Cardiovascular disease is the largest single cause of death worldwide. The major single category of CVD is coronary artery disease resulting in acute myocardial infarction. Cardiovascular biomarkers have played an important role in the assessment of chest pain patients in the Emergency Department. Cardiac troponins have demonstrated a high sensitivity and almost absolute myocardial tissue specificity. They are considered the standard biomarkers for the detection of myocardial injury. Introduction of a higher sensitivity troponin assays allow measurement of concentrations below conventional levels of detection and have revealed a spectrum of circulating cardiac troponin in healthy subjects. In order to assess the analytical and clinical performance of a sensitive troponin assay that may aid in screening for, or for early detection of CVD, a number of tests on patients (percent normal study, precision study, linearity study, patient comparison study and a stability study) were performed. All the samples were tested between the Clinical Blood Sciences laboratory and the Research laboratory in St George’s Hospital NHS Foundation Trust in London according with ethical principles. The present study allowed to confirm the sensitivity of this new cardiac troponin I assay and proved that Singulex Clarity System is a potential analyzer in an analytical performance view. However, due to its long maintenance, quality control time evaluation and because it only allows testing 48 samples at a time, it does not have a usability required for a routine laboratory. Although not yet used in the market, after some changes, it is expected that in the near future it will contribute to the detection of low levels of cardiac troponin facilitating the diagnosis and avoiding inappropriate hospital discharges. Advisors/Committee Members: Pereira, Maria de Lourdes Gomes (advisor), Gaze, David Christopher (advisor).