Cardiac breakthrough: Scientists find genetic clues to heart disease

The breakthrough study findings might pave way for the treatment and even prevention of the world's number one killer that claims more than 90,000 lives a year in the UK.

Dr Robert Roberts, of the University of Ottawa Heart Institute, Canada, said in a press release: “This is a landmark result because we have identified so many genes and most operate using completely unknown mechanisms to us right now.

“Now our job is to understand how these genes work, develop a new group of drugs to target them and identify people who will benefit most.”

Study details
In order to examine the genetic basis of heart disease, the researchers analyzed data collected from an international consortium of 150 researchers participating in 14 genomic studies conducted all over the world, including the United States, Iceland, Canada, and Great Britain.

For this purpose, the researchers studied genetic profiles of more than 140,000 people including more than 50,000 with coronary heart disease in order to identify the DNA variations among people suffering with the condition.

“The consortium examined more than 10 times the number of samples than the largest study ever published, so we magnified the power to detect small genetic variations,” said Dr. Roberts.

The study authors also focused on genetic links to the narrowing of the arteries that supply oxygen-rich blood to the heart. This narrowing, caused by the build up of fatty deposits or plaques, raises the odds of a host of ills, from blood clots to angina, heart attacks, heart failure and irregular heartbeats, the Daily Mail reports.

The study, called CARDIoGRAM (Coronary Artery Disease Genome-wide Replication and Meta-Analysis), is one of the world’s largest studies on heart disease risk.

Apart from lifestyle factors such as smoking, drinking alcohol, unhealthy eating, and lack of physical exercise that are known to increase the risk of heart attack and stroke, the researchers looked at the DNA maps of participants to find genes that might increase the cardiovascular risk.

Study findings
The study found that only three out of 13 new genes discovered were found to be linked with the traditional risk factors such as high cholesterol and blood pressure, diabetes, smoking and obesity.

Researchers say that up to 40 percent of heart disease can be prevented by modifying cholesterol, high blood pressure, smoking and other lifestyle causes. At the same time, it is known that about 50 percent of the risk of heart disease is due to genetic factors, the Telegraph reports.

It was found that the influence of majority of new genes is independent of the other established risk factors.

Professor Nilesh Samani, of the University of Leicester, who co-led the largest of the studies, said, “The most exciting thing about our study is that we have discovered several new genes not previously known to be involved in the development of coronary heart disease, which is the main cause of heart attacks.

“Understanding how these genes work, which is the next step, will vastly improve our knowledge of how the disease develops, and could lead to new treatments.”

The findings are published in the March 6 online issue of the journal 'Nature Genetics.'

Implications of the study
Researchers around the world are hopeful that the findings could lead to new and effective treatments for the disease and help diagnose those at the risk from the condition in future.

Themistocles Assimes of Stanford University School of Medicine in the United States, one of the scientists who worked on the study, "With such information we should be able to better identify people at high risk early on in life and quickly take the steps to neutralize that excess risk.

"Although we are inching closer to that day, we will probably need to reliably identify many more variants...over the next few years before it becomes useful perform this genetic profiling in a doctor's office."