A new study has identified a simple blood test that may accurately predict the heart attack risk of patients admitted to the ED with chest pain and provide a reliable way to identify patients that should be admitted for treatment rather than be sent home.
The study was published in the Journal of the American College of Cardiology and presented Sunday at the annual meeting of the American College of Cardiology in Washington.
The authors say the test could be used to prevent many unnecessary hospital admissions. Chest pain sends more than 15 million Americans and Europeans to the ED each year, although the symptoms often turn out to be anxiety, indigestion, or other less-serious conditions.
"Chest pain is a potentially life-threatening symptom, as well as being a very common one," says lead author Nadia Bandstein of the Karolinska University Hospital in Sweden, adding that there "are no established ways to quickly rule out heart attack, many patients are admitted to the hospital unnecessarily, at a large cost to the patient and to society."
Details of the study
For the study, researchers examined nearly 15,000 patients treated for chest pain from 2010 to 2012. Using a fast, highly sensitive test not yet available in the United States, the researchers found that 8,900 patients had low blood levels of a chemical substance called troponin, a factor that indicates signs of heart damage. An electrocardiogram found that the patients also had no signs of heart damage from reduced blood flow.
The study then tracked how many of the patients went on to have a heart attack within the next 30 days, comparing the data with how well a blood test and electrocardiogram would have predicted the patient fared. Only 39 of the 8,900 patients went on to have a heart attack, 15 of those patients had no signs of damage due to reduced blood flow, the researchers reported.
The researchers calculated that just one in 594 patients who arrive at the ED with chest pain but had low blood levels of troponin and no signs of heart damage had an immediate risk of heart attack. Overall, the test was able to predict with nearly 99% accuracy the subset of patients not at risk for heart attack. Moreover, it predicted with 100% accuracy the portion of patients who were not at risk of death.
Experts cautiously optimistic
Current guidelines recommend that patients be tested for troponin at least three hours after the onset of symptoms, which often requires that they be admitted. The study's authors said their findings suggest that only one testing would be necessary. In doing so, "20% to 25% of admissions to hospitals for chest pain may be avoided," Bandstein says.
Judd Hollander, an ED specialist at the University of Pennsylvania, says the study results are "almost too good to be true." A similar test in the United States would be "enormously useful," he says, adding that the amount of evidence that federal regulators are requiring to approve the test is too high.
However, Mayo Clinic cardiologist Allan Jaffe warned that the test may be so sensitive that it results in unnecessary testing for conditions unrelated to heart attack. "I think the strategy long-term will be proven," but more research is needed (AP/Modern Healthcare, 3/30 [subscription required]; Dallas, HealthDay, 3/31).
Power up your CV care management strategy
CV leaders need to develop a cohesive approach defined by five characteristics.
We've mapped out each and shared how these characteristics translate into outcomes.