BACKGROUND: Low concentrations of cardiac troponin (cTn) have been recommended for rapid rule-out of acute myocardial infarction (AMI). We examined the Beckman Coulter Access high-sensitivity cardiac troponin I (hs-cTnI) assay to identify a single test threshold that can safely rule out AMI. METHODS: This analysis used stored samples collected in 2 prospective observational studies. In all, 1871 patients presenting to a tertiary emergency department with symptoms of acute coronary syndrome had blood taken for measurement of cTnI on presentation. The endpoint was type 1 myocardial infarction (T1MI). Sensitivity and negative predictive value (NPV) were calculated for hs-cTnI values below the 99th percentile. RESULTS: Ninety-eight patients had T1MI (5.2%), and 638 (34.1%) patients had an hs-cTnI <2 ng/L (limit of detection), with sensitivity of 99.0% (95% CI, 94.4%-100%) and NPV of 99.8% (95% CI, 99.1%-100%). No hs-cTnI value above a concentration of 2 ng/L achieved sensitivity of 99%. However, an NPV of 99.5% was achieved at values <6 ng/L. A cutoff <6 ng/L enabled 1475 (78.8%) patients to be ruled out on presentation with sensitivity of 93.9% (95% CI, 87.1%-97.7%). CONCLUSIONS: A single baseline cTn <2 ng/L measured with the Access hs-cTnI assay performed well for rule-out of AMI. This cutoff concentration identified 99% of patients with AMI and could reduce the number of patients requiring lengthy assessment. A cutoff of <6 ng/L yielded a high NPV but missed more cases of AMI than would be acceptable to clinicians.
BACKGROUND: Low concentrations of cardiac troponin (cTn) have been recommended for rapid rule-out of acute myocardial infarction (AMI). We examined the Beckman Coulter Access high-sensitivity cardiac troponin I (hs-cTnI) assay to identify a single test threshold that can safely rule out AMI. METHODS: This analysis used stored samples collected in 2 prospective observational studies. In all, 1871 patients presenting to a tertiary emergency department with symptoms of acute coronary syndrome had blood taken for measurement of cTnI on presentation. The endpoint was type 1 myocardial infarction (T1MI). Sensitivity and negative predictive value (NPV) were calculated for hs-cTnI values below the 99th percentile. RESULTS: Ninety-eight patients had T1MI (5.2%), and 638 (34.1%) patients had an hs-cTnI <2 ng/L (limit of detection), with sensitivity of 99.0% (95% CI, 94.4%-100%) and NPV of 99.8% (95% CI, 99.1%-100%). No hs-cTnI value above a concentration of 2 ng/L achieved sensitivity of 99%. However, an NPV of 99.5% was achieved at values <6 ng/L. A cutoff <6 ng/L enabled 1475 (78.8%) patients to be ruled out on presentation with sensitivity of 93.9% (95% CI, 87.1%-97.7%). CONCLUSIONS: A single baseline cTn <2 ng/L measured with the Access hs-cTnI assay performed well for rule-out of AMI. This cutoff concentration identified 99% of patients with AMI and could reduce the number of patients requiring lengthy assessment. A cutoff of <6 ng/L yielded a high NPV but missed more cases of AMI than would be acceptable to clinicians.
Authors: Peter A Kavsak; Joshua O Cerasuolo; Dennis T Ko; Jinhui Ma; Jonathan Sherbino; Shawn E Mondoux; Natasha Clayton; Stephen A Hill; Matthew McQueen; Lauren E Griffith; Shamir R Mehta; Richard Perez; Hsien Seow; P J Devereaux; Andrew Worster Journal: CMAJ Open Date: 2020-11-02
Authors: Atul Anand; Kuan Ken Lee; Andrew R Chapman; Amy V Ferry; Phil D Adamson; Fiona E Strachan; Colin Berry; Iain Findlay; Anne Cruikshank; Alan Reid; Paul O Collinson; Fred S Apple; David A McAllister; Donogh Maguire; Keith A A Fox; David E Newby; Chris Tuck; Ronald Harkess; Catriona Keerie; Christopher J Weir; Richard A Parker; Alasdair Gray; Anoop S V Shah; Nicholas L Mills Journal: Circulation Date: 2021-03-23 Impact factor: 39.918
Authors: Edward Carlton; Sarah Campbell; Jenny Ingram; Rebecca Kandiyali; Hazel Taylor; Shahid Aziz; Peter Beresford; Jason Kendall; Adam Reuben; Jason Smith; Patricia Jane Vickery; Jonathan Richard Benger Journal: BMJ Open Date: 2018-10-02 Impact factor: 2.692
Authors: W Frank Peacock; Robert Christenson; Deborah B Diercks; Christian Fromm; Gary F Headden; Christopher J Hogan; Erik B Kulstad; Frank LoVecchio; Richard M Nowak; Jon W Schrock; Adam J Singer; Alan B Storrow; Joely Straseski; Alan H B Wu; Daniel P Zelinski Journal: Acad Emerg Med Date: 2020-03-27 Impact factor: 3.451
Authors: Edward Watts Carlton; Jenny Ingram; Hazel Taylor; Joel Glynn; Rebecca Kandiyali; Sarah Campbell; Lucy Beasant; Shahid Aziz; Peter Beresford; Jason Kendall; Adam Reuben; Jason E Smith; Rebecca Chapman; Siobhan Creanor; Jonathan Richard Benger Journal: Heart Date: 2020-05-05 Impact factor: 5.994