Implementation of cardiac biomarkers in ambulatory emergency medicine department

Vaike Viia1,*

1Central Laboratory, East-Tallinn Central Hospital, Tallinn, Estonia

Introduction: The prevalent cardiac markers tests are cardiac troponin T high sensitivity (cTnThs) and the MB isoenzyme of creatine kinase mass concentration (CK-MBm). There are 1200 cTnThs tests performed overall in a month and a smaller number of CK-MBm tests.  68% of these tests are ordered by emergency medicine department (EMD).

Objectives: This study observed in retrospective short term cTnThs and CK-MBm implementation in EMD in the month of October of 2013. In this period cTnThs test was ordered for 675 patients,  9%  patients were examined in serial testing cTnThs. Patients with normal or slightly decreased renal function were selected for the study. eGFR ≥60 ml/min/1,73m2 was used as discriminating parameter, calculated by CKD-EPI equation. 568 patients were engaged in the study, median age 63 year.

Methods: The measurements of cTnThs and CK-MBm were done with electrochemiluminescence methods on the cobas e411 instrument. The cTnThs method analytical imprecision on the level 22ng/L was 7,5% ; on the level 1780ng/L 1,9%.  The upper reference limit (99th percentile) value for cTnThs was 14ng/L and CK-MBm for men 6μg/L, for women 5μg/L. The patients were divided into groups by gender and age.

Results: For 31% of patients, the cTnThs results were upper  reference interval, the mean value was 4,9 times higher than upper reference limit (URL). For 19% of patients CK-MBm results were upper reference interval and the mean value was 3,2 times higher (URL). 7% of patients were hospitalised, the cTnThs 50th percentile value was 47 ng/L. In the groups by EMD patients the data analysis ascertained cTnThs results variation between the gender and age. CK-MBm results had a relative difference by gender, no difference was identifyed by age.

Conclusion: The cTnThs elevations indicated myocardial injury with necrosis, must be interpreted in relation to patients clinical status. Slightly elevated cTnThs results may be induced by age and gender. In this observation study CK-MBm was the modest indicator of cardiac events.

Keywords: Biochemistry