Routine creatine kinase testing does not provide clinical utility in the emergency department for diagnosis of acute...

Area of Science:

• Cardiology
• Clinical Chemistry
• Health Economics

Background:

• High-sensitivity troponin T assays (hsTnT) are sensitive and specific for diagnosing acute coronary syndrome (ACS).
• Despite hsTnT advancements, creatine kinase (CK) is still routinely measured for ACS diagnosis.
• The clinical utility and cost-effectiveness of routine CK testing in the hsTnT era remain unclear.

Purpose of the Study:

• To evaluate the clinical utility of routine creatine kinase (CK) measurement in diagnosing acute coronary syndrome (ACS).
• To assess the relevance of CK testing in clinical decision-making alongside high-sensitivity troponin T assays (hsTnT).
• To estimate potential cost savings from reducing routine CK testing.

Main Methods:

• Retrospective review of adult patients presenting with cardiac complaints in 2017.
• Identification of patients with non-diagnostic hsTnT and positive CK results.
• Chart review to confirm acute myocardial infarction (AMI) diagnosis.

Main Results:

• Out of 36,251 presentations, 8150 had CK measured; 2012 had non-diagnostic hsTnT with positive CK.
• Only 1 patient (0.012%) with non-diagnostic hsTnT and positive CK was diagnosed with AMI.
• CK provided no additional diagnostic benefit over hsTnT alone in over 99.9% of cases.
• Routine CK testing incurred an estimated annual cost of over $32,000 at the center.

Conclusions:

• Routine CK testing offers no significant benefit in patient care for ACS diagnosis when hsTnT assays are employed.
• Eliminating routine CK testing is recommended to reduce unnecessary healthcare system costs.
• Emergency departments should discontinue routine CK testing in the era of hsTnT assays.