Long Troponin T to Separate Troponin Elevations Among Patients With Atrial Fibrillation Versus Myocardial Infarction

BACKGROUND: Elevated troponin levels are a frequent finding in patients presenting with atrial fibrillation or atrial flutter (AF) to the emergency department but are seldom caused by myocardial infarction (MI). The current high-sensitivity cTnT (cardiac troponin T) assay measures both the intact and highly fragmented cTnT forms (total cTnT) and detects cTnT elevations in conditions causing myocardial injury or MI without distinction between the 2. METHODS: The SuperTROPO (Better Diagnostics of Myocardial Infarction With a Test for Special Forms of Troponin) study included 521 consecutive patients with AF only and 188 patients with MI only (139 Type 1 MI), all with a total cTnT value ≥14 ng/L at emergency department admission. Intact and long forms of cTnT (long cTnT) were analyzed from the first plasma samples using a novel immunoassay. The diagnostic performance of long cTnT and total cTnT assays was compared in these cases with elevated total cTnT. RESULTS: