Identification of acute myocardial infarction in elderly patients using optimized highly sensitive troponin I thresholds

Abstract

Purpose: Established diagnostic thresholds for high-sensitivity cardiac troponins (hs-cTn) might not apply for elderly patients as they are elevated irrespective of the presence of an acute myocardial infarction (AMI). Aim of the present study was to investigate hs-cTnI in elderly patients with suspected AMI and to calculate optimized diagnostic cutoffs.

Material and methods: Data from a prospective multi-centre study and from a second independent prospective single-centre cohort study were analysed. A number of 2903 patients were eligible for further analysis. Patients > 70 years were classified as elderly. hs-cTnI was measured upon admission.

Results: Around 34.7% of 2903 patients were classified as elderly. Around 22.5% of elderly patients were finally diagnosed with AMI. Elderly patients had higher hs-cTnI levels at admission irrespective of the final diagnosis (p < 0.001). According to the AUROC, hs-cTnI was a strong marker for detection of AMI in elderly patients. Application of the 99th percentile cutoffs showed a substantially lower specificity in elderly. By using optimized thresholds, specificity was improved to levels as in younger patients in both cohorts but accompanied with a decrease in sensitivity.

Conclusions: hs-cTnI levels have a lower specificity for detecting AMI in elderly patients. This lower specificity can be improved by using hs-cTnI thresholds optimized for elderly patients.

Keywords:

• Acute myocardial infarction
• troponin
• biomarkers
• elderly
• age

Acknowledgements

We thank the scientific staff at the hospitals in Koblenz, Hamburg and Mainz for help with patient recruiting, the participating graduate students for help with data acquisition, and the laboratory technicians for their help in biomarker determination. For ProsPECTUS, we acknowledge the study and data management by Charis Mamilou, Karen Buchtal, Yvonne Kirschner and Bianca Zäpf and all study nurses. We are also grateful to Elizabeth Martinson, PhD, of the KHFI Editorial Office for editorial assistance.

Disclosure statement

TK and AB received speaker honoraria from Abbott, Siemens, and BRAHMS Thermo Fisher; AB received speaker honoraria from Roche Diagnostics; TK and SB served as consultants for BRAHMS Thermo Fisher.

PSW received honoraria for lectures or consulting from Boehringer Ingelheim, Bayer HealthCare, AstraZenca, and Sanofi-Aventis.

CL reports non-financial support from Abbott Diagnostics, personal fees from Abbott Diagnostics, personal fees from Astra zeneca, personal fees from Bayer, personal fees from Berlin-Chemie, personal fees and other from Daiichi-Sankyo, outside the submitted work.

All other authors have no potential conflicts to disclose. None of the funders played any role with regard to design and conduct of the study, data collection, study management, analysis and interpretation of the data, preparation, review or approval of the manuscript and decision for publication.

Additional information

Funding

This analysis was supported by the European Union FP7 (BestAgeing, GA 306031). PSW has received research funding from Boehringer Ingelheim, PHILIPS Medical Systems, Sanofi-Aventis, Bayer Vital, and Daiichi Sankyo Europe. PSW is funded by the Federal Ministry of Education and Research (BMBF 01EO1503). KJL reports grants from Abbott Diagnostics, grants from Roche Diagnostics, grants from Siemens Healthcare, outside the submitted work.

The work was supported by unrestricted grants of Johannes Gutenberg University of Mainz research programs ‘Wissen schafft Zukunft’ and ‘Schwerpunkt Vaskuläre Prävention’ as well as the BRAHMS AG Germany and was also supported by the Preventive Cardiology and Preventive Medicine, the Centre for Translational Vascular Biology (CTVB), University Medical Center Mainz and the German Centre for Cardiovascular Research (DZHK; grants to PSW and TG).