New blood test can rule out heart attack faster
- A new blood test given in the emergency room ruled out whether a patient was having a heart attack more quickly than the assessment now in use, according to research in the American Heart Association journal Circulation.
- The cardiac troponin test ruled out 30% of patients immediately and an additional 25% at one hour in a study of 536 people who came to the emergency department at Parkland Health and Hospital System in Texas. The results compare with a traditional troponin test, which takes three hours to complete.
- The new test showed greater sensitivity and precision than the fourth-generation conventional test currently in use in the United States. Researchers said the early rule-out protocol also appears safe.
The cardiac troponin test is used to assess patients who come to the emergency room with heart attack symptoms, including chest pain and shortness of breath. Cardiac troponin is a protein released into the blood when the heart is damaged.
In the study of the high-sensitivity test, patients were classified into two categories: "ruled out" or "abnormal," based on troponin levels. Three cardiologists adjudicated the final diagnosis based on all available clinical information, including the conventional test. The average age of the patients was 55 and 44% were women.
"We did not miss any heart attacks using this test in this population," said lead author Rebecca Vigen, a cardiologist at the University of Texas Southwestern Medical Center. "The test also allowed us to determine faster that many patients who had symptoms of a heart attack were not having a heart attack than if we had relied on the traditional test."
The FDA last year approved a high-sensitivity troponin test sold by Swiss pharma Roche, which is already used in Europe.
"We anticipate that this procedure will allow many patients with chest pain to be given a 'yes' or 'no' diagnosis of whether they are having a heart attack faster," Vigen said.
The National Center for Advancing Translational Sciences of the National Institutes of Health funded the study.