Every minute matters when a patient in the emergency department is experiencing cardiac symptoms, as physicians work to determine whether the patient is having a heart attack. New data from a study conducted in New Zealand suggest that a point-of-care blood test now under development may be able to identify nearly three-fifths (56.7%) of people at low risk of experiencing a heart attack, providing results similar to those of a high-sensitivity troponin I blood test performed in a laboratory setting—but in as little as 15 minutes.1
More than seven billion diagnostic tests are run in the United States each year to help physicians make accurate, timely decisions about a person’s medical treatment.2 In hospital emergency departments, which are facing increased pressure to address overcrowding and longer wait times, providers have turned to point-of-care diagnostics that are often capable of providing test results within minutes. The challenge for such tests is to deliver results with accuracy similar to the gold standard of high-sensitivity lab tests.
Troponin proteins are released from the heart and can be found at elevated levels in the blood when the heart muscle has been damaged due to lack of blood flow. The recently published study findings indicate that the new point-of-care blood test could help physicians streamline how patients are triaged in the emergency department by reducing the time it takes to rule out a heart attack and accelerating a safe discharge for low-risk patients—all with accuracy comparable to a high sensitivity cardiac troponin test performed in a core laboratory.
The analysis is part of a prospective observational study. The study’s principal outcomes were the area under receiver-operator-characteristic curve (AUC), sensitivity, negative predictive value (NPV), and proportion negative at thresholds with 100% sensitivity.
“The initial findings from this study indicate that, for a substantial proportion of patients, it may be possible to safely rule out heart attacks within 15 minutes of blood drawn in the emergency department,” says Martin Than, MD, director of emergency medicine research at Christchurch Public Health Hospital and one of the study’s senior authors. “This is a major advancement in point-of-care test accuracy that may make possible significant improvements in patient care in both urban and rural settings.”
The New Zealand researchers evaluated 354 adults aged 18 years and older who entered an emergency department with symptoms of acute coronary syndrome, such as a heart attack. Physicians measured the patients’ levels of cardiac troponin—the standard for aiding doctors in checking for a heart attack—using two blood tests from Abbott, Abbott Park, Ill: the Architect High Sensitivity Troponin-I (hsTnI) assay, and the iStat TnI-Nx assay, a point-of-care diagnostic test under development. The study found:
- Similar levels of accuracy for the hsTnI and iStat TnI-Nx tests (AUC = 0.970 and 0.975, respectively).
- Similar abilities to rule out a heart attack using the emergency department assessment of chest pain score: 43.5% of patients were identified as low-risk using the hsTnI test; 56.7% of patients were identified as low-risk using the iStat TnI-Nx test.
Abbott’s iStat cardiac troponin test has been used in hospitals globally to help physicians diagnose heart attacks at the patient’s bedside. The high-sensitivity troponin I version of the point-of-care test used in the New Zealand study is not yet commercially available, and includes several enhancements, such as magnetic technology.
“When designing Abbott’s newest point-of-care cardiac testing, we wanted to combine the benefits of higher-sensitivity troponin tests with the speed of results when it matters most,” says Matt Bates, divisional vice president of research and development for point-of-care diagnostics at Abbott. “This initial data will help guide our research and development of the next generation of cardiac testing to help physicians and emergency departments make timely decisions with confidence.”
For further information, visit Abbott.
References
- Pickering JW, Young JM, George PM, et al. Validity of a novel point-of-care troponin assay for single-test rule-out of acute myocardial infarction. JAMA Cardiol. 2018;3(11):1108–1112; doi: 10.1001/jamacardio.2018.3368.
- Value of Lab Testing [online]. Washington, DC: American Clinical Laboratory Association, 2018. Available from www.acla.com/value-of-lab-testing. Accessed December 3, 2018.
Featured image: The iStat point-of-care reader by Abbott, Abbott Park, Ill.
