Creatine Kinase Testing Guidelines

Evidence Against Routine CK Testing

• The American College of Cardiology and other guidelines do not recommend routine measurement of CK in individuals receiving statin therapy, but rather suggest it should be reserved for those with muscle symptoms 1
• With contemporary troponin assays, CK-MB and other markers are not useful for diagnosis of acute coronary syndromes 3
• Measurement of total CK is not recommended for the diagnosis of myocardial infarction due to its large skeletal muscle distribution and lack of specificity 4

When CK Testing May Be Appropriate

• It may be reasonable to measure a baseline CK in patients with increased risk for adverse muscle events, including those with personal or family history of statin intolerance or muscle disease, clinical presentation that may increase likelihood of myopathy, or concomitant drug therapy that may increase risk of myopathy 1
• CK-MB remains useful in specific clinical situations, such as diagnosis of early infarct extension (reinfarction) due to CK-MB's shorter half-life compared to troponin, and evaluation of periprocedural myocardial injury during cardiac interventions 5

Interpretation of CK Results

• For patients with suspected myocardial infarction, troponin is the preferred biomarker due to its superior cardiac specificity 7, 5

Monitoring Recommendations When CK is Elevated

• In patients with muscle symptoms and elevated CK, temporary discontinuation of the offending medication (e.g., statins) should be considered 6