Researchers at Cedars-Smidt Sinai's Heart Institute are getting closer to identifying patients who are most at risk of suffering from sudden cardiac death, which is when the heart stops beating due to an electrical problem.

Researchers employed a polygenic risk score that has been successfully used to predict coronary artery disease to determine those who are most at risk. But this Cedars-Sinai study is the first to have its efficacy for identifying individuals with coronary artery disease who are most at risk for sudden cardiac death.

According to the study, patients with coronary artery disease who did not have severely compromised heart function had the highest polygenic risk scores, which translated to a 77% higher risk for sudden cardiac death. The study was published on August 23 in the Journal of the American College of Cardiology.

We must first comprehend the genetic relationship between sudden cardiac mortality and coronary artery disease, according to Roopinder Sandhu, MD, MPH, associate professor of cardiology and the study's first author.

We discovered that using data from this genetic risk score, in addition to other known risk factors, enhanced our capacity to predict sudden death. The ability of genetics to pinpoint people whose life expectancy was more likely to be shortened by unexpected death was the most exciting.

Contrary to heart attacks (myocardial infarctions), which are frequently brought on by blocked coronary arteries that reduce blood flow to the heart muscle, sudden cardiac death is typically brought on by the abrupt onset of erratic electrical activity that compromises the heart's ability to pump blood. Patients may experience little to no warning, and if no resuscitation is carried out, the illness usually results in death within minutes.

About 300,000 people die in the United States each year from sudden cardiac death, also known as sudden cardiac arrest, which accounts for 15% to 20% of all fatalities globally. The primary underlying cause of sudden cardiac death is coronary artery disease. Future research, according to Sandhu, may make it easier to pinpoint patients who might benefit most from life-saving treatments like a defibrillator.

Currently, 70% of sudden cardiac deaths occur in individuals who don't follow the recommendations for defibrillator therapy prevention. Therefore, a modern practice not only disregards the majority of people who experience sudden cardiac death but also has electrophysiologists implant defibrillators in patients with severe heart disease who are frequently unlikely to benefit from them due to short life spans.

The JACC study is based on data from the observational study PRE-DETERMINE, sponsored by the National Institutes of Health, which sought to more precisely identify people at risk for sudden cardiac death among the larger population of coronary artery disease patients who did not have advanced heart disease.

"This study indicates there is an opportunity to identify patients at highest risk for sudden cardiac death and then offer meaningful, preventative treatment solutions like a defibrillator," said Christine Albert, MD, MPH, chair of the Department of Cardiology at the Smidt Heart Institute and senior author. We now have the groundwork to accomplish this thanks to our crucial study.