Chest pain is a common presenting complaint among patients in the emergency department (ED). A large portion of patients with chest pain undergo lengthy assessment in the ED or are admitted to rule out acute oronary syndrome (ACS), often with stress testing, creating a substantial health care burden. The new high-sensitivity cardiac troponin assays allow use of shorter time intervals for repeated blood samples and may improve care for chest pain patients. The aim of this cohort is to evaluate high-sentivity troponin based protocols for ruling out and ruling in ACS in the ED.

This is a prospective observational study conducted at Skåne University Hospital (Lund, Sweden). Patients presenting with non-traumatic chest pain and for whom hs-cTnT testing was ordered at presentation will be enrolled between february 2013 to April 2014 after providing written informed consent. Patients with STEMI during index visit and those with severe communication barriers will not be enrolled. Enrolled patients will have a second blood sample for hs-cTnT analyzed 1 h after the first sample. Patients with hemolysis with a hemoglobin concentration >0.1 g/dl, H-index >=100 in either the 0- or

1-h sample will be excluded. Clinical data and 1-h high sensitivity troponin T samples will be collected by research assistants. Further diagnostic testing and treatment will be performed, as in routine care, at the discretion of the responsible physician.

Inclusion Criteria:

• >=18 years of age
• Presented to the ED with non-traumatic chest pain/discomfort
• Hs-cTnT testing was ordered at presentation

Exclusion Criteria:

• STEMI at presentation
• Severe communication barriers
• Hemolysis with a hemoglobin concentration>0.1 g/dl, H-index>=100

Consecutive ED chest pain patients

Data sharing will be made upon reasonable request