OBJECTIVES: To examine associations between concentrations of hsTnI (measured using a single molecule counting method) and obstructive CAD in 1844 stable, symptomatic outpatients with suspected CAD randomized to coronary computed tomography angiography (CTA) in the Prospective Multicenter Imaging Study for Evaluation of Chest Pain (PROMISE) trial. BACKGROUND: Elevated concentrations of high-sensitivity troponin I (hsTnI) are associated with coronary artery disease (CAD) in patients with myocardial infarction. The meaning of hsTnI concentrations in stable symptomatic outpatients is not well-understood. METHODS: Clinical characteristics and CTA results (including coronary artery calcium [CAC] scores) were expressed across hsTnI quartiles. Determinants of hsTnI concentration were identified. Multivariable logistic regression identified independent predictors of obstructive CAD(50) (≥50% stenosis in any vessel) and CAD(70) (≥70% stenosis or ≥50% left main). RESULTS: The median hsTnI concentration was 1.5 ng/L; nearly all (98.5%) subjects had measurable hsTnI, and 6.1% had concentrations ≥99(th) percentile concentration for this assay (6 ng/L). Higher CAC scores, as well as more prevalent and diffuse CAD, was seen in upper hsTnI quartiles (all P
