Major Breakthrough in Identifying Patients at High Risk of Sudden Cardiac Death
Researchers at the Smidt Heart Institute have recently enhanced a polygenic risk score that can identify patients who are most likely to experience sudden cardiac arrest. As a condition arising from the heart's electrical system, sudden cardiac arrest is fatal in 90% of cases.
Because it can rapidly lead to a swift loss of heart function, breathing, and consciousness, sudden cardiac arrest causes up to 300,000 deaths every year in the United States.
If the person experiencing this condition does not receive emergency treatment immediately, they will pass away.
The Smidt Heart Institute is the finest cardiology and heart surgery center in California and the premier center of expertise for transcatheter aortic valve replacements in the nation. It is part of the Cedars-Sinai academic health science center. To identify people who are the most susceptible to sudden cardiac arrest, researchers used a polygenic risk score that has proven successful in predicting coronary artery disease in the past. However, this study, which was published in the Journal of the American College of Cardiology, is the first that is effective in pinpointing coronary artery disease patients with the highest risk of sudden cardiac death.
According to the study, patients with coronary artery disease without severely impaired heart function had the highest polygenic risk score, which means they have a 77% greater risk for sudden cardiac death. "We found incorporating information from this genetic risk score improved our ability to predict sudden death beyond the contributions of other known risk markers. Most exciting, the genetics were able to identify patients where sudden death was more likely to limit their life expectancy," said Roopinder Sandhu, MD, MPH, first author of the study and associate professor of Cardiology.
Sudden cardiac arrest should not be mistaken for a heart attack, which is the result of clogged arteries reducing blood flow to the heart muscle
The former condition occurs when there is a sudden onset of abnormal electrical activity that impairs the heart's pumping function. Most patients are unaware they experience a sudden cardiac arrest, as they usually do not have symptoms. This is why the vast majority of sudden cardiac arrests lead to death. If resuscitation is not performed within several minutes, the person will lose their life.
Having coronary artery disease is the most common underlying cause of sudden cardiac death. "In order to better predict and prevent sudden cardiac death, we must first understand the genetic connection between it and coronary artery disease," said Roopinder Sandhu, MD, MPH. By having a better understanding of coronary artery disease, researchers believe they will be able to identify the patients at high risk of sudden cardiac arrest, which will grant these people access to lifesaving devices such as defibrillators. Currently, 70% of sudden cardiac deaths occur in patients who do not meet the guidelines for prevention with defibrillator therapy.
At the moment, contemporary practice neglects most individuals who are likely to experience sudden cardiac arrest. Furthermore, electrophysiologists often place defibrillators in patients with advanced heart disease who rarely benefit from these devices because of their short life expectancy. "This study indicates there is opportunity to identify patients at highest risk for sudden cardiac death, and then offering meaningful, preventative treatment solutions like a defibrillator. Based on our pivotal research, we now have the foundation to achieve this," said Christine Albert, MD, MPH, senior author and chair of the Department of Cardiology at the Smidt Heart Institute.