Author + information
- Received January 13, 2015
- Accepted February 11, 2015
- Published online April 28, 2015.
- Dina Melki, MD, PhD∗∗ (, )
- Johan Lugnegård, MD†,
- Joakim Alfredsson, MD, PhD‡,
- Suzanne Lind, MD, PhD§,
- Kai M. Eggers, MD, PhD‖,
- Bertil Lindahl, MD, PhD‖ and
- Tomas Jernberg, MD, PhD∗
- ∗Department of Medicine, Section of Cardiology, Huddinge, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- †Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- ‡Department of Cardiology and Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
- §Department of Laboratory Medicine, Division of Clinical Chemistry, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- ‖Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- ↵∗Reprint requests and correspondence:
Dr. Dina Melki, Department of Cardiology, Karolinska University Hospital, Huddinge, Institution of Medicine (H7), Huddinge, Karolinska Institutet, 141 86 Stockholm, Sweden.
Background Cardiac troponin is the preferred biomarker for diagnosing myocardial infarction (MI).
Objectives The aim of this study was to examine the implications of introducing high-sensitivity cardiac troponin T (hs-cTnT) into clinical practice and to define at what hs-cTnT level risk starts to increase.
Methods We analyzed data from 48,594 patients admitted because of symptoms suggesting an acute coronary syndrome and who were entered into a large national registry. Patients were divided into Group 1, those with hs-cTnT <6 ng/l; Group 2, those with hs-cTnT 6 to 13 ng/l; Group 3, those with hs-cTnT 14 to 49 ng/l (i.e., a group in which most patients would have had a negative cardiac troponin T with older assays); and Group 4, those with hs-cTnT ≥50 ng/l.
Results There were 5,790 (11.9%), 6,491 (13.4%), 10,476 (21.6%), and 25,837 (53.2%) patients in Groups 1, 2, 3, and 4, respectively. In Groups 1 to 4, the proportions with MI were 2.2%, 2.6%, 18.2%, and 81.2%. There was a stepwise increase in the proportion of patients with significant coronary stenoses, left ventricular systolic dysfunction, and death during follow-up. When dividing patients into 20 groups according to hs-cTnT level, the adjusted mortality started to increase at an hs-cTnT level of 14 ng/l.
Conclusions Introducing hs-cTnT into clinical practice has led to the recognition of a large proportion of patients with minor cardiac troponin increases (14 to 49 ng/l), the majority of whom do not have MI. Although a heterogeneous group, these patients remain at high risk, and the adjusted mortality rate started to increase at the level of the 99th percentile in healthy controls.
Dr. Lindahl has served as a consultant for Roche Diagnostics, Radiometer Medical, bioMérieux Clinical Diagnostics, Philips Healthcare, Thermo-Fisher, and Fiomi Diagnostics; and has received a research grant from Roche Diagnostics. Dr. Eggers has received honoraria from Abbott Laboratories, AstraZeneca, and Siemens Healthcare Diagnostics; and has served as a consultant for Abbott Laboratories and Fiomi Diagnostics. Dr. Melki has received honoraria from Roche Diagnostics. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.
- Received January 13, 2015.
- Accepted February 11, 2015.
- 2015 American College of Cardiology Foundation