Improved identification of acute coronary syndromes with second generation cardiac troponin I assay:: Utility of 2-hour delta cTnI ≥+0.02 ng/mL

It has been shown that the 2-h Stratus II delta (Delta) creatine kinase-MB (CK-MB) is more sensitive and is equally specific compared to a 2-h Stratus II CK-MB and to a 2-h Stratus II delta cardiac troponin-I (DeltacTnI) for identification of acute myocardial infarction and adverse outcome (AO). Because the newest generation of Stratus (Stratus CS) cTnI assay has an analytical sensitivity of 0.03 ng/mL, compared to 0.35 ng/mL for the first generation assay, we undertook a small pilot study of 120 chest pain patients to compare sensitivities and specificities for 30-day AO of the Stratus CS DeltacTnI inummoassay to the DeltaCK-MB and DeltacTnI, as measured by the Abbott Axsym immunoassay, and to the DeltaCK-MB, as measured by the Stratus CS'. A Stratus CS DeltacTnI greater than or equal to +0.02 ng/mL in 2 h was more sensitive (61.9%) than an Axsym DeltaCK-MB greater than or equal to+1.3 ng/mL (38.1%; p = 0.03), a Stratus CS DeltaCK-MB greater than or equal to+0.4 ng/mL (38.1%; p = 0.03), and an Axsym DeltacTnI greater than or equal to + 0.3 ng/mL (33.3 %; p = 0.03) for 30-day AO. There were no differences in specificities. Our data support enhanced identification of ACS with a second generation cTnI assay. Pending larger studies, patients with a rise in DeltacTnI of greater than or equal to+0.02 ng/mL in 2 h, as measured by the Stratus CS immunoassay, should receive consideration for aggressive anti-ischemic therapy and further diagnostic testing prior to making an exclusionary diagnosis of non-ischemic chest pain. (C) 2002 Elsevier Science Inc.