Article Figures & Data
Figures
- Fig 1.
Bar chart to demonstrate the frequency of cs-cTnI above upper limit of normal by clinical indication for testing. ECG = electrocardiography.
- Fig 2.
a) Median length of stay across cs-cTnI groups for the whole cohort. b) Thirty-day mortality across cs-cTnI groups for the whole cohort.
- Fig 3.
a) Median length of stay across cs-cTnI groups for those in whom the test was only performed as part of the study and the clinician was unaware of the result because there was no clinical suspicion of acute coronary syndrome. b) Thirty-day mortality across cs-cTnI groups for those in whom the test was only performed as part of the study.
Tables
- Table 1.
Frequency of cs-cTnI above the 99th percentile across emergency department locations
Location Percentage of patients with cs-cTnI above 99th percentile Clinically requested Study requested Eye casualty n/a 0.0% Minors 0.0% 2.0% Clinical decision unit 0.0% 5.0% Majors 5.7% 7.2% Generic emergency department 8.0% 6.2% Resuscitation 19.3% 28.8% Cs-cTnI Admission rate (whole cohort) Admission rate (clinically requested) Admission rate (study requested only) 0 ng/L 52.0% 49.7% 52.7% 1–9 ng/L 55.3% 54.9% 55.5% 10–19 ng/L 70.5% 69.6% 70.9% 20–40 ng/L 79.8% 79.7% 79.8% >40 ng/L 90.0% 96.2% 86.3% - Table 3.
Frequency of cardiovascular discharge diagnoses, the spread of cs-cTnI and the associated 30-day mortality
Diagnosis Number Cs-cTnI (median), ng/L Cs-cTnI (IQR), ng/L Cs-cTnI > ULN, n (%) Mortality, n (%) Arrhythmia 150 13 6–25 27 (18.0) 1 (0.7) Heart failure 45 38 22–84 20 (44.4) 5 (11.1) Acute coronary syndrome 90 112 29–657 63 (70.0) 7 (7.8) Cardiac arrest/cardiogenic shock 5 70 41–787 4 (80.0) 3 (60.0) Valvular heart disease 10 26 7–33 1 (10.0) 2 (20.0) Pericardial diseases 17 11 6–55 5 (29.4) 0 Stable ischaemic heart disease 39 16 10–39 8 (20.5) 0 Hypertension 10 10 7–30 1 (10.0) 0 Aortic diseases 3 14 n/a 0 1(33.3) Myocarditis 4 51 15–869 3 (75.0) 0 Device infection 5 37 13–368 2 (40.0) 1 (20.0) Other 39 4 0–8 1 (2.6) 0 Cs-cTnI = contemporary sensitivity troponin I; IQR = interquartile range; ULN = upper limit of normal.
Cohort Cs-cTnI threshold relative to ULN Sensitivity Specificity Positive predictive value Negative predictive value Whole population >ULN 48.0% 92.5% 13.7% 98.4% >10 × ULN 13.3% 98.9% 24.7% 97.7% Study requested cohort >ULN 44.4% 93.6% 16.7% 98.3% >10 × ULN 9.4% 99.3% 27.5% 97.4% Cs-cTnI = contemporary sensitivity troponin I; ULN = upper limit of normal.
- Table 5.
Cs-cTnI spread, length of stay and mortality by emergency department location and whether the test was clinically requested
Location Median cs-cTnI (IQR), ng/L P value Median length of stay (IQR), days P value Mortality, % P value Clinically requested Study requested Clinically requested Study requested Clinically requested Study requested Resus 21 (9–49) 11 (5–29) <0.001 2 (0–7) 3 (1– 10) 0.112 17.9 10.9 0.039 Majors 7 (3–12) 6 (2–12) 0.203 0 (0–1) 0 (0–2) <0.001 1.4 1.2 0.649 Generic ED 7 (3–12) 8 (3–14) 0.001 0 (0–1) 1 (0–4) <0.001 0.1 3.4 <0.001 Cs-cTnI = contemporary sensitivity troponin I; ED = emergency department; IQR = interquartile range; Resus = resuscitation. Underlining highlights a statistically significantly higher result.
Summary
What is known? Troponin testing forms a central part of the algorithm for the diagnosis of myocardial infarction in the emergency department (ED), as recommended by international guidelines.
A range of clinical factors are known to be associated with troponin concentrations above the manufacturer-defined upper limit of normal.
There is emerging evidence that higher-sensitivity troponin assays may have a role in prognosis even in patients without a presentation consistent with myocardial infarction.
What is the question? The study aimed to test whether a contemporary sensitivity troponin (cs-cTn), measured in ED, may be a biomarker for clinical outcome, irrespective of the indication for its measurement.
What was found? In a consecutive population of 5,708 patients presenting to ED, increasing contemporary sensitivity troponin concentrations were associated with increasing hospital admission, length of stay and mortality
Contemporary sensitivity troponin testing is already being performed outside its original purpose. These results should help further inform clinicians about the importance of interpreting abnormal contemporary sensitivity troponin results in the clinical context.
What is the implication for practice now? These results should help further inform clinicians about the importance of interpreting contemporary sensitivity troponin results in the clinical context.
This study suggests that contemporary sensitivity troponin may provide a useful marker of prognosis on presentation to the emergency medical services.
Further study is now required to evaluate the role of high-sensitivity troponin as a prognostic marker in other contexts and to assess whether any medical interventions can alter the prognosis in these patients.
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