Association between troponin level and medium-term mortality in 20 000 hospital patients.

INTRODUCTION: Cardiac troponin (cTn) concentrations above the manufacturer recommended upper limit of normal (ULN) are frequently seen in hospital patients without a clinical presentation consistent with type 1 myocardial infarction, and the significance of this is uncertain. The aim of this study was to assess the relationship between medium-term mortality and cTn concentration in a large consecutive hospital population, regardless of whether there was a clinical indication for performing the test. METHOD: This prospective observational study included 20 000 consecutive in-hospital and outpatient patients who had a blood test for any reason at a large teaching hospital, and in whom a hs-cTnI assay was measured, regardless of the original clinical indication. Mortality was obtained via NHS Digital. RESULTS: A total of 20 000 patients were included in the analysis and 18 282 of these (91.4%) did not have a clinical indication for cardiac troponin I (cTnI) testing. Overall, 2825 (14.1%) patients died at a median of 809 days. The mortality was significantly higher if the cTnI concentration was above the ULN (45.3% vs 12.3% p<0.001 log rank). Multivariable Cox analysis demonstrated that the log10 cTnI concentration was independently associated with mortality (HR 1.76 (95% CI 1.65 to 1.88)). Landmark analysis, excluding deaths within 30 days, showed the relationship between cTnI concentration and mortality persisted. CONCLUSION: In a large, unselected hospital population, in 91.4% of whom there was no clinical indication for testing, cTnI concentration was independently associated with medium-term cardiovascular and non-cardiovascular mortality in the statistical model tested.

Relation of High-Sensitivity Troponin to 1 Year Mortality in 20,000 Consecutive Hospital Patients Undergoing a Blood Test for Any Reason.

This was an observational study of the 1-year outcomes of the 20,000 patients included in the original CHARIOT study. The aim of the study was to assess the association between high sensitivity troponin I (hs-cTnI) concentration and 1 year mortality in this cohort. The original CHARIOT study included a consecutive cohort of in- and out-patients undergoing blood tests for any reason. Hs-cTnI concentrations were measured regardless of whether the clinician requested them. These results were nested and not revealed to the team unless requested for clinical reasons. One year mortality data was obtained from NHS Digital as originally planned. Overall, 1782 (8.9%) patients had died at 1 year. Multivariable Cox regression analysis showed that a hs-cTnI concentration above the upper limit of normal was independently associated with the hazard of mortality (HR 2.23; 95% confidence intervals 1.97 to 2.52). Furthermore, the log (10) hs-cTnI concentration was independently associated with the hazard of 1 year mortality (HR 1.77; 95% confidence intervals 1.64 to 1.91). In conclusion, in a large, unselected hospital population of both in- and out-patients, in 18,282 (91.4%) of whom there was no clinical indication for testing, hs-cTnI concentration was associated with 1 year mortality.

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

BACKGROUND: Contemporary sensitivity troponin (cs-cTn) concentrations above the upper limit of normal (ULN) are seen in a wide range of clinical conditions and evidence is growing that suggests cs-cTn may be a biomarker of future morbidity and mortality. OBJECTIVES: Our aim was to test the hypothesis that cs-cTn, measured in the emergency department, may be a biomarker for 30-day mortality, irrespective of the patient's presentation. METHOD: In all 5,708 consecutive cases, contemporary sensitivity troponin I (cs-cTnI) was measured either as requested by the clinical team or as part of the study, in which case both the clinical team and the patient were unaware of the result. Basic demographics were available from the original study and 30-day mortality was derived from NHS Digital data. RESULTS: In patients whose cs-cTnI test was requested solely as part of the study, 30-day mortality increased with increasing cs-cTnI concentrations (0% with undetectable concentrations to 14.7% with concentrations above the ULN). Multivariable Cox regression analysis showed that log(10)cs-cTnI concentration was independently associated with 30-day mortality. CONCLUSION: Increasing cs-cTnI concentrations are associated with higher short-term mortality as well as length of stay. As such, cs-cTnI measurements may provide useful prognostic information.

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

OBJECTIVE: To 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. DESIGN: Prospective, observational cohort study. SETTING: University Hospital Southampton NHS Foundation Trust, Southampton, United Kingdom, between 29 June 2017 and 24 August 2017. PARTICIPANTS: 20 000 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 MEASURES: Distribution of hs-cTnI concentrations of all study participants and specifically the 99th centile. RESULTS: The 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. CONCLUSIONS: Of 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 REGISTRATION: Clinicaltrials.gov NCT03047785.