High-Sensitivity Cardiac Troponin I Assay Validated

By LabMedica International staff writers
Posted on 20 Sep 2018

Myocardial infarction (MI), commonly known as a heart attack occurs when blood flow decreases or stops to a part of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which may travel into the shoulder, arm, back, neck, or jaw.

The diagnosis of myocardial infarction requires two out of three components, history, electrocardiogram (ECG), and levels of certain enzymes. When damage to the heart occurs, levels of cardiac markers rise over time, which is why blood tests for them are taken over a 24-hour period.

Image: High-sensitivity troponin I assays (TnIH) for the Atellica IM and ADVIA Centaur XP/XPT in vitro diagnostic analyzers to aid in the early diagnosis of myocardial infarctions (Photo courtesy of Siemens Healthineers).

Scientists at the University Hospital Basel (Basel, Switzerland) and their international colleagues enrolled 1,755 patients presenting to the emergency department with symptoms suggestive of acute myocardial infarction (AMI). Final diagnoses were centrally adjudicated by two independent cardiologists including all clinical information twice.

The team used serial Troponin T-high sensitive assay for primary analysis; secondly, they used using High Sensitive Troponin-I for secondary analysis measurements. In addition they clinically applied high sensitivity cardiac troponin (hs-cTnI), which was measured at presentation, one hour and two hours.

AMI was the final diagnosis in 318 of 1,755 (18%) patients using the Roche-hs-cTnT-Elecsys for adjudication. The area under the curve (AUC) at presentation for Siemens-hs-cTnI-Centaur was 0.94 and comparable with 0.95 for Roche-hs-cTnT-Elecsys and 0.93 for Abbott-hs-cTnI-Architect. Applying the derived Siemens-hs-cTnI-Centaur 0/1-h algorithm to the validation cohort, 46% of patients were ruled out (sensitivity, 99.1%, and 18% of patients were ruled in, specificity, 94.1%. The Siemens-hs-cTnI-Centaur 0/2-h algorithm ruled out 55% of patients (sensitivity, 100%), and ruled in 18% of patients (specificity, 96.0%). Findings were confirmed in the secondary analyses using serial measurements of Abbott-hs-cTnI-Architect for adjudication.

The authors concluded that diagnostic accuracy and clinical utility of the novel Siemens-hs-cTnI-Centaur assay are high and comparable with the established hs-cTn assays. The study was published in August 2018 in the journal Clinical Chemistry.

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University Hospital Basel