True 99th centile of high sensitivity cardiac troponin for hospital patients: prospective, observational cohort study

Abstract

ObjectiveTo determine the distribution, and specifically the true 99th centile, of high sensitivity cardiac troponin I (hs-cTnI) for a whole hospital population by applying the hs-cTnI assay currently used routinely at a large teaching hospital.DesignProspective, observational cohort study.SettingUniversity Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom, between 29 June 2017 and 24 August 2017.Participants20 000 consecutive inpatients and outpatients undergoing blood tests for any clinical reason. Hs-cTnI concentrations were measured in all study participants and nested for analysis except when the supervising doctor had requested hs-cTnI for clinical reasons.Main outcome measuresDistribution of hs-cTnI concentrations of all study participants and specifically the 99th centile.ResultsThe 99th centile of hs-cTnI for the whole population was 296 ng/L compared with the manufacturer’s quoted level of 40 ng/L (currently used clinically as the upper limit of normal; ULN). Hs-cTnI concentrations were greater than 40 ng/L in one in 20 (5.4%, n=1080) of the total population. After excluding participants diagnosed as having acute myocardial infarction (n=122) and those in whom hs-cTnI was requested for clinical reasons (n=1707), the 99th centile was 189 ng/L for the remainder (n=18 171). The 99th centile was 563 ng/L for inpatients (n=4759) and 65 ng/L for outpatients (n=9280). Patients from the emergency department (n=3706) had a 99th centile of 215 ng/L, with 6.07% (n=225) greater than the recommended ULN. 39.02% (n=48) of all patients from the critical care units (n=123) and 14.16% (n=67) of all medical inpatients had an hs-cTnI concentration greater than the recommended ULN.ConclusionsOf 20 000 consecutive patients undergoing a blood test for any clinical reason at our hospital, one in 20 had an hs-cTnI greater than the recommended ULN. These data highlight the need for clinical staff to interpret hs-cTnI concentrations carefully, particularly when applying the recommended ULN to diagnose acute myocardial infarction, in order to avoid misdiagnosis in the absence of an appropriate clinical presentation.Trial registrationClinicaltrials.govNCT03047785.

Implementation of rapid rule out of myocardial infarction using high-sensitivity troponin: cross-sectional survey of English hospitals

“…However, NICE guidance anticipated that implementation would lead to markedly reduced admissions, which is not yet obvious from routinely available data. It has been suggested elsewhere6 that high-sensitivity troponins could lead to overdiagnosis and overinvestigation. Further research could explore whether implementation of high-sensitivity troponin testing at different times across different Trusts over the last decade is associated with an effect on admissions with chest pain.…”

Distribution of contemporary sensitivity troponin in the emergency department and relationship to 30-day mortality: The CHARIOT-ED substudy

“…9 There is, however, evidence that both standard cTn and, to a greater degree, cs-cTn are frequently The CHARIOT-ED substudy detected in patients presenting to ED, despite only a small proportion having a T1MI. [10][11][12][13][14][15][16] In the CHARIOT study, we measured cs-cTn on 20,000 consecutive patients attending our institution for any reason, either inpatient or outpatient, with the aim of describing the true distribution and 99th percentile for cs-cTn in a hospital population. 16 In the current study, we report the distribution of cs-cTn in the subpopulation of CHARIOT who attended ED and in whom the assay was taken regardless of whether there was a clinical indication, and we assess a possible association between the cs-cTn concentration and both 30-day mortality and length of stay.…”

Heartbeat: is cardiovascular health affected by marital status, living alone or loneliness?

“…A point-counterpoint set of editorials in this issue of Heart debates the role of high-sensitivity cardiac troponin (hs-cTn) measurements in clinical practice 10 11. Collinson et al 10 discuss their concerns with the troponin measurements in the CHARIOT (Current Threshold for Diagnosis of ‘Abnormality’, Including Non-ST Elevation Myocardial Infarction, Using Raised Highly Sensitive Troponin Appropriate for a Hospital Population) study 12. They emphasise that: ‘It is important to remember that hs-cTn assays are extremely sensitive for myocardial injury, and that myocardial injury does not always (in fact most often), does not equate acute myocardial infarction (MI).…”