Hostname: page-component-88dd8db54-6znt5 Total loading time: 0 Render date: 2024-03-05T08:55:51.112Z Has data issue: false hasContentIssue false

LO61: Test characteristics of high sensitivity troponin T performed at emergency department arrival for acute myocardial infarction in patients with reduced kidney function

Published online by Cambridge University Press:  11 May 2018

A. D. McRae*
Affiliation:
University of Calgary, Calgary, AB
S. Vatanpour
Affiliation:
University of Calgary, Calgary, AB
J. Ji
Affiliation:
University of Calgary, Calgary, AB
H. Yang
Affiliation:
University of Calgary, Calgary, AB
D. Southern
Affiliation:
University of Calgary, Calgary, AB
D. Wang
Affiliation:
University of Calgary, Calgary, AB
I. Seiden-Long
Affiliation:
University of Calgary, Calgary, AB
L. DeKoning
Affiliation:
University of Calgary, Calgary, AB
M. Graham
Affiliation:
University of Calgary, Calgary, AB
E. S. Lang
Affiliation:
University of Calgary, Calgary, AB
G. Innes
Affiliation:
University of Calgary, Calgary, AB
J. E. Andruchow
Affiliation:
University of Calgary, Calgary, AB
P. Kavsak
Affiliation:
University of Calgary, Calgary, AB
M. James
Affiliation:
University of Calgary, Calgary, AB
*
*Corresponding author

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

Introduction: Patients with chronic kidney disease (CKD) are at high risk of cardiovascular events, and have worse outcomes following acute myocardial infarction (AMI). Cardiac troponin is often elevated in CKD, making the diagnosis of AMI challenging in this population. We sought to quantify test characteristics for AMI of a high-sensitivity troponin T (hsTnT) assay performed at emergency department (ED) arrival in CKD patients with chest pain, and to derive rule-out cutoffs specific to patient subgroups stratified by estimated glomerular filtration rate (eGFR). We also quantified the sensitivity and classification performance of the assays limit of detection (5 ng/L) and the FDA-approved limit of quantitation (6 ng/L) for ruling out AMI at ED arrival. Methods: Consecutive patients in four urban EDs from the 2013 calendar year with suspected cardiac chest pain who had a Roche Elecsys hsTnT assay performed on arrival were included f. This analysis was restricted to patients with an eGFR< 60 ml/min/1.73m2. The primary outcome was 7-day AMI. Secondary outcomes included major adverse cardiac events (death, AMI and revascularization). Test characteristics were calculated and ROC curves were generated for eGFR subgroups. Results: 1416 patients were included. 7-day AMI incidence was 10.1%. 73% of patients had an initial hsTnT concentration greater than the assays 99th percentile (14 ng/L). TCurrently accepted cutoffs to rule out MI at ED arrival ( 5 ng/L and 6 ng/L) had 100% sensitivity for AMI, but no patients with an eGFR less than 30 ml/min/1.73M had hsTnT concentrations below these thresholds. We derived eGFR-adjusted cutoffs to rule out MI with sensitivity >98% at ED arrival, which were able to rule out 6-42% of patients, depending on eGFR category. The proportion of patients able to be accurately ruled-in with a single hsTnT assay was substantially lower among patients with an eGFR <30 ml/min/1.73m2 (6-20% vs 25-43%). We also derived eGFR-adjusted cutoffs to rule-in AMI with specificity >90%, which accurately ruled-in up to 18% of patients. Conclusion: Cutoffs achieving acceptable diagnostic performance for AMI using single hsTnT sampling on ED arrival may have limited clinical utility, particularly among patients with very low eGFR. The ideal diagnostic strategy for AMI in patients with CKD likely involves serial high-sensitivity troponin testing with diagnostic thresholds customized to different eGFR categories.

Type
Oral Presentations
Copyright
Copyright © Canadian Association of Emergency Physicians 2018