Physicians propose eliminating CK-MB test to save costs, improve clinical practice

A popular cardiac biomarker test is now obsolete but continues to cost healthcare providers millions each year, according to a research article published in JAMA Internal Medicine.

Creatine kinase-myocardial band (CK-MB) testing has been used in emergency rooms for more than 30 years to diagnose acute myocardial infarction (AMI). However, cardiac troponin has replaced CK-MB as the biomarker of choice in the industry.

“While CK-MB was the predecessor of the troponin test, things have evolved such that the two were ordered together when the troponin was introduced about 20 years ago,” contributing author Jeffrey Trost, of the division of cardiology at Johns Hopkins Bayview Medical Center, said on a JAMA podcast. “Over the last 10 or 15 years or so, there’s been an increasing amount of evidence that troponin is far superior in terms of its clinical accuracy compared to CK-MB in terms of making the diagnosis of myocardial infarction, or heart attack. Therefore, CK-MB is thought to be of really no value in addition to troponin with regard to making the diagnosis of heart attack.”

Using Medicare’s 2016 Clinical Diagnostic Laboratory Fee Schedule, the authors estimated approximately $416 million is spent on cardiac biomarker tests each year. Eliminating one of the two widely used tests would both save money and avoid clinical confusion, Trost said.

“We would argue that elimination of routine CK-MB ordering is not only high value because it offers no benefit and results in considerable cost but also because elimination of CK-MB may reduce physician confusion, improve understanding of the proper use of cTn (cardiac troponin), and consequently reduce potential patient harm,” Trost and colleagues wrote.

Trost said the first step to eliminate CK-MB testing for the diagnosis of AMI is educating healthcare leaders and physicians on the evidence supporting the exclusive use of cardiac troponin. Additional steps include partnering with IT staff to remove CK-MB from standardized order sets and measuring data preintervention and postintervention, including cases of missed diagnoses, number of tests ordered and cost savings for both patients and hospitals.

“Though seemingly straightforward to articulate, we acknowledge that significant barriers to implementation exist, and in this case the biggest hurdle has been convincing physicians who have ordered CK-MB for years to change their practice,” Trost and colleagues wrote. “Successful deimplementation of CK-MB requires leadership support, education and reassurance that diagnostic efficacy will not be compromised.”