Normal CK, elevated MB predicts complications in acute coronary syndromes

Area of Science:

• Cardiology
• Biochemistry

Background:

• Elevated Creatine kinase-MB isoenzyme (CK-MB) with normal total CK in acute coronary syndromes lacks clear management guidelines.
• The prognostic significance of this specific biomarker profile remains uncertain.

Purpose of the Study:

• To prospectively assess outcomes in patients with suspected acute coronary syndromes, normal total CK, and elevated CK-MB.
• To establish the clinical implications of isolated CK-MB elevation.

Main Methods:

• Prospective evaluation of Emergency Department patients with suspected acute coronary syndromes and normal creatinine.
• Serial measurements of total CK and CK-MB fractions at presentation, 8, and 16 hours.
• Composite outcome assessment (death, Q-wave MI, revascularization) at index visit and 6 months.

Main Results:

• Among 698 patients, acute and 6-month adverse composite outcome rates were similar for elevated CK-MB, irrespective of total CK levels.
• Elevated CK-MB independently conferred a higher event rate compared to normal CK-MB.
• Acute composite outcome rate was 25%, with a 6-month rate of 6.3%.

Conclusions:

• Patients with suspected acute coronary syndromes and elevated CK-MB, even with normal total CK, exhibit similar adverse event rates.
• This biomarker pattern should be considered indicative of an acute coronary syndrome.
• Clinical management should account for elevated CK-MB as a significant indicator of cardiac events.