Biomarkers of Cardiovascular Disorders - Applications of Biotechnology in Cardiovascular Therapeutics - page 101

Copeptin may predict adverse outcome, especially in those with an elevated
NTproBNP (Khan et al. 2007 ). An assay based on C-Terminal Provasopressin
(Copeptin), a patented biomarker for AMI, was introduced by Thermo Fisher
Scientific in Europe in 2009 with plans to introduce it in the USA in 2010. In com-
bination with a troponin biomarker test, the copeptin assay enables physicians to
rule out or confirm the onset of myocardial infarction within minutes. Copeptin is
also a biomarker for prognosis of intracerebral hemorrhage.
Creatine Kinase Muscle Brain
Creatine kinase muscle brain (CK-MB), an enzyme that is involved in muscle
metabolism, is found in both heart muscle tissue and skeletal muscle, albeit at a
much lower concentration in the latter. CK-MB is released into the blood stream
when cardiac muscle is damaged, hits a plateau where its levels are highest, and
then eventually returns to lower levels. Although CK-MB analysis is currently the
benchmark for biomarker detection of MI, similar patterns of CK-MB release can
be caused by renal kidney failure, skeletal muscle trauma, and other unrelated
ailments.
Myoglobin
Myoglobin is a heme protein found in the cytosol of both cardiac and skeletal
muscle. Following the death of cardiac tissue, myoglobin is the first cardiac marker
to increase above normal levels in the blood. Myoglobin measurements have
proven useful as an early marker for heart attack but other noncardiac-related
trauma can also cause circulating levels of myoglobin to increase, so it cannot be
used exclusively.
Fatty Acid Binding Protein
Recent data suggest that serum-free fatty acid concentrations increase well before
markers of cardiac necrosis and are sensitive indicators of ischemia in MI. Fatty
acid binding protein (FABP) is abundant in cardiac muscle and is presumed to be
involved in myocardial lipid homeostasis. Similar to myoglobin, plasma FABP
increases within 3 h after onset of MI and returns to reference values within 12-24 h
(Azzazy et al. 2006 ). FABP is useful for detecting cardiac injury in acute coronary
syndromes and assays are available for this biomarker. Used with evidence investi-
gator ™ biochip system (Randolph Laboratories), FABP is the best early marker of
MI with a sensitivity superior to either myoglobin and troponin. In collaboration
with St James's hospital in Dublin, blood samples of chest pain patients were taken
over a period of months and a subset of the samples analyzed for novel and routine
biomarkers. Post pain onset was the best time point for diagnosis and FABP levels
at 4-7 h had better sensitivity than any other single cardiac marker. Further analyses
revealed that a combination of FABP, troponin, and CK-MB accurately identified