[First experience with the cobalt binding capacity (ACB) test in the diagnosis of acute coronary syndrome (a pilot...

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.

98 individuals, patients of the Department of Internal Medicine of the hospital in Sternberk, 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.

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).

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).