Biochemical markers
Venous blood samples were obtained from all patients from an antecubital
vein after at least 15 min of semisupine rest. Blood samples were
collected into tubes containing ethylenediaminetetraacetic acid (EDTA)
to prevent coagulation. Troponin-I levels were measured by
chemiluminescent immunoassay using an Immulite 2500 device (Siemens
Medical Solutions, Erlangen, Germany).