September 25, 2013 — A new clinical study of patients who died of sudden cardiac arrest, a usually fatal condition that causes the heart to stop beating, shows the majority who qualified to receive potentially lifesaving treatment did not receive it.
Researchers led by Sumeet Chugh, M.D., associate director of the Cedars-Sinai Heart Institute, examined medical records of 2,093 patients who died of sudden cardiac arrest and found that only 488 patients, or about 20 percent, were medically evaluated to see if they met the criteria to receive an implantable cardiac defibrillator, which can shock a stopped heart into beating. Of those 488 patients, 92 were eligible to receive this treatment. However, further analysis showed that just 12 patients of those who were eligible received a defibrillator.
“That tells us that even people who meet the guidelines, for some reason, are not getting this therapy,” said Chugh, the Pauline and Harold Price Chair in Cardiac Electrophysiology. “The data show that most people aren’t screened for sudden cardiac arrest, but even when they are eligible, they still are not getting proper treatment.”
The analysis of data from the Oregon Sudden Unexpected Death Study is published online by Circulation, the medical journal of the American Heart Assn., and is scheduled to appear in the printed edition of the publication dated Oct. 15, 2013.
“The purpose of guidelines is to deploy treatments in the right people,” Chugh said. “It’s not a question of more defibrillators or fewer, but a question of providing defibrillators to the patients who need it the most.”
Guidelines are standards of treatment established by a consensus of medical experts. Additionally, the U.S. Centers for Medicare & Medicaid Services establish criteria for which patients qualify for certain interventions, such as defibrillator implantation.
Currently, the guidelines call for patients to receive defibrillators if their heart’s ejection fraction — a measure of the heart’s ability to pump blood — is less than 35 percent. Of the 448 patients who did receive proper screening for sudden cardiac arrest, 304 or nearly 68 percent, were ineligible for a defibrillator because their ejection fraction was too high.
“The pumping function of the heart has to be weak to meet the defibrillator guidelines,” Chugh said. “Most of the people in our study don’t have a low ejection fraction, but they still died of sudden cardiac arrest, which leads me to suggest that we need to take another look at the guidelines.”
Although the general public often uses the terms “sudden cardiac arrest” and “heart attack” interchangeably, they are distinctly different medical conditions.
A heart attack is caused when there is a blockage, such as a blood clot, in one or more arteries of the heart, preventing the heart from receiving enough blood, resulting in damage to the heart muscle.
Sudden cardiac arrest, which accounts for half of all deaths caused by heart disease, is triggered by an electrical malfunction in the heart that causes an irregular heartbeat, called arrhythmia. Arrhythmia causes a disruption in the flow of blood to other organs throughout the body. Without treatment, the patient can die in seconds.
Chugh said more analysis is needed to determine why patients with low ejection fractions did not receive implantable defibrillators.
“Perhaps they had other health problems that drove the decision-making process, or possibly many didn’t have health insurance or access to care,” Chugh said. “It could be a variety of reasons.”
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