Could a Shot Reduce Heart Attack Risk by 40 to 90 Percent?

Researchers from the Harvard Stem Cell Institute (HSCI) along with those at the University of Pennsylvania have developed a single injection that could help reduce the risk of heart attacks in humans by 40-90 percent. Though the "genome-editing" approach that helps to reduce cholesterol has just been tested in mice at this time, the study, published in Circulation Research, could help to prevent this health issue.

"For the first iteration of an experiment, this was pretty remarkable," said Kiran Musunuru of HSCI, an assistant professor in Harvard's Department of Stem Cell and Regenerative Biology (SCRB), in a news release. He is also cardiologist at Harvard-affiliated Brigham and Women's Hospital. However, Musunuru stressed that getting the new approach to work successfully in humans could take over a decade.  

In 2003, a group of researchers in France studied families with high cholesterol levels and early heart attacks discovered through a liver gene called PCSK9. The team discovered that mutations found in the gene could have been responsible for high cholesterol levels and the heart attacks, resulting in these extremely rare mutations that cause such issues at a very young age.

However, an alternate research group in Texas discovered that about 3 percent of the population who carry this mutation in PCSK9 have the opposite effect, with 15 to 28 percent of individuals experiencing low-density lipoprotein (LDL) cholesterol levels. Those individuals had a heart attack risk that ranges from about 47 to 88 percent below average.

"Our reasoning was that nature has already done the experiment; you have people who have won the genetic lottery," said Musunuru, in the news release. "They are protected from heart attack, and there are no known adverse consequences. So that led us to reason that if we could find a way to replicate this, we could significantly protect people from heart attack."

"The PCSK9 gene is expressed primarily in the liver," explained Musunuru, "and produces a protein that is active in the bloodstream and prevents the removal of cholesterol from the blood. Several drug companies have been developing antibodies" to it, he said, but "the problem with antibody-based drugs is they don't last forever; you'd need an injection every few weeks. The main option for reducing cholesterol is statin drugs, such as Lipitor, but many people taking statin drugs every day still have heart attacks. So there is still a great need for other approaches."