Troponin in early presenters to rule out myocardial infarction
Matthew T.H. Lowry, Dimitrios Doudesis, Jasper Boeddinghaus, Dorien M Kimenai, Anda Bularga, Caelan Taggart, Ryan Wereski, Amy V. Ferry, Stacey Stewart, Christopher Tuck, Luca Koechlin, Thomas Nestelberger, Pedro López‐Ayala, Gabrielle Huré, Kuan Ken Lee, Andrew R. Chapman, David E. Newby, Atul Anand, Paul O Collinson, Christian Mueller, Nicholas L. Mills, High-STEACS Investigators, Nicholas L Mills, Fiona E. Strachan, Christopher Tuck, Atul Anand, Stephanie Barker, Jennifer Blades, Jasper Boeddinghaus, Anda Bularga, Andrew R Chapman, Dimitrios Doudesis, Amy V. Ferry, Takeshi Fujisawa, Konstantin Georgiev, Dorien M Kimenai, Kuan Ken Lee, Ziwen Li, Matthew T H Lowry, Lynn McKinlay, Michael McDermott, Jean McPherson, Filip Mendusic, Nicholas L Mills, Andrew Sorbie, Grace Souter, Stacey D. Schulberg, Caelan Taggart, Christopher Tuck, Daniel Perez-Vicencio, Yiqing Wang, Ryan Wereski, Kelly L. Williams, Nicholas L. Mills, David E Newby, Keith A.A. Fox, Colin Berry, Simon Walker, Christopher J. Weir, Ian Ford, Nicholas L Mills, David E Newby, Alasdair Gray, Keith A.A. Fox, Colin Berry, Simon Walker, Paul O Collinson, Fred S Apple, Alan Reid, Anne Cruikshank, Iain Findlay, Shannon Amoils, David McAllister, Donogh Maguire, Jennifer S. Stevens, John Norrie, Christopher J. Weir, Anoop Shah, Atul Anand, Andrew R Chapman, Kuan Ken Lee, Jack Andrews, Philip D Adamson, Alastair J. Moss, Mohamed Anwar, John Hung, Nicholas L. Mills, Simon Walker, Jonathan Malo, Alan Reid, Anne Cruikshank, Paul O Collinson, Colin Fischbacher, Bernard Croal, Stephen J Leslie, Catriona Keerie, Richard Parker, Allan Walker, Ronnie Harkess, Christopher Tuck
Abstract
AIMS: Whether a single cardiac troponin measurement can safely rule out myocardial infarction in patients presenting within a few hours of symptom onset is uncertain. The study aim was to assess the performance of troponin in early presenters. METHODS AND RESULTS: In patients with possible myocardial infarction, the diagnostic performance of a single measurement of high-sensitivity cardiac troponin I at presentation was evaluated and externally validated in those tested ≤3, 4-12, and >12 h from symptom onset. The limit-of-detection (2 ng/L), rule-out (5 ng/L), and sex-specific 99th centile (16 ng/L in women; 34 ng/L in men) thresholds were compared. In 41 103 consecutive patients [60 (17) years, 46% women], 12 595 (31%) presented within 3 h, and 3728 (9%) had myocardial infarction. In those presenting ≤3 h, a threshold of 2 ng/L had greater sensitivity and negative predictive value [99.4% (95% confidence interval 99.2%-99.5%) and 99.7% (99.6%-99.8%)] compared with 5 ng/L [96.5% (96.2%-96.8%) and 99.3% (99.1%-99.4%)]. In those presenting ≥3 h, the sensitivity and negative predictive value were similar for both thresholds. The sensitivity of the 99th centile was low in early and late presenters at 71.4% (70.6%-72.2%) and 92.5% (92.0%-93.0%), respectively. Findings were consistent in an external validation cohort of 7088 patients. CONCLUSION: In early presenters, a single measurement of high-sensitivity cardiac troponin I below the limit of detection may facilitate the safe rule out of myocardial infarction. The 99th centile should not be used to rule out myocardial infarction at presentation even in those presenting later following symptom onset.