First Experience with Cobalt Binding Capacity (ACB) Test in Diagnostics of Acute Coronary
Syndrome (A Pilot Study)
Stejskal D.1,2, Lačňák B.2, Juráková R.1, Adamovská S.1, Prošková J.1, Ochmanová R.2, Ožanová G.2
1Oddělení laboratorní medicíny Nemocnice, Šternberk, přednosta prim. MUDr. David Stejskal 2Interní oddělení Nemocnice, Šternberk, přednosta prim. MUDr. Bořek Lačňák |
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Summary:
Introduction: Commonly used laboratory markers of coronary damage in individuals with acute
coronary syndrome (ACS) are not specific for myocardial ischemia and prove only irreversible
myocardial damage. There have been concerns recently of a laboratory test able to distinguish
sufficiently an individual with myocardial ischemia and typical IHD symptoms from patients
without IHD. Since 1994 several works about cobalt binding capacity of albumin (ACB) have been
published in which a unique diagnostic sensitivity and specificity of this test for estimations of
the presence of myocardial ischemia has been described. In February 2003 this test was approved
by FDA for making an early diagnosis of ACS. Goal of the work: To verify a possibility to use ACB
test for making an early diagnosis of ACS. Metohod: 98 individuals, patients of the Department of
Internal Medicine of the hospital in Šternberk, hospitalised for suspicion of ACS but not indicated
for direct PTCA, have been examined. Respondents with ACS diagnosis were examined via coronarography.
All the respondents were examined for cTnI, myoglobin, and ACB immediately at the
admission (0) and 2, 6, and 12 hours after admission. Cobalt binding capacity of albumin has been
given in absorbance units. The group of respondents was subsequently divided into subgroups
according to presence of ACS and subgroups of respondents with/without AMI. Results: 55 respondents (56%) have been diagnosed with ACS. 16 respondents (16%) from them suffered from non-Q
AMI and 39 respondents (40%) suffered from unstable AP (UAP). 43 respondents (44%) suffered
from noncoronary sternal pain. Patients with ACS had ACB values significantly higher at admission
and 2 and 6 hours after admission compared to respondents without ACS (0: 0.62 ± 0.17 vs. 0.4 ±
0.11, 2: 0.61 ± 0.13 vs. 0.44 ± 0.12, 6: 0.58 ± 0.16 vs. 0.45 ± 0.1, p < 0.01). In ACB dynamics monitoring
in defined groups of respondents no significant differences have been identified among ACB
values of individual takings. There were no significant differences in ACB values 12 hours after
admission (0.53 ± 0.12 vs. 0.44 ± 0.16) in cut-off absorbance ACB 0.5 the diagnostic sensitivity at
admission was 69% and specificity 89%, 2 hours later 87% and 71% and 6 hours after admission
64% and 69%. 12 hours after admission ACB assessment has not been possible to be used for ACS
diagnosing (AUC of 0.55). First 2 hours after admission ACB test was more specific and sensitive
for diagnosing ACS compared to cTnI test (0: AUC 0.83 vs. 0.61, p = 0.015, 2: AUC 0.87 vs. 0.71, p =
0.04). However, ACB test could not be used in respondents with ACS to distinguish between acute
myocardial infarction and unstable angina pectoris (UAP) (AUC: ACB-0 0.51, ACB-2 0.56, ACB-6
0.51, ACB-12 0.57). Conclusion: ACB test is a quick, cheap and easy examination which is very
specific and sensitive for early diagnosing of acute coronary syndrome without regard whether it
is caused by UAP or AMI (up to 6 hours after admission) compared to commonly used markers.
This test could significantly contribute to the next fate of a patient (diagnostic procedures,
patient's prognosis).
Key words:
Cobalt binding capacity of albumin - Acute coronary syndrome - Laboratory markers
of myocardial damage
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