Context Early recognition of acute coronary syndrome (ACS) is essential. Cardiac troponins are not consistently elevated within the first hours after symptom onset.

Objective Review current guidelines recommendations regarding biomarkers in the early assessment of ACS and review the evidence for using established and specific new diagnostic biomarkers.

Data sources MEDLINE and EMBASE.

Study selection Articles on diagnostic accuracy of ACS biomarkers.

Data extraction Relevance of clinical domain, adequacy of measures of clinical utility and outcome assessment.

Results The 73 articles identified on early biochemical markers CK-MB, myoglobin, heart-type fatty acid binding protein (H-FABP), ischemia modified albumin (IMA), pregnancy-associated plasma protein A, glycogen phosphorylase isoenzyme BB and myeloid-related protein 8/14 often did not quantify clinical utility correctly.

Conclusions IMA and H-FABP seem to be promising biomarkers in the early assessment of ACS. There is an urgent need for adequately designed diagnostic studies of (novel) ACS markers against contemporary troponin assays.