Cardiac Biomarkers in ACSCardiac Biomarkers in ACS

Natalie Bermudez, RN, BSN, MS

Clinical Educator for Cardiac Telemetry

Telemetry

Course

Cardiac EnzymesCardiac EnzymesA.K.A. ACP (Acute Cardiac Profile)

Normal Ranges:CPK Total: 26 – 192

CK-MB: 0 – 3.60

Troponin I: 0 – 0.099Normal < 0.10

Borderline 0.10 – 0.50Abnormal (Critical Value) > 0.50

Cardiac EnzymesCardiac EnzymesOrdered for patients c/o chest pain

and suspected AMI

CE’s are drawn in sets of three 6 to 8 hours apart

Sometimes initial results are negative

CK-MB & Troponins are released within hours of a cardiac event

CPKCPKCreatine Kinase Total

Rises within 3 - 12 hours after an AMI

Peak @ 24 hours

Return to normal within 48 – 72 hours

(Davis, 2004, p. 102)

Cardiac EnzymesCardiac EnzymesCPKCPK

Creatine Kinase Total

• Most facilities have the ability to measure this lab

• Highly sensitive for MI diagnosis but not very specific (many false

negatives)• Should not be the sole lab value used

to confirm diagnosis(Davis, 2004, p. 102)

CK-MBCK-MBCreatine Kinase Isoenzyme

Rise within 3 - 12 hours after an AMI

Peak @ 24 hours (6x > normal)

Return to normal within 48 – 72 hours

(Moser & Riegel, 2008, p. 792)

CK-MBCK-MB• Readily available

• Point of Care Testing available• Highly sensitive but not as

specific as other tests• May be falsely elevated by trauma, surgery, hypothermia, DKA, seizures, intramuscular

injections, stroke, or strenuous exercise

(Moser & Riegel, 2008, p. 792)

Troponin ITroponin IRises within 3 – 12 hours of an

AMI Peaks at 24 hours

Normalizes within 5 – 10 days

Preferred cardiac enzyme in diagnosis of an AMI

(Moser & Riegel, 2008, p. 792)

Troponin ITroponin IExcellent sensitivity & specificity

• Point of Care Testing Available

• Not influenced by skeletal muscle disease or renal disease

(Moser & Riegel, 2008, p. 792)

CE’s & Critical ValuesCE’s & Critical ValuesLab will call nursing for critical lab

values

Physician needs to be notified immediately for Troponin > 0.50

Document in the “MD Notification & Critical Values” structured

note in eCOS

Cardiac EnzymesCardiac Enzymes

Patients with elevated CE’s usually undergo a stress test and/or cardiac catheterization

for further investigation of cause of chest pain.

ReferencesReferencesDavis, L. (2004). Cardiovascular nursing secrets. St. Louis, MO:

Elsevier Mosby.

Kee, J. L. (2005). Laboratory and diagnostic tests with nursing implications (7th ed.). Upper Saddle River, NJ: Pearson Prentice Hall.

Kee, J. L. & Paulanka, B. J. (2000). Handbook of fluid, electrolyte, and acid-base imbalances. Scarborough, Canada: Delmar Publishers.

Moser, D. K., & Riegel, B. (2008). Cardiac nursing: A compnion to braunwald’s heart disease. St. Louis, MO: Saunders Elsevier.

Smeltzer, S. C. et al. (2008). Brunner and suddarth’s textbook of medical-surgical nursing (11th ed.). Philadelphia, PA: Lippincott Williams and Wilkins.

Taber’s On-Line Medical Dictionary