Cardiac Troponin Assays With Improved Analytical Quality: A Trade-Off Between Enhanced Diagnostic Performance and Reduced Long-Term Prognostic Value

J Am Heart Assoc. 2020 Dec;9(23):e017465. doi: 10.1161/JAHA.120.017465. Epub 2020 Nov 26.

Abstract

Background Cardiac troponin (cTn) permits early rule-out/rule-in of patients admitted with possible non-ST-segment-elevation myocardial infarction. In this study, we developed an admission and a 0/1 hour rule-out/rule-in algorithm for a troponin assay with measurable results in >99% of healthy individuals. We then compared its diagnostic and long-term prognostic properties with other protocols. Methods and Results Blood samples were collected at 0, 1, 3, and 8 to 12 hours from patients admitted with possible non-ST-segment-elevation myocardial infarction. cTnT (Roche Diagnostics), cTnI(Abbott) (Abbott Diagnostics), and cTnI(sgx) (Singulex Clarity System) were measured in 971 admission and 465 1-hour samples. An admission and a 0/1 hour rule-out/rule-in algorithm were developed for the cTnI(sgx) assay and its diagnostic properties were compared with cTnTESC (European Society of Cardiology), cTnI(Abbott)ESC, and 2 earlier cTnI(sgx) algorithms. The prognostic composite end point was all-cause mortality and future nonfatal myocardial infarction during a median follow-up of 723 days. non-ST-segment-elevation myocardial infarction prevalence was 13%. The novel cTnI(sgx) algorithms showed similar performance regardless of time from symptom onset, and area under the curve was significantly better than comparators. The cTnI(sgx)0/1 hour algorithm classified 92% of patients to rule-in or rule-out compared with ≤78% of comparators. Patients allocated to rule-out by the prior published 0/1 hour algorithms had significantly fewer long-term events compared with the rule-in and observation groups. The novel cTnI(sgx)0/1 hour algorithm used a higher troponin baseline concentration for rule-out and did not allow for prognostication. Conclusions Increasingly sensitive troponin assays may improve identification of non-ST-segment-elevation myocardial infarction but could rule-out patients with subclinical chronic myocardial injury. Separate protocols for diagnosis and risk prediction seem appropriate.

Keywords: 0/1 hour algorithm; chest pain; chronic myocardial injury; myocardial infarction.

Publication types

  • Observational Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Algorithms
  • Biomarkers
  • Cross-Sectional Studies
  • Female
  • Hospitalization
  • Humans
  • Male
  • Middle Aged
  • Non-ST Elevated Myocardial Infarction / blood*
  • Non-ST Elevated Myocardial Infarction / diagnosis*
  • Non-ST Elevated Myocardial Infarction / mortality
  • Predictive Value of Tests
  • Prognosis
  • ROC Curve
  • Survival Rate
  • Time Factors
  • Troponin I / blood*
  • Troponin T / blood*

Substances

  • Biomarkers
  • Troponin I
  • Troponin T