One and Done? Performance of a single, low high-sensitivity troponin in a multisite United States cohort

Document Type

Conference Proceeding

Publication Date

7-2020

Publication Title

Academic emergency medicine

Abstract

Background and Objectives: European data suggest a single high-sensitivity troponin (hs-cTn) result below the limit of detection excludes major adverse cardiac events (MACE) in patients with symptoms concerning for acute coronary syndrome. However, the FDA limits hs-cTnT reporting to the limit of quantification (LOQ: 6 ng/L) and little US data exists evaluating this cut-point. The objective of this study is to test the diagnostic performance of an initial hs-cTnT measure below the LOQ in a multisite US cohort.

Methods: A prospective observational cohort study was conducted at 8 US sites. Adult ED patients with symptoms suggestive of acute coronary syndrome and without ST-segment elevation on ECG were enrolled. Blood samples were collected from participants and hs-cTnT concentrations were measured using the Roche (Basel, Switzerland) hs-cTnT assay. Patients with research blood collection >1 hour after their first clinical blood draw or insufficient sample volume were excluded from analysis. Treating providers were blinded to hs-cTnT results. Adjudicated outcomes included MACE (composite of cardiac death, myocardial infarction [MI], and coronary revascularization) at 30-days and cardiac death or MI at 30-days. The proportion of patients with an initial hs-cTnT measure below the LOQ was determined, and sensitivity and negative predictive value (NPV) for safety outcomes were calculated with exact 95% confidence intervals. Results: Among 1,460 with initial hs-cTnT measures, 46.3% (676/1,460) were women and 37.1% (542/1,460) were African American with a mean age of 57.6 (SD±12.8) years. MACE at 30-days occurred in 14.4% (210/1,460). The initial hs-cTnT measure was below the LOQ in 32.9% (479/1,460) of patients. Among these patients, 1.7% (8/479) had 30-day MACE, yielding a NPV of 98.3% (95%CI: 96.8-99.2%) and 1.0% (5/479) had 30-day cardiac death or MI with a NPV of 99.0% (95%CI: 97.6-99.6%). Sensitivity of the initial hs-cTnT measure below the LOQ was 96.2% (95%CI: 92.6-98.3%) and 97.4% (95%CI: 94.0-99.1%) for 30-day MACE and cardiac death or MI, respectively.

Conclusion: In a multisite prospective US cohort, a single hs-cTnT measure below the LOQ occurred in nearly a third of patients. However, the sensitivity and NPV of a single hs-cTnT measure may not be sufficient to rule-out 30-day MACE or 30-day cardiac death or MI.

Volume

27

First Page

S8

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