The Impact of Excessive Use of Troponin Tests in the Emergency Department – Too Much of a Good Thing?
Just as we have learned about blood transfusion overuse, so too we now know that overuse of lab tests can be costly and cause patient harm. Cardiac Troponins (cTn) are markers of myocardial necrosis, and because of their high cardiac-specificity, are the preferred biomarker for the diagnosis of myocardial infarction (MI). However, cTn can be elevated in a number of non-cardiac conditions and “false-positives” can lead to downstream cardiac tests such as noninvasive stress testing, echocardiography, and invasive procedures such as cardiac catheterization and percutaneous coronary intervention. Additionally, misutilization of cTn can be costly – sometimes leading to increased patient stay in the hospital.
The Scope and Justification of cTn Misutilization
Nationally, there is a lot of variation in cTn orders. One group of researchers retrospectively analyzed the nature of cTn requests over a period of one week.1 They specifically looked at indication and final diagnostic impact. In many cases, they found that cTn requests were made without any clinical justification. A separate study in the United Kingdom found that 40% of troponin requests were inappropriate. In addition, some of the patients were inappropriately started on an acute coronary syndrome protocol.2 Clinical guidelines recommend against using cTn more than three times in a 24-hour period. Nonetheless, a study at John Hopkins found that 20% of patients received the test more than three times in a 24-hour period!3
One of the main reasons for cTn orders made without a clinical justification is that requests are made from triage before the patient is even assessed by a clinician. Another reason is that it is included in “routine” workups, panels, or “rainbow draws” in the emergency department. In addition, cTn is often used as a differentiating tool. In other words cTn is often used in the absence of an appropriate history and physical with the hopes that it will provide a diagnosis.
Physicians Are Working to Reduce Overuse
To combat the issue, several working groups across the country are implementing change. At Johns Hopkins, a year-long intervention focused on changes to the computerized provider order entry system (CPOE) in conjunction with education. By the end of the year, they saw a 66% reduction in the number of cTn ordered, and a $1.25 million (50%) decrease in charges. The diagnosis of acute coronary syndrome actually increased slightly suggesting that the reduction in testing did not compromise patient care.3
In the Saskatoon Health Region in Canada, a working group implemented a cTn testing algorithm to reduce inappropriate test requests.4 They saw significant reduction in both test requests and cost without negatively impacting patients’ needs. Simply by asking physicians to follow the algorithm, cTn requests with more than three per patient were reduced by nearly 50%!
Physicians have never been busier. They have an ever-increasing workload and time constraints. As a consequence, clinicians are increasingly moving away from process of history and clinical examination, and beginning to rely too much on laboratory investigations. It is important to remember that cTn can easily be added to the same routine sample if MI is suspected later during a clinical assessment. Physicians can drive change and improve value. The message to make a difference here is simple: “Use Troponin No More Than Three Times.”
1 Gardezi, SA. BMJ Qual Improv Report 2015;4: doi:10.1136/bmjquality. u204560. w3221
2 Doolub, G. J Clin Exp Cardiolog 2012, S:12
3 Larouchelle, MR. JGIM. Nov 2014, 29(11):pp 1468-1474
4 Meng, QH. Am J Clin Pathol 2006; 126:195-199