Abstract 12816: Single High-Sensitivity Point of Care Whole Blood Cardiac Troponin I Measurement to Rule Out Acute Myocardial Infarction at Low Risk

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Introduction: High-sensitivity cardiac troponin (hs-cTn) laboratory assays are used to rule out myocardial infarction (MI) on presentation, but prolonged result turn-around times can delay patient management. Hypothesis: Our aim was to identify patients at low risk of index MI using a rapid, point of care (POC), whole blood hs-cTnI assay at presentation, with potential early patient discharge, with < 1% risk of adverse events. Methods: Consecutive emergency department patients from two prospective, observational studies with suspected acute coronary syndrome were enrolled. A POC hs-cTnI assay (Siemens Atellica ® VTLi) threshold using whole blood at presentation, that resulted in a negative predictive value (NPV) of ≥99.5% and sensitivity of > 99% for index MI, was derived (SEIGE) and validated using plasma (SAMIE). Event adjudications were established using hs-cTnI assay results from usual clinical care. The primary outcome was MI at 30-days. Results: 1086 patients (8.1% MI) were enrolled in a US derivation cohort (SEIGE) and 1486 (5.5% MI) in an Australian validation cohort (SAMIE). A derivation whole blood POC hs-cTnI concentration of <4ng/L provided a NPV of 99.5% (95% CI: 97.2-100%) and sensitivity of 98.9% (93.8-100%) for ruling out MI. In the validation cohort, NPV was 99.8% (99.1-100%) and sensitivity 98.8% (93.3-100%). 17.8% and 41.8%, respectively, were defined as low risk for discharge. 30-day adverse cardiac events were 0.1% (n=1) for SEIGE and 0.8% (n=5) for SAMIE. Conclusions: A point-of-care, whole blood hs-cTnI assay permits an accessible, rapid and safe exclusion of MI, and expedites discharge from the emergency department.