Early CK-MB elevations predict ischemic events in stable chest pain patients

Area of Science:

• Cardiology
• Emergency Medicine
• Biomarkers

Background:

• Chest pain is a common emergency department (ED) presentation.
• Early identification of myocardial ischemia is crucial for timely intervention.
• Creatine kinase-MB fraction (CK-MB) is a cardiac biomarker used in diagnosing myocardial infarction.

Purpose of the Study:

• To determine if elevated CK-MB levels within three hours of ED presentation predict subsequent ischemic events in clinically stable chest pain patients.
• To assess the association between early CK-MB elevations and adverse cardiac outcomes.

Main Methods:

• Prospective cohort study involving 449 chest pain patients (≥25 years) without hemodynamic instability or ST-segment elevation.
• Measured presenting and 3-hour CK-MB levels, ECG, and clinical outcomes.
• Monitored for ischemic events including myocardial infarction, need for revascularization, and death.

Main Results:

• Nine (2%) patients experienced ischemic events within 48 hours, all requiring revascularization.
• Elevated CK-MB levels were found in 44% of patients with 48-hour ischemic events.
• An elevated CK-MB level significantly increased the risk of ischemic events within 48 hours (RR 9.5) and one week (RR 5.2).

Conclusions:

• Early elevated CK-MB levels in stable chest pain patients are associated with subsequent ischemic events.
• CK-MB alone identifies only a subset of low-risk patients who develop ischemia.
• Additional diagnostic markers are needed for comprehensive myocardial ischemia assessment in the ED.