Specimens will be collected in 5.0 ml Gel tubes (Serum Separator Tube). A total of approximately 15 ml of blood will be collected from each patient. The blood sample will be processed at National Heart Centre Singapore (NHCS) laboratory. The clinical coordinators will store each patient's serum into 2 separate vials and freeze them in the freezer at ≤-80°C. The frozen serum samples will be used to perform the hsTnI assays on the Abbott ARCHITECT i2000 analyzer in NHCS and the ACCESS AccuTnI+3 assays on the Beckman Coulter UniCel Dxl 800 analyzer in SGH Pathology by the study coordinator and SGH Pathology lab staff respectively.