteful.
Chugh said that research has shown that a delay in electrical impulses as they travel through the heart ventricles, which is called a prolonged QRS duration, can lead to sudden cardiac arrest, and that studying the genomes of people with this QRS problem could lead to new ways to predict who may be most in need of treatments.
Chugh and his research partners are using a Portland, Ore.-based research effort to cultivate phenotype and genotype data on people who experience sudden cardiac arrests. The Oregon Sudden Unexpected Death Study generates information based on the roughly 1 million people in the Portland area, including clinical and medical information and blood samples that can be used for biomarker testing and for DNA. Whenever someone in the area has a sudden cardiac death, the study provides a range of data to Chugh's Portland-based research team.
"For the first time anywhere in the world we have been able to combine all the clinical issues a patient might have had and what happens in the community," he said. For example, "Are they rich or are they poor? What kind of work do they do? — and we're able to combine this with what is in their blood and what is in their genome," Chugh said.
Chugh's research at Cedars-Sinai has identified a spot in the genome that is linked to protection from cardiac arrest, and other research is pointing to genetic variants that may be predictive to those who are susceptible of cardiac arrest.
The researchers are conducting microarray-based studies in partnership with Johns Hopkins University to match genotype and phenotype correlations that could be used to develop a risk score for patients that could improve the ability to predict cardiac arrest.
"We know that there's not going to be one magic marker; it's a complicated illness. It's going to be a combination of genotype, phenotype, and environmental correlations," Chugh said.
Once such a risk scoring method is developed, he said, the goal will then be to move it into trials in a clinical setting. Chugh, a cardiologist who runs the Sudden Death Genomics Laboratory at the Heart Institute, said that he expects his team at Cedars-Sinai would be able to pursue such a test's use in the clinic.